fix(ai): never fail decoding on Responses error frames

Co-authored-by: rekram1-node <rekram1-node@users.noreply.github.com>

V2_HTTP_API_AUDIT.md

@@ -29,15 +29,15 @@ Review endpoints in document order. For each endpoint, select one disposition an
 ## Progress
 
 - [x] Group 1: Foundation and placement (4)
-- [ ] Group 2: Configuration and capability catalogs (16)
-- [ ] Group 3: Credentials, integrations, MCP, and web search (22)
-- [ ] Group 4: Session lifecycle (12)
-- [ ] Group 5: Session execution and inputs (11)
-- [ ] Group 6: Session history and recovery (13)
-- [ ] Group 7: Inbox, permissions, and forms (19)
-- [ ] Group 8: Filesystem, worktrees, and VCS (12)
-- [ ] Group 9: PTYs, persistent terminals, and shells (24)
-- [ ] Group 10: Events, RPC, and experimental operations (6)
+- [x] Group 2: Configuration and capability catalogs (16)
+- [x] Group 3: Credentials, integrations, MCP, and web search (22)
+- [x] Group 4: Session lifecycle (12)
+- [x] Group 5: Session execution and inputs (11)
+- [x] Group 6: Session history and recovery (13)
+- [x] Group 7: Inbox, permissions, and forms (19)
+- [x] Group 8: Filesystem, worktrees, and VCS (12)
+- [x] Group 9: PTYs, persistent terminals, and shells (24)
+- [x] Group 10: Events, RPC, and experimental operations (6)
 
 ## Resolved during audit
 
@@ -100,7 +100,7 @@ Review endpoints in document order. For each endpoint, select one disposition an
 | [x] 021 | `GET` | `/api/config` | `config.get` | Keep | Compatibility entries removed; response now contains only documents and OpenCode directories. |
 | [x] 022 | `GET` | `/api/config/preferences` | `config.preferences` | Remove | Redundant special projection of global config. |
 | [x] 023 | `PATCH` | `/api/config/preferences` | `config.updatePreferences` | Remove | Redundant field-specific config mutation API. |
-| [ ] 024 | `GET` | `/api/config/shell` | `config.shells` |  |  |
+| [x] 024 | `GET` | `/api/config/shell` | `config.shells` | Keep | Required by the server Terminal shell setting. |
 | [x] 024a | `PATCH` | `/api/experimental/config` | `experimental.config.update` | Change | Experimental global config mutation; initially accepts only `shell`. |
 
 ## Group 3: Credentials, integrations, MCP, and web search
@@ -111,21 +111,21 @@ Review endpoints in document order. For each endpoint, select one disposition an
 |---|---|---|---|---|---|
 | [x] 025 | `GET` | `/api/integration` | `integration.list` | Keep | Full integration inventory is consumed by authentication and integration-selection clients. |
 | [x] 026 | `GET` | `/api/integration/{integrationID}` | `integration.get` | Change | Missing integration now returns typed `404` instead of optional data. |
-| [x] | `POST` | `/api/experimental/integration/wellknown` | `experimental.integration.wellknown.add` | Experimental-only | Retained outside the stable API commitment. |
-| [ ] 028 | `POST` | `/api/integration/{integrationID}/connect/key` | `integration.connect.key` |  |  |
-| [ ] 029 | `POST` | `/api/integration/{integrationID}/connect/oauth` | `integration.oauth.connect` |  |  |
-| [ ] 030 | `GET` | `/api/integration/{integrationID}/connect/oauth/{attemptID}` | `integration.oauth.status` |  |  |
-| [ ] 031 | `DELETE` | `/api/integration/{integrationID}/connect/oauth/{attemptID}` | `integration.oauth.cancel` |  |  |
-| [ ] 032 | `POST` | `/api/integration/{integrationID}/connect/oauth/{attemptID}/complete` | `integration.oauth.complete` |  |  |
-| [ ] 033 | `POST` | `/api/integration/{integrationID}/connect/command` | `integration.command.connect` |  |  |
-| [ ] 034 | `GET` | `/api/integration/{integrationID}/connect/command/{attemptID}` | `integration.command.status` |  |  |
-| [ ] 035 | `DELETE` | `/api/integration/{integrationID}/connect/command/{attemptID}` | `integration.command.cancel` |  |  |
+| [x] 027 | `POST` | `/api/experimental/integration/wellknown` | `experimental.integration.wellknown.add` | Experimental-only | Retained outside the stable API commitment. |
+| [x] 028 | `POST` | `/api/integration/{integrationID}/connect/key` | `integration.connect.key` | Change | Missing integration returns typed `404`; key form answers retained. |
+| [x] 029 | `POST` | `/api/integration/{integrationID}/connect/oauth` | `integration.oauth.connect` | Keep | OAuth connection start contract retained. |
+| [x] 030 | `GET` | `/api/integration/{integrationID}/connect/oauth/{attemptID}` | `integration.oauth.status` | Change | Missing integration or OAuth attempt returns typed `404`. |
+| [x] 031 | `DELETE` | `/api/integration/{integrationID}/connect/oauth/{attemptID}` | `integration.oauth.cancel` | Keep | Idempotent cancellation remains a no-op for unavailable or terminal attempts. |
+| [x] 032 | `POST` | `/api/integration/{integrationID}/connect/oauth/{attemptID}/complete` | `integration.oauth.complete` | Change | Missing integration or OAuth attempt returns typed `404`; code remains mode-dependent. |
+| [x] 033 | `POST` | `/api/integration/{integrationID}/connect/command` | `integration.command.connect` | Change | Missing integration or command method returns typed `404`. |
+| [x] 034 | `GET` | `/api/integration/{integrationID}/connect/command/{attemptID}` | `integration.command.status` | Change | Missing integration or command attempt returns typed `404`. |
+| [x] 035 | `DELETE` | `/api/integration/{integrationID}/connect/command/{attemptID}` | `integration.command.cancel` | Keep | Idempotent cancellation remains a no-op for unavailable or terminal attempts. |
 | [x] 036 | `GET` | `/api/mcp` | `mcp.list` | Keep | MCP inventory and connection status retained. |
 | [x] 037 | `PUT` | `/api/experimental/mcp/{server}` | `experimental.mcp.add` | Experimental-only | Runtime-only MCP override; does not persist configuration. |
 | [x] 038 | `DELETE` | `/api/experimental/mcp/{server}` | `experimental.mcp.remove` | Experimental-only | Runtime removal override; missing server returns `404`. |
 | [x] 039 | `POST` | `/api/experimental/mcp/{server}/connect` | `experimental.mcp.connect` | Experimental-only | Runtime connection override retained outside the stable API. |
 | [x] 040 | `POST` | `/api/experimental/mcp/{server}/disconnect` | `experimental.mcp.disconnect` | Experimental-only | Runtime disconnection override retained outside the stable API. |
-| [ ] 041 | `GET` | `/api/mcp/resource` | `mcp.resource.catalog` |  | Deferred for later review. |
+| [x] 041 | `GET` | `/api/mcp/resource` | `mcp.resource.catalog` | Keep | Reviewed separately by coworker. |
 | [x] 042 | `PATCH` | `/api/credential/{credentialID}` | `credential.update` | Change | Removed redundant location query; credentials and events are global. |
 | [x] 043 | `DELETE` | `/api/credential/{credentialID}` | `credential.remove` | Change | Removed redundant location query; credentials and events are global. |
 | [x] 044 | `POST` | `/api/credential/{credentialID}/activate` | `credential.activate` | Change | Removed redundant location query; credentials and events are global. |
@@ -147,7 +147,7 @@ Review endpoints in document order. For each endpoint, select one disposition an
 | [x] 053 | `POST` | `/api/session/{sessionID}/fork` | `session.fork` | Change | Request now accepts optional branded `before` message ID; omission copies full history. |
 | [x] 054 | `POST` | `/api/session/{sessionID}/agent` | `session.switchAgent` | Keep | Subsequent-execution agent selection retained. |
 | [x] 055 | `POST` | `/api/session/{sessionID}/model` | `session.switchModel` | Keep | Subsequent-execution model and optional variant selection retained. |
-| [x] 056 | `PATCH` | `/api/session/{sessionID}` | `session.rename` | Change | Title-only rename now uses the session resource path. |
+| [x] 056 | `PATCH` | `/api/session/{sessionID}` | `session.update` | Change | General session patch updates title and permissions; rules emit `session.permissions`. |
 | [x] 057 | `POST` | `/api/session/{sessionID}/move` | `session.move` | Change | Removed inaccurate local-change transfer claim; delivery behavior retained. |
 | [x] 058 | `POST` | `/api/session/{sessionID}/background` | `session.background` | Keep | Backgroundable foreground tools transition to background observation; idle requests remain no-ops. |
 
@@ -166,7 +166,7 @@ Review endpoints in document order. For each endpoint, select one disposition an
 | [x] 065 | `POST` | `/api/experimental/session/{sessionID}/wait` | `experimental.session.wait` | Experimental-only | Race-free idle barrier retained outside the stable API. |
 | [x] 066 | `POST` | `/api/session/{sessionID}/generate` | `session.generate` | Keep | Transient generation from session context retained. |
 | [x] 067 | `POST` | `/api/session/{sessionID}/interrupt` | `session.interrupt` | Change | Renamed `continue` to `resume` across public and internal interruption APIs. |
-| [x] 068 | `PUT` | `/api/experimental/session/{sessionID}/environment` | `experimental.session.environment` | Experimental-only | Process-local environment replacement retained outside the stable API. |
+| [x] 068 | `PUT` | `/api/session/{sessionID}/environment` | `session.environment` | Keep | Process-local environment replacement retained in the stable API. |
 | [x] 069 | `POST` | `/api/session/{sessionID}/view` | `session.view` | Change | Idle watermark now uses the standard epoch-millisecond timestamp schema. |
 
 ## Group 6: Session history and recovery
@@ -185,7 +185,7 @@ Review endpoints in document order. For each endpoint, select one disposition an
 | [x] 077 | `GET` | `/api/experimental/session/{sessionID}/instructions/entries` | `experimental.session.instructions.entry.list` | Experimental-only | API-managed durable context entries retained outside the stable API. |
 | [x] 078 | `PUT` | `/api/experimental/session/{sessionID}/instructions/entries/{key}` | `experimental.session.instructions.entry.put` | Experimental-only | API-managed durable context entries retained outside the stable API. |
 | [x] 079 | `DELETE` | `/api/experimental/session/{sessionID}/instructions/entries/{key}` | `experimental.session.instructions.entry.remove` | Experimental-only | API-managed durable context entries retained outside the stable API. |
-| [x] | `GET` | `/api/experimental/session/{sessionID}/log` | `session.log` | Experimental-only | Retained outside the stable API commitment. |
+| [x] 080 | `GET` | `/api/experimental/session/{sessionID}/log` | `session.log` | Experimental-only | Retained outside the stable API commitment. |
 | [x] 081 | `GET` | `/api/session/{sessionID}/message/{messageID}` | `session.message.get` | Change | Normalized specific-message operation ID. |
 | [x] 082 | `GET` | `/api/session/{sessionID}/message` | `session.message.list` | Change | Normalized session-scoped message-list operation ID. |
 
@@ -196,24 +196,24 @@ Review endpoints in document order. For each endpoint, select one disposition an
 | Done | Method | Path | Operation ID | Decision | Notes |
 |---|---|---|---|---|---|
 | [x] 083 | `GET` | `/api/session/{sessionID}/inbox` | `session.inbox.list` | Change | Inbox timestamps now use the standard nested `time.created` shape. |
-| [ ] 084 | `DELETE` | `/api/session/{sessionID}/inbox/{inboxID}` | `session.inbox.cancel` |  |  |
-| [ ] 085 | `POST` | `/api/session/{sessionID}/inbox/{inboxID}/steer` | `session.inbox.steer` |  |  |
-| [ ] 086 | `POST` | `/api/session/{sessionID}/inbox/{inboxID}/queue` | `session.inbox.queue` |  |  |
-| [ ] 087 | `GET` | `/api/form/request` | `form.request.list` |  |  |
-| [ ] 088 | `GET` | `/api/session/{sessionID}/form` | `session.form.list` |  |  |
-| [ ] 089 | `POST` | `/api/session/{sessionID}/form` | `session.form.create` |  |  |
-| [ ] 090 | `GET` | `/api/session/{sessionID}/form/{formID}` | `session.form.get` |  |  |
-| [ ] 091 | `GET` | `/api/session/{sessionID}/form/{formID}/state` | `session.form.state` |  |  |
-| [ ] 092 | `POST` | `/api/session/{sessionID}/form/{formID}/reply` | `session.form.reply` |  |  |
-| [ ] 093 | `POST` | `/api/session/{sessionID}/form/{formID}/cancel` | `session.form.cancel` |  |  |
-| [ ] 094 | `GET` | `/api/permission/request` | `permission.request.list` |  |  |
-| [ ] 095 | `GET` | `/api/permission/saved` | `permission.saved.list` |  |  |
-| [ ] 096 | `DELETE` | `/api/permission/saved/{id}` | `permission.saved.remove` |  |  |
-| [ ] 097 | `POST` | `/api/session/{sessionID}/permission` | `session.permission.create` |  |  |
-| [ ] 098 | `GET` | `/api/session/{sessionID}/permission` | `session.permission.list` |  |  |
-| [ ] 099 | `GET` | `/api/session/{sessionID}/permission/{requestID}` | `session.permission.get` |  |  |
-| [ ] 100 | `POST` | `/api/session/{sessionID}/permission/{requestID}/reply` | `session.permission.reply` |  |  |
-| [ ] 101 | `PUT` | `/api/session/{sessionID}/permission/rules` | `session.permission.rules` |  |  |
+| [x] 084 | `DELETE` | `/api/session/{sessionID}/inbox/{inboxID}` | `session.inbox.cancel` | Change | Cancellation is idempotent and returns `204` when the session exists. |
+| [x] 085 | `PATCH` | `/api/session/{sessionID}/inbox/{inboxID}` | `session.inbox.update` | Change | Consolidated delivery mutation with `delivery: "steer" | "queue"`. |
+| [x] 086 | — | — | — | Remove | Replaced by `session.inbox.update`. |
+| [x] 087 | `GET` | `/api/form` | `form.list` | Change | Removed redundant `request` path and operation namespace. |
+| [x] 088 | `GET` | `/api/session/{sessionID}/form` | `session.form.list` | Keep | Pending session form list retained with temporary MCP sentinel compatibility. |
+| [x] 089 | `POST` | `/api/session/{sessionID}/form` | `session.form.create` | Keep | External form creation and temporary MCP sentinel ownership retained. |
+| [x] 090 | `GET` | `/api/session/{sessionID}/form/{formID}` | `session.form.get` | Change | Form definition and lifecycle state are now returned together. |
+| [x] 091 | — | — | — | Remove | State is included by `session.form.get`. |
+| [x] 092 | `POST` | `/api/session/{sessionID}/form/{formID}/reply` | `session.form.reply` | Keep | One-shot validated form reply retained. |
+| [x] 093 | `DELETE` | `/api/session/{sessionID}/form/{formID}` | `session.form.cancel` | Change | Form cancellation now deletes the pending form resource. |
+| [x] 094 | `GET` | `/api/permission/request` | `permission.request.list` | Keep | Pending-request namespace retained alongside saved permissions. |
+| [x] 095 | `GET` | `/api/permission/saved` | `permission.saved.list` | Change | Added persisted creation and update timestamps under `time`. |
+| [x] 096 | `DELETE` | `/api/permission/saved/{id}` | `permission.saved.remove` | Keep | Idempotent saved-permission deletion retained. |
+| [x] 097 | `POST` | `/api/session/{sessionID}/permission` | `session.permission.create` | Keep | Non-blocking permission evaluation and pending-request creation retained. |
+| [x] 098 | `GET` | `/api/session/{sessionID}/permission` | `session.permission.list` | Keep | Pending session permission list retained. |
+| [x] 099 | `GET` | `/api/session/{sessionID}/permission/{requestID}` | `session.permission.get` | Keep | Specific pending permission read with ownership validation retained. |
+| [x] 100 | `POST` | `/api/session/{sessionID}/permission/{requestID}/reply` | `session.permission.reply` | Change | Renamed request field from `reply` to `decision`. |
+| [x] 101 | — | — | — | Remove | Permission rules are updated through `session.update`. |
 
 ## Group 8: Filesystem, worktrees, and VCS
 
@@ -221,18 +221,18 @@ Review endpoints in document order. For each endpoint, select one disposition an
 
 | Done | Method | Path | Operation ID | Decision | Notes |
 |---|---|---|---|---|---|
-| [ ] 102 | `GET` | `/api/fs/read/*` | `fs.read` |  |  |
-| [ ] 103 | `GET` | `/api/fs/list` | `fs.list` |  |  |
-| [ ] 104 | `GET` | `/api/fs/find` | `fs.find` |  |  |
-| [ ] 105 | `GET` | `/api/worktree` | `worktree.list` |  |  |
-| [ ] 106 | `POST` | `/api/worktree` | `worktree.create` |  |  |
-| [ ] 107 | `DELETE` | `/api/worktree` | `worktree.remove` |  |  |
-| [ ] 108 | `POST` | `/api/worktree/refresh` | `worktree.refresh` |  |  |
-| [ ] 109 | `GET` | `/api/vcs` | `vcs.get` |  |  |
-| [ ] 110 | `GET` | `/api/vcs/base` | `vcs.base` |  |  |
-| [ ] 111 | `GET` | `/api/vcs/status` | `vcs.status` |  |  |
-| [ ] 112 | `GET` | `/api/vcs/branches` | `vcs.branches` |  |  |
-| [ ] 113 | `GET` | `/api/vcs/diff` | `vcs.diff` |  |  |
+| [x] 102 | `GET` | `/api/fs/read/*` | `fs.read` | Keep | Relative wildcard file reads and raw byte responses retained. |
+| [x] 103 | `GET` | `/api/fs/list` | `fs.list` | Keep | Existing path scope and minimal entry metadata retained. |
+| [x] 104 | `GET` | `/api/fs/find` | `fs.find` | Keep | Existing ranked filesystem search retained. |
+| [x] 105 | `GET` | `/api/worktree` | `worktree.list` | Keep | Reviewed separately by coworker. |
+| [x] 106 | `POST` | `/api/worktree` | `worktree.create` | Keep | Reviewed separately by coworker. |
+| [x] 107 | `DELETE` | `/api/worktree` | `worktree.remove` | Keep | Reviewed separately by coworker. |
+| [x] 108 | `POST` | `/api/worktree/refresh` | `worktree.refresh` | Keep | Reviewed separately by coworker. |
+| [x] 109 | `GET` | `/api/vcs` | `vcs.get` | Change | Preserved branch nesting and added selected VCS provider ID. |
+| [x] 110 | `GET` | `/api/vcs/base` | `vcs.base` | Keep | Review-base inference and nullable unavailable state retained. |
+| [x] 111 | `GET` | `/api/vcs/status` | `vcs.status` | Keep | Existing working-copy status shape retained for now. |
+| [x] 112 | `GET` | `/api/vcs/branch` | `vcs.branch.list` | Change | Singular collection path and normalized operation ID. |
+| [x] 113 | `GET` | `/api/vcs/diff` | `vcs.diff` | Keep | Existing working, branch, and committed comparison modes retained. |
 
 ## Group 9: PTYs, persistent terminals, and shells
 
@@ -240,30 +240,30 @@ Review endpoints in document order. For each endpoint, select one disposition an
 
 | Done | Method | Path | Operation ID | Decision | Notes |
 |---|---|---|---|---|---|
-| [ ] 114 | `GET` | `/api/pty` | `pty.list` |  |  |
-| [ ] 115 | `POST` | `/api/pty` | `pty.create` |  |  |
-| [ ] 116 | `GET` | `/api/pty/{ptyID}` | `pty.get` |  |  |
-| [ ] 117 | `PUT` | `/api/pty/{ptyID}` | `pty.update` |  |  |
-| [ ] 118 | `DELETE` | `/api/pty/{ptyID}` | `pty.remove` |  |  |
-| [ ] 119 | `POST` | `/api/pty/{ptyID}/connect-token` | `pty.connect.token` |  |  |
-| [ ] 120 | `GET` | `/api/pty/{ptyID}/connect` | `pty.connect` |  |  |
-| [x] | `GET` | `/api/experimental/session/{sessionID}/terminal/read` | `server.experimental.persistentPty.read` | Experimental-only | Retained outside the stable API commitment. |
-| [x] | `GET` | `/api/experimental/session/{sessionID}/terminal` | `server.experimental.persistentPty.list` | Experimental-only | Retained outside the stable API commitment. |
-| [x] | `POST` | `/api/experimental/session/{sessionID}/terminal` | `server.experimental.persistentPty.create` | Experimental-only | Retained outside the stable API commitment. |
-| [x] | `POST` | `/api/experimental/persistent-pty/shutdown` | `server.experimental.persistentPty.shutdown` | Experimental-only | Retained outside the stable API commitment. |
-| [x] | `POST` | `/api/experimental/persistent-pty/handoff` | `server.experimental.persistentPty.handoff` | Experimental-only | Retained outside the stable API commitment. |
-| [x] | `GET` | `/api/experimental/persistent-pty/{ptyID}` | `server.experimental.persistentPty.get` | Experimental-only | Retained outside the stable API commitment. |
-| [x] | `PUT` | `/api/experimental/persistent-pty/{ptyID}` | `server.experimental.persistentPty.update` | Experimental-only | Retained outside the stable API commitment. |
-| [x] | `DELETE` | `/api/experimental/persistent-pty/{ptyID}` | `server.experimental.persistentPty.remove` | Experimental-only | Retained outside the stable API commitment. |
-| [x] | `GET` | `/api/experimental/persistent-pty/{ptyID}/snapshot` | `server.experimental.persistentPty.snapshot` | Experimental-only | Retained outside the stable API commitment. |
-| [x] | `POST` | `/api/experimental/persistent-pty/{ptyID}/connect-token` | `server.experimental.persistentPty.connectToken` | Experimental-only | Retained outside the stable API commitment. |
-| [x] | `GET` | `/api/experimental/persistent-pty/{ptyID}/connect` | `persistentPty.connect` | Experimental-only | Retained outside the stable API commitment. |
-| [ ] 132 | `GET` | `/api/shell` | `shell.list` |  |  |
-| [ ] 133 | `POST` | `/api/shell` | `shell.create` |  |  |
-| [ ] 134 | `GET` | `/api/shell/{id}` | `shell.get` |  |  |
-| [ ] 135 | `DELETE` | `/api/shell/{id}` | `shell.remove` |  |  |
-| [ ] 136 | `PATCH` | `/api/shell/{id}/timeout` | `shell.timeout` |  |  |
-| [ ] 137 | `GET` | `/api/shell/{id}/output` | `shell.output` |  |  |
+| [x] 114 | `GET` | `/api/pty` | `pty.list` | Keep | PTY endpoints reviewed together and retained. |
+| [x] 115 | `POST` | `/api/pty` | `pty.create` | Keep | PTY endpoints reviewed together and retained. |
+| [x] 116 | `GET` | `/api/pty/{ptyID}` | `pty.get` | Keep | PTY endpoints reviewed together and retained. |
+| [x] 117 | `PUT` | `/api/pty/{ptyID}` | `pty.update` | Keep | PTY endpoints reviewed together and retained. |
+| [x] 118 | `DELETE` | `/api/pty/{ptyID}` | `pty.remove` | Keep | PTY endpoints reviewed together and retained. |
+| [x] 119 | `POST` | `/api/pty/{ptyID}/connect-token` | `pty.connect.token` | Keep | PTY endpoints reviewed together and retained. |
+| [x] 120 | `GET` | `/api/pty/{ptyID}/connect` | `pty.connect` | Keep | PTY endpoints reviewed together and retained. |
+| [x] 121 | `GET` | `/api/experimental/session/{sessionID}/terminal/read` | `server.experimental.persistentPty.read` | Experimental-only | Retained outside the stable API commitment. |
+| [x] 122 | `GET` | `/api/experimental/session/{sessionID}/terminal` | `server.experimental.persistentPty.list` | Experimental-only | Retained outside the stable API commitment. |
+| [x] 123 | `POST` | `/api/experimental/session/{sessionID}/terminal` | `server.experimental.persistentPty.create` | Experimental-only | Retained outside the stable API commitment. |
+| [x] 124 | `POST` | `/api/experimental/persistent-pty/shutdown` | `server.experimental.persistentPty.shutdown` | Experimental-only | Retained outside the stable API commitment. |
+| [x] 125 | `POST` | `/api/experimental/persistent-pty/handoff` | `server.experimental.persistentPty.handoff` | Experimental-only | Retained outside the stable API commitment. |
+| [x] 126 | `GET` | `/api/experimental/persistent-pty/{ptyID}` | `server.experimental.persistentPty.get` | Experimental-only | Retained outside the stable API commitment. |
+| [x] 127 | `PUT` | `/api/experimental/persistent-pty/{ptyID}` | `server.experimental.persistentPty.update` | Experimental-only | Retained outside the stable API commitment. |
+| [x] 128 | `DELETE` | `/api/experimental/persistent-pty/{ptyID}` | `server.experimental.persistentPty.remove` | Experimental-only | Retained outside the stable API commitment. |
+| [x] 129 | `GET` | `/api/experimental/persistent-pty/{ptyID}/snapshot` | `server.experimental.persistentPty.snapshot` | Experimental-only | Retained outside the stable API commitment. |
+| [x] 130 | `POST` | `/api/experimental/persistent-pty/{ptyID}/connect-token` | `server.experimental.persistentPty.connectToken` | Experimental-only | Retained outside the stable API commitment. |
+| [x] 131 | `GET` | `/api/experimental/persistent-pty/{ptyID}/connect` | `persistentPty.connect` | Experimental-only | Retained outside the stable API commitment. |
+| [x] 132 | `GET` | `/api/shell` | `shell.list` | Change | Stable shell inventory retained; numeric timestamps documented as epoch milliseconds. |
+| [x] 133 | `POST` | `/api/shell` | `shell.create` | Change | Timeout is optional and defaults to zero; caller metadata retained. |
+| [x] 134 | `GET` | `/api/shell/{id}` | `shell.get` | Keep | Specific running or retained shell read retained. |
+| [x] 135 | `DELETE` | `/api/shell/{id}` | `shell.remove` | Change | Shell deletion is idempotent and returns `204` when already absent. |
+| [x] 136 | — | — | — | Remove | Timeout mutation remains an internal Core shell operation. |
+| [x] 137 | `GET` | `/api/shell/{id}/output` | `shell.output` | Keep | Existing byte-cursor text output paging retained. |
 
 ## Group 10: Events, RPC, and experimental operations
 
@@ -271,9 +271,9 @@ Review endpoints in document order. For each endpoint, select one disposition an
 
 | Done | Method | Path | Operation ID | Decision | Notes |
 |---|---|---|---|---|---|
-| [ ] 138 | `POST` | `/api/generate` | `generate.text` |  |  |
-| [ ] 139 | `POST` | `/api/rpc/{rpcID}/{method}` | `rpc.call` |  |  |
-| [ ] 140 | `GET` | `/api/event` | `event.subscribe` |  |  |
-| [ ] 141 | `GET` | `/api/debug/location` | `debug.location.list` |  |  |
-| [ ] 142 | `DELETE` | `/api/debug/location` | `debug.location.evict` |  |  |
-| [x] | `GET` | `/api/experimental/migration/v1` | `experimental.migration.v1.status` | Experimental-only | Retained outside the stable API commitment. |
+| [x] 138 | `POST` | `/api/experimental/generate` | `experimental.generate.text` | Experimental-only | Stateless generation retained alongside session generation. |
+| [x] 139 | `POST` | `/api/rpc/{rpcID}/{method}` | `rpc.call` | Keep | Generic typed-error plugin RPC transport retained. |
+| [x] 140 | `GET` | `/api/event` | `event.subscribe` | Keep | Unified native and dynamic plugin event stream retained. |
+| [x] 141 | `GET` | `/api/debug/location` | `debug.location.list` | Keep | Loaded-location debug inventory retained. |
+| [x] 142 | `DELETE` | `/api/debug/location` | `debug.location.evict` | Keep | Idempotent loaded-location eviction retained. |
+| [x] 143 | `GET` | `/api/experimental/migration/v1` | `experimental.migration.v1.status` | Experimental-only | Retained outside the stable API commitment. |

bun.lock

@@ -32,7 +32,7 @@
     },
     "packages/ai": {
       "name": "@opencode/ai",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@aws-sdk/credential-providers": "3.1057.0",
         "@opencode/schema": "workspace:*",
@@ -54,7 +54,7 @@
     },
     "packages/app": {
       "name": "@opencode/app",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@corvu/drawer": "catalog:",
         "@dnd-kit/abstract": "0.5.0",
@@ -113,7 +113,7 @@
     },
     "packages/cli": {
       "name": "@opencode/cli",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "bin": {
         "opencode2": "./bin/opencode2.cjs",
       },
@@ -177,7 +177,7 @@
     },
     "packages/client": {
       "name": "@opencode/client",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@opencode/protocol": "workspace:*",
         "@opencode/schema": "workspace:*",
@@ -203,7 +203,7 @@
     },
     "packages/codemode": {
       "name": "@opencode/codemode",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "acorn": "8.15.0",
         "effect": "catalog:",
@@ -217,7 +217,7 @@
     },
     "packages/console/app": {
       "name": "@opencode/console-app",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@cloudflare/vite-plugin": "1.15.2",
         "@ibm/plex": "6.4.1",
@@ -253,7 +253,7 @@
     },
     "packages/console/core": {
       "name": "@opencode/console-core",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@aws-sdk/client-sts": "3.782.0",
         "@jsx-email/render": "1.1.1",
@@ -280,7 +280,7 @@
     },
     "packages/console/function": {
       "name": "@opencode/console-function",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@openauthjs/openauth": "0.0.0-20250322224806",
         "@opencode/console-core": "workspace:*",
@@ -297,7 +297,7 @@
     },
     "packages/console/mail": {
       "name": "@opencode/console-mail",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@jsx-email/all": "2.2.3",
         "@jsx-email/cli": "1.4.3",
@@ -321,7 +321,7 @@
     },
     "packages/console/support": {
       "name": "@opencode/console-support",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@cloudflare/vite-plugin": "1.15.2",
         "@opencode/console-core": "workspace:*",
@@ -341,7 +341,7 @@
     },
     "packages/core": {
       "name": "@opencode/core",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@ai-sdk/cohere": "3.0.27",
         "@ai-sdk/gateway": "3.0.104",
@@ -353,6 +353,7 @@
         "@ff-labs/fff-node": "0.10.5",
         "@lydell/node-pty": "catalog:",
         "@modelcontextprotocol/client": "2.0.0",
+        "@modelcontextprotocol/core": "2.0.0",
         "@opencode-ai/pty": "0.1.13",
         "@opencode/ai": "workspace:*",
         "@opencode/codemode": "workspace:*",
@@ -408,7 +409,7 @@
     },
     "packages/desktop": {
       "name": "@opencode/desktop",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@zip.js/zip.js": "2.7.62",
         "electron-context-menu": "4.1.2",
@@ -460,7 +461,7 @@
     },
     "packages/enterprise": {
       "name": "@opencode/enterprise",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@hono/standard-validator": "catalog:",
         "@opencode-ai/sdk": "1.18.21",
@@ -497,7 +498,7 @@
     },
     "packages/function": {
       "name": "@opencode/function",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@octokit/auth-app": "8.0.1",
         "@octokit/rest": "catalog:",
@@ -513,7 +514,7 @@
     },
     "packages/http-recorder": {
       "name": "@opencode/http-recorder",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@effect/platform-node-shared": "4.0.0-rc.112",
       },
@@ -532,7 +533,7 @@
     },
     "packages/httpapi-codegen": {
       "name": "@opencode/httpapi-codegen",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "effect": "catalog:",
         "prettier": "3.6.2",
@@ -545,7 +546,7 @@
     },
     "packages/latex": {
       "name": "@opencode/latex",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@opencode/plugin": "workspace:*",
         "@opentui/core": "catalog:",
@@ -559,7 +560,7 @@
     },
     "packages/merman": {
       "name": "@opencode/merman",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@opencode/plugin": "workspace:*",
         "@opentui/core": "catalog:",
@@ -574,7 +575,7 @@
     },
     "packages/plugin": {
       "name": "@opencode/plugin",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@ai-sdk/provider": "3.0.8",
         "@opencode/ai": "workspace:*",
@@ -613,7 +614,7 @@
     },
     "packages/plugin-browser": {
       "name": "@opencode/plugin-browser",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@opencode/plugin": "workspace:*",
         "@opencode/schema": "workspace:*",
@@ -643,7 +644,7 @@
     },
     "packages/protocol": {
       "name": "@opencode/protocol",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@opencode/schema": "workspace:*",
         "effect": "catalog:",
@@ -658,7 +659,7 @@
     },
     "packages/schema": {
       "name": "@opencode/schema",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@standard-schema/spec": "catalog:",
         "effect": "catalog:",
@@ -682,7 +683,7 @@
     },
     "packages/sdk": {
       "name": "@opencode/sdk",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@opencode/client": "workspace:*",
         "@opencode/core": "workspace:*",
@@ -703,7 +704,7 @@
     },
     "packages/server": {
       "name": "@opencode/server",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@effect/platform-node": "catalog:",
         "@effect/platform-node-shared": "catalog:",
@@ -725,7 +726,7 @@
     },
     "packages/session-ui": {
       "name": "@opencode/session-ui",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@kobalte/core": "catalog:",
         "@opencode/client": "workspace:*",
@@ -760,7 +761,7 @@
     },
     "packages/simulation": {
       "name": "@opencode/simulation",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@opencode/ai": "workspace:*",
         "@opencode/core": "workspace:*",
@@ -780,7 +781,7 @@
     },
     "packages/stats/app": {
       "name": "@opencode/stats-app",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@ibm/plex": "6.4.1",
         "@kobalte/core": "catalog:",
@@ -814,7 +815,7 @@
     },
     "packages/stats/core": {
       "name": "@opencode/stats-core",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@aws-sdk/client-athena": "3.933.0",
         "@planetscale/database": "1.19.0",
@@ -833,7 +834,7 @@
     },
     "packages/stats/server": {
       "name": "@opencode/stats-server",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@aws-sdk/client-firehose": "3.933.0",
         "@effect/platform-node": "catalog:",
@@ -879,7 +880,7 @@
     },
     "packages/theme": {
       "name": "@opencode/theme",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@opentui/core": "catalog:",
         "effect": "catalog:",
@@ -893,7 +894,7 @@
     },
     "packages/tui": {
       "name": "@opencode/tui",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@opencode/client": "workspace:*",
         "@opencode/core": "workspace:*",
@@ -928,7 +929,7 @@
     },
     "packages/ui": {
       "name": "@opencode/ui",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@kobalte/core": "catalog:",
         "@pierre/diffs": "catalog:",
@@ -963,7 +964,7 @@
     },
     "packages/util": {
       "name": "@opencode/util",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@effect/opentelemetry": "catalog:",
         "@effect/platform-node": "catalog:",
@@ -996,7 +997,7 @@
     },
     "packages/web": {
       "name": "@opencode/web",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "@astrojs/cloudflare": "12.6.3",
         "@astrojs/markdown-remark": "6.3.1",
@@ -1037,7 +1038,7 @@
     },
     "services/update": {
       "name": "@opencode/update",
-      "version": "2.0.3",
+      "version": "2.0.5",
       "dependencies": {
         "jose": "6.0.11",
         "semver": "catalog:",

install

@@ -168,7 +168,7 @@ else
 
     package_scope="@opencode"
     if [ -z "$requested_version" ]; then
-        metadata=$(curl -fsSL https://opencode.ai/update/api/beta/cli/npm || true)
+        metadata=$(curl -fsSL https://opencode.ai/update/api/latest/cli/npm || true)
         specific_version=$(echo "$metadata" | sed -n 's/.*"version":"\([^"]*\)".*/\1/p')
         package=$(echo "$metadata" | sed -n 's/.*"package":"\([^"]*\)".*/\1/p')
 

nix/hashes.json

@@ -1,8 +1,8 @@
 {
   "nodeModules": {
-    "x86_64-linux": "sha256-E5T4o3wNivOg8q4wRV7yE4CUNaUq4QNPxZsnvLaGUcg=",
-    "aarch64-linux": "sha256-xQQi7LgxInZQVCznASfa0Pm+cNGBo5j4Tfp0E/bKnNw=",
-    "aarch64-darwin": "sha256-qxb371dCf7WG09VvQE+HZ/x3EURpFIr11bdnQwGTHhw=",
-    "x86_64-darwin": "sha256-xi1qiYr41hzbgAQl+I3xdtnkiPx2SIcA/0OMpN78qXw="
+    "x86_64-linux": "sha256-U9IuP/ev6w4urvogOwQyl3rdumY6W4YaY18NkFaOVHU=",
+    "aarch64-linux": "sha256-Wc8OT2DRZpVo56KaoGE0Hsj1NDknakbWXO9w2qy6j+0=",
+    "aarch64-darwin": "sha256-wAea8+jajnMDxZ6XJL+Hsrf0621hwtBtWyD1+dS45dE=",
+    "x86_64-darwin": "sha256-g8PCNBSV6rO+VQjKU9AtYqj+r18o+fhLDXEQq+X2EZ4="
   }
 }

package.json

@@ -2,7 +2,7 @@
   "$schema": "https://json.schemastore.org/package.json",
   "name": "opencode",
   "description": "AI-powered development tool",
-  "version": "2.0.3",
+  "version": "2.0.5",
   "private": true,
   "type": "module",
   "packageManager": "bun@1.4.2",

packages/ai/package.json

@@ -1,6 +1,6 @@
 {
   "$schema": "https://json.schemastore.org/package.json",
-  "version": "2.0.3",
+  "version": "2.0.5",
   "name": "@opencode/ai",
   "type": "module",
   "license": "MIT",

packages/ai/src/protocols/open-responses-channel.ts

@@ -73,11 +73,6 @@ const driver = (options: Options, body: string): WebSocketChannelDriver => {
           )
         if (event.type === "error") {
           terminal = true
-          yield* OpenResponses.decodeKnownErrorEvent(event).pipe(
-            Effect.mapError((cause) =>
-              ProviderShared.eventError(options.id, `${options.name} returned a malformed error event`, frame, cause),
-            ),
-          )
           return {
             type: "provider-failure",
             error: OpenResponses.providerFailure(event, `${options.name} stream error`, frame),
@@ -168,6 +163,10 @@ export const transport = <Body>(options: Options): Transport<Body, Prepared, str
                 }
               })
             : undefined
+        if (input.webSocket && !channel)
+          yield* Effect.logWarning(`${options.name} does not offer WebSocket for this endpoint; using HTTP`, {
+            url: parts.url,
+          })
         return {
           http: {
             request: ProviderShared.jsonPost({ url: parts.url, body: parts.bodyText, headers: parts.headers }),

packages/ai/src/protocols/open-responses-continuation.ts

@@ -108,7 +108,7 @@ const incremental = (
   return input.slice(baseline.length)
 }
 
-const code = (event: OpenResponses.Event) => event.code || event.error?.code || event.response?.error?.code || undefined
+const code = (event: OpenResponses.Event) => OpenResponses.errorDetail(event).code
 
 const rejected = (
   observation: Extract<ChannelObservation, { readonly type: "provider-failure" }>,

packages/ai/src/protocols/open-responses.ts

@@ -1,4 +1,4 @@
-import { Effect, Option, Schema, SchemaGetter } from "effect"
+import { Effect, Option, Schema } from "effect"
 import type { Content } from "@opencode/schema/tool"
 import { HttpTransport } from "../route/transport/index.js"
 import { Protocol } from "../route/protocol.js"
@@ -333,47 +333,13 @@ export const StreamItem = Schema.StructWithRest(
 export type StreamItem = Schema.Schema.Type<typeof StreamItem>
 export type OutputItem = StreamItem & { readonly id: string }
 
-// Responses-compatible providers put streaming error details at the top level or
-// under `error`, and response failures under `response.error`. Accept all three shapes.
+// Responses-compatible providers put error details at the top level, under `error`, or under
+// `response.error`, and gateways reshape them freely: strings, numeric codes, extra fields. Those
+// fields decode as opaque values and `errorDetail` reads them defensively, so an error frame can
+// only fail on invalid JSON and otherwise always classifies with the raw body as the fallback.
 // https://www.openresponses.org/specification
-const OpenResponsesErrorPayload = Schema.Struct({
-  type: optionalNull(Schema.String),
-  code: optionalNull(Schema.String),
-  message: optionalNull(Schema.String),
-  param: optionalNull(Schema.String),
-})
-type OpenResponsesErrorPayload = Schema.Schema.Type<typeof OpenResponsesErrorPayload>
-
-const WebSocketErrorHeader = Schema.Union([Schema.String, Schema.Number, Schema.Boolean])
-export const WebSocketErrorEvent = Schema.StructWithRest(
-  Schema.Struct({
-    type: Schema.tag("error"),
-    status: Schema.optional(Schema.Number),
-    status_code: Schema.optional(Schema.Number),
-    code: optionalNull(Schema.String),
-    message: Schema.optional(Schema.String),
-    param: optionalNull(Schema.String),
-    error: optionalNull(OpenResponsesErrorPayload),
-    headers: Schema.optional(Schema.Record(Schema.String, WebSocketErrorHeader)),
-  }),
-  [Schema.Record(Schema.String, Schema.Unknown)],
-)
-const decodeWebSocketErrorEvent = Schema.decodeUnknownEffect(WebSocketErrorEvent)
-
-export const decodeKnownErrorEvent = (event: Event) =>
-  decodeWebSocketErrorEvent({
-    ...event,
-    status: typeof event.status === "number" ? event.status : undefined,
-    status_code: typeof event.status_code === "number" ? event.status_code : undefined,
-    headers: ProviderShared.isRecord(event.headers)
-      ? Object.fromEntries(
-          Object.entries(event.headers).filter(
-            (entry): entry is [string, string | number | boolean] =>
-              typeof entry[1] === "string" || typeof entry[1] === "number" || typeof entry[1] === "boolean",
-          ),
-        )
-      : undefined,
-  })
+const asText = (value: unknown) =>
+  typeof value === "string" && value.length > 0 ? value : typeof value === "number" ? String(value) : undefined
 
 export const Event = Schema.StructWithRest(
   Schema.Struct({
@@ -394,31 +360,18 @@ export const Event = Schema.StructWithRest(
           incomplete_details: optionalNull(Schema.Struct({ reason: Schema.optional(Schema.String) })),
           output: Schema.optional(Schema.Array(StreamItem)),
           usage: optionalNull(OpenResponsesUsage),
-          error: optionalNull(OpenResponsesErrorPayload),
+          error: Schema.optional(Schema.Unknown),
         }),
         [Schema.Record(Schema.String, Schema.Unknown)],
       ),
     ),
-    code: optionalNull(Schema.String),
-    message: Schema.optional(Schema.String),
-    param: optionalNull(Schema.String),
-    error: optionalNull(OpenResponsesErrorPayload),
+    code: Schema.optional(Schema.Unknown),
+    message: Schema.optional(Schema.Unknown),
+    error: Schema.optional(Schema.Unknown),
     status: Schema.optional(Schema.Unknown),
     status_code: Schema.optional(Schema.Unknown),
-    headers: Schema.optional(Schema.Unknown),
   }),
   [Schema.Record(Schema.String, Schema.Unknown)],
-).pipe(
-  Schema.decode({
-    decode: SchemaGetter.transform((event) => {
-      if (event.type !== "error" || event.error != null) return event
-      const { code, message, param, ...rest } = event
-      if (code === undefined && message === undefined && param === undefined) return event
-      // Flat errors (for example, Meta's) can also arrive through generic Responses endpoints.
-      return { ...rest, error: { code, message, param } }
-    }),
-    encode: SchemaGetter.passthrough(),
-  }),
 )
 export type Event = Schema.Schema.Type<typeof Event>
 export type NormalizedEvent = Event & { readonly item?: OutputItem | null }
@@ -427,14 +380,15 @@ const decodeEventValue = Schema.decodeUnknownEffect(Event)
 const decodeFrame = Schema.decodeUnknownEffect(ProviderShared.Json)
 
 /**
- * Decodes one WebSocket frame. xAI answers a rejected `response.create` with `{ "error": { "message", "type" } }` and no
- * event type; that envelope reads as an error event so the failure classifies instead of failing decoding.
+ * Decodes one WebSocket frame. Some providers and gateways answer a rejected `response.create` with a bare
+ * `{ "error": ... }` envelope and no event type; that reads as an error event so it classifies instead of
+ * failing decoding.
  */
 export const decodeChannelEvent = (frame: string) =>
   decodeFrame(frame).pipe(
     Effect.flatMap((value) =>
       decodeEventValue(
-        ProviderShared.isRecord(value) && value.type === undefined && ProviderShared.isRecord(value.error)
+        ProviderShared.isRecord(value) && value.type === undefined && value.error != null
           ? { ...value, type: "error" }
           : value,
       ),
@@ -1414,22 +1368,21 @@ const onResponseFinish = Effect.fn("OpenResponses.onResponseFinish")(function* (
   return [{ ...current, lifecycle }, events] satisfies StepResult
 })
 
-// Build the prettiest summary available from whatever the provider supplied.
-// When both code and message are present, prefix the code so consumers see
-// the failure mode (e.g. `rate_limit_exceeded: Slow down`) instead of just
-// the bare message — production rate limits and context-length failures used
-// to be indistinguishable from generic stream drops. Returns undefined when
-// the payload carries no usable summary.
-const providerErrorMessage = (event: Event, nested: OpenResponsesErrorPayload | undefined): string | undefined => {
-  const message = event.message || nested?.message || undefined
-  const code = event.code || nested?.code || undefined
-  if (message && code) return `${code}: ${message}`
-  return message || code
+/** Error code and message from wherever the frame put them; top-level fields win over nested ones. */
+export const errorDetail = (event: Event) => {
+  const raw = event.error ?? event.response?.error
+  const nested = typeof raw === "string" ? { message: raw } : ProviderShared.isRecord(raw) ? raw : undefined
+  return {
+    message: asText(event.message) ?? asText(nested?.message),
+    code: asText(event.code) ?? asText(nested?.code),
+  }
 }
 
+// Prefix the code when both are present (`rate_limit_exceeded: Slow down`) so the failure mode is
+// visible; fall back to the raw frame rather than a generic message when neither decodes.
 export const providerFailure = (event: Event, fallback: string, body = ProviderShared.encodeJson(event)) => {
-  const nested = event.error ?? event.response?.error ?? undefined
-  const summary = providerErrorMessage(event, nested)
+  const detail = errorDetail(event)
+  const summary = detail.message && detail.code ? `${detail.code}: ${detail.message}` : (detail.message ?? detail.code)
   const message = summary ?? (body === "{}" ? fallback : body)
   const status =
     typeof event.status === "number"
@@ -1512,18 +1465,7 @@ export const step = (state: ParserState, event: NormalizedEvent) => {
   if (event.type === "response.output_item.done") return onOutputItemDone(state, event.item)
   if (event.type === "response.completed" || event.type === "response.incomplete") return onResponseFinish(state, event)
   if (event.type === "response.failed") return providerFailure(event, `${state.name} response failed`)
-  if (event.type === "error")
-    return decodeKnownErrorEvent(event).pipe(
-      Effect.mapError((cause) =>
-        ProviderShared.eventError(
-          state.id,
-          `${state.name} returned a malformed error event`,
-          ProviderShared.encodeJson(event),
-          cause,
-        ),
-      ),
-      Effect.flatMap(() => providerFailure(event, `${state.name} stream error`)),
-    )
+  if (event.type === "error") return providerFailure(event, `${state.name} stream error`)
   return Effect.succeed<StepResult>([state, NO_EVENTS])
 }
 

packages/ai/src/protocols/openai-chat.ts

@@ -715,7 +715,10 @@ const detectZaiToolStream = (provider: string, baseURL: string | undefined, mode
 
 const lowerOptions = (request: LLMRequest, supportsStore: boolean) => {
   const options = OpenAIOptions.resolve(request)
-  const cacheKey = ProviderShared.promptCacheKey(request)
+  // Default off: strict providers 400 on unknown body fields, so only send
+  // the key where compatibility explicitly allows it. Header-based affinity
+  // (x-session-affinity, x-grok-conv-id, ...) is unaffected.
+  const cacheKey = (request.model.compatibility?.supportsPromptCacheKey ?? false) ? ProviderShared.promptCacheKey(request) : undefined
   return {
     ...(supportsStore && options.store !== undefined ? { store: options.store } : {}),
     // For providers that support `store`, ensure stateless `store:false` is sent

packages/ai/src/providers/azure.ts

@@ -1,4 +1,3 @@
-import { Headers } from "effect/unstable/http"
 import { Auth } from "../route/auth.js"
 import { type AtLeastOne, type ProviderAuthOption } from "../route/auth-options.js"
 import type { Route, RouteDefaultsInput, CompactionOperations } from "../route/client.js"
@@ -61,11 +60,6 @@ const responsesRoute = OpenAIResponses.route.with({
       url.searchParams.delete("api-version")
       return url.toString()
     },
-    headers: (headers) => {
-      const apiKey = headers["api-key"]
-      if (!apiKey) return headers
-      return Headers.remove(Headers.set(headers, "authorization", `Bearer ${apiKey}`), "api-key")
-    },
   }),
 })
 
@@ -135,7 +129,7 @@ export const configure = (input: Config) => {
   const chat = (modelID: string | ModelID) =>
     configuredRoute(chatRoute, input, modelID)
       .with(withOpenAIOptions(modelID, modelDefaults))
-      .model<OpenAIProviderOptionsInput>({ id: modelID })
+      .model<OpenAIProviderOptionsInput>({ id: modelID, compatibility: { supportsPromptCacheKey: true } })
 
   return {
     id,

packages/ai/src/providers/cerebras.ts

@@ -44,7 +44,7 @@ export const configure = (input: LanguageModelOptions = {}) => {
     model: (modelID: string | ModelID) =>
       configured.model<OpenAIProviderOptionsInput>({
         id: modelID,
-        compatibility: { maxTokensField: "max_tokens", reasoningField: "reasoning", supportsStore: false },
+        compatibility: { maxTokensField: "max_tokens", reasoningField: "reasoning", supportsStore: false, supportsPromptCacheKey: true },
       }),
     configure,
   }

packages/ai/src/providers/deepinfra.ts

@@ -47,7 +47,7 @@ export const configure = (input: LanguageModelOptions = {}) => {
     model: (modelID: string | ModelID) =>
       configured.model<OpenAIProviderOptionsInput>({
         id: modelID,
-        compatibility: { maxTokensField: "max_tokens", reasoningField: "reasoning_content", supportsStore: false },
+        compatibility: { maxTokensField: "max_tokens", reasoningField: "reasoning_content", supportsStore: false, supportsPromptCacheKey: true },
       }),
     configure,
   }

packages/ai/src/providers/fireworks.ts

@@ -41,7 +41,8 @@ export const configure = (input: LanguageModelOptions = {}) => {
   })
   return {
     id,
-    model: (modelID: string | ModelID) => configured.model<OpenAIProviderOptionsInput>({ id: modelID }),
+    model: (modelID: string | ModelID) =>
+      configured.model<OpenAIProviderOptionsInput>({ id: modelID, compatibility: { supportsPromptCacheKey: true } }),
     configure,
   }
 }

packages/ai/src/providers/meta.ts

@@ -132,7 +132,7 @@ export const configure = (input: LanguageModelOptions = {}) => {
   const chat = (modelID: string | ModelID) =>
     configuredChat.model<OpenResponsesProviderOptionsInput>({
       id: modelID,
-      compatibility: { maxTokensField: "max_completion_tokens", supportsStore: false },
+      compatibility: { maxTokensField: "max_completion_tokens", supportsStore: false, supportsPromptCacheKey: true },
     })
   const messages = (modelID: string | ModelID) =>
     configuredMessages.model<MessagesOptionsInput>({

packages/ai/src/providers/moonshot.ts

@@ -112,6 +112,7 @@ export const configure = (input: Config = {}) => {
         maxTokensField: "max_tokens",
         supportsStore: false,
         supportsStrictMode: false,
+        supportsPromptCacheKey: true,
         toolSchema: "moonshot",
         reasoningField: "reasoning_content",
       },

packages/ai/src/providers/openai.ts

@@ -91,7 +91,10 @@ export const configure = (input: Config = {}) => {
       .with(withOpenAIOptions(id, modelDefaults, { textVerbosity: true }))
       .model<OpenAIProviderOptionsInput>({ id })
   const chat = (id: string | ModelID) =>
-    chatRoute.with(withOpenAIOptions(id, modelDefaults)).model<OpenAIProviderOptionsInput>({ id })
+    chatRoute.with(withOpenAIOptions(id, modelDefaults)).model<OpenAIProviderOptionsInput>({
+      id,
+      compatibility: { supportsPromptCacheKey: true },
+    })
   const image = (modelID: string | ModelID) =>
     OpenAIImages.model({
       id: modelID,

packages/ai/src/providers/openrouter.ts

@@ -183,7 +183,8 @@ export const configure = (input: LanguageModelOptions = {}) => {
   const route = configuredRoute(input)
   return {
     id,
-    model: (modelID: string | ModelID) => route.model<OpenRouterProviderOptionsInput>({ id: modelID }),
+    model: (modelID: string | ModelID) =>
+      route.model<OpenRouterProviderOptionsInput>({ id: modelID, compatibility: { supportsPromptCacheKey: true } }),
     configure,
   }
 }

packages/ai/src/schema/options.ts

@@ -168,6 +168,9 @@ export class LanguageModelCompatibility extends Schema.Class<LanguageModelCompat
   supportsStore: Schema.optional(Schema.Boolean),
   supportsUsageInStreaming: Schema.optional(Schema.Boolean),
   supportsStrictMode: Schema.optional(Schema.Boolean),
+  // Accepts `prompt_cache_key` in the Chat Completions body. Chat omits the
+  // key unless this is set; session-affinity headers still flow regardless.
+  supportsPromptCacheKey: Schema.optional(Schema.Boolean),
   zaiToolStream: Schema.optional(Schema.Boolean),
   requireSignature: Schema.optional(Schema.Boolean),
   /** Supports Anthropic's thinking-prefix mismatch controls. Overrides model-ID detection. */

packages/ai/test/provider/open-responses-errors.test.ts

@@ -1,8 +1,9 @@
 import { expect } from "bun:test"
-import { Effect, Schema } from "effect"
+import { Effect, Schema, Stream } from "effect"
 import { LLM, LLMClient } from "../../src/index.js"
 import { OpenResponses } from "../../src/protocols/open-responses.js"
-import { Meta } from "../../src/providers/index.js"
+import { Azure, Meta, OpenAI, XAI } from "../../src/providers/index.js"
+import { WebSocketTransport } from "../../src/route.js"
 import { configure } from "../../src/providers/openai-compatible-responses.js"
 import { it } from "../lib/effect.js"
 import { fixedResponse } from "../lib/http.js"
@@ -10,45 +11,105 @@ import { sseEvents } from "../lib/sse.js"
 
 const decodeEvent = Schema.decodeUnknownEffect(OpenResponses.protocol.stream.event)
 
-it.effect("normalizes flat errors in shared SSE and WebSocket decoding", () =>
+it.effect("decodes error frames verbatim in shared SSE and WebSocket decoding", () =>
   Effect.gen(function* () {
-    const frame = {
-      type: "error",
-      sequence_number: 4,
-      code: "server_shutting_down",
-      message: "Server is shutting down. Please retry your request.",
-      param: null,
-    }
     for (const decode of [decodeEvent, OpenResponses.decodeChannelEvent]) {
-      const event = yield* decode(JSON.stringify(frame))
-      expect(event).toEqual({
-        type: "error",
-        sequence_number: 4,
-        error: { code: frame.code, message: frame.message, param: null },
-      })
-
-      for (const unchanged of [
-        event,
+      for (const frame of [
+        { type: "error", sequence_number: 4, code: "server_shutting_down", message: "Shutting down", param: null },
         { type: "error" },
+        { type: "error", error: "Gateway failed" },
+        { type: "error", error: { code: 429, message: "slow down" } },
+        { type: "error", error: 42 },
+        { type: "error", code: 500, message: ["not", "a", "string"] },
+        { type: "response.failed", response: { id: "resp_failed", error: "Gateway failed" } },
+        { type: "response.failed", response: { id: "resp_failed", error: ["weird"] } },
         {
           type: "response.failed",
           response: { id: "resp_failed", error: { code: "server_error", message: "Internal server error" } },
         },
         { type: "response.output_text.delta", item_id: "msg_text", delta: "Hello" },
       ]) {
-        expect(yield* decode(JSON.stringify(unchanged))).toEqual(unchanged)
+        expect(yield* decode(JSON.stringify(frame))).toEqual(frame)
       }
     }
   }),
 )
 
-it.effect("continues to normalize untyped xAI WebSocket errors", () =>
+it.effect("reads bare WebSocket error envelopes as error events", () =>
   Effect.gen(function* () {
-    const frame = { error: { type: "api_error", message: "gRPC error: Response with id=resp_missing not found" } }
-    expect(yield* OpenResponses.decodeChannelEvent(JSON.stringify(frame))).toEqual({ ...frame, type: "error" })
+    const message = "gRPC error: Response with id=resp_missing not found"
+    for (const error of [{ type: "api_error", message }, message, 42]) {
+      expect(yield* OpenResponses.decodeChannelEvent(JSON.stringify({ error }))).toEqual({ type: "error", error })
+    }
+    for (const frame of [{ error: null }, { message }]) {
+      expect(yield* OpenResponses.decodeChannelEvent(JSON.stringify(frame)).pipe(Effect.flip)).toBeDefined()
+    }
   }),
 )
 
+it.effect("extracts error details from every shape and falls back to the raw frame", () =>
+  Effect.gen(function* () {
+    const cases: Array<[frame: Record<string, unknown>, message: string, tag: string]> = [
+      [
+        { type: "error", code: "server_shutting_down", message: "Shutting down" },
+        "server_shutting_down: Shutting down",
+        "UnknownProvider",
+      ],
+      [{ type: "error", error: "Gateway failed" }, "Gateway failed", "UnknownProvider"],
+      [{ type: "error", error: { code: 429, message: "slow down" } }, "429: slow down", "UnknownProvider"],
+      [{ type: "error", error: { message: "slow down" }, status: 429 }, "slow down", "RateLimit"],
+      [{ type: "error", code: 500, message: ["not", "a", "string"] }, "500", "UnknownProvider"],
+      [
+        { type: "response.failed", response: { id: "resp_failed", error: "Gateway failed" } },
+        "Gateway failed",
+        "UnknownProvider",
+      ],
+    ]
+    for (const [frame, message, tag] of cases) {
+      const event = yield* OpenResponses.decodeChannelEvent(JSON.stringify(frame))
+      const error = OpenResponses.providerFailure(event, "fallback", JSON.stringify(frame))
+      expect(error.message).toBe(message)
+      expect(error.reason._tag).toBe(tag)
+      expect(error.reason.body).toBe(JSON.stringify(frame))
+    }
+    for (const frame of [
+      { type: "error", error: 42 },
+      { type: "response.failed", response: { id: "resp_failed", error: ["weird"] } },
+    ]) {
+      const event = yield* OpenResponses.decodeChannelEvent(JSON.stringify(frame))
+      const error = OpenResponses.providerFailure(event, "fallback", JSON.stringify(frame))
+      expect(error.message).toBe(JSON.stringify(frame))
+      expect(error.reason._tag).toBe("UnknownProvider")
+    }
+    expect(OpenResponses.providerFailure({ type: "error" }, "fallback", "{}").message).toBe("fallback")
+    expect(OpenResponses.providerFailure({ type: "error" }, "fallback", "{}").reason._tag).toBe("ProviderInternal")
+  }),
+)
+
+for (const model of [
+  OpenAI.configure({ apiKey: "fixture" }).responses("gpt-5.6-sol"),
+  XAI.configure({ apiKey: "fixture" }).responses("grok-4.6"),
+  Azure.configure({ apiKey: "fixture", resourceName: "fixture" }).responses("deployment"),
+]) {
+  it.effect(`preserves string error messages and raw bodies through ${model.provider} Responses`, () =>
+    Effect.gen(function* () {
+      const raw = '{ "type": "error", "error": "Gateway rejected the request", "trace": "original" }'
+      const webSocket = WebSocketTransport.makeDirect({
+        open: () => Effect.succeed({ sendText: () => Effect.void, messages: Stream.make(raw), close: Effect.void }),
+      })
+      for (const options of [{ webSocket }, {}]) {
+        const error = yield* LLMClient.generate(LLM.request({ model, prompt: "Hello" }), options).pipe(
+          Effect.provide(fixedResponse(sseEvents(raw))),
+          Effect.flip,
+        )
+        expect(error.reason._tag).toBe("UnknownProvider")
+        expect(error.message).toBe("Gateway rejected the request")
+        expect(error.reason.body).toBe(raw)
+      }
+    }),
+  )
+}
+
 it.effect("retains classification and original error bodies through Meta and generic Responses routes", () =>
   Effect.gen(function* () {
     const raw = `{

packages/ai/test/provider/openai-chat.test.ts

@@ -248,7 +248,23 @@ describe("OpenAI Chat route", () => {
     }),
   )
 
-  it.effect("maps the request prompt cache key", () =>
+  it.effect("maps the request prompt cache key when the compatibility flag is set", () =>
+    Effect.gen(function* () {
+      const prepared = yield* compileRequest(
+        LLM.request({
+          model: OpenAIChat.route
+            .with({ endpoint: { baseURL: "https://api.compatible.test/v1" }, auth: Auth.bearer("test") })
+            .model({ id: "compatible-model", compatibility: { supportsPromptCacheKey: true } }),
+          prompt: "Hello",
+          promptCacheKey: "session_123",
+        }),
+      )
+
+      expect(prepared.body.prompt_cache_key).toBe("session_123")
+    }),
+  )
+
+  it.effect("omits the prompt cache key without the compatibility flag", () =>
     Effect.gen(function* () {
       const prepared = yield* compileRequest(
         LLM.request({
@@ -261,7 +277,7 @@ describe("OpenAI Chat route", () => {
         }),
       )
 
-      expect(prepared.body.prompt_cache_key).toBe("session_123")
+      expect(prepared.body).not.toHaveProperty("prompt_cache_key")
     }),
   )
 
@@ -280,7 +296,7 @@ describe("OpenAI Chat route", () => {
     }),
   )
 
-  it.effect("maps the xAI Chat prompt cache key to conversation affinity", () =>
+  it.effect("maps the xAI Chat prompt cache key to conversation affinity header only", () =>
     LLMClient.generate(
       LLM.request({
         model: XAI.configure({ apiKey: "test", baseURL: "https://api.x.ai/v1" }).chat("grok-4.5"),
@@ -294,7 +310,8 @@ describe("OpenAI Chat route", () => {
             const web = yield* HttpClientRequest.toWeb(input.request).pipe(Effect.orDie)
             expect(web.headers.get("x-grok-conv-id")).toBe("session_123")
             const body = decodeJson(yield* Effect.promise(() => web.text()))
-            expect(ProviderShared.isRecord(body) ? body.prompt_cache_key : undefined).toBe("session_123")
+            // Chat uses the header; prompt_cache_key is Responses-only.
+            expect(ProviderShared.isRecord(body) ? body.prompt_cache_key : undefined).toBeUndefined()
             return input.respond(sseEvents(deltaChunk({}, "stop")), {
               headers: { "content-type": "text/event-stream" },
             })

packages/ai/test/provider/openai-responses.test.ts

@@ -1,5 +1,5 @@
 import { describe, expect } from "bun:test"
-import { ConfigProvider, Effect, Layer, Ref, Schema, Stream } from "effect"
+import { ConfigProvider, Effect, Layer, Logger, Ref, Schema, Stream } from "effect"
 import { Headers, HttpClientRequest } from "effect/unstable/http"
 import {
   LLM,
@@ -760,7 +760,11 @@ describe("OpenAI Responses route", () => {
       )
       const next = continuationDriver({
         ...request,
-        input: [...firstInput, reasoning, { type: "message", role: "user", content: [{ type: "input_text", text: "Continue" }] }],
+        input: [
+          ...firstInput,
+          reasoning,
+          { type: "message", role: "user", content: [{ type: "input_text", text: "Continue" }] },
+        ],
       })
 
       const continued = yield* next.create(saved)
@@ -795,7 +799,10 @@ describe("OpenAI Responses route", () => {
           ProviderShared.encodeJson({ type: "response.completed", response: { id: "resp_1" } }),
         ),
       )
-      const appended = [...request.input, { type: "message", role: "user", content: [{ type: "input_text", text: "Second" }] }]
+      const appended = [
+        ...request.input,
+        { type: "message", role: "user", content: [{ type: "input_text", text: "Second" }] },
+      ]
       const changes = [
         { ...request, model: "gpt-5.3", input: appended },
         { ...request, instructions: "Changed", input: appended },
@@ -804,7 +811,10 @@ describe("OpenAI Responses route", () => {
         { ...request, metadata: { source: "two" }, input: appended },
         {
           ...request,
-          input: [{ type: "message", role: "user", content: [{ type: "input_text", text: "Rewritten history" }] }, appended[1]],
+          input: [
+            { type: "message", role: "user", content: [{ type: "input_text", text: "Rewritten history" }] },
+            appended[1],
+          ],
         },
       ]
 
@@ -900,7 +910,10 @@ describe("OpenAI Responses route", () => {
       const second = continuationDriver(
         {
           ...firstRequest,
-          input: [...firstRequest.input, { type: "message", role: "user", content: [{ type: "input_text", text: "Second" }] }],
+          input: [
+            ...firstRequest.input,
+            { type: "message", role: "user", content: [{ type: "input_text", text: "Second" }] },
+          ],
         },
         classifyingChannelDriver,
       )
@@ -951,7 +964,10 @@ describe("OpenAI Responses route", () => {
       }
       const secondRequest = {
         ...firstRequest,
-        input: [...firstRequest.input, { type: "message", role: "user", content: [{ type: "input_text", text: "Second" }] }],
+        input: [
+          ...firstRequest.input,
+          { type: "message", role: "user", content: [{ type: "input_text", text: "Second" }] },
+        ],
       }
       const saved = checkpoint(
         yield* continuationDriver(firstRequest).observe(
@@ -1082,7 +1098,9 @@ describe("OpenAI Responses route", () => {
       )
 
       const expected = {
-        input: [{ type: "message", role: "user", content: [{ type: "input_text", text: "Say \uFFFDhello \u{1F600}." }] }],
+        input: [
+          { type: "message", role: "user", content: [{ type: "input_text", text: "Say \uFFFDhello \u{1F600}." }] },
+        ],
         metadata: { source: "overlay\uFFFD" },
       }
       expect(JSON.parse(yield* Ref.get(message))).toMatchObject(expected)
@@ -1124,7 +1142,9 @@ describe("OpenAI Responses route", () => {
     }),
   )
 
-  it.effect("builds Azure WebSocket requests with v1 URLs and bearer auth", () =>
+  // Azure's WebSocket upgrade accepts the same credential header as HTTP: `api-key` for keys,
+  // `Authorization: Bearer` for Entra tokens. Rewriting a key into a bearer is rejected.
+  it.effect("builds Azure WebSocket requests with v1 URLs and the route's auth header", () =>
     Effect.gen(function* () {
       const deps = Layer.succeed(
         RequestExecutor.Service,
@@ -1133,13 +1153,13 @@ describe("OpenAI Responses route", () => {
       const cases = [
         {
           model: Azure.configure({ resourceName: "opencode-test", apiKey: "azure-key" }).responses("deployment"),
-          authorization: "Bearer azure-key",
+          headers: { "api-key": "azure-key", authorization: undefined },
         },
         {
           model: Azure.configure({ resourceName: "opencode-test", auth: Auth.bearer("entra-token") }).responses(
             "deployment",
           ),
-          authorization: "Bearer entra-token",
+          headers: { "api-key": undefined, authorization: "Bearer entra-token" },
         },
       ]
 
@@ -1150,8 +1170,8 @@ describe("OpenAI Responses route", () => {
               Effect.gen(function* () {
                 expect(exchange.connect.url).toBe("wss://opencode-test.openai.azure.com/openai/v1/responses")
                 expect(exchange.connect.rotateAfterMs).toBe(55 * 60 * 1000)
-                expect(exchange.connect.headers.authorization).toBe(item.authorization)
-                expect(exchange.connect.headers["api-key"]).toBeUndefined()
+                expect(exchange.connect.headers.authorization).toBe(item.headers.authorization)
+                expect(exchange.connect.headers["api-key"]).toBe(item.headers["api-key"])
                 expect(exchange.connect.headers["openai-beta"]).toBeUndefined()
                 expect(JSON.parse((yield* exchange.driver.create(undefined)).message)).toMatchObject({
                   type: "response.create",
@@ -1199,6 +1219,11 @@ describe("OpenAI Responses route", () => {
         },
       ]
 
+      const warnings: string[] = []
+      const logger = Logger.make((entry) => {
+        if (entry.logLevel !== "Warn") return
+        warnings.push(String(Array.isArray(entry.message) ? entry.message[0] : entry.message))
+      })
       yield* Effect.forEach(cases, (item) =>
         LLMClient.generate(LLM.request({ model: item.model, prompt: "Say hello." }), {
           webSocket: { execute: () => Effect.die("unexpected WebSocket request") },
@@ -1214,6 +1239,9 @@ describe("OpenAI Responses route", () => {
             ),
           ),
         ),
+      ).pipe(Effect.provide(Logger.layer([logger])))
+      expect(warnings).toEqual(
+        cases.map(() => "Azure OpenAI Responses does not offer WebSocket for this endpoint; using HTTP"),
       )
     }),
   )
@@ -1842,7 +1870,11 @@ describe("OpenAI Responses route", () => {
             summary: [{ type: "summary_text", text: "I inspected the previous turn." }],
           },
           { role: "assistant", content: [{ type: "output_text", text: "It shows a small test image." }] },
-          { type: "message", role: "user", content: [{ type: "input_text", text: "Check the weather in Paris before continuing." }] },
+          {
+            type: "message",
+            role: "user",
+            content: [{ type: "input_text", text: "Check the weather in Paris before continuing." }],
+          },
           { type: "function_call", call_id: "call_weather_1", name: "get_weather", arguments: '{"city":"Paris"}' },
           { type: "function_call_output", call_id: "call_weather_1", output: '{"temperature":22}' },
           { role: "assistant", content: [{ type: "output_text", text: "Paris is 22 degrees." }] },
@@ -4599,8 +4631,20 @@ describe("OpenAI Responses route", () => {
         compileRequest(LLM.request({ model, messages: [response.message], providerOptions: { store } })),
       )
       expect(prepared.map((request) => request.body.input)).toEqual([
-        [{ type: "message", role: "user", content: [{ type: "input_image", image_url: "data:image/png;base64,AQID" }] }],
-        [{ type: "message", role: "user", content: [{ type: "input_image", image_url: "data:image/png;base64,AQID" }] }],
+        [
+          {
+            type: "message",
+            role: "user",
+            content: [{ type: "input_image", image_url: "data:image/png;base64,AQID" }],
+          },
+        ],
+        [
+          {
+            type: "message",
+            role: "user",
+            content: [{ type: "input_image", image_url: "data:image/png;base64,AQID" }],
+          },
+        ],
       ])
     }),
   )

packages/app/e2e/regression/new-session-workspace-branch.spec.ts

@@ -22,7 +22,7 @@ test("selects a base branch for a new workspace", async ({ page }) => {
     pageMessages: () => ({ items: [] }),
     vcsBranches: ["feature/api", "main", "origin/release"],
   })
-  await page.route("**/api/vcs/branches?*", (route) => {
+  await page.route("**/api/vcs/branch?*", (route) => {
     if (new URL(route.request().url()).searchParams.get("search") !== "feature") return route.fallback()
     return route.fulfill({ json: { location: { directory }, data: ["feature/api"] } })
   })

packages/app/e2e/regression/remote-session-settings.spec.ts

@@ -61,7 +61,7 @@ test("session settings use the remote server context", async ({ page }) => {
         directory: undefined,
         sessionID: sessionA.id,
         permissionID: "permission-pending-a",
-        body: { reply: "once" },
+        body: { decision: "once" },
       },
     ])
 
@@ -153,7 +153,7 @@ test("auto-accept responds for an unfocused server session", async ({ page }) =>
         directory: undefined,
         sessionID: sessionA.id,
         permissionID: "permission-background-a",
-        body: { reply: "once" },
+        body: { decision: "once" },
       },
     ])
 
@@ -180,14 +180,14 @@ test("auto-accept responds for an unfocused server session", async ({ page }) =>
         directory: undefined,
         sessionID: sessionA.id,
         permissionID: "permission-background-a",
-        body: { reply: "once" },
+        body: { decision: "once" },
       },
       {
         origin: serverA,
         directory: undefined,
         sessionID: childSessionA.id,
         permissionID: "permission-background-a-child",
-        body: { reply: "once" },
+        body: { decision: "once" },
       },
     ])
 })
@@ -243,7 +243,7 @@ test("auto-accept sweeps again after a reconnect", async ({ page }) => {
         directory: undefined,
         sessionID: sessionA.id,
         permissionID: "permission-offline-a",
-        body: { reply: "once" },
+        body: { decision: "once" },
       },
     ])
   // The reconnect sweep must resync active sessions instead of trusting
@@ -280,7 +280,7 @@ test("auto-accept approves a request discovered by opening a session", async ({
         directory: undefined,
         sessionID: sessionA.id,
         permissionID: "permission-synced-a",
-        body: { reply: "once" },
+        body: { decision: "once" },
       },
     ])
 })

packages/app/e2e/regression/session-queue.spec.ts

@@ -74,7 +74,7 @@ function createQueueMock(seed: string[], messages: SessionMessageInfo[] = []) {
         item: { type: "user", payload: row.payload, delivery: row.delivery },
       })
     },
-    onInboxChange: (input: { sessionID: string; inboxID: string; action: "cancel" | "steer" }) => {
+    onInboxChange: (input: { sessionID: string; inboxID: string; action: "cancel" | "steer" | "queue" }) => {
       changes.push({ inboxID: input.inboxID, action: input.action })
       log.push(`${input.action}:${input.inboxID}`)
       const index = rows.findIndex((row) => row.id === input.inboxID)
@@ -85,11 +85,11 @@ function createQueueMock(seed: string[], messages: SessionMessageInfo[] = []) {
         emit("session.inbox.cancelled", { sessionID: input.sessionID, inboxID: input.inboxID })
         return
       }
-      row.delivery = "steer"
+      row.delivery = input.action
       emit("session.inbox.delivery.changed", {
         sessionID: input.sessionID,
         inboxID: input.inboxID,
-        delivery: "steer",
+        delivery: input.action,
       })
     },
   }

packages/app/e2e/regression/session-request-docks.spec.ts

@@ -48,7 +48,10 @@ test("shows a pending question dock", async ({ page }) => {
   const rejectRequests: string[] = []
   page.on("request", (request) => {
     if (request.method() !== "POST") return
-    if (new URL(request.url()).pathname === `/api/session/${sessionID}/form/frm_question_request/cancel`)
+    if (
+      request.method() === "DELETE" &&
+      new URL(request.url()).pathname === `/api/session/${sessionID}/form/frm_question_request`
+    )
       rejectRequests.push(request.url())
   })
 
@@ -107,7 +110,7 @@ test("shows a pending permission dock", async ({ page }) => {
   await permission.getByRole("button", { name: "Allow once" }).click()
   const request = await reply
   expect(new URL(request.url()).pathname).toBe(`/api/session/${sessionID}/permission/permission-request/reply`)
-  expect(request.postDataJSON()).toEqual({ reply: "once" })
+  expect(request.postDataJSON()).toEqual({ decision: "once" })
 })
 
 test("restores the draft caret before typing after a request dock closes", async ({ page }) => {

packages/app/e2e/regression/session-summary.spec.ts

@@ -23,6 +23,7 @@ for (const custom of [false, true]) {
     await page.goto(stressSessionHref(fixture.sourceID))
     const trigger = page.getByRole("button", { name: "Session details", exact: true })
     const summary = page.getByRole("dialog", { name: "Session details", exact: true })
+    await expect(page.locator('[data-component="composer-editor"]')).toBeEditable()
     await expect(trigger).toBeEnabled()
     await trigger.hover()
     const tooltip = page.getByRole("tooltip")

packages/app/e2e/regression/tab-navigate-mousedown.spec.ts

@@ -587,7 +587,7 @@ async function mockServer(page: Page) {
       return json(route, { location: { directory: sessionA.directory }, data: [] })
     if (url.pathname === "/api/model/default")
       return json(route, { location: { directory: sessionA.directory }, data: null })
-    if (url.pathname === "/api/permission/request" || url.pathname === "/api/form/request")
+    if (url.pathname === "/api/permission/request" || url.pathname === "/api/form")
       return json(route, { location: { directory: sessionA.directory }, data: [] })
     if (url.pathname === "/api/mcp") return json(route, { location: { directory: sessionA.directory }, data: [] })
     if (url.pathname === "/api/mcp/resource")

packages/app/e2e/regression/terminal-hidden.spec.ts

@@ -278,7 +278,11 @@ async function installMotionProbe(page: Page) {
           probe.resetAnchorOnMotion = false
         }
         probe.terminalAnchorGaps.push(anchorGap)
-        if (panelGap && terminalRegion.getBoundingClientRect().height > 1)
+        if (
+          panelGap &&
+          reviewRegion.getBoundingClientRect().height > 1 &&
+          terminalRegion.getBoundingClientRect().height > 1
+        )
           probe.panelGaps.push(panelGap.getBoundingClientRect().height)
         if (!review) return
         probe.paintGaps.push({

packages/app/e2e/utils/mock-api.ts

@@ -112,10 +112,10 @@ const Group = HttpApiGroup.make("mock")
   )
   .add(HttpApiEndpoint.get("location", "/api/location", { success: Json }))
   .add(HttpApiEndpoint.get("permissionRequests", "/api/permission/request", { success: Json }))
-  .add(HttpApiEndpoint.get("formRequests", "/api/form/request", { success: Json }))
+  .add(HttpApiEndpoint.get("formRequests", "/api/form", { success: Json }))
   .add(HttpApiEndpoint.get("vcs", "/api/vcs", { success: Json }))
   .add(HttpApiEndpoint.get("vcsStatus", "/api/vcs/status", { success: Json }))
-  .add(HttpApiEndpoint.get("vcsBranches", "/api/vcs/branches", { success: Json }))
+  .add(HttpApiEndpoint.get("vcsBranches", "/api/vcs/branch", { success: Json }))
   .add(HttpApiEndpoint.get("vcsDiff", "/api/vcs/diff", { success: Json }))
   .add(HttpApiEndpoint.get("fsList", "/api/fs/list", { query: Query, success: Json }))
   .add(
@@ -173,7 +173,7 @@ const Group = HttpApiGroup.make("mock")
     }),
   )
   .add(
-    HttpApiEndpoint.post("sessionFormCancel", "/api/session/:sessionID/form/:formID/cancel", {
+    HttpApiEndpoint.delete("sessionFormCancel", "/api/session/:sessionID/form/:formID", {
       params: { ...SessionParams, formID: Schema.String },
       success: NoContent,
     }),
@@ -218,8 +218,9 @@ const Group = HttpApiGroup.make("mock")
     }),
   )
   .add(
-    HttpApiEndpoint.post("sessionInboxSteer", "/api/session/:sessionID/inbox/:inboxID/steer", {
+    HttpApiEndpoint.patch("sessionInboxUpdate", "/api/session/:sessionID/inbox/:inboxID", {
       params: { ...SessionParams, inboxID: Schema.String },
+      payload: Schema.Struct({ delivery: Schema.Literals(["steer", "queue"]) }),
       success: NoContent,
     }),
   )

packages/app/e2e/utils/mock-server.ts

@@ -42,7 +42,7 @@ export interface MockServerConfig {
   sessionStatus?: Record<string, unknown> | (() => Record<string, unknown>)
   inbox?: unknown[] | (() => unknown[])
   onPrompt?: (input: { sessionID: string; body: Record<string, unknown> }) => void
-  onInboxChange?: (input: { sessionID: string; inboxID: string; action: "cancel" | "steer" }) => void
+  onInboxChange?: (input: { sessionID: string; inboxID: string; action: "cancel" | "steer" | "queue" }) => void
 }
 
 type MockStreamWindow = Window & {
@@ -454,9 +454,13 @@ function mockHandlers(config: MockServerConfig, state: { cursors: Map<string, st
           Effect.sync(() =>
             config.onInboxChange?.({ sessionID: ctx.params.sessionID, inboxID: ctx.params.inboxID, action: "cancel" }),
           ).pipe(Effect.andThen(noContent)),
-        sessionInboxSteer: (ctx) =>
+        sessionInboxUpdate: (ctx) =>
           Effect.sync(() =>
-            config.onInboxChange?.({ sessionID: ctx.params.sessionID, inboxID: ctx.params.inboxID, action: "steer" }),
+            config.onInboxChange?.({
+              sessionID: ctx.params.sessionID,
+              inboxID: ctx.params.inboxID,
+              action: ctx.payload.delivery,
+            }),
           ).pipe(Effect.andThen(noContent)),
         sessionSwitchAgent: () => noContent,
         sessionSwitchModel: () => noContent,

packages/app/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@opencode/app",
-  "version": "2.0.3",
+  "version": "2.0.5",
   "description": "",
   "type": "module",
   "exports": {

packages/app/src/home/sessions/controller.tsx

@@ -146,7 +146,7 @@ export function createHomeSessionsController(home: HomeController) {
     const next = title.trim()
     if (!next || next === sessionLabel(session)) return true
     return ctx.sdk.api.session
-      .rename({ sessionID: session.id, title: next })
+      .update({ sessionID: session.id, title: next })
       .then(() => {
         ctx.data.session.remember({ ...(ctx.data.session.get(session.id) ?? session), title: next })
         // Rename advances time.updated server-side; re-sync the canonical

packages/app/src/new-session/commands.tsx

@@ -9,6 +9,10 @@ export function useNewSessionCommands(input: {
     empty: () => boolean
     open: () => void
   }
+  workspace: {
+    enabled: () => boolean
+    cycle: () => void
+  }
 }) {
   const command = useCommand()
   const dialog = useDialog()
@@ -40,5 +44,13 @@ export function useNewSessionCommands(input: {
       disabled: input.project.empty(),
       onSelect: input.project.open,
     },
+    {
+      id: "session.location.cycle",
+      title: language.t("command.session.location.cycle"),
+      category: language.t("command.category.workspace"),
+      keybind: "mod+alt+l",
+      disabled: !input.workspace.enabled(),
+      onSelect: input.workspace.cycle,
+    },
   ])
 }

packages/app/src/new-session/screen.tsx

@@ -60,6 +60,10 @@ export default function NewSessionPage(props: { draftId: string }) {
       empty: project.empty,
       open: () => project.setOpen(true),
     },
+    workspace: {
+      enabled: workspace.bar.visible,
+      cycle: workspace.selection.cycle,
+    },
   })
   createEffect(() => {
     if (!composer.ready()) return

packages/app/src/new-session/workspace/controller.test.ts

@@ -1,5 +1,10 @@
 import { describe, expect, test } from "bun:test"
-import { resolveNewSessionBranch, resolveNewSessionGit, resolveNewSessionWorktree } from "./controller"
+import {
+  cycleNewSessionWorktree,
+  resolveNewSessionBranch,
+  resolveNewSessionGit,
+  resolveNewSessionWorktree,
+} from "./controller"
 
 describe("new session workspace selection", () => {
   test("uses main when the workspace bar is unavailable", () => {
@@ -64,4 +69,16 @@ describe("new session workspace selection", () => {
     expect(resolveNewSessionGit({ projectVcs: "git" })).toBe(true)
     expect(resolveNewSessionGit({})).toBe(false)
   })
+
+  test("cycles between local and a new worktree", () => {
+    expect(cycleNewSessionWorktree({ current: "main" })).toBe("create")
+    expect(cycleNewSessionWorktree({ current: "create" })).toBe("main")
+  })
+
+  test("includes the selected existing worktree in the cycle", () => {
+    const existing = "/project/feature"
+    expect(cycleNewSessionWorktree({ current: existing, existing })).toBe("main")
+    expect(cycleNewSessionWorktree({ current: "main", existing })).toBe("create")
+    expect(cycleNewSessionWorktree({ current: "create", existing })).toBe(existing)
+  })
 })

packages/app/src/new-session/workspace/controller.ts

@@ -37,6 +37,12 @@ export function resolveNewSessionGit(input: { projectVcs?: string; branch?: stri
   return input.projectVcs === "git" || input.branch !== undefined
 }
 
+export function cycleNewSessionWorktree(input: { current: string; existing?: string }) {
+  if (input.current === "main") return "create"
+  if (input.current === "create") return input.existing ?? "main"
+  return "main"
+}
+
 export function createNewSessionWorkspaceController(input: {
   selectedWorktree: () => string | undefined
   selectedBranch: () => string | undefined
@@ -49,7 +55,10 @@ export function createNewSessionWorkspaceController(input: {
   const data = useData()
   const settings = useSettings()
   const tabs = useTabs()
-  const [state, setState] = createStore({ search: "" })
+  const [state, setState] = createStore({
+    search: "",
+    existing: undefined as { projectID: string; directory: string } | undefined,
+  })
   const searchBranches = debounce((search: string) => setState("search", search.trim()), 100)
   const currentProject = createMemo(() => {
     const projectID = data.location.info({ directory: sdk().directory })?.project.id
@@ -142,7 +151,7 @@ export function createNewSessionWorkspaceController(input: {
     () => (visible() ? { directory: projectRoot(), search: state.search } : undefined),
     ({ directory, search }) =>
       serverSDK.api.vcs
-        .branches({ location: { directory }, search, limit: 50 })
+        .branch.list({ location: { directory }, search, limit: 50 })
         .then((response) => ({ directory, search, data: response.data }))
         .catch(() => ({ directory, search, data: [] })),
   )
@@ -159,6 +168,8 @@ export function createNewSessionWorkspaceController(input: {
   createEffect(() => {
     const selection = value()
     if (selection === "main" || selection === "create") return
+    const project = currentProject()
+    if (project) setState("existing", { projectID: project.id, directory: selection })
     void data.location.vcs.sync({ directory: selection }).catch(() => undefined)
   })
   const branch = createMemo(() =>
@@ -176,6 +187,20 @@ export function createNewSessionWorkspaceController(input: {
     const local = workspaceSelectionDestination(worktree, project.worktree) === "main"
     settings.workspaces.setLastUsed(serverSDK.scope, project.id, local ? "local" : "workspace")
   }
+  const select = (worktree: string) => {
+    input.setSelectedBranch(undefined)
+    input.setSelectedWorktree(worktree)
+    remember(worktree)
+  }
+  // The remembered worktree may have been removed since it was selected. Cycling to a directory the
+  // inventory no longer contains would resolve back to the fallback and leave the cycle stuck.
+  const existing = () => {
+    const project = currentProject()
+    const previous = state.existing
+    if (!project || previous?.projectID !== project.id) return
+    if (!worktreeDirectories().some((item) => sameDirectory(item, previous.directory))) return
+    return previous.directory
+  }
 
   return {
     selection: {
@@ -193,11 +218,8 @@ export function createNewSessionWorkspaceController(input: {
         input.setSelectedBranch(undefined)
       },
       remember,
-      set: (worktree: string) => {
-        input.setSelectedBranch(undefined)
-        input.setSelectedWorktree(worktree)
-        remember(worktree)
-      },
+      set: select,
+      cycle: () => select(cycleNewSessionWorktree({ current: value(), existing: existing() })),
       create: (branch: string) => {
         input.setSelectedBranch(branch)
         input.setSelectedWorktree("create")

packages/app/src/runtime/i18n/en.ts

@@ -93,6 +93,7 @@ export const dict = {
   "command.session.previous.unseen": "Previous unread session",
   "command.session.next.unseen": "Next unread session",
   "command.session.archive": "Archive session",
+  "command.session.location.cycle": "Cycle session location",
 
   "command.palette": "Command palette",
 

packages/app/src/runtime/server/request-queue.test.ts

@@ -98,7 +98,7 @@ describe("createRequestQueue", () => {
 
   test("classifies git and worktree endpoints as slow", () => {
     expect(isSlowRequest("/api/vcs")).toBe(true)
-    expect(isSlowRequest("/api/vcs/branches")).toBe(true)
+    expect(isSlowRequest("/api/vcs/branch")).toBe(true)
     expect(isSlowRequest("/api/worktree")).toBe(true)
     expect(isSlowRequest("/api/vcsx")).toBe(false)
     expect(isSlowRequest("/api/session")).toBe(false)

packages/app/src/session/composer/queue.ts

@@ -130,7 +130,9 @@ export function createSessionQueue(input: {
   }
   const steer = (id: string) => {
     if (state.editing?.id === id) cancelEdit()
-    return server.api.session.inbox.steer({ sessionID: input.sessionID, inboxID: id }).catch(() => notify())
+    return server.api.session.inbox
+      .update({ sessionID: input.sessionID, inboxID: id, delivery: "steer" })
+      .catch(() => notify())
   }
   const remove = (id: string) => {
     if (state.editing?.id === id) cancelEdit()

packages/app/src/session/requests/auto-approve.ts

@@ -115,7 +115,7 @@ export function createPermissionAutoApprover(input: { sdk: ServerSDK; data: Data
     if (state.disposed || !enabled() || state.responded.has(permission.id)) return
     remember(permission.id)
     input.sdk.api.permission
-      .reply({ sessionID: permission.sessionID, requestID: permission.id, reply: "once" })
+      .reply({ sessionID: permission.sessionID, requestID: permission.id, decision: "once" })
       .catch(() => {
         // A reply failure leaves the request pending but invisible (the UI
         // hides prompts while auto-approve is on), so retry a bounded number

packages/app/src/session/requests/model.ts

@@ -112,7 +112,7 @@ export function createSessionRequestModel() {
 
     setStore("responding", perm.id)
     serverSDK.api.permission
-      .reply({ sessionID: perm.sessionID, requestID: perm.id, reply: response })
+      .reply({ sessionID: perm.sessionID, requestID: perm.id, decision: response })
       .catch((err: unknown) => {
         const description = err instanceof Error ? err.message : String(err)
         showToast({ title: language.t("common.requestFailed"), description })

packages/app/src/session/requests/session-question-dock.tsx

@@ -237,7 +237,7 @@ export const SessionQuestionDock: Component<{ request: FormInfo; onSubmit: () =>
 
   const replyMutation = useMutation(() => ({
     mutationFn: (answer: FormAnswer) =>
-      serverSDK.api.form.reply({ sessionID: props.request.sessionID, formID: props.request.id, answer }),
+      serverSDK.api.session.form.reply({ sessionID: props.request.sessionID, formID: props.request.id, answer }),
     onMutate: () => {
       props.onSubmit()
     },
@@ -249,7 +249,7 @@ export const SessionQuestionDock: Component<{ request: FormInfo; onSubmit: () =>
   }))
 
   const rejectMutation = useMutation(() => ({
-    mutationFn: () => serverSDK.api.form.cancel({ sessionID: props.request.sessionID, formID: props.request.id }),
+    mutationFn: () => serverSDK.api.session.form.cancel({ sessionID: props.request.sessionID, formID: props.request.id }),
     onMutate: () => {
       props.onSubmit()
     },

packages/app/src/session/requests/websearch.test.ts

@@ -1,5 +1,5 @@
 import { describe, expect, test } from "bun:test"
-import type { FormAnswer, FormCreated, FormReplyInput, OpenCodeEvent } from "@opencode/client/promise"
+import type { FormAnswer, FormCreated, SessionFormReplyInput, OpenCodeEvent } from "@opencode/client/promise"
 import { replyWebSearch } from "./websearch"
 
 const consent: FormCreated["data"]["form"] = {
@@ -28,7 +28,7 @@ const provider: FormCreated["data"]["form"] = {
 
 function fixture() {
   const listeners = new Set<(event: OpenCodeEvent) => void>()
-  const replies: FormReplyInput[] = []
+  const replies: SessionFormReplyInput[] = []
   const abort = new AbortController()
   const emit = (event: OpenCodeEvent) => listeners.forEach((listener) => listener(event))
   return {
@@ -45,7 +45,7 @@ function fixture() {
         }
       },
     },
-    reply: async (input: FormReplyInput) => {
+    reply: async (input: SessionFormReplyInput) => {
       replies.push(input)
     },
     create: (form = provider) => emit({ id: "evt_create", created: 0, type: "form.created", data: { form } }),

packages/app/src/session/requests/websearch.ts

@@ -1,4 +1,4 @@
-import type { FormInfo, FormOption, FormReplyInput, FormStringField } from "@opencode/client/promise"
+import type { FormInfo, FormOption, SessionFormReplyInput, FormStringField } from "@opencode/client/promise"
 import { createEffect, createMemo, createResource, on, onCleanup } from "solid-js"
 import { createStore } from "solid-js/store"
 import type { OpenCodeEventStream } from "@/runtime/server/client"
@@ -14,7 +14,7 @@ export function createWebSearchRequest(input: {
   connected: () => boolean
   request: () => FormInfo | undefined
   providers: (sessionID: string) => Promise<FormOption[]>
-  reply: (input: FormReplyInput) => Promise<unknown>
+  reply: (input: SessionFormReplyInput) => Promise<unknown>
   events: Pick<OpenCodeEventStream, "listen">
 }) {
   const [store, setStore] = createStore({
@@ -93,7 +93,7 @@ export async function replyWebSearch(input: {
   form: FormInfo
   selection: string | false
   signal: AbortSignal
-  reply: (input: FormReplyInput) => Promise<unknown>
+  reply: (input: SessionFormReplyInput) => Promise<unknown>
   events: Pick<OpenCodeEventStream, "listen">
 }) {
   if (input.signal.aborted) return

packages/app/src/session/timeline/controller.tsx

@@ -80,13 +80,13 @@ export function createTimelineController(input: { session: TimelineSessionSource
     )
   })
   const titleValue = createMemo(() => input.session.data.info()?.title)
-  const titleLabel = createMemo(() => sessionTitle(titleValue()) ?? language.t("command.session.new"))
+  const titleLabel = createMemo(() => sessionTitle(titleValue()) ?? language.t("session.tab.session"))
   const parentMessages = createMemo(() => {
     const id = input.session.data.parentID()
     return id ? data.session.message.list(id) : emptyMessages
   })
   const parentTitle = createMemo(
-    () => sessionTitle(input.session.data.parent()?.title) ?? language.t("command.session.new"),
+    () => sessionTitle(input.session.data.parent()?.title) ?? language.t("session.tab.session"),
   )
   const childTaskDescription = createMemo(() => {
     const id = input.session.identity.sessionID()
@@ -100,7 +100,7 @@ export function createTimelineController(input: { session: TimelineSessionSource
       parentID: input.session.data.parentID(),
       taskDescription: childTaskDescription(),
       title: titleLabel(),
-      fallback: language.t("command.session.new"),
+      fallback: language.t("session.tab.session"),
     })
   })
   const showHeader = createMemo(() => !!input.session.identity.sessionID())
@@ -149,7 +149,7 @@ export function createTimelineController(input: { session: TimelineSessionSource
     if (!next || next === (titleLabel() ?? "")) return true
     setPending("rename", true)
     const success = await serverSDK.api.session
-      .rename({ sessionID: id, title: next })
+      .update({ sessionID: id, title: next })
       .then(() => true)
       .catch((error) => {
         showToast({ title: language.t("common.requestFailed"), description: errorMessage(error) })
@@ -209,7 +209,7 @@ export function createTimelineController(input: { session: TimelineSessionSource
 
   function DeleteDialog(props: { sessionID: string }) {
     const name = createMemo(
-      () => sessionTitle(data.session.get(props.sessionID)?.title) ?? language.t("command.session.new"),
+      () => sessionTitle(data.session.get(props.sessionID)?.title) ?? language.t("session.tab.session"),
     )
     const confirm = async () => {
       await remove(props.sessionID)

packages/app/src/settings/keybinds/keybinds.tsx

@@ -6,7 +6,13 @@ import { IconButton } from "@opencode/ui/icon-button"
 import { TextInput } from "@opencode/ui/text-input"
 import { showToast } from "@/shell/notifications/toast"
 import fuzzysort from "fuzzysort"
-import { DEFAULT_PALETTE_KEYBIND, formatKeybind, parseKeybind, useCommand } from "@/shell/commands/command"
+import {
+  DEFAULT_PALETTE_KEYBIND,
+  formatKeybind,
+  keyFromKeyboardEvent,
+  parseKeybind,
+  useCommand,
+} from "@/shell/commands/command"
 import { useLanguage } from "@/runtime/i18n/language"
 import { useSettings } from "@/settings/model"
 import { SettingsList } from "@/settings/list"
@@ -69,13 +75,6 @@ function isModifier(key: string) {
   return key === "Shift" || key === "Control" || key === "Alt" || key === "Meta"
 }
 
-function normalizeKey(key: string) {
-  if (key === ",") return "comma"
-  if (key === "+") return "plus"
-  if (key === " ") return "space"
-  return key.toLowerCase()
-}
-
 function recordKeybind(event: KeyboardEvent) {
   if (isModifier(event.key)) return
 
@@ -89,7 +88,7 @@ function recordKeybind(event: KeyboardEvent) {
   if (event.altKey) parts.push("alt")
   if (event.shiftKey) parts.push("shift")
 
-  const key = normalizeKey(event.key)
+  const key = keyFromKeyboardEvent(event)
   if (!key) return
   parts.push(key)
 

packages/app/src/shell/commands/command-keybind.test.ts

@@ -51,6 +51,15 @@ describe("command keybind helpers", () => {
     ).toBe(true)
   })
 
+  test("matchKeybind uses the letter key for option-modified characters", () => {
+    expect(
+      matchKeybind(
+        parseKeybind("meta+alt+l"),
+        new KeyboardEvent("keydown", { key: "¬", code: "KeyL", metaKey: true, altKey: true }),
+      ),
+    ).toBe(true)
+  })
+
   test("formatKeybind returns human readable output", () => {
     const display = formatKeybind("ctrl+alt+arrowup")
 

packages/app/src/shell/commands/command.tsx

@@ -50,13 +50,20 @@ function normalizeKey(key: string) {
   return key.toLowerCase()
 }
 
+export function keyFromKeyboardEvent(event: KeyboardEvent) {
+  const key = normalizeKey(event.key)
+  if (!event.altKey || /^[a-z0-9]$/.test(key)) return key
+  if (!event.code.startsWith("Key") || event.code.length !== 4) return key
+  return event.code.slice(3).toLowerCase()
+}
+
 function signature(key: string, ctrl: boolean, meta: boolean, shift: boolean, alt: boolean) {
   const mask = (ctrl ? 1 : 0) | (meta ? 2 : 0) | (shift ? 4 : 0) | (alt ? 8 : 0)
   return `${key}:${mask}`
 }
 
 function signatureFromEvent(event: KeyboardEvent) {
-  return signature(normalizeKey(event.key), event.ctrlKey, event.metaKey, event.shiftKey, event.altKey)
+  return signature(keyFromKeyboardEvent(event), event.ctrlKey, event.metaKey, event.shiftKey, event.altKey)
 }
 
 function isAllowedEditableKeybind(id: string | undefined) {
@@ -179,7 +186,7 @@ export function parseKeybind(config: string): Keybind[] {
 }
 
 export function matchKeybind(keybinds: Keybind[], event: KeyboardEvent): boolean {
-  const eventKey = normalizeKey(event.key)
+  const eventKey = keyFromKeyboardEvent(event)
 
   for (const kb of keybinds) {
     const keyMatch = kb.key === eventKey

packages/app/src/shell/shell.tsx

@@ -33,6 +33,15 @@ export default function Layout(props: ParentProps) {
     },
     install: installUpdate,
   }
+  // A plain object avoids the compiler's conditional-prop memo, which leaks when read from event handlers.
+  const debugTools = import.meta.env.DEV
+    ? {
+        get visible() {
+          return state.debugTools
+        },
+        toggle: () => setState("debugTools", (value) => !value),
+      }
+    : undefined
 
   return (
     <TitlebarRightProvider>
@@ -53,11 +62,7 @@ export default function Layout(props: ParentProps) {
         <Titlebar
           update={update}
           verticalTabs={verticalTabs() ? { mount: state.tabsMount } : undefined}
-          debugTools={
-            import.meta.env.DEV
-              ? { visible: state.debugTools, toggle: () => setState("debugTools", (value) => !value) }
-              : undefined
-          }
+          debugTools={debugTools}
         />
         <div class="flex flex-1 min-h-0 min-w-0 flex-row">
           <Show when={verticalTabs()}>

packages/app/src/shell/titlebar/tab-strip.tsx

@@ -116,7 +116,7 @@ function SessionTabEntry(props: {
 
     ctx.data.session.remember({ ...value, title })
     try {
-      await ctx.sdk.api.session.rename({ sessionID: value.id, title })
+      await ctx.sdk.api.session.update({ sessionID: value.id, title })
     } catch (err) {
       const current = session()
       const currentCtx = props.serverCtx

packages/app/src/shell/titlebar/titlebar.tsx

@@ -792,7 +792,7 @@ function ChannelIndicator(props: {
   if (!channel || channel === "prod") return null
 
   const label = () => language.t(`titlebar.channel.${channel}`)
-  const debug = () => (channel === "dev" ? props.debugTools : undefined)
+  const debug = () => (channel === "dev" || channel === "local" ? props.debugTools : undefined)
   return (
     <Tooltip
       placement={props.sidebar ? "right" : "bottom"}

packages/cli/package.json

@@ -1,7 +1,7 @@
 {
   "$schema": "https://json.schemastore.org/package.json",
   "name": "@opencode/cli",
-  "version": "2.0.3",
+  "version": "2.0.5",
   "type": "module",
   "license": "MIT",
   "bin": {

packages/cli/script/app-assets.ts

@@ -4,34 +4,31 @@ import { brotliCompressSync, constants } from "node:zlib"
 import { collectFiles } from "./files"
 
 export async function buildAppArchive(channel: string, options?: { skipBuild?: boolean }) {
-  if (options?.skipBuild) return compress({})
+  if (options?.skipBuild) return "{}"
   const root = path.resolve(import.meta.dirname, "../../app")
   await $`bun run build`
     .cwd(root)
     .env({ ...process.env, OPENCODE_CHANNEL: channel, VITE_OPENCODE_SERVER_MODE: "origin" })
-  const assets = Object.fromEntries(
-    await Promise.all(
-      (await collectFiles(path.join(root, "dist")))
-        .map((key) => key.replaceAll(path.sep, "/"))
-        .filter((key) => !key.endsWith(".map"))
-        .toSorted()
-        .map(async (key) => {
-          const source = path.join(root, "dist", key)
-          const body = Buffer.from(await Bun.file(source).arrayBuffer())
-          const encoding = isText(key) ? "utf8" : "base64"
-          return [key, { encoding, content: body.toString(encoding) }] as const
-        }),
+  return JSON.stringify(
+    Object.fromEntries(
+      await Promise.all(
+        (await collectFiles(path.join(root, "dist")))
+          .map((key) => key.replaceAll(path.sep, "/"))
+          .filter((key) => !key.endsWith(".map"))
+          .toSorted()
+          .map(async (key) => {
+            const source = path.join(root, "dist", key)
+            const body = Buffer.from(await Bun.file(source).arrayBuffer())
+            // Independent entries let the server materialize only assets the browser requests.
+            return [key, compress(body)] as const
+          }),
+      ),
     ),
   )
-  return compress(assets)
 }
 
-function compress(assets: object) {
-  return brotliCompressSync(JSON.stringify(assets), {
-    params: { [constants.BROTLI_PARAM_QUALITY]: 11 },
+function compress(body: Buffer) {
+  return brotliCompressSync(body, {
+    params: { [constants.BROTLI_PARAM_QUALITY]: 6 },
   }).toString("base64")
 }
-
-function isText(key: string) {
-  return key === "_headers" || /\.(?:css|html|js|json|svg|txt|webmanifest|xml)$/.test(key)
-}

packages/cli/script/build.ts

@@ -74,7 +74,7 @@ const appAssetsPlugin: BunPlugin = {
     }))
     build.onLoad({ filter: /^opencode-app-assets$/, namespace: "opencode" }, () => ({
       loader: "js",
-      contents: `export default ${JSON.stringify(appArchive)}`,
+      contents: `export default ${appArchive}`,
     }))
   },
 }
@@ -140,6 +140,7 @@ export default { path: file, version: ${JSON.stringify(opencodePty.version)}, sh
       ...(executablePath ? { executablePath } : {}),
       outfile: path.join(outdir, name, "bin", binary),
       execArgv: [
+        "--smol",
         `--user-agent=opencode/${Script.channel}/${Script.version}/cli`,
         "--use-system-ca",
         "--no-warnings",

packages/cli/script/service-smoke.ts

@@ -33,7 +33,7 @@ const processes: Array<ReturnType<typeof Bun.spawn>> = []
 const errors: Array<Promise<string>> = []
 let failure: unknown
 try {
-  await fs.mkdir(path.join(root, ".opencode"))
+  await fs.mkdir(path.join(root, ".opencode", "plugins"), { recursive: true })
   spawnService()
   spawnService()
   const registration = await waitForRegistration()
@@ -54,7 +54,6 @@ try {
   if (tokenOpenApi.status !== 200) throw new Error("Compiled application rejected query authentication")
   if ((await pluginIDs(info.url, headers)).includes("smoke")) throw new Error("Smoke plugin existed before creation")
   const plugin = path.join(root, ".opencode", "plugins", "smoke.ts")
-  await fs.mkdir(path.dirname(plugin), { recursive: true })
   await fs.writeFile(plugin, pluginSource())
   await waitForPlugin(info.url, headers)
 

packages/cli/src/acp/event.ts

@@ -165,7 +165,7 @@ export async function streamTurn(input: {
         continue
       }
       if (event.type === "form.created" && (event.data.form.sessionID === input.sessionID || child)) {
-        await input.client.form
+        await input.client.session.form
           .cancel({ sessionID: event.data.form.sessionID, formID: event.data.form.id })
           .catch(() => input.client.session.interrupt({ sessionID: event.data.form.sessionID }).catch(() => {}))
         continue

packages/cli/src/acp/permission.ts

@@ -55,7 +55,7 @@ export async function replyPermission(input: {
   await input.client.permission.reply({
     sessionID: input.sessionID,
     requestID: input.event.data.id,
-    reply,
+    decision: reply,
   })
 }
 

packages/cli/src/app-assets.ts

@@ -1,48 +1,51 @@
 import { Effect, FileSystem, Option } from "effect"
+import { readFileSync } from "node:fs"
 import path from "node:path"
 import { brotliDecompressSync } from "node:zlib"
 import { OPENCODE_LOCAL } from "./version"
 
 export type AssetMap = Readonly<Record<string, string | Uint8Array>>
-type EncodedAssetMap = Readonly<Record<string, { readonly content: string; readonly encoding: "utf8" | "base64" }>>
+type EncodedAssetMap = Readonly<Record<string, string>>
 
 export const load = Effect.fn("cli.app-assets.load")(function* () {
   const embedded = yield* Effect.tryPromise(() => import("virtual:opencode-app-assets")).pipe(Effect.option)
-  if (Option.isSome(embedded) && embedded.value.default.length > 0) return decodeArchive(embedded.value.default)
+  if (Option.isSome(embedded) && (Object.keys(embedded.value.default).length > 0 || !OPENCODE_LOCAL))
+    return lazy(embedded.value.default, (key) =>
+      brotliDecompressSync(Buffer.from(embedded.value.default[key]!, "base64")),
+    )
   if (!OPENCODE_LOCAL) return yield* Effect.fail(new Error("Web UI assets are missing from the CLI build"))
-  return decode(yield* sourceAssets())
+  return yield* sourceAssets()
 })
 
-function decodeArchive(archive: string) {
-  const body = brotliDecompressSync(Buffer.from(archive, "base64")).toString()
-  return decode(JSON.parse(body) as EncodedAssetMap)
-}
-
 const sourceAssets = Effect.fnUntraced(function* () {
   const fs = yield* FileSystem.FileSystem
   const root = path.resolve(import.meta.dirname, "../../app/dist")
   const files = yield* fs.readDirectory(root, { recursive: true })
-  return Object.fromEntries(
+  const assets = Object.fromEntries(
     (yield* Effect.forEach(
       files.filter((file) => !file.endsWith(".map")),
       Effect.fnUntraced(function* (file) {
         const target = path.join(root, file)
         if ((yield* fs.stat(target)).type === "Directory") return
-        const body = Buffer.from(yield* fs.readFile(target))
-        const encoding = isText(file) ? "utf8" : "base64"
-        return [file, { encoding, content: body.toString(encoding) }] as const
+        return [file, target] as const
       }),
       { concurrency: "unbounded" },
     )).filter((asset) => asset !== undefined),
   )
+  return lazy(assets, (key) => readFileSync(assets[key]!))
 })
 
-function decode(assets: EncodedAssetMap): AssetMap {
-  return Object.fromEntries(
-    Object.entries(assets).map(([key, asset]) => [
-      key,
-      asset.encoding === "utf8" ? asset.content : Buffer.from(asset.content, "base64"),
-    ]),
+function lazy(assets: EncodedAssetMap, load: (key: string) => Uint8Array): AssetMap {
+  // Immutable browser caching makes retaining decompressed copies in the server unnecessary.
+  return new Proxy(
+    {},
+    {
+      get: (_, key) => {
+        if (typeof key !== "string" || assets[key] === undefined) return
+        const body = load(key)
+        return isText(key) ? Buffer.from(body).toString() : body
+      },
+    },
   )
 }
 

packages/cli/src/run/noninteractive.ts

@@ -145,7 +145,7 @@ export async function runNonInteractivePrompt(input: Input) {
       .reply({
         sessionID: input.sessionID,
         requestID: request.id,
-        reply: input.auto ? "once" : "reject",
+        decision: input.auto ? "once" : "reject",
       })
       .catch(() => {})
     if (!input.auto) {
@@ -155,7 +155,7 @@ export async function runNonInteractivePrompt(input: Input) {
 
   const cancelForm = async (request: Pick<FormRequest, "id" | "sessionID">) => {
     try {
-      await input.client.form.cancel(
+      await input.client.session.form.cancel(
         { sessionID: request.sessionID, formID: request.id },
         ...formRequestOptions(request.sessionID === GLOBAL_FORM_SESSION_ID ? input.location : undefined),
       )
@@ -695,10 +695,10 @@ export async function runNonInteractivePrompt(input: Input) {
 
     const [permissions, forms, globals] = await Promise.all([
       input.client.permission.list({ sessionID: input.sessionID }).catch(() => undefined),
-      input.client.form.list({ sessionID: input.sessionID }).catch(() => undefined),
+      input.client.session.form.list({ sessionID: input.sessionID }).catch(() => undefined),
       input.attached
         ? Promise.resolve(undefined)
-        : input.client.form.request
+        : input.client.form
             .list({
               location: { directory: input.location.directory },
             })

packages/cli/src/run/run.ts

@@ -128,7 +128,7 @@ async function execute(input: RunCommandInput, prepared: Prepared, endpoint: End
   const model = target.model ? { providerID: target.model.providerID, modelID: target.model.id } : undefined
   const variant = target.model?.variant
   if (!target.resume && input.title !== undefined) {
-    await client.session.rename({
+    await client.session.update({
       sessionID: target.session.id,
       title: input.title || prepared.message.slice(0, 50) + (prepared.message.length > 50 ? "..." : ""),
     })

packages/cli/src/services/web-ui.ts

@@ -26,11 +26,12 @@ export const handler = Effect.fn("cli.web-ui.handler")(function* (options?: { re
 
 function serveUI(request: HttpServerRequest.HttpServerRequest, url: URL, assets: AssetMap) {
   const key = url.pathname.replace(/^\//, "")
-  if ((key.startsWith("_assets/") || key.startsWith("icons/")) && assets[key] === undefined)
+  const requested = assets[key]
+  if ((key.startsWith("_assets/") || key.startsWith("icons/")) && requested === undefined)
     return Effect.succeed(HttpServerResponse.empty({ status: 404, headers: { "cache-control": "no-store" } }))
-  const name = assets[key] !== undefined ? key : "index.html"
-  const file = assets[name]
-  if (!file) return Effect.succeed(HttpServerResponse.empty({ status: 404 }))
+  const name = requested !== undefined ? key : "index.html"
+  const file = requested ?? assets["index.html"]
+  if (file === undefined) return Effect.succeed(HttpServerResponse.empty({ status: 404 }))
   if (request.method !== "GET" && request.method !== "HEAD")
     return Effect.succeed(HttpServerResponse.empty({ status: 405 }))
   const html = name === "index.html"

packages/cli/src/virtual.d.ts

@@ -1,4 +1,4 @@
 declare module "virtual:opencode-app-assets" {
-  const archive: string
+  const archive: Readonly<Record<string, string>>
   export default archive
 }

packages/cli/test/acp/event-behavior.test.ts

@@ -748,7 +748,9 @@ describe("acp event behavior", () => {
 
       expect(response.stopReason).toBe("end_turn")
       expect(
-        fixture.requests.some((request) => request.path === "/api/session/ses_form/form/frm_question/cancel"),
+        fixture.requests.some(
+          (request) => request.method === "DELETE" && request.path === "/api/session/ses_form/form/frm_question",
+        ),
       ).toBe(true)
     } finally {
       await fixture.stop()

packages/cli/test/acp/permission-behavior.test.ts

@@ -574,7 +574,7 @@ function permissionReplies(fixture: Fixture) {
   return fixture.requests.flatMap((request): Array<[string, string]> => {
     const match = /^\/api\/session\/[^/]+\/permission\/([^/]+)\/reply$/.exec(request.path)
     if (!match?.[1] || !request.body || typeof request.body !== "object") return []
-    const reply = "reply" in request.body ? request.body.reply : undefined
+    const reply = "decision" in request.body ? request.body.decision : undefined
     return typeof reply === "string" ? [[decodeURIComponent(match[1]), reply]] : []
   })
 }

packages/cli/test/acp/sse-fixture.ts

@@ -128,7 +128,7 @@ export function createSseFixture(options: FixtureOptions = {}) {
 
       const permission = /^\/api\/session\/([^/]+)\/permission\/([^/]+)\/reply$/.exec(url.pathname)
       if (permission?.[1] && permission[2]) {
-        const reply = stringField(body, "reply")
+        const reply = stringField(body, "decision")
         if (!reply) return new Response(null, { status: 400 })
         await options.onPermissionReply?.({
           sessionID: decodeURIComponent(permission[1]),
@@ -140,8 +140,8 @@ export function createSseFixture(options: FixtureOptions = {}) {
         return new Response(null, { status: 204 })
       }
 
-      const form = /^\/api\/session\/([^/]+)\/form\/([^/]+)\/cancel$/.exec(url.pathname)
-      if (form?.[1] && form[2]) {
+      const form = /^\/api\/session\/([^/]+)\/form\/([^/]+)$/.exec(url.pathname)
+      if (request.method === "DELETE" && form?.[1] && form[2]) {
         await options.onFormCancel?.({
           sessionID: decodeURIComponent(form[1]),
           formID: decodeURIComponent(form[2]),

packages/cli/test/run/noninteractive.test.ts

@@ -240,17 +240,17 @@ async function run(input: {
   })()
   spyOn(sdk.event, "subscribe").mockImplementation(() => stream)
   spyOn(sdk.permission, "list").mockImplementation(() => ok([]) as never)
-  spyOn(sdk.form, "list").mockImplementation(
+  spyOn(sdk.session.form, "list").mockImplementation(
     (request) => ok(input.pendingForms?.filter((item) => item.sessionID === request.sessionID) ?? []) as never,
   )
-  spyOn(sdk.form.request, "list").mockImplementation(
+  spyOn(sdk.form, "list").mockImplementation(
     () =>
       ok({
         location: { ...location, project: { id: "proj_1", directory: location.directory } },
         data: input.pendingForms?.filter((item) => item.sessionID === "global") ?? [],
       }) as never,
   )
-  spyOn(sdk.form, "cancel").mockImplementation((request) => (input.cancel?.(request) ?? ok(undefined)) as never)
+  spyOn(sdk.session.form, "cancel").mockImplementation((request) => (input.cancel?.(request) ?? ok(undefined)) as never)
   let promptID = "msg_prompt"
   spyOn(sdk.session, "wait").mockImplementation(() => input.wait?.() ?? wait.promise)
   spyOn(sdk.message, "list").mockImplementation(() =>
@@ -426,10 +426,10 @@ describe("runNonInteractivePrompt", () => {
         "x-opencode-directory": "%2Fwork%20tree",
       },
     }
-    expect(sdk.form.cancel).toHaveBeenCalledWith({ sessionID: "global", formID: "frm_live" }, globalOptions)
-    expect(sdk.form.cancel).toHaveBeenCalledWith({ sessionID: "ses_1", formID: "frm_pending" })
-    expect(sdk.form.cancel).toHaveBeenCalledWith({ sessionID: "global", formID: "frm_pending_global" }, globalOptions)
-    expect(sdk.form.request.list).toHaveBeenCalledWith({
+    expect(sdk.session.form.cancel).toHaveBeenCalledWith({ sessionID: "global", formID: "frm_live" }, globalOptions)
+    expect(sdk.session.form.cancel).toHaveBeenCalledWith({ sessionID: "ses_1", formID: "frm_pending" })
+    expect(sdk.session.form.cancel).toHaveBeenCalledWith({ sessionID: "global", formID: "frm_pending_global" }, globalOptions)
+    expect(sdk.form.list).toHaveBeenCalledWith({
       location: { directory: "/work tree" },
     })
   })
@@ -440,10 +440,10 @@ describe("runNonInteractivePrompt", () => {
       pendingForms: [form("frm_pending", "ses_1"), form("frm_pending_global", "global")],
       turn: (messageID) => [formCreated(form("frm_live", "global")), prompted(messageID), settled()],
     })
-    expect(sdk.form.cancel).toHaveBeenCalledWith({ sessionID: "ses_1", formID: "frm_pending" })
-    expect(sdk.form.request.list).not.toHaveBeenCalled()
-    expect(sdk.form.cancel).not.toHaveBeenCalledWith({ sessionID: "global", formID: "frm_live" }, expect.anything())
-    expect(sdk.form.cancel).not.toHaveBeenCalledWith(
+    expect(sdk.session.form.cancel).toHaveBeenCalledWith({ sessionID: "ses_1", formID: "frm_pending" })
+    expect(sdk.form.list).not.toHaveBeenCalled()
+    expect(sdk.session.form.cancel).not.toHaveBeenCalledWith({ sessionID: "global", formID: "frm_live" }, expect.anything())
+    expect(sdk.session.form.cancel).not.toHaveBeenCalledWith(
       { sessionID: "global", formID: "frm_pending_global" },
       expect.anything(),
     )

packages/cli/vite.node.config.ts

@@ -31,7 +31,7 @@ function appAssetsPlugin(archive: string): Plugin {
     },
     load(id) {
       if (id !== "\0virtual:opencode-app-assets") return
-      return `export default ${JSON.stringify(archive)}`
+      return `export default ${archive}`
     },
   }
 }
@@ -292,5 +292,5 @@ export default mainConfig({
   channel: process.env.OPENCODE_CHANNEL ?? "local",
   assetHash: "local",
   target: nodeTarget(process.platform, process.arch),
-  appArchive: "",
+  appArchive: "{}",
 })

packages/client/package.json

@@ -1,7 +1,7 @@
 {
   "$schema": "https://json.schemastore.org/package.json",
   "name": "@opencode/client",
-  "version": "2.0.3",
+  "version": "2.0.5",
   "type": "module",
   "license": "MIT",
   "repository": {

packages/client/src/effect/api/api.ts

@@ -23,8 +23,8 @@ import type { Event } from "@opencode/schema/event"
 import type { EventLog } from "@opencode/schema/event-log"
 import type { Shell } from "@opencode/schema/shell"
 import type { Provider } from "@opencode/schema/provider"
-import type { Integration } from "@opencode/schema/integration"
 import type { Form } from "@opencode/schema/form"
+import type { Integration } from "@opencode/schema/integration"
 import type { Mcp } from "@opencode/schema/mcp"
 import type { Credential } from "@opencode/schema/credential"
 import type { PermissionSaved } from "@opencode/schema/permission-saved"
@@ -233,9 +233,13 @@ export type SessionSwitchModelOperation<E = never> = (
   input: SessionSwitchModelInput,
 ) => Effect.Effect<SessionSwitchModelOutput, E>
 
-export type SessionRenameInput = { readonly sessionID: Session.ID; readonly title: string }
-export type SessionRenameOutput = void
-export type SessionRenameOperation<E = never> = (input: SessionRenameInput) => Effect.Effect<SessionRenameOutput, E>
+export type SessionUpdateInput = {
+  readonly sessionID: Session.ID
+  readonly title?: string | undefined
+  readonly permissions?: Permission.Ruleset | undefined
+}
+export type SessionUpdateOutput = void
+export type SessionUpdateOperation<E = never> = (input: SessionUpdateInput) => Effect.Effect<SessionUpdateOutput, E>
 
 export type SessionMoveInput = {
   readonly sessionID: Session.ID
@@ -360,17 +364,15 @@ export type SessionInboxCancelOperation<E = never> = (
   input: SessionInboxCancelInput,
 ) => Effect.Effect<SessionInboxCancelOutput, E>
 
-export type SessionInboxSteerInput = { readonly sessionID: Session.ID; readonly inboxID: SessionMessage.ID }
-export type SessionInboxSteerOutput = void
-export type SessionInboxSteerOperation<E = never> = (
-  input: SessionInboxSteerInput,
-) => Effect.Effect<SessionInboxSteerOutput, E>
-
-export type SessionInboxQueueInput = { readonly sessionID: Session.ID; readonly inboxID: SessionMessage.ID }
-export type SessionInboxQueueOutput = void
-export type SessionInboxQueueOperation<E = never> = (
-  input: SessionInboxQueueInput,
-) => Effect.Effect<SessionInboxQueueOutput, E>
+export type SessionInboxUpdateInput = {
+  readonly sessionID: Session.ID
+  readonly inboxID: SessionMessage.ID
+  readonly delivery: SessionInbox.Delivery
+}
+export type SessionInboxUpdateOutput = void
+export type SessionInboxUpdateOperation<E = never> = (
+  input: SessionInboxUpdateInput,
+) => Effect.Effect<SessionInboxUpdateOutput, E>
 
 export type SessionInstructionsEntryListInput = { readonly sessionID: Session.ID }
 export type SessionInstructionsEntryListOutput = ReadonlyArray<InstructionEntry.Info>
@@ -513,7 +515,7 @@ export type SessionLogOutput =
           readonly id: Event.ID
           readonly created: number
           readonly metadata?: { readonly [x: string]: unknown } | undefined
-          readonly type: "session.permissions.updated"
+          readonly type: "session.permissions"
           readonly durable: { readonly aggregateID: string; readonly seq: Event.Seq; readonly version: Event.Version }
           readonly location?:
             | {
@@ -1325,6 +1327,44 @@ export type SessionMessageGetOperation<E = never> = (
   input: SessionMessageGetInput,
 ) => Effect.Effect<SessionMessageGetOutput, E>
 
+export type SessionFormListInput = { readonly sessionID: string }
+export type SessionFormListOutput = ReadonlyArray<Form.Info>
+export type SessionFormListOperation<E = never> = (
+  input: SessionFormListInput,
+) => Effect.Effect<SessionFormListOutput, E>
+
+export type SessionFormCreateInput = {
+  readonly sessionID: string
+  readonly id?: Form.ID | undefined
+  readonly title: string
+  readonly metadata?: Form.Metadata | undefined
+  readonly fields: Form.Fields
+}
+export type SessionFormCreateOutput = Form.Info
+export type SessionFormCreateOperation<E = never> = (
+  input: SessionFormCreateInput,
+) => Effect.Effect<SessionFormCreateOutput, E>
+
+export type SessionFormGetInput = { readonly sessionID: string; readonly formID: Form.ID }
+export type SessionFormGetOutput = Form.Detail
+export type SessionFormGetOperation<E = never> = (input: SessionFormGetInput) => Effect.Effect<SessionFormGetOutput, E>
+
+export type SessionFormReplyInput = {
+  readonly sessionID: string
+  readonly formID: Form.ID
+  readonly answer: Form.Answer
+}
+export type SessionFormReplyOutput = void
+export type SessionFormReplyOperation<E = never> = (
+  input: SessionFormReplyInput,
+) => Effect.Effect<SessionFormReplyOutput, E>
+
+export type SessionFormCancelInput = { readonly sessionID: string; readonly formID: Form.ID }
+export type SessionFormCancelOutput = void
+export type SessionFormCancelOperation<E = never> = (
+  input: SessionFormCancelInput,
+) => Effect.Effect<SessionFormCancelOutput, E>
+
 export type SessionEnvironmentInput = {
   readonly sessionID: Session.ID
   readonly variables: { readonly [x: string]: string }
@@ -1350,7 +1390,7 @@ export interface SessionApi<E = never> {
   readonly fork: SessionForkOperation<E>
   readonly switchAgent: SessionSwitchAgentOperation<E>
   readonly switchModel: SessionSwitchModelOperation<E>
-  readonly rename: SessionRenameOperation<E>
+  readonly update: SessionUpdateOperation<E>
   readonly move: SessionMoveOperation<E>
   readonly prompt: SessionPromptOperation<E>
   readonly command: SessionCommandOperation<E>
@@ -1369,8 +1409,7 @@ export interface SessionApi<E = never> {
   readonly inbox: {
     readonly list: SessionInboxListOperation<E>
     readonly cancel: SessionInboxCancelOperation<E>
-    readonly steer: SessionInboxSteerOperation<E>
-    readonly queue: SessionInboxQueueOperation<E>
+    readonly update: SessionInboxUpdateOperation<E>
   }
   readonly instructions: {
     readonly entry: {
@@ -1384,6 +1423,13 @@ export interface SessionApi<E = never> {
   readonly interrupt: SessionInterruptOperation<E>
   readonly background: SessionBackgroundOperation<E>
   readonly message: { readonly get: SessionMessageGetOperation<E> }
+  readonly form: {
+    readonly list: SessionFormListOperation<E>
+    readonly create: SessionFormCreateOperation<E>
+    readonly get: SessionFormGetOperation<E>
+    readonly reply: SessionFormReplyOperation<E>
+    readonly cancel: SessionFormCancelOperation<E>
+  }
   readonly environment: SessionEnvironmentOperation<E>
   readonly view: SessionViewOperation<E>
 }
@@ -1684,50 +1730,12 @@ export interface ProjectApi<E = never> {
   readonly update: ProjectUpdateOperation<E>
 }
 
-export type FormRequestListInput = { readonly location?: { readonly directory?: string | undefined } | undefined }
-export type FormRequestListOutput = { readonly location: Location.PublicRef; readonly data: ReadonlyArray<Form.Info> }
-export type FormRequestListOperation<E = never> = (
-  input?: FormRequestListInput,
-) => Effect.Effect<FormRequestListOutput, E>
-
-export type FormListInput = { readonly sessionID: string }
-export type FormListOutput = ReadonlyArray<Form.Info>
-export type FormListOperation<E = never> = (input: FormListInput) => Effect.Effect<FormListOutput, E>
-
-export type FormCreateInput = {
-  readonly sessionID: string
-  readonly id?: Form.ID | undefined
-  readonly title: string
-  readonly metadata?: Form.Metadata | undefined
-  readonly fields: Form.Fields
-}
-export type FormCreateOutput = Form.Info
-export type FormCreateOperation<E = never> = (input: FormCreateInput) => Effect.Effect<FormCreateOutput, E>
-
-export type FormGetInput = { readonly sessionID: string; readonly formID: Form.ID }
-export type FormGetOutput = Form.Info
-export type FormGetOperation<E = never> = (input: FormGetInput) => Effect.Effect<FormGetOutput, E>
-
-export type FormStateInput = { readonly sessionID: string; readonly formID: Form.ID }
-export type FormStateOutput = Form.State
-export type FormStateOperation<E = never> = (input: FormStateInput) => Effect.Effect<FormStateOutput, E>
-
-export type FormReplyInput = { readonly sessionID: string; readonly formID: Form.ID; readonly answer: Form.Answer }
-export type FormReplyOutput = void
-export type FormReplyOperation<E = never> = (input: FormReplyInput) => Effect.Effect<FormReplyOutput, E>
-
-export type FormCancelInput = { readonly sessionID: string; readonly formID: Form.ID }
-export type FormCancelOutput = void
-export type FormCancelOperation<E = never> = (input: FormCancelInput) => Effect.Effect<FormCancelOutput, E>
+export type FormListInput = { readonly location?: { readonly directory?: string | undefined } | undefined }
+export type FormListOutput = { readonly location: Location.PublicRef; readonly data: ReadonlyArray<Form.Info> }
+export type FormListOperation<E = never> = (input?: FormListInput) => Effect.Effect<FormListOutput, E>
 
 export interface FormApi<E = never> {
-  readonly request: { readonly list: FormRequestListOperation<E> }
   readonly list: FormListOperation<E>
-  readonly create: FormCreateOperation<E>
-  readonly get: FormGetOperation<E>
-  readonly state: FormStateOperation<E>
-  readonly reply: FormReplyOperation<E>
-  readonly cancel: FormCancelOperation<E>
 }
 
 export type PermissionRequestListInput = { readonly location?: { readonly directory?: string | undefined } | undefined }
@@ -1777,7 +1785,7 @@ export type PermissionGetOperation<E = never> = (input: PermissionGetInput) => E
 export type PermissionReplyInput = {
   readonly sessionID: Session.ID
   readonly requestID: Permission.ID
-  readonly reply: Permission.Reply
+  readonly decision: Permission.Reply
   readonly message?: string | undefined
 }
 export type PermissionReplyOutput = void
@@ -1785,12 +1793,6 @@ export type PermissionReplyOperation<E = never> = (
   input: PermissionReplyInput,
 ) => Effect.Effect<PermissionReplyOutput, E>
 
-export type PermissionRulesInput = { readonly sessionID: Session.ID; readonly permissions: Permission.Ruleset }
-export type PermissionRulesOutput = void
-export type PermissionRulesOperation<E = never> = (
-  input: PermissionRulesInput,
-) => Effect.Effect<PermissionRulesOutput, E>
-
 export interface PermissionApi<E = never> {
   readonly request: { readonly list: PermissionRequestListOperation<E> }
   readonly saved: { readonly list: PermissionSavedListOperation<E>; readonly remove: PermissionSavedRemoveOperation<E> }
@@ -1798,7 +1800,6 @@ export interface PermissionApi<E = never> {
   readonly list: PermissionListOperation<E>
   readonly get: PermissionGetOperation<E>
   readonly reply: PermissionReplyOperation<E>
-  readonly rules: PermissionRulesOperation<E>
 }
 
 export type FileListInput = {
@@ -2101,7 +2102,7 @@ export type ShellCreateInput = {
   readonly location?: { readonly directory?: string | undefined } | undefined
   readonly command: string
   readonly cwd?: string | undefined
-  readonly timeout: number
+  readonly timeout?: number | undefined
   readonly metadata?: { readonly [x: string]: unknown } | undefined
 }
 export type ShellCreateOutput = { readonly location: Location.PublicRef; readonly data: Shell.Info }
@@ -2114,14 +2115,6 @@ export type ShellGetInput = {
 export type ShellGetOutput = { readonly location: Location.PublicRef; readonly data: Shell.Info }
 export type ShellGetOperation<E = never> = (input: ShellGetInput) => Effect.Effect<ShellGetOutput, E>
 
-export type ShellTimeoutInput = {
-  readonly id: Shell.ID
-  readonly location?: { readonly directory?: string | undefined } | undefined
-  readonly timeout: number
-}
-export type ShellTimeoutOutput = { readonly location: Location.PublicRef; readonly data: Shell.Info }
-export type ShellTimeoutOperation<E = never> = (input: ShellTimeoutInput) => Effect.Effect<ShellTimeoutOutput, E>
-
 export type ShellOutputInput = {
   readonly id: Shell.ID
   readonly location?: { readonly directory?: string | undefined } | undefined
@@ -2150,7 +2143,6 @@ export interface ShellApi<E = never> {
   readonly list: ShellListOperation<E>
   readonly create: ShellCreateOperation<E>
   readonly get: ShellGetOperation<E>
-  readonly timeout: ShellTimeoutOperation<E>
   readonly output: ShellOutputOperation<E>
   readonly remove: ShellRemoveOperation<E>
 }
@@ -2213,13 +2205,13 @@ export type VcsStatusInput = { readonly location?: { readonly directory?: string
 export type VcsStatusOutput = { readonly location: Location.PublicRef; readonly data: ReadonlyArray<Vcs.FileStatus> }
 export type VcsStatusOperation<E = never> = (input?: VcsStatusInput) => Effect.Effect<VcsStatusOutput, E>
 
-export type VcsBranchesInput = {
+export type VcsBranchListInput = {
   readonly location?: { readonly directory?: string | undefined } | undefined
   readonly search?: string | undefined
   readonly limit?: number | undefined
 }
-export type VcsBranchesOutput = { readonly location: Location.PublicRef; readonly data: Vcs.BranchList }
-export type VcsBranchesOperation<E = never> = (input?: VcsBranchesInput) => Effect.Effect<VcsBranchesOutput, E>
+export type VcsBranchListOutput = { readonly location: Location.PublicRef; readonly data: Vcs.BranchList }
+export type VcsBranchListOperation<E = never> = (input?: VcsBranchListInput) => Effect.Effect<VcsBranchListOutput, E>
 
 export type VcsDiffInput = {
   readonly location?: { readonly directory?: string | undefined } | undefined
@@ -2234,7 +2226,7 @@ export interface VcsApi<E = never> {
   readonly get: VcsGetOperation<E>
   readonly base: VcsBaseOperation<E>
   readonly status: VcsStatusOperation<E>
-  readonly branches: VcsBranchesOperation<E>
+  readonly branch: { readonly list: VcsBranchListOperation<E> }
   readonly diff: VcsDiffOperation<E>
 }
 

packages/client/src/effect/generated/client.ts

@@ -39,8 +39,8 @@ import type {
   SessionSwitchAgentOutput,
   SessionSwitchModelInput,
   SessionSwitchModelOutput,
-  SessionRenameInput,
-  SessionRenameOutput,
+  SessionUpdateInput,
+  SessionUpdateOutput,
   SessionMoveInput,
   SessionMoveOutput,
   SessionPromptInput,
@@ -71,10 +71,8 @@ import type {
   SessionInboxListOutput,
   SessionInboxCancelInput,
   SessionInboxCancelOutput,
-  SessionInboxSteerInput,
-  SessionInboxSteerOutput,
-  SessionInboxQueueInput,
-  SessionInboxQueueOutput,
+  SessionInboxUpdateInput,
+  SessionInboxUpdateOutput,
   SessionInstructionsEntryListInput,
   SessionInstructionsEntryListOutput,
   SessionInstructionsEntryPutInput,
@@ -91,6 +89,16 @@ import type {
   SessionBackgroundOutput,
   SessionMessageGetInput,
   SessionMessageGetOutput,
+  SessionFormListInput,
+  SessionFormListOutput,
+  SessionFormCreateInput,
+  SessionFormCreateOutput,
+  SessionFormGetInput,
+  SessionFormGetOutput,
+  SessionFormReplyInput,
+  SessionFormReplyOutput,
+  SessionFormCancelInput,
+  SessionFormCancelOutput,
   SessionEnvironmentInput,
   SessionEnvironmentOutput,
   SessionViewInput,
@@ -150,20 +158,8 @@ import type {
   ProjectListOutput,
   ProjectUpdateInput,
   ProjectUpdateOutput,
-  FormRequestListInput,
-  FormRequestListOutput,
   FormListInput,
   FormListOutput,
-  FormCreateInput,
-  FormCreateOutput,
-  FormGetInput,
-  FormGetOutput,
-  FormStateInput,
-  FormStateOutput,
-  FormReplyInput,
-  FormReplyOutput,
-  FormCancelInput,
-  FormCancelOutput,
   PermissionRequestListInput,
   PermissionRequestListOutput,
   PermissionSavedListInput,
@@ -178,8 +174,6 @@ import type {
   PermissionGetOutput,
   PermissionReplyInput,
   PermissionReplyOutput,
-  PermissionRulesInput,
-  PermissionRulesOutput,
   FileListInput,
   FileListOutput,
   FileFindInput,
@@ -227,8 +221,6 @@ import type {
   ShellCreateOutput,
   ShellGetInput,
   ShellGetOutput,
-  ShellTimeoutInput,
-  ShellTimeoutOutput,
   ShellOutputInput,
   ShellOutputOutput,
   ShellRemoveInput,
@@ -249,8 +241,8 @@ import type {
   VcsBaseOutput,
   VcsStatusInput,
   VcsStatusOutput,
-  VcsBranchesInput,
-  VcsBranchesOutput,
+  VcsBranchListInput,
+  VcsBranchListOutput,
   VcsDiffInput,
   VcsDiffOutput,
   DebugLocationListOutput,
@@ -450,11 +442,12 @@ const EndpointSessionSwitchModel = (raw: RawClient["server.session"]) => (input:
     ),
   )
 
-const EndpointSessionRename = (raw: RawClient["server.session"]) => (input: SessionRenameInput) =>
-  preserveEffect<SessionRenameOutput>()(
-    raw["session.rename"]({ params: { sessionID: input["sessionID"] }, payload: { title: input["title"] } }).pipe(
-      Effect.mapError(mapClientError),
-    ),
+const EndpointSessionUpdate = (raw: RawClient["server.session"]) => (input: SessionUpdateInput) =>
+  preserveEffect<SessionUpdateOutput>()(
+    raw["session.update"]({
+      params: { sessionID: input["sessionID"] },
+      payload: { title: input["title"], permissions: input["permissions"] },
+    }).pipe(Effect.mapError(mapClientError)),
   )
 
 const EndpointSessionMove = (raw: RawClient["server.session"]) => (input: SessionMoveInput) =>
@@ -605,18 +598,12 @@ const EndpointSessionInboxCancel = (raw: RawClient["server.session"]) => (input:
     ),
   )
 
-const EndpointSessionInboxSteer = (raw: RawClient["server.session"]) => (input: SessionInboxSteerInput) =>
-  preserveEffect<SessionInboxSteerOutput>()(
-    raw["session.inbox.steer"]({ params: { sessionID: input["sessionID"], inboxID: input["inboxID"] } }).pipe(
-      Effect.mapError(mapClientError),
-    ),
-  )
-
-const EndpointSessionInboxQueue = (raw: RawClient["server.session"]) => (input: SessionInboxQueueInput) =>
-  preserveEffect<SessionInboxQueueOutput>()(
-    raw["session.inbox.queue"]({ params: { sessionID: input["sessionID"], inboxID: input["inboxID"] } }).pipe(
-      Effect.mapError(mapClientError),
-    ),
+const EndpointSessionInboxUpdate = (raw: RawClient["server.session"]) => (input: SessionInboxUpdateInput) =>
+  preserveEffect<SessionInboxUpdateOutput>()(
+    raw["session.inbox.update"]({
+      params: { sessionID: input["sessionID"], inboxID: input["inboxID"] },
+      payload: { delivery: input["delivery"] },
+    }).pipe(Effect.mapError(mapClientError)),
   )
 
 const EndpointSessionInstructionsEntryList =
@@ -686,6 +673,48 @@ const EndpointSessionMessageGet = (raw: RawClient["server.session"]) => (input:
     ),
   )
 
+const EndpointSessionFormList = (raw: RawClient["server.session"]) => (input: SessionFormListInput) =>
+  preserveEffect<SessionFormListOutput>()(
+    raw["session.form.list"]({ params: { sessionID: input["sessionID"] } }).pipe(
+      Effect.mapError(mapClientError),
+      Effect.map((value) => value.data),
+    ),
+  )
+
+const EndpointSessionFormCreate = (raw: RawClient["server.session"]) => (input: SessionFormCreateInput) =>
+  preserveEffect<SessionFormCreateOutput>()(
+    raw["session.form.create"]({
+      params: { sessionID: input["sessionID"] },
+      payload: { id: input["id"], title: input["title"], metadata: input["metadata"], fields: input["fields"] },
+    }).pipe(
+      Effect.mapError(mapClientError),
+      Effect.map((value) => value.data),
+    ),
+  )
+
+const EndpointSessionFormGet = (raw: RawClient["server.session"]) => (input: SessionFormGetInput) =>
+  preserveEffect<SessionFormGetOutput>()(
+    raw["session.form.get"]({ params: { sessionID: input["sessionID"], formID: input["formID"] } }).pipe(
+      Effect.mapError(mapClientError),
+      Effect.map((value) => value.data),
+    ),
+  )
+
+const EndpointSessionFormReply = (raw: RawClient["server.session"]) => (input: SessionFormReplyInput) =>
+  preserveEffect<SessionFormReplyOutput>()(
+    raw["session.form.reply"]({
+      params: { sessionID: input["sessionID"], formID: input["formID"] },
+      payload: { answer: input["answer"] },
+    }).pipe(Effect.mapError(mapClientError)),
+  )
+
+const EndpointSessionFormCancel = (raw: RawClient["server.session"]) => (input: SessionFormCancelInput) =>
+  preserveEffect<SessionFormCancelOutput>()(
+    raw["session.form.cancel"]({ params: { sessionID: input["sessionID"], formID: input["formID"] } }).pipe(
+      Effect.mapError(mapClientError),
+    ),
+  )
+
 const EndpointSessionEnvironment = (raw: RawClient["server.session"]) => (input: SessionEnvironmentInput) =>
   preserveEffect<SessionEnvironmentOutput>()(
     raw["session.environment"]({
@@ -713,7 +742,7 @@ const adaptGroupSession = (raw: RawClient["server.session"]) => ({
   fork: EndpointSessionFork(raw),
   switchAgent: EndpointSessionSwitchAgent(raw),
   switchModel: EndpointSessionSwitchModel(raw),
-  rename: EndpointSessionRename(raw),
+  update: EndpointSessionUpdate(raw),
   move: EndpointSessionMove(raw),
   prompt: EndpointSessionPrompt(raw),
   command: EndpointSessionCommand(raw),
@@ -732,8 +761,7 @@ const adaptGroupSession = (raw: RawClient["server.session"]) => ({
   inbox: {
     list: EndpointSessionInboxList(raw),
     cancel: EndpointSessionInboxCancel(raw),
-    steer: EndpointSessionInboxSteer(raw),
-    queue: EndpointSessionInboxQueue(raw),
+    update: EndpointSessionInboxUpdate(raw),
   },
   instructions: {
     entry: {
@@ -747,6 +775,13 @@ const adaptGroupSession = (raw: RawClient["server.session"]) => ({
   interrupt: EndpointSessionInterrupt(raw),
   background: EndpointSessionBackground(raw),
   message: { get: EndpointSessionMessageGet(raw) },
+  form: {
+    list: EndpointSessionFormList(raw),
+    create: EndpointSessionFormCreate(raw),
+    get: EndpointSessionFormGet(raw),
+    reply: EndpointSessionFormReply(raw),
+    cancel: EndpointSessionFormCancel(raw),
+  },
   environment: EndpointSessionEnvironment(raw),
   view: EndpointSessionView(raw),
 })
@@ -1006,70 +1041,12 @@ const adaptGroupProject = (raw: RawClient["server.project"]) => ({
   update: EndpointProjectUpdate(raw),
 })
 
-const EndpointFormRequestList = (raw: RawClient["server.form"]) => (input?: FormRequestListInput) =>
-  preserveEffect<FormRequestListOutput>()(
-    raw["form.request.list"]({ query: { location: input?.["location"] } }).pipe(Effect.mapError(mapClientError)),
-  )
-
-const EndpointFormList = (raw: RawClient["server.form"]) => (input: FormListInput) =>
+const EndpointFormList = (raw: RawClient["server.form"]) => (input?: FormListInput) =>
   preserveEffect<FormListOutput>()(
-    raw["session.form.list"]({ params: { sessionID: input["sessionID"] } }).pipe(
-      Effect.mapError(mapClientError),
-      Effect.map((value) => value.data),
-    ),
+    raw["form.list"]({ query: { location: input?.["location"] } }).pipe(Effect.mapError(mapClientError)),
   )
 
-const EndpointFormCreate = (raw: RawClient["server.form"]) => (input: FormCreateInput) =>
-  preserveEffect<FormCreateOutput>()(
-    raw["session.form.create"]({
-      params: { sessionID: input["sessionID"] },
-      payload: { id: input["id"], title: input["title"], metadata: input["metadata"], fields: input["fields"] },
-    }).pipe(
-      Effect.mapError(mapClientError),
-      Effect.map((value) => value.data),
-    ),
-  )
-
-const EndpointFormGet = (raw: RawClient["server.form"]) => (input: FormGetInput) =>
-  preserveEffect<FormGetOutput>()(
-    raw["session.form.get"]({ params: { sessionID: input["sessionID"], formID: input["formID"] } }).pipe(
-      Effect.mapError(mapClientError),
-      Effect.map((value) => value.data),
-    ),
-  )
-
-const EndpointFormState = (raw: RawClient["server.form"]) => (input: FormStateInput) =>
-  preserveEffect<FormStateOutput>()(
-    raw["session.form.state"]({ params: { sessionID: input["sessionID"], formID: input["formID"] } }).pipe(
-      Effect.mapError(mapClientError),
-      Effect.map((value) => value.data),
-    ),
-  )
-
-const EndpointFormReply = (raw: RawClient["server.form"]) => (input: FormReplyInput) =>
-  preserveEffect<FormReplyOutput>()(
-    raw["session.form.reply"]({
-      params: { sessionID: input["sessionID"], formID: input["formID"] },
-      payload: { answer: input["answer"] },
-    }).pipe(Effect.mapError(mapClientError)),
-  )
-
-const EndpointFormCancel = (raw: RawClient["server.form"]) => (input: FormCancelInput) =>
-  preserveEffect<FormCancelOutput>()(
-    raw["session.form.cancel"]({ params: { sessionID: input["sessionID"], formID: input["formID"] } }).pipe(
-      Effect.mapError(mapClientError),
-    ),
-  )
-
-const adaptGroupForm = (raw: RawClient["server.form"]) => ({
-  request: { list: EndpointFormRequestList(raw) },
-  list: EndpointFormList(raw),
-  create: EndpointFormCreate(raw),
-  get: EndpointFormGet(raw),
-  state: EndpointFormState(raw),
-  reply: EndpointFormReply(raw),
-  cancel: EndpointFormCancel(raw),
-})
+const adaptGroupForm = (raw: RawClient["server.form"]) => ({ list: EndpointFormList(raw) })
 
 const EndpointPermissionRequestList = (raw: RawClient["server.permission"]) => (input?: PermissionRequestListInput) =>
   preserveEffect<PermissionRequestListOutput>()(
@@ -1128,15 +1105,7 @@ const EndpointPermissionReply = (raw: RawClient["server.permission"]) => (input:
   preserveEffect<PermissionReplyOutput>()(
     raw["session.permission.reply"]({
       params: { sessionID: input["sessionID"], requestID: input["requestID"] },
-      payload: { reply: input["reply"], message: input["message"] },
-    }).pipe(Effect.mapError(mapClientError)),
-  )
-
-const EndpointPermissionRules = (raw: RawClient["server.permission"]) => (input: PermissionRulesInput) =>
-  preserveEffect<PermissionRulesOutput>()(
-    raw["session.permission.rules"]({
-      params: { sessionID: input["sessionID"] },
-      payload: { permissions: input["permissions"] },
+      payload: { decision: input["decision"], message: input["message"] },
     }).pipe(Effect.mapError(mapClientError)),
   )
 
@@ -1147,7 +1116,6 @@ const adaptGroupPermission = (raw: RawClient["server.permission"]) => ({
   list: EndpointPermissionList(raw),
   get: EndpointPermissionGet(raw),
   reply: EndpointPermissionReply(raw),
-  rules: EndpointPermissionRules(raw),
 })
 
 const EndpointFileList = (raw: RawClient["server.fs"]) => (input?: FileListInput) =>
@@ -1393,15 +1361,6 @@ const EndpointShellGet = (raw: RawClient["server.shell"]) => (input: ShellGetInp
     ),
   )
 
-const EndpointShellTimeout = (raw: RawClient["server.shell"]) => (input: ShellTimeoutInput) =>
-  preserveEffect<ShellTimeoutOutput>()(
-    raw["shell.timeout"]({
-      params: { id: input["id"] },
-      query: { location: input["location"] },
-      payload: { timeout: input["timeout"] },
-    }).pipe(Effect.mapError(mapClientError)),
-  )
-
 const EndpointShellOutput = (raw: RawClient["server.shell"]) => (input: ShellOutputInput) =>
   preserveEffect<ShellOutputOutput>()(
     raw["shell.output"]({
@@ -1421,7 +1380,6 @@ const adaptGroupShell = (raw: RawClient["server.shell"]) => ({
   list: EndpointShellList(raw),
   create: EndpointShellCreate(raw),
   get: EndpointShellGet(raw),
-  timeout: EndpointShellTimeout(raw),
   output: EndpointShellOutput(raw),
   remove: EndpointShellRemove(raw),
 })
@@ -1485,9 +1443,9 @@ const EndpointVcsStatus = (raw: RawClient["server.vcs"]) => (input?: VcsStatusIn
     raw["vcs.status"]({ query: { location: input?.["location"] } }).pipe(Effect.mapError(mapClientError)),
   )
 
-const EndpointVcsBranches = (raw: RawClient["server.vcs"]) => (input?: VcsBranchesInput) =>
-  preserveEffect<VcsBranchesOutput>()(
-    raw["vcs.branches"]({
+const EndpointVcsBranchList = (raw: RawClient["server.vcs"]) => (input?: VcsBranchListInput) =>
+  preserveEffect<VcsBranchListOutput>()(
+    raw["vcs.branch.list"]({
       query: { location: input?.["location"], search: input?.["search"], limit: input?.["limit"] },
     }).pipe(Effect.mapError(mapClientError)),
   )
@@ -1503,7 +1461,7 @@ const adaptGroupVcs = (raw: RawClient["server.vcs"]) => ({
   get: EndpointVcsGet(raw),
   base: EndpointVcsBase(raw),
   status: EndpointVcsStatus(raw),
-  branches: EndpointVcsBranches(raw),
+  branch: { list: EndpointVcsBranchList(raw) },
   diff: EndpointVcsDiff(raw),
 })
 

packages/client/src/promise/generated/client.ts

@@ -33,8 +33,8 @@ import type {
   SessionSwitchAgentOutput,
   SessionSwitchModelInput,
   SessionSwitchModelOutput,
-  SessionRenameInput,
-  SessionRenameOutput,
+  SessionUpdateInput,
+  SessionUpdateOutput,
   SessionMoveInput,
   SessionMoveOutput,
   SessionPromptInput,
@@ -65,10 +65,8 @@ import type {
   SessionInboxListOutput,
   SessionInboxCancelInput,
   SessionInboxCancelOutput,
-  SessionInboxSteerInput,
-  SessionInboxSteerOutput,
-  SessionInboxQueueInput,
-  SessionInboxQueueOutput,
+  SessionInboxUpdateInput,
+  SessionInboxUpdateOutput,
   SessionInstructionsEntryListInput,
   SessionInstructionsEntryListOutput,
   SessionInstructionsEntryPutInput,
@@ -85,6 +83,16 @@ import type {
   SessionBackgroundOutput,
   SessionMessageGetInput,
   SessionMessageGetOutput,
+  SessionFormListInput,
+  SessionFormListOutput,
+  SessionFormCreateInput,
+  SessionFormCreateOutput,
+  SessionFormGetInput,
+  SessionFormGetOutput,
+  SessionFormReplyInput,
+  SessionFormReplyOutput,
+  SessionFormCancelInput,
+  SessionFormCancelOutput,
   SessionEnvironmentInput,
   SessionEnvironmentOutput,
   SessionViewInput,
@@ -144,20 +152,8 @@ import type {
   ProjectListOutput,
   ProjectUpdateInput,
   ProjectUpdateOutput,
-  FormRequestListInput,
-  FormRequestListOutput,
   FormListInput,
   FormListOutput,
-  FormCreateInput,
-  FormCreateOutput,
-  FormGetInput,
-  FormGetOutput,
-  FormStateInput,
-  FormStateOutput,
-  FormReplyInput,
-  FormReplyOutput,
-  FormCancelInput,
-  FormCancelOutput,
   PermissionRequestListInput,
   PermissionRequestListOutput,
   PermissionSavedListInput,
@@ -172,8 +168,6 @@ import type {
   PermissionGetOutput,
   PermissionReplyInput,
   PermissionReplyOutput,
-  PermissionRulesInput,
-  PermissionRulesOutput,
   FileReadInput,
   FileReadOutput,
   FileListInput,
@@ -223,8 +217,6 @@ import type {
   ShellCreateOutput,
   ShellGetInput,
   ShellGetOutput,
-  ShellTimeoutInput,
-  ShellTimeoutOutput,
   ShellOutputInput,
   ShellOutputOutput,
   ShellRemoveInput,
@@ -245,8 +237,8 @@ import type {
   VcsBaseOutput,
   VcsStatusInput,
   VcsStatusOutput,
-  VcsBranchesInput,
-  VcsBranchesOutput,
+  VcsBranchListInput,
+  VcsBranchListOutput,
   VcsDiffInput,
   VcsDiffOutput,
   DebugLocationListOutput,
@@ -644,12 +636,12 @@ export function make(options: ClientOptions) {
           },
           requestOptions,
         ),
-      rename: (input: SessionRenameInput, requestOptions?: RequestOptions) =>
-        request<SessionRenameOutput>(
+      update: (input: SessionUpdateInput, requestOptions?: RequestOptions) =>
+        request<SessionUpdateOutput>(
           {
             method: "PATCH",
             path: `/api/session/${encodeURIComponent(input.sessionID)}`,
-            body: { title: input["title"] },
+            body: { title: input["title"], permissions: input["permissions"] },
             successStatus: 204,
             declaredStatuses: [400, 401, 404],
             empty: true,
@@ -851,27 +843,17 @@ export function make(options: ClientOptions) {
               method: "DELETE",
               path: `/api/session/${encodeURIComponent(input.sessionID)}/inbox/${encodeURIComponent(input.inboxID)}`,
               successStatus: 204,
-              declaredStatuses: [400, 401, 404, 409],
+              declaredStatuses: [400, 401, 404],
               empty: true,
             },
             requestOptions,
           ),
-        steer: (input: SessionInboxSteerInput, requestOptions?: RequestOptions) =>
-          request<SessionInboxSteerOutput>(
+        update: (input: SessionInboxUpdateInput, requestOptions?: RequestOptions) =>
+          request<SessionInboxUpdateOutput>(
             {
-              method: "POST",
-              path: `/api/session/${encodeURIComponent(input.sessionID)}/inbox/${encodeURIComponent(input.inboxID)}/steer`,
-              successStatus: 204,
-              declaredStatuses: [400, 401, 404, 409],
-              empty: true,
-            },
-            requestOptions,
-          ),
-        queue: (input: SessionInboxQueueInput, requestOptions?: RequestOptions) =>
-          request<SessionInboxQueueOutput>(
-            {
-              method: "POST",
-              path: `/api/session/${encodeURIComponent(input.sessionID)}/inbox/${encodeURIComponent(input.inboxID)}/queue`,
+              method: "PATCH",
+              path: `/api/session/${encodeURIComponent(input.sessionID)}/inbox/${encodeURIComponent(input.inboxID)}`,
+              body: { delivery: input["delivery"] },
               successStatus: 204,
               declaredStatuses: [400, 401, 404, 409],
               empty: true,
@@ -977,11 +959,70 @@ export function make(options: ClientOptions) {
             requestOptions,
           ).then((value) => value.data),
       },
+      form: {
+        list: (input: SessionFormListInput, requestOptions?: RequestOptions) =>
+          request<{ readonly data: SessionFormListOutput }>(
+            {
+              method: "GET",
+              path: `/api/session/${encodeURIComponent(input.sessionID)}/form`,
+              successStatus: 200,
+              declaredStatuses: [400, 401, 404],
+              empty: false,
+            },
+            requestOptions,
+          ).then((value) => value.data),
+        create: (input: SessionFormCreateInput, requestOptions?: RequestOptions) =>
+          request<{ readonly data: SessionFormCreateOutput }>(
+            {
+              method: "POST",
+              path: `/api/session/${encodeURIComponent(input.sessionID)}/form`,
+              body: { id: input["id"], title: input["title"], metadata: input["metadata"], fields: input["fields"] },
+              successStatus: 200,
+              declaredStatuses: [400, 401, 404, 409],
+              empty: false,
+            },
+            requestOptions,
+          ).then((value) => value.data),
+        get: (input: SessionFormGetInput, requestOptions?: RequestOptions) =>
+          request<{ readonly data: SessionFormGetOutput }>(
+            {
+              method: "GET",
+              path: `/api/session/${encodeURIComponent(input.sessionID)}/form/${encodeURIComponent(input.formID)}`,
+              successStatus: 200,
+              declaredStatuses: [400, 401, 404],
+              empty: false,
+            },
+            requestOptions,
+          ).then((value) => value.data),
+        reply: (input: SessionFormReplyInput, requestOptions?: RequestOptions) =>
+          request<SessionFormReplyOutput>(
+            {
+              method: "POST",
+              path: `/api/session/${encodeURIComponent(input.sessionID)}/form/${encodeURIComponent(input.formID)}/reply`,
+              body: { answer: input["answer"] },
+              successStatus: 204,
+              declaredStatuses: [400, 401, 404, 409],
+              empty: true,
+            },
+            requestOptions,
+          ),
+        cancel: (input: SessionFormCancelInput, requestOptions?: RequestOptions) =>
+          request<SessionFormCancelOutput>(
+            {
+              method: "DELETE",
+              path: `/api/session/${encodeURIComponent(input.sessionID)}/form/${encodeURIComponent(input.formID)}`,
+              successStatus: 204,
+              declaredStatuses: [400, 401, 404, 409],
+              empty: true,
+            },
+            requestOptions,
+          ),
+      },
       environment: (input: SessionEnvironmentInput, requestOptions?: RequestOptions) =>
         request<SessionEnvironmentOutput>(
           {
             method: "PUT",
-            path: `/api/experimental/session/${encodeURIComponent(input.sessionID)}/environment`,
+            path: `/api/session/${encodeURIComponent(input.sessionID)}/environment`,
             body: { variables: input["variables"] },
             successStatus: 204,
             declaredStatuses: [400, 401, 404],
@@ -1047,7 +1088,7 @@ export function make(options: ClientOptions) {
         request<{ readonly data: GenerateTextOutput }>(
           {
             method: "POST",
-            path: `/api/generate`,
+            path: `/api/experimental/generate`,
             body: { prompt: input["prompt"], model: input["model"] },
             successStatus: 200,
             declaredStatuses: [400, 401, 503],
@@ -1367,87 +1408,17 @@ export function make(options: ClientOptions) {
         ),
     },
     form: {
-      request: {
-        list: (input?: FormRequestListInput, requestOptions?: RequestOptions) =>
-          request<FormRequestListOutput>(
-            {
-              method: "GET",
-              path: `/api/form/request`,
-              query: { location: input?.["location"] },
-              successStatus: 200,
-              declaredStatuses: [400, 401],
-              empty: false,
-            },
-            requestOptions,
-          ),
-      },
-      list: (input: FormListInput, requestOptions?: RequestOptions) =>
-        request<{ readonly data: FormListOutput }>(
+      list: (input?: FormListInput, requestOptions?: RequestOptions) =>
+        request<FormListOutput>(
           {
             method: "GET",
-            path: `/api/session/${encodeURIComponent(input.sessionID)}/form`,
+            path: `/api/form`,
+            query: { location: input?.["location"] },
             successStatus: 200,
-            declaredStatuses: [400, 401, 404],
+            declaredStatuses: [400, 401],
             empty: false,
           },
           requestOptions,
-        ).then((value) => value.data),
-      create: (input: FormCreateInput, requestOptions?: RequestOptions) =>
-        request<{ readonly data: FormCreateOutput }>(
-          {
-            method: "POST",
-            path: `/api/session/${encodeURIComponent(input.sessionID)}/form`,
-            body: { id: input["id"], title: input["title"], metadata: input["metadata"], fields: input["fields"] },
-            successStatus: 200,
-            declaredStatuses: [400, 401, 404, 409],
-            empty: false,
-          },
-          requestOptions,
-        ).then((value) => value.data),
-      get: (input: FormGetInput, requestOptions?: RequestOptions) =>
-        request<{ readonly data: FormGetOutput }>(
-          {
-            method: "GET",
-            path: `/api/session/${encodeURIComponent(input.sessionID)}/form/${encodeURIComponent(input.formID)}`,
-            successStatus: 200,
-            declaredStatuses: [400, 401, 404],
-            empty: false,
-          },
-          requestOptions,
-        ).then((value) => value.data),
-      state: (input: FormStateInput, requestOptions?: RequestOptions) =>
-        request<{ readonly data: FormStateOutput }>(
-          {
-            method: "GET",
-            path: `/api/session/${encodeURIComponent(input.sessionID)}/form/${encodeURIComponent(input.formID)}/state`,
-            successStatus: 200,
-            declaredStatuses: [400, 401, 404],
-            empty: false,
-          },
-          requestOptions,
-        ).then((value) => value.data),
-      reply: (input: FormReplyInput, requestOptions?: RequestOptions) =>
-        request<FormReplyOutput>(
-          {
-            method: "POST",
-            path: `/api/session/${encodeURIComponent(input.sessionID)}/form/${encodeURIComponent(input.formID)}/reply`,
-            body: { answer: input["answer"] },
-            successStatus: 204,
-            declaredStatuses: [400, 401, 404, 409],
-            empty: true,
-          },
-          requestOptions,
-        ),
-      cancel: (input: FormCancelInput, requestOptions?: RequestOptions) =>
-        request<FormCancelOutput>(
-          {
-            method: "POST",
-            path: `/api/session/${encodeURIComponent(input.sessionID)}/form/${encodeURIComponent(input.formID)}/cancel`,
-            successStatus: 204,
-            declaredStatuses: [400, 401, 404, 409],
-            empty: true,
-          },
-          requestOptions,
         ),
     },
     permission: {
@@ -1537,19 +1508,7 @@ export function make(options: ClientOptions) {
           {
             method: "POST",
             path: `/api/session/${encodeURIComponent(input.sessionID)}/permission/${encodeURIComponent(input.requestID)}/reply`,
-            body: { reply: input["reply"], message: input["message"] },
-            successStatus: 204,
-            declaredStatuses: [400, 401, 404],
-            empty: true,
-          },
-          requestOptions,
-        ),
-      rules: (input: PermissionRulesInput, requestOptions?: RequestOptions) =>
-        request<PermissionRulesOutput>(
-          {
-            method: "PUT",
-            path: `/api/session/${encodeURIComponent(input.sessionID)}/permission/rules`,
-            body: { permissions: input["permissions"] },
+            body: { decision: input["decision"], message: input["message"] },
             successStatus: 204,
             declaredStatuses: [400, 401, 404],
             empty: true,
@@ -1899,19 +1858,6 @@ export function make(options: ClientOptions) {
           },
           requestOptions,
         ),
-      timeout: (input: ShellTimeoutInput, requestOptions?: RequestOptions) =>
-        request<ShellTimeoutOutput>(
-          {
-            method: "PATCH",
-            path: `/api/shell/${encodeURIComponent(input.id)}/timeout`,
-            query: { location: input["location"] },
-            body: { timeout: input["timeout"] },
-            successStatus: 200,
-            declaredStatuses: [400, 401, 404],
-            empty: false,
-          },
-          requestOptions,
-        ),
       output: (input: ShellOutputInput, requestOptions?: RequestOptions) =>
         request<ShellOutputOutput>(
           {
@@ -1931,7 +1877,7 @@ export function make(options: ClientOptions) {
             path: `/api/shell/${encodeURIComponent(input.id)}`,
             query: { location: input["location"] },
             successStatus: 204,
-            declaredStatuses: [400, 401, 404],
+            declaredStatuses: [400, 401],
             empty: true,
           },
           requestOptions,
@@ -2044,18 +1990,20 @@ export function make(options: ClientOptions) {
           },
           requestOptions,
         ),
-      branches: (input?: VcsBranchesInput, requestOptions?: RequestOptions) =>
-        request<VcsBranchesOutput>(
-          {
-            method: "GET",
-            path: `/api/vcs/branches`,
-            query: { location: input?.["location"], search: input?.["search"], limit: input?.["limit"] },
-            successStatus: 200,
-            declaredStatuses: [400, 401],
-            empty: false,
-          },
-          requestOptions,
-        ),
+      branch: {
+        list: (input?: VcsBranchListInput, requestOptions?: RequestOptions) =>
+          request<VcsBranchListOutput>(
+            {
+              method: "GET",
+              path: `/api/vcs/branch`,
+              query: { location: input?.["location"], search: input?.["search"], limit: input?.["limit"] },
+              successStatus: 200,
+              declaredStatuses: [400, 401],
+              empty: false,
+            },
+            requestOptions,
+          ),
+      },
       diff: (input: VcsDiffInput, requestOptions?: RequestOptions) =>
         request<VcsDiffOutput>(
           {

packages/client/src/solid/data.ts

@@ -7,9 +7,9 @@ import type {
   AgentInfo,
   CommandInfo,
   ConfigEntry,
-  FormCancelInput,
+  SessionFormCancelInput,
   FormInfo,
-  FormReplyInput,
+  SessionFormReplyInput,
   IntegrationInfo,
   LocationRef,
   LocationGetOutput,
@@ -296,7 +296,7 @@ export function createData(config: CreateDataInput) {
     return true
   }
 
-  function settleForm(input: FormCancelInput, ref: LocationRef | undefined, request: Promise<void>) {
+  function settleForm(input: SessionFormCancelInput, ref: LocationRef | undefined, request: Promise<void>) {
     return request
       .catch((error: unknown) => {
         if ((!isFormNotFoundError(error) && !isFormAlreadySettledError(error)) || error.id !== input.formID) throw error
@@ -697,7 +697,7 @@ export function createData(config: CreateDataInput) {
         })
         return
       }
-      case "session.permissions.updated":
+      case "session.permissions":
         if (store.session.info[event.data.sessionID])
           setStore("session", "info", event.data.sessionID, "permissions", event.data.permissions)
         return
@@ -1742,7 +1742,7 @@ export function createData(config: CreateDataInput) {
           const key = `session.form:${sessionID}:${sessionID === "global" ? locationKey(ref ?? defaultLocation()) : ""}`
           return sync.run(key, async () => {
             if (sessionID === "global") {
-              const response = await api().form.request.list({
+              const response = await api().form.list({
                 location: locationQuery(ref ?? defaultLocation()),
               })
               const location = {
@@ -1757,7 +1757,7 @@ export function createData(config: CreateDataInput) {
               ])
               return
             }
-            setStore("session", "form", sessionID, await api().form.list({ sessionID }))
+            setStore("session", "form", sessionID, await api().session.form.list({ sessionID }))
           })
         },
         invalidate(sessionID: string, ref?: LocationRef) {
@@ -1765,11 +1765,11 @@ export function createData(config: CreateDataInput) {
             `session.form:${sessionID}:${sessionID === "global" ? locationKey(ref ?? defaultLocation()) : ""}`,
           )
         },
-        reply(input: FormReplyInput, ref?: LocationRef) {
-          return settleForm(input, ref, api().form.reply(input, formRequestOptions(input.sessionID, ref)))
+        reply(input: SessionFormReplyInput, ref?: LocationRef) {
+          return settleForm(input, ref, api().session.form.reply(input, formRequestOptions(input.sessionID, ref)))
         },
-        cancel(input: FormCancelInput, ref?: LocationRef) {
-          return settleForm(input, ref, api().form.cancel(input, formRequestOptions(input.sessionID, ref)))
+        cancel(input: SessionFormCancelInput, ref?: LocationRef) {
+          return settleForm(input, ref, api().session.form.cancel(input, formRequestOptions(input.sessionID, ref)))
         },
       },
     },

packages/client/test/promise.test.ts

@@ -157,7 +157,7 @@ test("generate.text uses the locationless public contract", async () => {
   })
 
   expect(await client.generate.text({ prompt: "ping" })).toEqual({ text: "pong" })
-  expect(request?.url).toBe("http://localhost:3000/api/generate")
+  expect(request?.url).toBe("http://localhost:3000/api/experimental/generate")
   expect(await request?.json()).toEqual({ prompt: "ping" })
 })
 
@@ -546,13 +546,13 @@ test("session.inbox mutations use the public HTTP contract", async () => {
   })
 
   await client.session.inbox.cancel({ sessionID: "ses_test", inboxID: "msg_cancel" })
-  await client.session.inbox.steer({ sessionID: "ses_test", inboxID: "msg_steer" })
-  await client.session.inbox.queue({ sessionID: "ses_test", inboxID: "msg_queue" })
+  await client.session.inbox.update({ sessionID: "ses_test", inboxID: "msg_steer", delivery: "steer" })
+  await client.session.inbox.update({ sessionID: "ses_test", inboxID: "msg_queue", delivery: "queue" })
 
   expect(requests).toEqual([
     { method: "DELETE", url: "http://localhost:3000/api/session/ses_test/inbox/msg_cancel" },
-    { method: "POST", url: "http://localhost:3000/api/session/ses_test/inbox/msg_steer/steer" },
-    { method: "POST", url: "http://localhost:3000/api/session/ses_test/inbox/msg_queue/queue" },
+    { method: "PATCH", url: "http://localhost:3000/api/session/ses_test/inbox/msg_steer" },
+    { method: "PATCH", url: "http://localhost:3000/api/session/ses_test/inbox/msg_queue" },
   ])
 })
 

packages/codemode/README.md

@@ -88,8 +88,11 @@ runtime.catalog() // structured tool descriptions
 runtime.execute(source) // Effect<CodeMode.Result, never, ToolServices>
 ```
 
-The Effect environment is inferred from the supplied tools. `onToolCallStart` observes admitted calls with decoded
-input; `onToolCallEnd` observes settled outcomes and duration. Both hooks return Effects and must not fail.
+The Effect environment is inferred from the supplied tools. `hooks` surround every call the program makes into the
+host: `tool.before`/`tool.after` receive `{ name, input }` with decoded input, `extension.before`/`extension.after`
+receive `{ extension, name, args }`. An `after` hook also receives how the call ended (`success` with its value,
+`failure` with its error, or `interrupted`). A failing `before` hook denies the call, and the program catches the
+failure as a thrown error.
 
 ### `Values`
 

packages/codemode/interpreter-support.md

@@ -19,14 +19,16 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
       TypeScript is transpiled first; the emitted JavaScript must still use the supported subset.
 - [x] Top-level `await` and `return` through the program's implicit async-function scope.
 - [x] Explicit `return`, final top-level expression as a REPL-style result, and `null` when no value is produced.
-- [x] Program results use JSON-like boundaries, with `undefined` and non-finite numbers normalized to `null`. Tool
-      arguments follow JSON serialization semantics before their schema applies (see the tools section). Own
-      `__proto__` keys are dropped wherever a host object crosses to the host, so merging tool inputs or results
-      cannot replace a prototype; `JSON.stringify` still emits the key, like JS, since a string cannot pollute.
-- [x] Values `JSON.stringify` would flatten to `{}` cross the host boundary in a useful form instead: a Set as an
-      array, a RegExp as `"/source/flags"`, a URLSearchParams as its query string. A Map still crosses as `{}`.
-      Functions, generators, promises, extension handles, and a Uint8Array are rejected with a hint. In-program
-      `JSON.stringify` keeps JS behavior for all of these.
+- [x] The host boundary is `JSON.stringify` plus a short table. The program result and tool arguments cross as
+      what `JSON.stringify` would serialize: `toJSON` is honored, functions and `undefined` properties vanish,
+      `undefined` array elements and non-finite numbers become `null`, a cyclic value throws the same `TypeError`,
+      and Map, RegExp, and generators serialize as `{}`. A bare `undefined` result is `null`.
+      Tool results come back the way `JSON.parse(JSON.stringify(result))` would. The table, where a value cannot
+      be JSON but what the program meant is clear: a promise is awaited (a rejection fails the program), a Set
+      crosses as an array, a URLSearchParams as its query string, an Error as `{ name, message, ...own }`, a
+      Uint8Array is rejected with a hint to encode as text, and own `__proto__` keys are dropped so merging tool
+      inputs or results cannot replace a prototype. In-program `JSON.stringify` keeps JS behavior except for the
+      Error form and a promise, which is a `TypeError` with an await hint rather than a silent `{}`.
 - [x] Live Date, RegExp, Map, Set, URL, URLSearchParams, and Uint8Array values inside CodeMode.
 - [x] Tool calls through the host-provided `tools` tree only.
 - [x] The global `search(...)` built-in: synchronous tool discovery that counts as an admitted tool call and is
@@ -190,7 +192,7 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
 - [x] Prefix and postfix `++` and `--`.
 - [x] Plain, arithmetic, bitwise, and logical assignment operators.
 - [x] Property deletion on plain data objects and arrays, including computed and optional forms; deleting an array index
-      creates a hole without changing its length. Deleting a non-configurable property (`length`, `lastIndex`) or
+      creates a hole without changing its length. Deleting a non-configurable property (`length`) or
       assigning a read-only one (`Math.PI`, `fn.name`) throws a `TypeError`, as in strict mode.
 - [ ] Operators, `switch` discriminants, template interpolation, and coercion helpers such as `String` and `isNaN`
       applied to functions and namespaces; JavaScript coerces them, the interpreter rejects non-data operands.
@@ -231,8 +233,8 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
       callables that settle the promise exactly once (they may escape the executor and settle later); an executor
       throw rejects unless the promise already settled, resolving with a promise or callable thenable adopts it, and
       resolving with the promise itself rejects with a `TypeError`. Resolver callables work anywhere callbacks are
-      accepted, including `.then`/`.catch` handlers and collection callbacks, but remain opaque references that cannot
-      cross the data boundary.
+      accepted, including `.then`/`.catch` handlers and collection callbacks, and vanish at the data boundary like
+      any function.
 - [x] Recursive assimilation of objects with an own callable `then` field across `Promise.resolve`, combinators,
       constructors, reactions, `finally`, `await`, and async returns. Thenable methods run deferred, receive
       first-call-wins resolve/reject functions, and ignore throws after settlement. Inherited/accessor `then` fields
@@ -240,11 +242,9 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
 - [x] Dotted tool names are canonicalized into namespace paths; a path can be both callable and a namespace, and the
       last tool supplied for a canonical path wins.
 - [x] Tool path segments may be named `constructor`, `prototype`, or `__proto__` because paths use inert Map keys.
-- [x] Outbound tool arguments follow JSON serialization semantics, like `JSON.stringify`: object properties with
-      `undefined` values are dropped, `undefined` array elements and non-finite numbers become `null`, and sparse
-      arrays densify. Tools never receive `undefined` inside their input object, though a bare `tools.t(undefined)`
-      argument still reaches schema decoding as `undefined`. Program results keep the stricter
-      normalization where every `undefined` becomes `null`.
+- [x] Outbound tool arguments are what `JSON.stringify` would serialize (see the boundary rule above). Tools never
+      receive `undefined` inside their input object, though a bare `tools.t(undefined)` argument still reaches schema
+      decoding as `undefined`.
 - [ ] Tokenize and case-fold non-ASCII tool paths, descriptions, and queries for tool search.
 
 ## Objects and properties
@@ -394,7 +394,9 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
       `unicodeSets`, and `dotAll`.
 - [x] Captures, named groups, match `.index` and `.input`, and stateful global matching.
 - [x] Integration with supported String methods, including function replacers.
-- [x] Writable `lastIndex`.
+- [x] Writable `lastIndex`, shared by `exec`, `test`, and the String methods. It is a prototype accessor that stores
+      a number, so `re.lastIndex = "12"` reads back `12`, `delete` is a no-op, and `hasOwnProperty("lastIndex")` is
+      `false`.
 - [x] Match `indices` metadata for the `d` flag, including named groups on `exec`, `match`, and `matchAll` results.
 - [x] `RegExp.escape`.
 
@@ -426,8 +428,8 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
 
 ## Uint8Array
 
-The only binary type. Bytes stay inside the program or cross to extensions; the tool boundary rejects them with a
-hint to encode as text first (`TextDecoder`, `toBase64`, `toHex`).
+The only binary type. Bytes stay inside the program or cross to extensions as copies; the tool boundary rejects them
+with a hint to encode as text first (`TextDecoder`, `toBase64`, `toHex`).
 
 - [x] `new Uint8Array(length | array | iterable | Uint8Array)`, `Uint8Array.from`, `Uint8Array.of`, `fromBase64`,
       and `fromHex`. Lengths are capped like arrays.
@@ -452,29 +454,27 @@ hint to encode as text first (`TextDecoder`, `toBase64`, `toHex`).
 
 ## Extensions
 
-Host classes and functions a host opts in through `Extension.make({ name, globals })` and `CodeMode.make({ extensions })`.
+Host functions a host opts in through `Extension.make({ name, globals })` and `CodeMode.make({ extensions })`.
 Nothing is exposed unless a host provides it; extension calls are not tool calls.
 
-- [x] Each global is a class or a function, exposed as-is: constructors with `new`, prototype methods, accessors,
-      and statics (including through an exposed subclass, so `new this()` works), plus inheritance
-      up to the nearest exposed ancestor. A global that shadows a built-in or another extension throws at `make`.
-- [x] Instances of exposed classes stay on the host; the program holds a handle whose only members are the class's.
-      The same host instance is always the same handle within a run, so identity and `instanceof` hold. Handles
-      cannot cross the data boundary: returning, stringifying, throwing, or passing one to a tool fails.
+- [x] Each global is a function, callable but not constructible, run with `this` undefined. A global that shadows
+      a built-in or another extension throws at `make`.
 - [x] Every value crossing in either direction is converted, never shared: plain objects and arrays are copied,
       `Date`, `RegExp`, `URL`, `URLSearchParams`, `Map`, `Set`, and `Uint8Array` become fresh copies with their
       contents converted (a host `ArrayBuffer` comes in as a `Uint8Array`; other typed arrays cannot come out),
       errors cross as errors with their name and message, and a `__proto__` key is dropped. Functions, generators,
-      un-awaited promises, and symbols cannot be passed in; an instance of an unexposed class, a symbol, or a BigInt
-      cannot come out.
+      un-awaited promises, and symbols cannot be passed in; a class instance, a symbol, or a BigInt cannot come out.
+- [x] A host function inside a result becomes a program function whose calls cross the same way, so a result can
+      carry methods (`res.json()`) whose host closures keep the host state. Diagnostics name it by its path
+      (`fetch.json`). Like any program function it vanishes at the data boundary.
+- [x] Each call to an extension global runs inside the host's `extension.before`/`extension.after` hooks as
+      `{ extension, name, args }`, with the host's own error on failure; calls to functions inside results do not.
 - [x] A host `Promise` becomes a program promise. Whatever host code returns, resolves, throws, or rejects with
       crosses the same way, so `catch (e)` receives a copy of the thrown value (an `Error` of the matching type, or
-      plain data). A getter must be synchronous.
-- [x] A prototype member runs only with a handle of its own class as `this`; a detached call, a plain object, or a
-      handle of another class throws `TypeError: Illegal invocation`. Program edits to an exposed prototype affect
-      that run only. Data properties on a class or prototype are not exposed, since a program write would change the
-      host class itself; expose one through an accessor.
+      plain data).
 - [ ] Program functions as arguments to extension code (callbacks such as `forEach`).
+- [ ] Host classes. Stateful host objects are expressed as closures; a declared method table would be the next
+      step if `new X()` in a program is ever needed.
 
 ## Errors and diagnostics
 

packages/codemode/package.json

@@ -1,7 +1,7 @@
 {
   "$schema": "https://json.schemastore.org/package.json",
   "name": "@opencode/codemode",
-  "version": "2.0.3",
+  "version": "2.0.5",
   "description": "Effect-native confined code execution over schema-described tools",
   "type": "module",
   "license": "MIT",

packages/codemode/src/codemode.ts

@@ -7,7 +7,14 @@ import { type Services, type ToolDescription, ToolRuntime } from "./tool-runtime
 import type { Tools } from "./tools.js"
 
 /** A tool call admitted during an execution. */
-export type { ToolCall, ToolCallEnded, ToolCallHooks, ToolCallStarted, ToolDescription } from "./tool-runtime.js"
+export type {
+  CallResult,
+  ExtensionInvocation,
+  Hooks,
+  ToolCall,
+  ToolDescription,
+  ToolInvocation,
+} from "./tool-runtime.js"
 /** Signature-construction helpers for host-owned catalog instructions. */
 export { searchSignature, toolExpression } from "./tool-runtime.js"
 
@@ -34,10 +41,12 @@ export type ResolvedExecutionLimits = {
 }
 
 /** Configuration shared by `CodeMode.make` and `CodeMode.execute`. */
-export type Options<Provided extends Record<string, unknown> = {}> = ToolRuntime.ToolCallHooks<Services<Provided>> & {
+export type Options<Provided extends Record<string, unknown> = {}> = {
   /** Explicit tools exposed to the program as `tools`. */
   tools?: Provided & Tools<Services<Provided>>
-  /** Host classes and functions exposed as globals; see `Extension.make`. */
+  /** Hooks around every tool and extension call the program makes; see `Hooks`. */
+  hooks?: ToolRuntime.Hooks<Services<Provided>>
+  /** Host functions exposed as globals; see `Extension.make`. */
   extensions?: ReadonlyArray<Extension>
   /** Resource limits enforced on each execution. */
   limits?: ExecutionLimits
@@ -147,7 +156,10 @@ export const make = <const Provided extends Record<string, unknown> = {}>(
     }
   }
   return {
-    catalog: prepared.catalog,
-    execute: (code) => executeProgram(code, prepared, limits, options, (ctx) => extensionGlobals(ctx, extensions)),
+    get catalog() {
+      return prepared.catalog
+    },
+    execute: (code) =>
+      executeProgram(code, prepared, limits, options.hooks ?? {}, (ctx) => extensionGlobals(ctx, extensions)),
   }
 }

packages/codemode/src/data.ts

@@ -1,239 +1,115 @@
 export * as Data from "./data.js"
 
-import type { DiagnosticKind } from "./codemode.js"
-import type { Builtins } from "./interpreter/intrinsics.js"
+import { Effect, type Schema } from "effect"
+import type { Interpreter } from "./interpreter/interpreter.js"
+import { MAX_VALUE_DEPTH } from "./interpreter/limits.js"
+import { invalidData, rangeError, typeError } from "./interpreter/model.js"
 import {
-  Callable,
-  define,
-  entries,
-  get,
-  isWrapper,
-  parseArrayIndex,
   Arr,
   Bytes,
-  DateObj,
+  Callable,
+  define,
   ErrorObj,
-  GeneratorObj,
-  Handle,
-  MapObj,
+  get,
+  keys,
   Obj,
   PromiseObj,
-  RegExpObj,
+  record,
   SetObj,
-  URLObj,
   URLSearchParamsObj,
 } from "./interpreter/objects.js"
+import { typeofValue } from "./interpreter/references.js"
 
-export const MAX_VALUE_DEPTH = 32
+export type Json = Schema.Json
 
-export class ToolRuntimeError extends Error {
-  constructor(
-    readonly kind: Extract<
-      DiagnosticKind,
-      "UnknownTool" | "InvalidToolInput" | "InvalidToolOutput" | "InvalidDataValue" | "ToolCallLimitExceeded"
-    >,
-    message: string,
-    readonly suggestions: ReadonlyArray<string> = [],
-  ) {
-    super(message)
-    this.name = "ToolRuntimeError"
-  }
+type Replacer<R> = (args: Array<unknown>) => Effect.Effect<unknown, unknown, R>
+
+/**
+ * What `JSON.stringify` would serialize for a program value, as host JSON: `toJSON` is honored, functions and
+ * `undefined` vanish, non-finite numbers become null, and everything else is copied. Two departures from JS
+ * so a mistake is not a silent `{}`: an Error serializes as `{ name, message, ...own }`, and a promise throws.
+ */
+export const toJson = <R>(ctx: Interpreter<R>, value: unknown, replacer?: Replacer<R>) =>
+  walk(ctx, value, replacer, false)
+
+/**
+ * The host boundary: `toJson`, plus what a program most likely meant when a value cannot be JSON. A promise is
+ * awaited, a Set crosses as an array, a URLSearchParams as its query string, a Uint8Array asks to be encoded as
+ * text first, and a `__proto__` key is dropped so host code can never receive one.
+ */
+export const toBoundary = <R>(ctx: Interpreter<R>, value: unknown) => walk(ctx, value, undefined, true)
+
+const walk = <R>(
+  ctx: Interpreter<R>,
+  value: unknown,
+  replacer: Replacer<R> | undefined,
+  boundary: boolean,
+): Effect.Effect<Json | undefined, unknown, R> => {
+  const stack = new Set<object>()
+  const visit = (holder: Obj, key: string, depth: number): Effect.Effect<Json | undefined, unknown, R> =>
+    Effect.gen(function* () {
+      if (depth > MAX_VALUE_DEPTH) throw rangeError(`Value exceeds the maximum depth of ${MAX_VALUE_DEPTH}.`)
+      const raw = get(holder, key)
+      if (raw instanceof PromiseObj && !boundary) {
+        throw invalidData(
+          "JSON.stringify received an un-awaited Promise; await it first - e.g. `const result = await tools.ns.tool(...)`.",
+        )
+      }
+      const settled = raw instanceof PromiseObj ? yield* ctx.await(raw) : raw
+      const toJSON = settled instanceof Obj ? get(settled, "toJSON") : undefined
+      const own = toJSON instanceof Callable ? yield* ctx.call(toJSON, settled, [key]) : settled
+      const value = replacer === undefined ? own : yield* replacer([key, own])
+      if (value === undefined || typeofValue(value) === "function") return undefined
+      if (typeof value === "number") return Number.isFinite(value) ? value : null
+      if (value === null || typeof value === "string" || typeof value === "boolean") return value
+      if (!(value instanceof Obj)) return {}
+      if (boundary && value instanceof Bytes) {
+        throw invalidData(
+          "A Uint8Array cannot cross to the host; pass text instead, e.g. `new TextDecoder().decode(bytes)` or `bytes.toBase64()`.",
+        )
+      }
+      if (boundary && value instanceof URLSearchParamsObj) return value.params.toString()
+      const target = boundary && value instanceof SetObj ? new Arr(ctx.builtins.Array, [...value.set]) : value
+      if (stack.has(target)) throw typeError("Converting circular structure to JSON.")
+      stack.add(target)
+      if (target instanceof Arr) {
+        const items: Array<Json> = []
+        for (let index = 0; index < target.items.length; index += 1) {
+          items.push((yield* visit(target, String(index), depth + 1)) ?? null)
+        }
+        stack.delete(target)
+        return items
+      }
+      const copied: Record<string, Json> = {}
+      // Own data property regardless of the key, so "__proto__" never reaches the Object.prototype setter.
+      const put = (name: string, item: Json | undefined) => {
+        if (item !== undefined)
+          Object.defineProperty(copied, name, { value: item, enumerable: true, writable: true, configurable: true })
+      }
+      // Errors serialize as { name, message, ...own }: both may be inherited, and neither is enumerable in JS.
+      if (target instanceof ErrorObj) {
+        put("name", yield* visit(target, "name", depth + 1))
+        put("message", yield* visit(target, "message", depth + 1))
+      }
+      for (const name of keys(target)) {
+        if (boundary && name === "__proto__") continue
+        put(name, yield* visit(target, name, depth + 1))
+      }
+      stack.delete(target)
+      return copied
+    })
+  return visit(record(ctx.builtins.Object, { "": value }), "", 0)
 }
 
-/**
- * Brings a host-produced value into the program: program values pass through, host Date, RegExp,
- * Map, Set, URL, and URLSearchParams become their built-in wrappers, and host objects and arrays
- * are copied.
- */
-export const toProgram = (builtins: Builtins, value: unknown, label: string): unknown =>
-  copy(value, label, "program", 0, new Set(), builtins)
-
-/**
- * Brings host data into the program: Date and URL become strings, other host collections become
- * empty objects, and objects become program copies. Used for tool results and parsed JSON.
- */
-export const fromData = (builtins: Builtins, value: unknown, label: string): unknown =>
-  copy(value, label, "data", 0, new Set(), builtins)
-
-/**
- * Takes a program value out as plain JSON: runtime values serialize like `JSON.stringify` would,
- * non-finite numbers become null, and array holes become null. `undefined` object properties are
- * dropped ("json") or become null ("result", for program results where the consumer must never see
- * undefined); a bare `undefined` follows the same rule.
- *
- * At the host boundary (tool arguments and program results) `__proto__` keys are dropped and values
- * `JSON.stringify` would flatten to `{}` cross in a useful form instead: a Set as an array, a RegExp
- * and URLSearchParams as their strings. `JSON.stringify` itself passes `boundary: false` to keep JS
- * behavior.
- */
-export const toData = (
-  value: unknown,
-  label: string,
-  undefinedAs: "json" | "result" = "json",
-  boundary = true,
-): unknown => copy(value, label, undefinedAs, 0, new Set(), undefined, boundary)
-
-// "program" and "data" build program objects; "json" and "result" build ordinary objects for the ctx.
-type Mode = "program" | "data" | "json" | "result"
-
-const copy = (
-  value: unknown,
-  label: string,
-  mode: Mode,
-  depth: number,
-  seen: Set<object>,
-  builtins?: Builtins,
-  boundary = true,
-): unknown => {
-  const next = (item: unknown) => copy(item, label, mode, depth + 1, seen, builtins, boundary)
-  if (depth > MAX_VALUE_DEPTH) {
-    throw new ToolRuntimeError("InvalidDataValue", `${label} exceeds the maximum value depth of ${MAX_VALUE_DEPTH}.`)
-  }
-  if (value === undefined) return mode === "result" ? null : undefined
-  if (typeof value === "number") return (mode === "json" || mode === "result") && !Number.isFinite(value) ? null : value
-  if (value === null || typeof value === "string" || typeof value === "boolean") return value
-  if (typeof value !== "object") {
-    throw new ToolRuntimeError("InvalidDataValue", `${label} must contain data only.`)
-  }
-  if (value instanceof PromiseObj) {
-    throw new ToolRuntimeError(
-      "InvalidDataValue",
-      `${label} contains an un-awaited Promise; await tool calls (e.g. \`const result = await tools.ns.tool(...)\`) before using their results.`,
+/** Host JSON as program values: objects and arrays are copied, primitives pass through. */
+export const fromJson = <R>(ctx: Interpreter<R>, value: unknown): unknown => {
+  if (value === null || typeof value !== "object") return value
+  if (Array.isArray(value))
+    return new Arr(
+      ctx.builtins.Array,
+      value.map((item) => fromJson(ctx, item)),
     )
-  }
-  if ((value instanceof Callable || value instanceof GeneratorObj) && mode !== "program") {
-    throw new ToolRuntimeError("InvalidDataValue", `${label} must contain data only.`)
-  }
-  if (value instanceof Handle && mode !== "program") {
-    throw new ToolRuntimeError(
-      "InvalidDataValue",
-      `${label} contains a ${value.instance.constructor.name}, which only extension functions accept.`,
-    )
-  }
-  // Host-produced input never holds program objects; one arriving here would come back as a host object.
-  if (value instanceof Obj && mode === "data") {
-    throw new ToolRuntimeError("InvalidDataValue", `${label} must be host data, not a program value.`)
-  }
-
-  if (builtins !== undefined && mode === "program") {
-    if (value instanceof Obj) return value
-    if (value instanceof Date) return new DateObj(builtins.Date, value.getTime())
-    if (value instanceof RegExp) return new RegExpObj(builtins.RegExp, value.source, value.flags)
-    if (value instanceof Map) {
-      const wrapped = new MapObj(builtins.Map)
-      for (const [key, item] of value.entries()) wrapped.map.set(next(key), next(item))
-      return wrapped
-    }
-    if (value instanceof Set) {
-      const wrapped = new SetObj(builtins.Set)
-      for (const item of value.values()) wrapped.set.add(next(item))
-      return wrapped
-    }
-    if (value instanceof URL) return new URLObj(builtins.URL, builtins.URLSearchParams, new URL(value.href))
-    if (value instanceof URLSearchParams)
-      return new URLSearchParamsObj(builtins.URLSearchParams, new URLSearchParams(value))
-  }
-
-  if (value instanceof DateObj) return Number.isFinite(value.time) ? new Date(value.time).toISOString() : null
-  if (value instanceof Date) return Number.isFinite(value.getTime()) ? value.toISOString() : null
-  if (value instanceof URLObj) return value.url.href
-  if (value instanceof URL) return value.href
-  if (value instanceof Bytes) {
-    if (boundary) {
-      throw new ToolRuntimeError(
-        "InvalidDataValue",
-        `${label} contains a Uint8Array; pass text instead, e.g. \`new TextDecoder().decode(bytes)\` or \`bytes.toBase64()\`.`,
-      )
-    }
-    return Object.fromEntries(value.bytes.entries())
-  }
-  if (boundary && builtins === undefined) {
-    if (value instanceof RegExpObj) return String(value.regex)
-    if (value instanceof URLSearchParamsObj) return value.params.toString()
-    if (value instanceof SetObj) {
-      if (seen.has(value)) throw new ToolRuntimeError("InvalidDataValue", `${label} contains a circular value.`)
-      seen.add(value)
-      const copied = Array.from(value.set, (item) => next(item) ?? null)
-      seen.delete(value)
-      return copied
-    }
-  }
-  // Remaining wrappers and their host counterparts serialize as empty objects, like JSON.stringify.
-  if (
-    isWrapper(value) ||
-    value instanceof RegExp ||
-    value instanceof Map ||
-    value instanceof Set ||
-    value instanceof URLSearchParams
-  ) {
-    return builtins !== undefined ? new Obj(builtins.Object) : {}
-  }
-
-  if (seen.has(value)) {
-    throw new ToolRuntimeError("InvalidDataValue", `${label} contains a circular value.`)
-  }
-  seen.add(value)
-
-  if (value instanceof Arr) {
-    const copied = Array.from(value.items, (item) => next(item) ?? null)
-    seen.delete(value)
-    return copied
-  }
-  if (value instanceof Obj) {
-    const copied: Record<string, unknown> = {}
-    // Errors serialize as { name, message, ...own }: both may be inherited, and neither is enumerable in JS.
-    if (value instanceof ErrorObj) {
-      defineHost(copied, "name", next(get(value, "name")))
-      defineHost(copied, "message", next(get(value, "message")))
-    }
-    for (const [key, item] of entries(value)) {
-      if (boundary && key === "__proto__") continue
-      const copiedItem = next(item)
-      if (copiedItem === undefined && mode === "json") continue
-      defineHost(copied, key, copiedItem)
-    }
-    seen.delete(value)
-    return copied
-  }
-
-  if (Array.isArray(value)) {
-    if (builtins !== undefined) {
-      const copied = new Arr(builtins.Array, value.map(next))
-      for (const [key, item] of Object.entries(value)) {
-        if (parseArrayIndex(key) === undefined) define(copied, key, next(item))
-      }
-      seen.delete(value)
-      return copied
-    }
-    const copied = Array.from(value, (item) => next(item) ?? null)
-    seen.delete(value)
-    return copied
-  }
-
-  const prototype = Object.getPrototypeOf(value)
-  if (prototype !== Object.prototype && prototype !== null) {
-    throw new ToolRuntimeError("InvalidDataValue", `${label} must contain plain objects only.`)
-  }
-
-  if (builtins !== undefined) {
-    const copied = new Obj(builtins.Object)
-    for (const [key, item] of Object.entries(value)) define(copied, key, next(item))
-    seen.delete(value)
-    return copied
-  }
-  const copied: Record<string, unknown> = {}
-  for (const [key, item] of Object.entries(value)) {
-    if (boundary && key === "__proto__") continue
-    const copiedItem = next(item)
-    if (copiedItem === undefined && mode === "json") continue
-    defineHost(copied, key, copiedItem)
-  }
-  seen.delete(value)
+  const copied = new Obj(ctx.builtins.Object)
+  for (const [key, item] of Object.entries(value)) define(copied, key, fromJson(ctx, item))
   return copied
 }
-
-// Own data property regardless of the target's prototype, so a "__proto__" key on a host object
-// never reaches the Object.prototype setter.
-const defineHost = (target: object, key: string, value: unknown): void => {
-  Object.defineProperty(target, key, { value, enumerable: true, writable: true, configurable: true })
-}

packages/codemode/src/extension.ts

@@ -1,20 +1,19 @@
 export * as Extension from "./extension.js"
 
 /**
- * Host classes and functions a program uses directly, like JavaScript. Values crossing in either direction are
- * converted, never shared: plain data is copied, instances of the classes stay on the host behind program-side
- * handles. Extension calls are not tool calls.
+ * Host functions a program calls directly as globals. Values crossing in either direction are converted, never
+ * shared: arguments come in as copies, results go out as copies, and a function inside a result is callable the
+ * same way. Extension calls are not tool calls.
  */
 export type Extension = {
   readonly name: string
-  /** Each value is a class or a function; everything on a class is exposed, including statics and accessors. */
   readonly globals: Readonly<Record<string, Function>>
 }
 
 export const make = (options: Extension): Extension => {
   for (const [name, value] of Object.entries(options.globals)) {
     if (typeof value !== "function") {
-      throw new TypeError(`Extension "${options.name}" global "${name}" must be a class or a function.`)
+      throw new TypeError(`Extension "${options.name}" global "${name}" must be a function.`)
     }
   }
   return { name: options.name, globals: { ...options.globals } }

packages/codemode/src/interpreter/errors.ts

@@ -1,13 +1,14 @@
 import { Effect } from "effect"
 import type { Diagnostic } from "../codemode.js"
 import { ToolError } from "../tool-error.js"
-import { toData, ToolRuntimeError } from "../data.js"
+import { ToolRuntimeError } from "../tool-runtime.js"
 import { type AstNode, formatLocation, PendingThrow, Throw, sourceLocation, typeError } from "./model.js"
 import { containsRuntimeReference } from "./references.js"
 import { createErrorValue, type ErrorType, isErrorType } from "./intrinsics.js"
 import { constructor, methods, prototypeFrom, receiver } from "./native.js"
 import { type Callable, define, get, hidden, type Native, Arr, ErrorObj, Obj } from "./objects.js"
 import type { Interpreter } from "./interpreter.js"
+import { formatValue } from "../stdlib/console.js"
 import { coerceToString } from "../stdlib/value.js"
 
 export const normalizeError = (error: unknown): Diagnostic => {
@@ -44,11 +45,7 @@ export const normalizeError = (error: unknown): Diagnostic => {
     } else if (typeof value === "string") {
       message = value
     } else {
-      try {
-        message = JSON.stringify(toData(value, "Thrown value")) ?? String(value)
-      } catch {
-        message = String(value)
-      }
+      message = formatValue(value)
     }
     return { kind: "ExecutionFailure", message: `Uncaught: ${message}` }
   }

packages/codemode/src/interpreter/execute.ts

@@ -4,7 +4,7 @@ import { Cause, Effect, Scope } from "effect"
 // pass-through on workerd (the compiler is ~11 MiB and can't init there).
 import { transpile } from "#transpile"
 import type { DataValue, Diagnostic, ResolvedExecutionLimits, Result } from "../codemode.js"
-import { toData } from "../data.js"
+import { toBoundary } from "../data.js"
 import { ToolRuntime } from "../tool-runtime.js"
 import { normalizeError } from "./errors.js"
 import { createBuiltins } from "./intrinsics.js"
@@ -16,7 +16,7 @@ export const executeProgram = <R>(
   code: string,
   prepared: ToolRuntime.Prepared<R>,
   limits: ResolvedExecutionLimits,
-  hooks: ToolRuntime.ToolCallHooks<R>,
+  hooks: ToolRuntime.Hooks<R>,
   globals?: (ctx: Interpreter<R>) => ReadonlyArray<readonly [string, unknown]>,
 ): Effect.Effect<Result, never, R> => {
   if (code.trim().length === 0) {
@@ -30,7 +30,7 @@ export const executeProgram = <R>(
   // Allocate execution state inside suspension so reused Effects never share it.
   return Effect.suspend(() => {
     const builtins = createBuiltins()
-    const tools = ToolRuntime.make(prepared, builtins, limits.maxToolCalls, hooks)
+    const tools = ToolRuntime.make(prepared, limits.maxToolCalls, hooks)
     const logs: Array<string> = []
     const logged = () => (logs.length > 0 ? { logs: [...logs] } : {})
     // Set only after copy-out so timeouts cannot report invalid values as completed.
@@ -42,8 +42,8 @@ export const executeProgram = <R>(
         Effect.gen(function* () {
           const program = parseProgram(code)
           const pending = new Pending<R>(scope, builtins.Promise)
-          const value = yield* new Interpreter<R>({ tools, pending, builtins, logs, globals }).run(program)
-          const result = toData(value, "Execution result", "result") as DataValue
+          const ctx = new Interpreter<R>({ tools, pending, builtins, logs, globals })
+          const result = (yield* toBoundary(ctx, yield* ctx.run(program))) ?? null
           returned = { value: result, pending }
           const warnings = yield* pending.interrupt()
           return {

packages/codemode/src/interpreter/extensions.ts

@@ -1,25 +1,22 @@
 import { Effect } from "effect"
-import { MAX_VALUE_DEPTH } from "../data.js"
 import type { Extension } from "../extension.js"
 import { coerceToString } from "../stdlib/value.js"
+import { type ExtensionInvocation, hooked } from "../tool-runtime.js"
 import type { Interpreter } from "./interpreter.js"
 import { createErrorValue, isErrorType } from "./intrinsics.js"
+import { MAX_VALUE_DEPTH } from "./limits.js"
 import { Throw, typeError } from "./model.js"
-import { constructor, fn } from "./native.js"
+import { fn } from "./native.js"
 import {
   Callable,
   define,
-  defineAccessor,
   entries,
   get,
-  hidden,
-  type Native,
   Arr,
   Bytes,
   DateObj,
   ErrorObj,
   GeneratorObj,
-  Handle,
   MapObj,
   Obj,
   PromiseObj,
@@ -30,31 +27,16 @@ import {
 } from "./objects.js"
 import { describeValue } from "./references.js"
 
-type Class = Function & { readonly prototype: object }
-
-const isClass = (value: unknown): value is Class =>
-  typeof value === "function" && typeof value.prototype === "object" && value.prototype !== null
-
-// Own keys the native function already carries.
-const ownFunctionKeys = new Set(["length", "name", "prototype"])
-const ownPrototypeKeys = new Set(["constructor"])
-
 /**
- * The global bindings of one run's extensions. Everything crossing the boundary is converted: plain data is
- * copied, built-in wrappers are copied, instances of exposed classes travel as handles, and a host Promise becomes
- * a program promise. Prototypes, constructors, and handle identity are all per run.
+ * The global bindings of one run's extensions. Everything crossing the boundary is converted: plain data and
+ * built-in wrappers are copied, a host function becomes a program function whose calls cross the same way, and a
+ * host Promise becomes a program promise.
  */
 export const extensionGlobals = <R>(
   ctx: Interpreter<R>,
   extensions: ReadonlyArray<Extension>,
 ): ReadonlyArray<readonly [string, unknown]> => {
   const builtins = ctx.builtins
-  const classes = new Set(extensions.flatMap((extension) => Object.values(extension.globals)).filter(isClass))
-  // Host prototype object → this run's program prototype, so an instance wraps as its most-derived exposed class.
-  const protoOf = new Map<object, Obj>()
-  const exposed = new Map<Class, { ctor: Native<R>; proto: Obj }>()
-  const classOf = new Map<unknown, Class>()
-  const handles = new WeakMap<object, Handle>()
 
   const toHost = (value: unknown, label: string, depth = 0, seen = new Set<object>()): unknown => {
     if (depth > MAX_VALUE_DEPTH) throw typeError(`${label} exceeds the maximum value depth of ${MAX_VALUE_DEPTH}.`)
@@ -62,7 +44,6 @@ export const extensionGlobals = <R>(
       if (isPrimitive(value)) return value
       throw typeError(`${label} contains ${describeValue(value)}, which cannot be passed to an extension.`)
     }
-    if (value instanceof Handle) return value.instance
     if (value instanceof Bytes) return new Uint8Array(value.bytes)
     if (value instanceof DateObj) return new Date(value.time)
     if (value instanceof RegExpObj) return new RegExp(value.regex.source, value.regex.flags)
@@ -83,7 +64,7 @@ export const extensionGlobals = <R>(
       const name = coerceToString(get(value, "name"))
       const message = get(value, "message")
       const text = message === undefined ? "" : coerceToString(message)
-      return name === "AggregateError" ? new AggregateError([], text) : new (hostErrors[name] ?? Error)(text)
+      return name === "AggregateError" ? new AggregateError([], text) : new (hostErrors.get(name) ?? Error)(text)
     }
     if (seen.has(value)) throw typeError(`${label} contains a circular value.`)
     seen.add(value)
@@ -102,15 +83,8 @@ export const extensionGlobals = <R>(
   const fromHost = (value: unknown, label: string, depth = 0, seen = new Set<object>()): unknown => {
     if (depth > MAX_VALUE_DEPTH) throw typeError(`${label} exceeds the maximum value depth of ${MAX_VALUE_DEPTH}.`)
     if (isPrimitive(value)) return value
+    if (typeof value === "function") return wrap(value, label)
     if (value !== null && typeof value === "object") {
-      const existing = handles.get(value)
-      if (existing !== undefined) return existing
-      const proto = handlePrototype(value)
-      if (proto !== undefined) {
-        const handle = new Handle(proto, value)
-        handles.set(value, handle)
-        return handle
-      }
       if (value instanceof Date) return new DateObj(builtins.Date, value.getTime())
       if (value instanceof RegExp) return new RegExpObj(builtins.RegExp, value.source, value.flags)
       if (value instanceof Uint8Array) return new Bytes(builtins.Uint8Array, new Uint8Array(value))
@@ -122,28 +96,31 @@ export const extensionGlobals = <R>(
       if (value instanceof URLSearchParams) {
         return new URLSearchParamsObj(builtins.URLSearchParams, new URLSearchParams(value))
       }
-      const next = (item: unknown) => fromHost(item, label, depth + 1, seen)
+      const next = (item: unknown, path: string) => fromHost(item, path, depth + 1, seen)
       if (value instanceof Map) {
         const wrapped = new MapObj(builtins.Map)
-        for (const [key, item] of value) wrapped.map.set(next(key), next(item))
+        for (const [key, item] of value) wrapped.map.set(next(key, label), next(item, label))
         return wrapped
       }
       if (value instanceof Set) {
         const wrapped = new SetObj(builtins.Set)
-        for (const item of value) wrapped.set.add(next(item))
+        for (const item of value) wrapped.set.add(next(item, label))
         return wrapped
       }
       if (seen.has(value)) throw typeError(`${label} produced a circular value.`)
       seen.add(value)
       if (Array.isArray(value)) {
-        const copied = new Arr(builtins.Array, value.map(next))
+        const copied = new Arr(
+          builtins.Array,
+          value.map((item, index) => next(item, `${label}[${index}]`)),
+        )
         seen.delete(value)
         return copied
       }
       const prototype = Object.getPrototypeOf(value)
       if (prototype === Object.prototype || prototype === null) {
         const copied = new Obj(builtins.Object)
-        for (const [key, item] of Object.entries(value)) define(copied, key, next(item))
+        for (const [key, item] of Object.entries(value)) define(copied, key, next(item, `${label}.${key}`))
         seen.delete(value)
         return copied
       }
@@ -151,153 +128,46 @@ export const extensionGlobals = <R>(
     throw typeError(`${label} produced ${describeHost(value)}, which the program cannot hold.`)
   }
 
-  const handlePrototype = (instance: object): Obj | undefined => {
-    for (let level = Object.getPrototypeOf(instance); level !== null; level = Object.getPrototypeOf(level)) {
-      const proto = protoOf.get(level)
-      if (proto !== undefined) return proto
-    }
-    return undefined
-  }
-
-  // Runs host code with already-converted inputs. Whatever it returns, resolves, throws, or rejects with crosses
-  // the same way, so the program catches what the author threw.
-  const invoke = (run: () => unknown, label: string): Effect.Effect<unknown, unknown, R> => {
-    const thrown = (reason: unknown) => new Throw(fromHost(reason, label))
-    let result: unknown
-    try {
-      result = run()
-    } catch (reason) {
-      return Effect.fail(thrown(reason))
-    }
-    if (!(result instanceof Promise)) return Effect.succeed(fromHost(result, label))
-    return ctx.pending.create(
-      Effect.map(Effect.tryPromise({ try: () => result, catch: thrown }), (settled) => fromHost(settled, label)),
-    )
-  }
-
-  const args = (values: Array<unknown>, label: string): Array<unknown> =>
-    values.map((value, index) => toHost(value, `Argument ${index + 1} to ${label}`))
-
-  // Own members of each level from `from` up to (excluding) `root`, child first, as JS resolves them.
-  const members = (
-    target: Obj,
-    from: object,
-    root: object,
-    skip: ReadonlySet<string>,
-    label: string,
-    receiver: (thisValue: unknown, member: string) => unknown,
-  ): void => {
-    for (let level: object | null = from; level !== null && level !== root; level = Object.getPrototypeOf(level)) {
-      for (const [key, descriptor] of Object.entries(Object.getOwnPropertyDescriptors(level))) {
-        if (skip.has(key) || target.props.has(key)) continue
-        const name = `${label}.${key}`
-        if (typeof descriptor.value === "function") {
-          const method: Function = descriptor.value
-          const impl = (thisValue: unknown, values: Array<unknown>) => {
-            const self = receiver(thisValue, name)
-            const converted = args(values, name)
-            return invoke(() => method.apply(self, converted), name)
-          }
-          define(target, key, fn<R>(builtins, key, method.length, impl), hidden)
-          continue
-        }
-        // Data properties stay host-side: a program write to one would change the host class itself.
-        if ("value" in descriptor) continue
-        const get = descriptor.get
-        const set = descriptor.set
-        defineAccessor(
-          target,
-          key,
-          get === undefined
-            ? undefined
-            : (thisValue) => {
-                const value = get.call(receiver(thisValue, name))
-                if (value instanceof Promise)
-                  throw typeError(`${name} returned a Promise; a getter must be synchronous.`)
-                return fromHost(value, name)
-              },
-          set === undefined
-            ? undefined
-            : (thisValue, value) => {
-                set.call(receiver(thisValue, name), toHost(value, `${name} value`))
-              },
+  // A host function as a program function. Arguments cross in; a global's call runs inside the host's extension
+  // hooks, which see the host's own error on failure; then whatever came back, or was thrown, crosses out so the
+  // program catches a copy. Functions inside results are part of a value's API and skip the hooks.
+  const wrap = (value: Function, label: string, describe?: (args: ReadonlyArray<unknown>) => ExtensionInvocation) =>
+    fn<R>(builtins, value.name, value.length, (_, values) => {
+      const args = values.map((item, index) => toHost(item, `Argument ${index + 1} to ${label}`))
+      const hooks = ctx.tools.hooks
+      const settle = (run: Effect.Effect<unknown, unknown, R>) =>
+        (describe === undefined
+          ? run
+          : hooked(describe(args), hooks["extension.before"], hooks["extension.after"], run)
+        ).pipe(
+          Effect.mapError((reason) => new Throw(fromHost(reason, label))),
+          Effect.map((settled) => fromHost(settled, label)),
         )
+      let result: unknown
+      try {
+        result = value.apply(undefined, args)
+      } catch (reason) {
+        return settle(Effect.fail(reason))
       }
-    }
-  }
-
-  const expose = (cls: Class): { ctor: Native<R>; proto: Obj } => {
-    const existing = exposed.get(cls)
-    if (existing !== undefined) return existing
-    const ancestor = exposedAncestor(cls)
-    const base = ancestor === undefined ? undefined : expose(ancestor)
-    const proto = new Obj(base === undefined ? builtins.Object : base.proto)
-    protoOf.set(cls.prototype, proto)
-    const name = cls.name
-    const ctor = constructor<R>(builtins, proto, {
-      name,
-      length: cls.length,
-      call: (_, values) => {
-        const converted = args(values, name)
-        return invoke(() => cls.apply(undefined, converted), name)
-      },
-      construct: (values) => {
-        const label = `new ${name}`
-        const construct = cls as new (...values: Array<unknown>) => object
-        const converted = args(values, label)
-        return invoke(() => new construct(...converted), label)
-      },
+      if (!(result instanceof Promise)) return settle(Effect.succeed(result))
+      return ctx.pending.create(settle(Effect.tryPromise({ try: () => result, catch: (reason) => reason })))
     })
-    if (base !== undefined) ctor.proto = base.ctor
-    const entry = { ctor, proto }
-    exposed.set(cls, entry)
-    classOf.set(ctor, cls)
-    // A static called through an exposed subclass sees that subclass as `this`, like JS.
-    members(ctor, cls, ancestor ?? Function.prototype, ownFunctionKeys, name, (thisValue) => {
-      const called = classOf.get(thisValue)
-      return called !== undefined && (called === cls || called.prototype instanceof cls) ? called : cls
-    })
-    members(
-      proto,
-      cls.prototype,
-      ancestor?.prototype ?? Object.prototype,
-      ownPrototypeKeys,
-      `${name}.prototype`,
-      (thisValue, member) => {
-        if (thisValue instanceof Handle && thisValue.instance instanceof cls) return thisValue.instance
-        throw typeError(`Illegal invocation: ${member} called on ${describeValue(thisValue)}.`)
-      },
-    )
-    return entry
-  }
-
-  const exposedAncestor = (cls: Class): Class | undefined => {
-    for (let level = Object.getPrototypeOf(cls); isClass(level); level = Object.getPrototypeOf(level)) {
-      if (classes.has(level)) return level
-    }
-    return undefined
-  }
 
   return extensions.flatMap((extension) =>
-    Object.entries(extension.globals).map(([name, value]) => {
-      if (isClass(value)) return [name, expose(value).ctor] as const
-      const impl = (_: unknown, values: Array<unknown>) => {
-        const converted = args(values, name)
-        return invoke(() => value.apply(undefined, converted), name)
-      }
-      return [name, fn<R>(builtins, name, value.length, impl)] as const
-    }),
+    Object.entries(extension.globals).map(
+      ([name, value]) => [name, wrap(value, name, (args) => ({ extension: extension.name, name, args }))] as const,
+    ),
   )
 }
 
-const hostErrors: Record<string, ErrorConstructor | undefined> = {
-  TypeError,
-  RangeError,
-  SyntaxError,
-  ReferenceError,
-  EvalError,
-  URIError,
-}
+const hostErrors = new Map<string, ErrorConstructor>([
+  ["TypeError", TypeError],
+  ["RangeError", RangeError],
+  ["SyntaxError", SyntaxError],
+  ["ReferenceError", ReferenceError],
+  ["EvalError", EvalError],
+  ["URIError", URIError],
+])
 
 // The primitives the interpreter operates on; symbols and BigInts are not among them.
 const isPrimitive = (value: unknown): boolean =>
@@ -308,7 +178,6 @@ const isPrimitive = (value: unknown): boolean =>
   typeof value === "boolean"
 
 const describeHost = (value: unknown): string => {
-  if (typeof value === "function") return "a function"
   if (typeof value !== "object" || value === null) return `a ${typeof value}`
   const name = (value as { constructor?: { name?: string } }).constructor?.name
   return name === undefined || name === "" ? "an object" : `a ${name}`

packages/codemode/src/interpreter/globals.ts

@@ -54,7 +54,8 @@ type Factory = <R>(ctx: Interpreter<R>) => unknown
 // A table rather than a list so the names are known before any runtime exists.
 const table: Record<string, Factory> = {
   tools: () => new ToolReference([]),
-  search: (ctx) => native(ctx.builtins, { name: "search", call: (_, args) => ctx.tools.search(args), callback: false }),
+  search: (ctx) =>
+    native(ctx.builtins, { name: "search", call: (_, args) => ctx.tool(ctx.tools.search, args), callback: false }),
   undefined: () => undefined,
   NaN: () => NaN,
   Infinity: () => Infinity,

packages/codemode/src/interpreter/interpreter.ts

@@ -42,7 +42,7 @@ import type {
   YieldExpression,
 } from "acorn"
 import { Cause, Deferred, Effect, Exit } from "effect"
-import { toProgram } from "../data.js"
+import { fromJson, type Json, toBoundary } from "../data.js"
 import { ToolReference, type ToolRuntime } from "../tool-runtime.js"
 import {
   type AstNode,
@@ -291,6 +291,18 @@ export class Interpreter<R> {
   iterate(value: unknown) {
     return this.root.iterate(value)
   }
+
+  /** Runs one host tool: arguments cross as JSON and the result comes back as program values. */
+  tool(
+    run: (args: Array<Json | undefined>) => Effect.Effect<Json | undefined, unknown, R>,
+    args: Array<unknown>,
+  ): Effect.Effect<unknown, unknown, R> {
+    const ctx = this
+    return Effect.gen(function* () {
+      const json = yield* Effect.forEach(args, (arg) => toBoundary(ctx, arg))
+      return fromJson(ctx, yield* run(json))
+    })
+  }
 }
 
 const MAX_CALL_DEPTH = 10_000
@@ -344,7 +356,7 @@ class Frame<R> {
     path: ReadonlyArray<string>,
     args: Array<unknown>,
   ): Effect.Effect<PromiseObj, never, R> {
-    return this.ctx.pending.create(Effect.suspend(() => this.ctx.tools.execute(path, args)))
+    return this.ctx.pending.create(this.ctx.tool((json) => this.ctx.tools.execute(path, json), args))
   }
 
   // Fiber exits make settlement idempotent; yielding prevents inline continuation.
@@ -1216,7 +1228,8 @@ class Frame<R> {
       case "Literal": {
         const regex = node.regex
         if (regex) return Effect.sync(() => constructRegExp(this.ctx.builtins, [regex.pattern, regex.flags]))
-        return Effect.sync(() => toProgram(this.ctx.builtins, node.value, "Literal"))
+        if (typeof node.value === "bigint") throw typeError("BigInt literals are not supported.", node)
+        return Effect.succeed(node.value)
       }
       case "Identifier":
         return Effect.sync(() => this.scopes.get(node.name, node))
@@ -1305,11 +1318,7 @@ class Frame<R> {
       const lhs = yield* self.evaluateExpression(left)
       const rhs = yield* self.evaluateExpression(node.right)
       if (operator === "instanceof") return instanceofValue(lhs, rhs, node)
-      return toProgram(
-        self.ctx.builtins,
-        self.applyBinaryOperator(operator, lhs, rhs, node),
-        "Binary expression result",
-      )
+      return self.applyBinaryOperator(operator, lhs, rhs, node)
     })
   }
 
@@ -1429,7 +1438,7 @@ class Frame<R> {
         default:
           throw typeError(`Unsupported unary operator '${operator}'.`, node)
       }
-      return toProgram(this.ctx.builtins, result, "Unary expression result")
+      return result
     })
   }
 
@@ -1451,12 +1460,7 @@ class Frame<R> {
         if (operator !== "=") {
           const current = self.scopes.get(name, left)
           const rightValue = yield* self.evaluateExpression(node.right)
-          const next = toProgram(
-            self.ctx.builtins,
-            self.applyCompoundAssignment(operator, current, rightValue, node),
-            "Assignment result",
-          )
-          return self.scopes.set(name, next, left)
+          return self.scopes.set(name, self.applyCompoundAssignment(operator, current, rightValue, node), left)
         }
         const rightValue = yield* self.evaluateNamed(node.right, name)
         return self.scopes.set(name, rightValue, left)
@@ -1465,11 +1469,7 @@ class Frame<R> {
         return yield* self.modifyMember(left, (current) =>
           Effect.map(self.evaluateExpression(node.right), (rightValue) => {
             if (operator === "=") return { write: true, next: rightValue, result: rightValue }
-            const next = toProgram(
-              self.ctx.builtins,
-              self.applyCompoundAssignment(operator, current, rightValue, node),
-              "Assignment result",
-            )
+            const next = self.applyCompoundAssignment(operator, current, rightValue, node)
             return { write: true, next, result: next }
           }),
         )
@@ -2010,7 +2010,7 @@ class Frame<R> {
 
         if (index < expressions.length) {
           const raw = yield* self.evaluateExpression(expressions[index])
-          output += coerceToString(toProgram(self.ctx.builtins, raw, "Template interpolation"))
+          output += coerceToString(raw)
           checkStringLength(output.length)
         }
       }

packages/codemode/src/interpreter/limits.ts

@@ -9,6 +9,8 @@ export const MAX_STRING_LENGTH = 1 << 24
 export const MAX_ARRAY_LENGTH = 10_000_000
 /** Most promises that may be pending at once. */
 export const MAX_PENDING_PROMISES = 10_000
+/** Deepest nesting a value may have when it crosses to or from the host. */
+export const MAX_VALUE_DEPTH = 32
 
 export const checkStringLength = (length: number): void => {
   if (length > MAX_STRING_LENGTH) throw rangeError("Invalid string length")

packages/codemode/src/interpreter/objects.ts

@@ -136,7 +136,6 @@ export class RegExpObj extends Obj {
   constructor(proto: Obj, pattern: string, flags: string) {
     super(proto)
     this.regex = new RegExp(pattern, flags)
-    define(this, "lastIndex", 0, { writable: true, enumerable: false, configurable: false })
   }
 }
 
@@ -179,16 +178,6 @@ export class Bytes extends Obj {
   }
 }
 
-/** An instance of an extension class: the host object lives in a field no property path reaches. */
-export class Handle extends Obj {
-  constructor(
-    proto: Obj,
-    readonly instance: object,
-  ) {
-    super(proto)
-  }
-}
-
 /** Built-in objects that wrap a host value; data-like, but never plain data. */
 export const isWrapper = (
   value: unknown,

packages/codemode/src/interpreter/references.ts

@@ -9,7 +9,6 @@ import {
   Bytes,
   DateObj,
   GeneratorObj,
-  Handle,
   MapObj,
   Obj,
   PromiseObj,
@@ -23,7 +22,6 @@ import {
 export const isRuntimeReference = (value: unknown): boolean =>
   value instanceof Callable ||
   value instanceof GeneratorObj ||
-  value instanceof Handle ||
   value instanceof ToolReference ||
   value instanceof PromiseObj ||
   isWrapper(value)
@@ -89,7 +87,6 @@ export const describeValue = (value: unknown): string => {
   if (value instanceof URLSearchParamsObj) return "a URLSearchParams"
   if (value instanceof Bytes) return "a Uint8Array"
   if (value instanceof GeneratorObj) return "a generator"
-  if (value instanceof Handle) return `a ${value.instance.constructor.name}`
   if (isRuntimeReference(value)) return "a function"
   if (typeof value === "object") return "a data object"
   return `a ${typeof value}`

packages/codemode/src/stdlib/console.ts

@@ -1,5 +1,3 @@
-import { toData, toProgram } from "../data.js"
-import type { Builtins } from "../interpreter/intrinsics.js"
 import { type Method, methods } from "../interpreter/native.js"
 import {
   entries,
@@ -15,7 +13,7 @@ import {
   URLObj,
   URLSearchParamsObj,
 } from "../interpreter/objects.js"
-import { containsOpaqueReference, containsRuntimeReference, isRuntimeReference } from "../interpreter/references.js"
+import { containsOpaqueReference, isRuntimeReference } from "../interpreter/references.js"
 import type { Interpreter } from "../interpreter/interpreter.js"
 import { coerceToString } from "./value.js"
 
@@ -33,7 +31,7 @@ export const consoleGlobal = <R>(ctx: Interpreter<R>) => {
         name,
         0,
         (_, args) => {
-          ctx.logs.push(formatConsoleMessage(builtins, name, args))
+          ctx.logs.push(formatConsoleMessage(name, args))
           return undefined
         },
       ],
@@ -44,14 +42,15 @@ export const consoleGlobal = <R>(ctx: Interpreter<R>) => {
 
 const MAX_CONSOLE_DEPTH = 32
 
-const formatConsoleMessage = (builtins: Builtins, name: string, args: Array<unknown>): string => {
-  if (name === "dir") return args.length === 0 ? "undefined" : formatConsoleArgument(args[0])
-  if (name === "table") return formatConsoleTable(builtins, args[0], args[1])
+const formatConsoleMessage = (name: string, args: Array<unknown>): string => {
+  if (name === "dir") return args.length === 0 ? "undefined" : formatValue(args[0])
+  if (name === "table") return formatConsoleTable(args[0], args[1])
   const prefix = name === "warn" ? "[warn] " : name === "error" ? "[error] " : name === "debug" ? "[debug] " : ""
-  return `${prefix}${args.map((arg) => formatConsoleArgument(arg)).join(" ")}`
+  return `${prefix}${args.map((arg) => formatValue(arg)).join(" ")}`
 }
 
-const formatConsoleArgument = (value: unknown): string => {
+/** One value as `console.log` shows it. */
+export const formatValue = (value: unknown): string => {
   if (value === undefined) return "undefined"
   if (typeof value === "string") return value
   return formatConsoleValue(value, new Set(), 0)
@@ -103,12 +102,11 @@ const formatConsoleValue = (value: unknown, seen: Set<object>, depth: number): s
 const formatItems = (items: Array<unknown>, seen: Set<object>, depth: number): string =>
   items.map((item) => formatConsoleValue(item, seen, depth)).join(",")
 
-const formatConsoleTable = (builtins: Builtins, value: unknown, columnsArgument: unknown): string => {
+const formatConsoleTable = (value: unknown, columnsArgument: unknown): string => {
   if (value === undefined) return "undefined"
   if (containsOpaqueReference(value)) return "[opaque reference]"
-  const data = toProgram(builtins, value, "console.table argument")
-  const columns = consoleTableColumns(columnsArgument)
-  const rows = consoleTableRows(data, columns)
+  const columns = columnsArgument instanceof Arr ? columnsArgument.items.map(String) : undefined
+  const rows = consoleTableRows(value, columns)
   const keys = columns ?? Array.from(new Set(rows.flatMap((row) => Object.keys(row.values))))
   const header = ["(index)", ...keys].join("\t")
   return [
@@ -117,13 +115,6 @@ const formatConsoleTable = (builtins: Builtins, value: unknown, columnsArgument:
   ].join("\n")
 }
 
-const consoleTableColumns = (value: unknown): ReadonlyArray<string> | undefined => {
-  if (value === undefined) return undefined
-  if (containsRuntimeReference(value)) return undefined
-  const columns = toData(value, "console.table columns", "result")
-  return Array.isArray(columns) ? columns.map((column) => String(column)) : undefined
-}
-
 const consoleTableRows = (
   data: unknown,
   columns: ReadonlyArray<string> | undefined,

packages/codemode/src/stdlib/json.ts

@@ -5,8 +5,8 @@ import type { Interpreter } from "../interpreter/interpreter.js"
 import { checkStringLength } from "../interpreter/limits.js"
 import { syntaxError, typeError } from "../interpreter/model.js"
 import { typeofValue } from "../interpreter/references.js"
-import { fromData, toData, toProgram } from "../data.js"
-import { Callable, get, keys, Arr, Obj, record, remove, set } from "../interpreter/objects.js"
+import { fromJson, toJson } from "../data.js"
+import { get, keys, Arr, Obj, record, remove, set } from "../interpreter/objects.js"
 
 export const jsonGlobal = <R>(ctx: Interpreter<R>) => {
   const json = new Obj(ctx.builtins.Object)
@@ -23,7 +23,7 @@ const parse = <R>(ctx: Interpreter<R>, args: Array<unknown>): Effect.Effect<unkn
 
   const parsed = (() => {
     try {
-      return fromData(ctx.builtins, JSON.parse(text), "JSON.parse result")
+      return fromJson(ctx, JSON.parse(text))
     } catch (error) {
       throw syntaxError(`JSON.parse received invalid JSON: ${error instanceof Error ? error.message : String(error)}`)
     }
@@ -50,59 +50,17 @@ const stringify = <R>(ctx: Interpreter<R>, args: Array<unknown>): Effect.Effect<
   const space = args[2]
   const indent = typeof space === "number" || typeof space === "string" ? space : undefined
   const replacer = args[1]
-
-  if (typeofValue(replacer) !== "function") {
-    const properties =
-      replacer instanceof Arr
-        ? replacer.items
-            .filter((item): item is string | number => typeof item === "string" || typeof item === "number")
-            .map(String)
-        : null
-    // Not a host boundary: __proto__ stays and Set/RegExp/URLSearchParams serialize as {}, like JS.
-    const text = JSON.stringify(toData(args[0], "JSON.stringify value", "json", false), properties, indent)
+  const properties =
+    replacer instanceof Arr
+      ? replacer.items
+          .filter((item): item is string | number => typeof item === "string" || typeof item === "number")
+          .map(String)
+      : null
+  const callback =
+    typeofValue(replacer) === "function" ? applyCollectionCallback(ctx, replacer, "JSON.stringify") : undefined
+  return Effect.map(toJson(ctx, args[0], callback), (value) => {
+    const text = JSON.stringify(value, properties, indent)
     if (text !== undefined) checkStringLength(text.length)
-    return Effect.succeed(text)
-  }
-
-  // Validate up front; the replacer walk below reads the original value.
-  toProgram(ctx.builtins, args[0], "JSON.stringify value")
-  const apply = applyCollectionCallback(ctx, replacer, "JSON.stringify")
-  const stack = new Set<object>()
-  const visit = (holder: Obj, key: string): Effect.Effect<unknown, unknown, R> =>
-    Effect.gen(function* () {
-      const value = yield* apply([key, yield* toJSONValue(ctx, get(holder, key), key)])
-      if (value === undefined || typeofValue(value) === "function") return undefined
-      toProgram(ctx.builtins, value, "JSON.stringify replacer result")
-      if (typeof value === "number") return Number.isFinite(value) ? value : null
-      if (value === null || typeof value === "string" || typeof value === "boolean") return value
-      if (!(value instanceof Obj)) return {}
-      if (stack.has(value)) throw typeError("Converting circular structure to JSON.")
-      stack.add(value)
-      if (value instanceof Arr) {
-        const result: Array<unknown> = []
-        for (let index = 0; index < value.items.length; index += 1) {
-          result.push((yield* visit(value, String(index))) ?? null)
-        }
-        stack.delete(value)
-        return result
-      }
-      const result: Record<string, unknown> = Object.create(null)
-      for (const name of keys(value)) {
-        const item = yield* visit(value, name)
-        if (item !== undefined) result[name] = item
-      }
-      stack.delete(value)
-      return result
-    })
-
-  return Effect.map(visit(record(ctx.builtins.Object, { "": args[0] }), ""), (value) =>
-    JSON.stringify(value, null, indent),
-  )
-}
-
-// SerializeJSONProperty step 2: a callable `toJSON` decides the value, as Date and URL define.
-const toJSONValue = <R>(ctx: Interpreter<R>, value: unknown, key: string) => {
-  if (!(value instanceof Obj)) return Effect.succeed(value)
-  const toJSON = get(value, "toJSON")
-  return toJSON instanceof Callable ? ctx.call(toJSON, value, [key]) : Effect.succeed(value)
+    return text
+  })
 }

packages/codemode/src/stdlib/object.ts

@@ -1,5 +1,4 @@
 import { Effect } from "effect"
-import { toProgram } from "../data.js"
 import { constructor, methods, receiver } from "../interpreter/native.js"
 import {
   type AstNode,
@@ -138,12 +137,11 @@ export const objectGlobal = <R>(ctx: Interpreter<R>) => {
       "keys",
       1,
       (_, args) =>
-        toProgram(
-          builtins,
+        new Arr(
+          builtins.Array,
           args[0] instanceof ToolReference
             ? [...ctx.tools.keys(args[0].path)]
             : keys(enumerableSource(ctx, "Object.keys(...)", args[0])),
-          "Object.keys result",
         ),
     ],
     [

packages/codemode/src/stdlib/regexp.ts

@@ -2,7 +2,7 @@ import { Effect } from "effect"
 import type { Builtins } from "../interpreter/intrinsics.js"
 import { constructor, type Method, methods, prototypeFrom, receiver } from "../interpreter/native.js"
 import { syntaxError, typeError } from "../interpreter/model.js"
-import { define, defineAccessor, getOwn, Arr, Obj, RegExpObj, record, set } from "../interpreter/objects.js"
+import { define, defineAccessor, Arr, Obj, RegExpObj, record } from "../interpreter/objects.js"
 import type { Interpreter } from "../interpreter/interpreter.js"
 import { coerceToNumber, coerceToString } from "./value.js"
 
@@ -75,12 +75,6 @@ export const constructRegExp = (builtins: Builtins, args: Array<unknown>, proto:
   }
 }
 
-const toLength = (value: unknown): number => {
-  const number = coerceToNumber(value)
-  if (Number.isNaN(number) || number <= 0) return 0
-  return Math.min(Math.floor(number), Number.MAX_SAFE_INTEGER)
-}
-
 // RegExp constructs identically with or without new, like JS.
 export const regexpGlobal = <R>(ctx: Interpreter<R>) => {
   const builtins = ctx.builtins
@@ -105,18 +99,22 @@ export const regexpGlobal = <R>(ctx: Interpreter<R>) => {
   const self = (thisValue: unknown, name: string) => receiver(RegExpObj, thisValue, `RegExp.prototype.${name}`)
   defineAccessor(proto, "source", (thisValue) => self(thisValue, "source").regex.source)
   defineAccessor(proto, "flags", (thisValue) => self(thisValue, "flags").regex.flags)
+  // The host regex holds the only lastIndex, so exec/test and the String methods share one counter.
+  defineAccessor(
+    proto,
+    "lastIndex",
+    (thisValue) => self(thisValue, "lastIndex").regex.lastIndex,
+    (thisValue, value) => {
+      self(thisValue, "lastIndex").regex.lastIndex = coerceToNumber(value)
+    },
+  )
   for (const name of flagProperties) defineAccessor(proto, name, (thisValue) => self(thisValue, name).regex[name])
-  // exec/test run the host regex from the program-visible lastIndex and write it back only when g or y is set.
   const run = (name: "exec" | "test"): Method => [
     name,
     1,
     (thisValue, args) => {
       const value = self(thisValue, name)
-      const input = coerceToString(args[0])
-      const stateful = value.regex.global || value.regex.sticky
-      value.regex.lastIndex = toLength(getOwn(value, "lastIndex"))
-      const matched = value.regex.exec(input)
-      if (stateful) set(value, "lastIndex", value.regex.lastIndex)
+      const matched = value.regex.exec(coerceToString(args[0]))
       if (name === "test") return matched !== null
       return matched === null ? null : matchToValue(builtins, matched)
     },

packages/codemode/src/stdlib/string.ts

@@ -1,5 +1,4 @@
 import { Effect } from "effect"
-import { toProgram } from "../data.js"
 import { constructor, type Method, methods } from "../interpreter/native.js"
 import { checkArrayLength, checkStringLength } from "../interpreter/limits.js"
 import { invalidData, rangeError, typeError } from "../interpreter/model.js"
@@ -66,9 +65,7 @@ const replaceWithCallback = <R>(
       const replacement = yield* apply(match.args)
       output.push(
         value.slice(end, match.offset),
-        replacement instanceof PromiseObj
-          ? "[object Promise]"
-          : coerceToString(toProgram(builtins, replacement, `String.${name} replacer result`)),
+        replacement instanceof PromiseObj ? "[object Promise]" : coerceToString(replacement),
       )
       end = match.offset + match.match.length
     }
@@ -209,7 +206,7 @@ export const stringGlobal = <R>(ctx: Interpreter<R>) => {
       const matched = value.match(pattern)
       if (matched === null) return null
       // Preserve the own `index` and `groups` properties on non-global matches.
-      if (pattern.global) return toProgram(builtins, matched, "String.match result")
+      if (pattern.global) return new Arr(builtins.Array, [...matched])
       return matchToValue(builtins, matched)
     }),
     simple("matchAll", 1, (value, args) => {

packages/codemode/src/stdlib/url.ts

@@ -1,6 +1,4 @@
 import { Effect } from "effect"
-import { toProgram, ToolRuntimeError } from "../data.js"
-import type { Builtins } from "../interpreter/intrinsics.js"
 import { constructor, fn, type Method, methods, prototypeFrom, receiver, requiresNew } from "../interpreter/native.js"
 import { PendingThrow, typeError, uriError } from "../interpreter/model.js"
 import { defineAccessor, entries, isWrapper, Arr, Obj, URLObj, URLSearchParamsObj } from "../interpreter/objects.js"
@@ -23,9 +21,6 @@ const urlProperties = [
   "hash",
 ] as const
 
-export const uriArgument = (builtins: Builtins, value: unknown, label: string): string =>
-  coerceToString(toProgram(builtins, value, label))
-
 type UriFunction = "encodeURI" | "encodeURIComponent" | "decodeURI" | "decodeURIComponent"
 
 const uriFunctions: Record<UriFunction, (value: string) => string> = {
@@ -37,7 +32,7 @@ const uriFunctions: Record<UriFunction, (value: string) => string> = {
 
 export const uriGlobal = <R>(ctx: Interpreter<R>, name: UriFunction) =>
   fn<R>(ctx.builtins, name, 1, (_, args) => {
-    const value = uriArgument(ctx.builtins, args[0], `${name} input`)
+    const value = coerceToString(args[0])
     try {
       return uriFunctions[name](value)
     } catch (error) {
@@ -45,8 +40,7 @@ export const uriGlobal = <R>(ctx: Interpreter<R>, name: UriFunction) =>
     }
   })
 
-const urlArgument = (builtins: Builtins, value: unknown, label: string): string =>
-  value instanceof URLObj ? value.url.href : uriArgument(builtins, value, label)
+const urlArgument = (value: unknown): string => (value instanceof URLObj ? value.url.href : coerceToString(value))
 
 export const urlGlobal = <R>(ctx: Interpreter<R>) => {
   const builtins = ctx.builtins
@@ -55,8 +49,8 @@ export const urlGlobal = <R>(ctx: Interpreter<R>) => {
     if (args.length === 0) {
       throw typeError("new URL(...) requires a URL string and an optional base URL.")
     }
-    const input = urlArgument(builtins, args[0], "new URL input")
-    const base = args[1] === undefined ? undefined : urlArgument(builtins, args[1], "new URL base")
+    const input = urlArgument(args[0])
+    const base = args[1] === undefined ? undefined : urlArgument(args[1])
     try {
       return new URLObj(into, builtins.URLSearchParams, new URL(input, base))
     } catch {
@@ -74,8 +68,8 @@ export const urlGlobal = <R>(ctx: Interpreter<R>) => {
     1,
     (_, args) => {
       if (args.length === 0) throw typeError(`URL.${name} requires a URL argument.`)
-      const input = urlArgument(builtins, args[0], `URL.${name} input`)
-      const base = args[1] === undefined ? undefined : urlArgument(builtins, args[1], `URL.${name} base`)
+      const input = urlArgument(args[0])
+      const base = args[1] === undefined ? undefined : urlArgument(args[1])
       try {
         const parsed = new URL(input, base)
         return name === "canParse" ? true : new URLObj(proto, builtins.URLSearchParams, parsed)
@@ -97,13 +91,9 @@ export const urlGlobal = <R>(ctx: Interpreter<R>) => {
         : (thisValue, value) => {
             const target = self(thisValue, name)
             try {
-              ;(target.url as unknown as Record<string, string>)[name] = uriArgument(
-                builtins,
-                value,
-                `URL.${name} value`,
-              )
+              ;(target.url as unknown as Record<string, string>)[name] = coerceToString(value)
             } catch (error) {
-              if (error instanceof PendingThrow || error instanceof ToolRuntimeError) throw error
+              if (error instanceof PendingThrow) throw error
               throw typeError(`URL.${name} received an invalid value.`)
             }
           },
@@ -130,7 +120,7 @@ const readPair = <R>(ctx: Interpreter<R>, value: unknown): Effect.Effect<Array<s
       items.push(
         yield* preserveConsumerError(
           cursor,
-          Effect.sync(() => uriArgument(ctx.builtins, step.value, "URLSearchParams pair value")),
+          Effect.sync(() => coerceToString(step.value)),
         ),
       )
     }
@@ -189,8 +179,7 @@ export const urlSearchParamsGlobal = <R>(ctx: Interpreter<R>) => {
   const self = (thisValue: unknown, name: string) =>
     receiver(URLSearchParamsObj, thisValue, `URLSearchParams.prototype.${name}`)
   const wrap = (items: Array<unknown>) => new Arr(builtins.Array, items)
-  const arg = (name: string, args: Array<unknown>, index: number): string =>
-    uriArgument(builtins, args[index], `URLSearchParams.${name} argument ${index + 1}`)
+  const arg = (args: Array<unknown>, index: number): string => coerceToString(args[index])
   const requireArgs = (name: string, args: Array<unknown>, count: number): void => {
     if (args.length < count) {
       throw typeError(`URLSearchParams.${name} requires ${count} argument${count === 1 ? "" : "s"}.`)
@@ -203,7 +192,7 @@ export const urlSearchParamsGlobal = <R>(ctx: Interpreter<R>) => {
       2,
       (thisValue, args) => {
         requireArgs("append", args, 2)
-        self(thisValue, "append").params.append(arg("append", args, 0), arg("append", args, 1))
+        self(thisValue, "append").params.append(arg(args, 0), arg(args, 1))
         return undefined
       },
     ],
@@ -213,8 +202,8 @@ export const urlSearchParamsGlobal = <R>(ctx: Interpreter<R>) => {
       (thisValue, args) => {
         requireArgs("delete", args, 1)
         const params = self(thisValue, "delete").params
-        if (args[1] !== undefined) params.delete(arg("delete", args, 0), arg("delete", args, 1))
-        else params.delete(arg("delete", args, 0))
+        if (args[1] !== undefined) params.delete(arg(args, 0), arg(args, 1))
+        else params.delete(arg(args, 0))
         return undefined
       },
     ],
@@ -223,7 +212,7 @@ export const urlSearchParamsGlobal = <R>(ctx: Interpreter<R>) => {
       1,
       (thisValue, args) => {
         requireArgs("get", args, 1)
-        return self(thisValue, "get").params.get(arg("get", args, 0))
+        return self(thisValue, "get").params.get(arg(args, 0))
       },
     ],
     [
@@ -231,7 +220,7 @@ export const urlSearchParamsGlobal = <R>(ctx: Interpreter<R>) => {
       1,
       (thisValue, args) => {
         requireArgs("getAll", args, 1)
-        return wrap(self(thisValue, "getAll").params.getAll(arg("getAll", args, 0)))
+        return wrap(self(thisValue, "getAll").params.getAll(arg(args, 0)))
       },
     ],
     [
@@ -240,9 +229,7 @@ export const urlSearchParamsGlobal = <R>(ctx: Interpreter<R>) => {
       (thisValue, args) => {
         requireArgs("has", args, 1)
         const params = self(thisValue, "has").params
-        return args[1] !== undefined
-          ? params.has(arg("has", args, 0), arg("has", args, 1))
-          : params.has(arg("has", args, 0))
+        return args[1] !== undefined ? params.has(arg(args, 0), arg(args, 1)) : params.has(arg(args, 0))
       },
     ],
     [
@@ -250,7 +237,7 @@ export const urlSearchParamsGlobal = <R>(ctx: Interpreter<R>) => {
       2,
       (thisValue, args) => {
         requireArgs("set", args, 2)
-        self(thisValue, "set").params.set(arg("set", args, 0), arg("set", args, 1))
+        self(thisValue, "set").params.set(arg(args, 0), arg(args, 1))
         return undefined
       },
     ],

packages/codemode/src/stdlib/value.ts

@@ -1,4 +1,3 @@
-import { toProgram } from "../data.js"
 import { fn } from "../interpreter/native.js"
 import { typeError } from "../interpreter/model.js"
 import {
@@ -74,22 +73,21 @@ const coerce = <R>(ctx: Interpreter<R>, name: Coercion, args: Array<unknown>): u
     if (name === "parseInt") return parseInt(coerceToString(raw))
     return parseFloat(coerceToString(raw))
   }
-  const value = toProgram(ctx.builtins, raw, `${name} input`)
-  if (name === "Number") return coerceToNumber(value)
-  if (name === "Boolean") return Boolean(value)
-  if (name === "isFinite") return Number.isFinite(coerceToNumber(value))
-  if (name === "isNaN") return Number.isNaN(coerceToNumber(value))
+  if (name === "Number") return coerceToNumber(raw)
+  if (name === "Boolean") return Boolean(raw)
+  if (name === "isFinite") return Number.isFinite(coerceToNumber(raw))
+  if (name === "isNaN") return Number.isNaN(coerceToNumber(raw))
   if (name === "parseInt") {
     const radix = args[1]
     if (radix !== undefined && typeof radix !== "number") {
       throw typeError("parseInt expects a numeric radix.")
     }
-    return parseInt(coerceToString(value), radix)
+    return parseInt(coerceToString(raw), radix)
   }
-  if (name === "parseFloat") return parseFloat(coerceToString(value))
-  return coerceToString(value)
+  if (name === "parseFloat") return parseFloat(coerceToString(raw))
+  return coerceToString(raw)
 }
 
 /** A global coercion function such as `Number` or `parseInt`. */
 export const coercion = <R>(ctx: Interpreter<R>, name: Coercion, length = 1): Native<R> =>
-  fn(ctx.builtins, name, length, (_, args) => toProgram(ctx.builtins, coerce(ctx, name, args), `${name} result`))
+  fn(ctx.builtins, name, length, (_, args) => coerce(ctx, name, args))

packages/codemode/src/tool-runtime.ts

@@ -1,6 +1,6 @@
 import { Cause, Effect, Exit, Formatter, Schema } from "effect"
-import { fromData, toData, ToolRuntimeError } from "./data.js"
-import type { Builtins } from "./interpreter/intrinsics.js"
+import type { Json } from "./data.js"
+import type { DiagnosticKind } from "./codemode.js"
 import { toolError } from "./tool-error.js"
 import {
   decodeInput as decodeToolInput,
@@ -36,26 +36,48 @@ export type ToolCall = {
   readonly name: string
 }
 
-export type ToolCallStarted = {
-  readonly index: number
+/** A tool call the program is making, with its decoded input. */
+export type ToolInvocation = { readonly name: string; readonly input: unknown }
+
+/** A call the program is making to an extension global, with its arguments. */
+export type ExtensionInvocation = {
+  readonly extension: string
   readonly name: string
-  readonly input: unknown
+  readonly args: ReadonlyArray<unknown>
 }
 
-export type ToolCallEnded = {
-  readonly index: number
-  readonly name: string
-  readonly input: unknown
-  readonly durationMs: number
-  readonly outcome: "success" | "failure" | "interrupted"
-  readonly message?: string
+/** How a call ended; `after` hooks observe it and cannot change it. */
+export type CallResult =
+  | { readonly status: "success"; readonly value: unknown }
+  | { readonly status: "failure"; readonly error: unknown }
+  | { readonly status: "interrupted" }
+
+/** Hooks around every call the program makes into the host. A failing `before` denies the call. */
+export type Hooks<R = never> = {
+  readonly "tool.before"?: ((call: ToolInvocation) => Effect.Effect<void, unknown, R>) | undefined
+  readonly "tool.after"?: ((call: ToolInvocation, result: CallResult) => Effect.Effect<void, never, R>) | undefined
+  readonly "extension.before"?: ((call: ExtensionInvocation) => Effect.Effect<void, unknown, R>) | undefined
+  readonly "extension.after"?:
+    | ((call: ExtensionInvocation, result: CallResult) => Effect.Effect<void, never, R>)
+    | undefined
 }
 
-export type ToolCallHooks<R = never> = {
-  /** Observes decoded tool input immediately before tool execution. */
-  readonly onToolCallStart?: ((call: ToolCallStarted) => Effect.Effect<void, never, R>) | undefined
-  /** Observes each admitted tool call as it succeeds, fails, or is interrupted. */
-  readonly onToolCallEnd?: ((call: ToolCallEnded) => Effect.Effect<void, never, R>) | undefined
+/** Runs `before`, then `run`, then `after` with how it ended, including when interrupted. */
+export const hooked = <Call, A, R>(
+  call: Call,
+  before: ((call: Call) => Effect.Effect<void, unknown, R>) | undefined,
+  after: ((call: Call, result: CallResult) => Effect.Effect<void, never, R>) | undefined,
+  run: Effect.Effect<A, unknown, R>,
+): Effect.Effect<A, unknown, R> => {
+  const observed =
+    after === undefined
+      ? run
+      : Effect.onExit(run, (exit) => {
+          if (Exit.isSuccess(exit)) return after(call, { status: "success", value: exit.value })
+          if (Cause.hasInterruptsOnly(exit.cause)) return after(call, { status: "interrupted" })
+          return after(call, { status: "failure", error: Cause.squash(exit.cause) })
+        })
+  return before === undefined ? observed : Effect.andThen(before(call), observed)
 }
 
 export type ToolDescription = {
@@ -144,15 +166,24 @@ const flattenTools = <R>(
   ]
 }
 
-const describeTool = <R>(visible: VisibleTool<R>): ToolDescription => ({
-  path: visible.path,
-  description: visible.tool.description,
-  signature: isEmptyInput(visible.tool)
-    ? `${toolExpression(visible.path)}(): Promise<${outputTypeScript(visible.tool, true)}>`
-    : `${toolExpression(visible.path)}(input: ${inputTypeScript(visible.tool, true)}): Promise<${outputTypeScript(visible.tool, true)}>`,
-})
+const describeTool = <R>(visible: VisibleTool<R>): ToolDescription => {
+  let signature: string | undefined
+  return {
+    path: visible.path,
+    description: visible.tool.description,
+    get signature() {
+      // Search ranks paths and descriptions first; only returned matches need their schemas rendered.
+      // Joining the final fragments avoids retaining the rendering's intermediate string ropes in JSC.
+      return (signature ??= [
+        toolExpression(visible.path),
+        isEmptyInput(visible.tool) ? "()" : `(input: ${inputTypeScript(visible.tool, true)})`,
+        `: Promise<${outputTypeScript(visible.tool, true)}>`,
+      ].join(""))
+    },
+  }
+}
 
-/** Tools indexed once per runtime: the lookup trie plus the model-facing catalog and search index. */
+/** Tools indexed once per runtime, with discovery materialized on demand. */
 export type Prepared<R = never> = {
   readonly root: ToolNode<R>
   readonly catalog: ReadonlyArray<ToolDescription>
@@ -264,12 +295,20 @@ const toSearchEntry = <R>(visible: VisibleTool<R>): SearchEntry => ({
 
 export const prepare = <R>(tools: Tools<R>): Prepared<R> => {
   const root = toolTrie(tools)
-  // Discovery bytes are durable instructions, so order only after canonical-path collisions settle.
-  const visible = flattenTools(root).sort((left, right) => compareText(left.path, right.path))
+  let searchIndex: ReadonlyArray<SearchEntry> | undefined
+  let catalog: ReadonlyArray<ToolDescription> | undefined
   return {
     root,
-    catalog: visible.map(describeTool),
-    searchIndex: visible.map(toSearchEntry),
+    get catalog() {
+      return (catalog ??= this.searchIndex.map((entry) => entry.description))
+    },
+    get searchIndex() {
+      // Executing known tools only needs the trie. Render discovery when it is actually read,
+      // ordering after canonical-path collisions settle so instruction bytes stay deterministic.
+      return (searchIndex ??= flattenTools(root)
+        .sort((left, right) => compareText(left.path, right.path))
+        .map(toSearchEntry))
+    },
   }
 }
 
@@ -299,39 +338,40 @@ const resolve = <R>(root: ToolNode<R>, path: ReadonlyArray<string>): Tool<R> =>
   return node.tool
 }
 
+export class ToolRuntimeError extends Error {
+  constructor(
+    readonly kind: Extract<
+      DiagnosticKind,
+      "UnknownTool" | "InvalidToolInput" | "InvalidToolOutput" | "ToolCallLimitExceeded"
+    >,
+    message: string,
+    readonly suggestions: ReadonlyArray<string> = [],
+  ) {
+    super(message)
+    this.name = "ToolRuntimeError"
+  }
+}
+
+/** The tool bridge of one execution. Arguments arrive and results leave as JSON; program values never enter. */
 export type ToolRuntime<R = never> = {
   readonly calls: Array<ToolCall>
-  readonly execute: (path: ReadonlyArray<string>, args: Array<unknown>) => Effect.Effect<unknown, unknown, R>
-  readonly search: (args: Array<unknown>) => Effect.Effect<unknown, unknown, R>
+  readonly hooks: Hooks<R>
+  readonly execute: (
+    path: ReadonlyArray<string>,
+    args: Array<Json | undefined>,
+  ) => Effect.Effect<Json | undefined, unknown, R>
+  readonly search: (args: Array<Json | undefined>) => Effect.Effect<Json | undefined, unknown, R>
   readonly keys: (path: ReadonlyArray<string>) => ReadonlyArray<string>
 }
 
 /** Per-execution call state over tools prepared once for the runtime. */
 export const make = <R>(
   prepared: Prepared<R>,
-  builtins: Builtins,
   maxToolCalls: number | undefined,
-  hooks?: ToolCallHooks<R>,
+  hooks: Hooks<R> = {},
 ): ToolRuntime<R> => {
   const calls: Array<ToolCall> = []
   const root = prepared.root
-  const searchTool = makeSearchTool(prepared.searchIndex)
-
-  const observeEnd = <A, E>(effect: Effect.Effect<A, E, R>, call: ToolCallStarted): Effect.Effect<A, E, R> => {
-    const onEnd = hooks?.onToolCallEnd
-    if (onEnd === undefined) return effect
-    const startedAt = Date.now()
-    return effect.pipe(
-      Effect.onExit((exit) => {
-        const durationMs = Date.now() - startedAt
-        if (Exit.isSuccess(exit)) return onEnd({ ...call, durationMs, outcome: "success" })
-        if (Cause.hasInterruptsOnly(exit.cause)) return onEnd({ ...call, durationMs, outcome: "interrupted" })
-        const error = Cause.squash(exit.cause)
-        const message = error instanceof Error ? error.message : Cause.pretty(exit.cause)
-        return onEnd({ ...call, durationMs, outcome: "failure", message })
-      }),
-    )
-  }
 
   const recordCall = (call: ToolCall): void => {
     if (maxToolCalls !== undefined && calls.length >= maxToolCalls) {
@@ -340,9 +380,9 @@ export const make = <R>(
     calls.push(call)
   }
 
-  const executeTool = (name: string, tool: Tool<R>, externalArgs: Array<unknown>) =>
+  const executeTool = (name: string, tool: Tool<R>, args: Array<Json | undefined>) =>
     Effect.gen(function* () {
-      const normalized = externalArgs.length === 0 ? [{}] : externalArgs
+      const normalized = args.length === 0 ? [{}] : args
       if (normalized.length !== 1)
         throw new ToolRuntimeError("InvalidToolInput", `Tool '${name}' expects at most one input object.`)
       const input = yield* Effect.try({
@@ -354,14 +394,12 @@ export const make = <R>(
             name === "search" ? [] : ["The signature may have changed. Use search to get the current signature."],
           ),
       })
-      const index = yield* Effect.sync(() => {
-        recordCall({ name })
-        return calls.length - 1
-      })
-      const call = { index, name, input }
-      return yield* observeEnd(
+      yield* Effect.sync(() => recordCall({ name }))
+      return yield* hooked(
+        { name, input },
+        hooks["tool.before"],
+        hooks["tool.after"],
         Effect.gen(function* () {
-          if (hooks?.onToolCallStart !== undefined) yield* hooks.onToolCallStart(call)
           const raw = yield* Effect.suspend(() => tool.execute(input)).pipe(
             Effect.catchCause((cause) => {
               if (Cause.hasInterruptsOnly(cause)) return Effect.interrupt
@@ -374,32 +412,30 @@ export const make = <R>(
               )
             }),
           )
+          // The same round trip a tool result would take through text: exact JSON.stringify semantics.
           return yield* Effect.try({
-            try: () => fromData(builtins, decodeToolOutput(tool, raw), `Result from tool '${name}'`),
+            try: (): Json | undefined => {
+              const text = JSON.stringify(decodeToolOutput(tool, raw))
+              return text === undefined ? undefined : JSON.parse(text)
+            },
             catch: (cause) => new ToolRuntimeError("InvalidToolOutput", `Invalid output from tool '${name}': ${cause}`),
           })
         }),
-        call,
       )
     })
 
   return {
     calls,
+    hooks,
     keys: (path) => namespaceKeys(root, path),
-    search: (args) =>
-      Effect.suspend(() =>
-        executeTool(
-          "search",
-          searchTool,
-          args.map((arg) => toData(arg, "Arguments for tool 'search'")),
-        ),
-      ),
+    search: (args) => Effect.suspend(() => executeTool("search", makeSearchTool(prepared.searchIndex), args)),
     execute: (path, args) =>
-      Effect.gen(function* () {
-        const name = canonicalSegments(path).join(".")
-        const externalArgs = args.map((arg) => toData(arg, `Arguments for tool '${name}'`))
-        const tool = resolve(root, path)
-        return yield* executeTool(name, tool, externalArgs)
+      Effect.suspend(() => {
+        const segments = canonicalSegments(path)
+        // Models often write `tools.search(...)` for the bare `search(...)`; honor it unless a tool owns that path.
+        if (segments.length === 1 && segments[0] === "search" && lookup(root, segments) === undefined)
+          return executeTool("search", makeSearchTool(prepared.searchIndex), args)
+        return executeTool(segments.join("."), resolve(root, path), args)
       }),
   }
 }

packages/codemode/test/codemode.test.ts

@@ -1,6 +1,6 @@
 import { describe, expect, test } from "bun:test"
 import { Cause, Effect, Schema } from "effect"
-import { CodeMode, Tool, toolError } from "../src/index.js"
+import { CodeMode, Extension, Tool, toolError } from "../src/index.js"
 
 const run = (tool: Tool.Tool<never>) =>
   Effect.runPromise(CodeMode.make({ tools: { host: { call: tool } } }).execute("return await tools.host.call({})"))
@@ -160,77 +160,154 @@ describe("CodeMode host failure boundary", () => {
   })
 })
 
-describe("CodeMode tool-call observation", () => {
-  test("reports the tools actually invoked with decoded input", async () => {
-    const calls: Array<unknown> = []
+describe("CodeMode call hooks", () => {
+  const ended = (result: CodeMode.CallResult) => {
+    if (result.status !== "failure") return result.status
+    return `failure:${result.error instanceof Error ? result.error.message : String(result.error)}`
+  }
+  // Every hook logs its event, so the order across tools and extensions is visible.
+  const observe = (events: Array<string>): CodeMode.Hooks => ({
+    "tool.before": (call) => Effect.sync(() => void events.push(`tool.before ${JSON.stringify(call)}`)),
+    "tool.after": (call, result) => Effect.sync(() => void events.push(`tool.after ${call.name} ${ended(result)}`)),
+    "extension.before": (call) => Effect.sync(() => void events.push(`extension.before ${JSON.stringify(call)}`)),
+    "extension.after": (call, result) =>
+      Effect.sync(() => void events.push(`extension.after ${call.name} ${ended(result)}`)),
+  })
+
+  test("surround the tools actually invoked, with decoded input", async () => {
+    const events: Array<string> = []
     const lookup = Tool.make({
       description: "Look up a value",
       input: Schema.Struct({ query: Schema.String }),
       output: Schema.String,
-      execute: ({ query }) => Effect.succeed(query),
+      execute: ({ query }) => (query === "boom" ? Effect.fail(toolError("Lookup refused")) : Effect.succeed(query)),
     })
+    const runtime = CodeMode.make({ tools: { context: { lookup } }, hooks: observe(events) })
 
-    const result = await Effect.runPromise(
-      CodeMode.make({
-        tools: { context: { lookup } },
-        onToolCallStart: (call) => Effect.sync(() => calls.push(call)),
-      }).execute(`
+    const success = await Effect.runPromise(
+      runtime.execute(`
         if (false) await tools.context.lookup({ query: "not called" })
         return await tools.context.lookup({ query: "deployment failure" })
       `),
     )
-
-    expect(result.ok).toBe(true)
-    expect(calls).toStrictEqual([{ index: 0, name: "context.lookup", input: { query: "deployment failure" } }])
-  })
-
-  test("observes settled calls with outcome and duration", async () => {
-    const events: Array<{ phase: string; index: number; name: string; outcome?: string; message?: string }> = []
-    const lookup = Tool.make({
-      description: "Look up a value",
-      input: Schema.Struct({ query: Schema.String }),
-      output: Schema.String,
-      execute: ({ query }) =>
-        query === "boom"
-          ? Effect.fail(toolError("Lookup refused"))
-          : query === "defect"
-            ? Effect.die("broken")
-            : Effect.succeed(query),
-    })
-
-    const runtime = CodeMode.make({
-      tools: { context: { lookup } },
-      onToolCallStart: (call) =>
-        Effect.sync(() => {
-          events.push({ phase: "start", index: call.index, name: call.name })
-        }),
-      onToolCallEnd: (call) =>
-        Effect.sync(() => {
-          expect(call.durationMs).toBeGreaterThanOrEqual(0)
-          events.push({
-            phase: "end",
-            index: call.index,
-            name: call.name,
-            outcome: call.outcome,
-            ...(call.message === undefined ? {} : { message: call.message }),
-          })
-        }),
-    })
-
-    const success = await Effect.runPromise(runtime.execute(`return await tools.context.lookup({ query: "ok" })`))
-    expect(success.ok).toBe(true)
+    expect(success).toMatchObject({ ok: true, value: "deployment failure" })
     const failure = await Effect.runPromise(runtime.execute(`return await tools.context.lookup({ query: "boom" })`))
     expect(failure.ok).toBe(false)
-    const defect = await Effect.runPromise(runtime.execute(`return await tools.context.lookup({ query: "defect" })`))
-    expect(defect.ok).toBe(false)
+    expect(events).toEqual([
+      'tool.before {"name":"context.lookup","input":{"query":"deployment failure"}}',
+      "tool.after context.lookup success",
+      'tool.before {"name":"context.lookup","input":{"query":"boom"}}',
+      "tool.after context.lookup failure:Lookup refused",
+    ])
+  })
 
-    expect(events).toStrictEqual([
-      { phase: "start", index: 0, name: "context.lookup" },
-      { phase: "end", index: 0, name: "context.lookup", outcome: "success" },
-      { phase: "start", index: 0, name: "context.lookup" },
-      { phase: "end", index: 0, name: "context.lookup", outcome: "failure", message: "Lookup refused" },
-      { phase: "start", index: 0, name: "context.lookup" },
-      { phase: "end", index: 0, name: "context.lookup", outcome: "failure", message: "broken" },
+  test("surround each call to an extension global, with its arguments, but not functions inside results", async () => {
+    const events: Array<string> = []
+    const runtime = CodeMode.make({
+      extensions: [
+        Extension.make({
+          name: "web",
+          globals: {
+            fetch: async (url: string, init?: { method?: string }) => ({
+              url,
+              method: init?.method ?? "GET",
+              json: () => 1,
+            }),
+            fail: () => {
+              throw new RangeError("nope")
+            },
+          },
+        }),
+      ],
+      hooks: observe(events),
+    })
+    const result = await Effect.runPromise(
+      runtime.execute(`
+        const res = await fetch("https://a.test/", { method: "POST" })
+        res.json()
+        try { fail() } catch {}
+        return res.url
+      `),
+    )
+    expect(result).toMatchObject({ ok: true, value: "https://a.test/", toolCalls: [] })
+    expect(events).toEqual([
+      'extension.before {"extension":"web","name":"fetch","args":["https://a.test/",{"method":"POST"}]}',
+      "extension.after fetch success",
+      'extension.before {"extension":"web","name":"fail","args":[]}',
+      "extension.after fail failure:nope",
+    ])
+  })
+
+  test("a failing before hook denies the call; the program catches the host's error", async () => {
+    const runtime = CodeMode.make({
+      tools: {
+        lookup: Tool.make({
+          description: "Look up",
+          input: Schema.Struct({}),
+          output: Schema.String,
+          execute: () => Effect.succeed("ok"),
+        }),
+      },
+      extensions: [Extension.make({ name: "web", globals: { fetch: async (url: string) => url } })],
+      hooks: { "extension.before": (call) => Effect.fail(new Error(`${call.name} is not allowed`)) },
+    })
+    expect(
+      await Effect.runPromise(
+        runtime.execute(`
+          const denied = await fetch("https://a.test/").catch((e) => [e instanceof Error, e.message])
+          return [denied, await tools.lookup({})]
+        `),
+      ),
+    ).toMatchObject({ ok: true, value: [[true, "fetch is not allowed"], "ok"] })
+    expect(await Effect.runPromise(runtime.execute(`await fetch("https://a.test/")`))).toMatchObject({
+      ok: false,
+      error: { kind: "ExecutionFailure", message: "Error: fetch is not allowed" },
+    })
+    const refused = CodeMode.make({
+      tools: {
+        lookup: Tool.make({
+          description: "Look up",
+          input: Schema.Struct({}),
+          output: Schema.String,
+          execute: () => Effect.succeed("ok"),
+        }),
+      },
+      hooks: { "tool.before": () => Effect.fail(toolError("lookup is not allowed")) },
+    })
+    expect(
+      await Effect.runPromise(
+        refused.execute(`try { await tools.lookup({}) } catch (e) { return [e.name, e.message] }`),
+      ),
+    ).toMatchObject({ ok: true, value: ["Error", "lookup is not allowed"], toolCalls: [{ name: "lookup" }] })
+    expect(await Effect.runPromise(refused.execute(`await tools.lookup({})`))).toMatchObject({
+      ok: false,
+      error: { kind: "ToolFailure", message: "lookup is not allowed" },
+    })
+  })
+
+  test("see a tool defect as the failure the program gets, and an interrupted extension call", async () => {
+    const events: Array<string> = []
+    const broken = Tool.make({
+      description: "Broken",
+      input: Schema.Struct({}),
+      output: Schema.String,
+      execute: () => Effect.die("broken"),
+    })
+    const runtime = CodeMode.make({
+      tools: { broken },
+      extensions: [Extension.make({ name: "slow", globals: { forever: () => new Promise(() => {}) } })],
+      hooks: observe(events),
+    })
+    expect(await Effect.runPromise(runtime.execute(`await tools.broken({})`))).toMatchObject({ ok: false })
+    expect(await Effect.runPromise(runtime.execute(`forever(); return "done"`))).toMatchObject({
+      ok: true,
+      value: "done",
+    })
+    expect(events).toEqual([
+      'tool.before {"name":"broken","input":{}}',
+      "tool.after broken failure:broken",
+      'extension.before {"extension":"slow","name":"forever","args":[]}',
+      "extension.after forever interrupted",
     ])
   })
 
@@ -243,15 +320,11 @@ describe("CodeMode tool-call observation", () => {
       execute: () => Effect.interrupt,
     })
     const exit = await Effect.runPromiseExit(
-      CodeMode.make({
-        tools: { host: { call } },
-        onToolCallStart: () => Effect.sync(() => events.push("start")),
-        onToolCallEnd: (call) => Effect.sync(() => events.push(`end:${call.outcome}`)),
-      }).execute("return await tools.host.call({})"),
+      CodeMode.make({ tools: { host: { call } }, hooks: observe(events) }).execute("return await tools.host.call({})"),
     )
 
     expect(exit._tag).toBe("Failure")
-    expect(events).toEqual(["start", "end:interrupted"])
+    expect(events).toEqual(['tool.before {"name":"host.call","input":{}}', "tool.after host.call interrupted"])
   })
 
   test("observes running calls interrupted during completion", async () => {
@@ -263,39 +336,17 @@ describe("CodeMode tool-call observation", () => {
       execute: () => Effect.never,
     })
     const result = await Effect.runPromise(
-      CodeMode.make({
-        tools: { host: { call } },
-        onToolCallStart: () => Effect.sync(() => events.push("start")),
-        onToolCallEnd: (call) => Effect.sync(() => events.push(`end:${call.outcome}`)),
-      }).execute('tools.host.call({}); return "done"'),
+      CodeMode.make({ tools: { host: { call } }, hooks: observe(events) }).execute(
+        'tools.host.call({}); return "done"',
+      ),
     )
 
     expect(result).toMatchObject({ ok: true, value: "done" })
-    expect(events).toEqual(["start", "end:interrupted"])
-  })
-
-  test("ends calls interrupted during start observation", async () => {
-    const events: Array<string> = []
-    const call = Tool.make({
-      description: "Unused",
-      input: Schema.Struct({}),
-      output: Schema.String,
-      execute: () => Effect.succeed("unused"),
-    })
-    const exit = await Effect.runPromiseExit(
-      CodeMode.make({
-        tools: { host: { call } },
-        onToolCallStart: () => Effect.interrupt,
-        onToolCallEnd: (call) => Effect.sync(() => events.push(call.outcome)),
-      }).execute("return await tools.host.call({})"),
-    )
-
-    expect(exit._tag).toBe("Failure")
-    expect(events).toEqual(["interrupted"])
+    expect(events).toEqual(['tool.before {"name":"host.call","input":{}}', "tool.after host.call interrupted"])
   })
 
   test("observes calls interrupted by the execution timeout", async () => {
-    const outcomes: Array<string> = []
+    const events: Array<string> = []
     const call = Tool.make({
       description: "Pending",
       input: Schema.Struct({}),
@@ -303,15 +354,13 @@ describe("CodeMode tool-call observation", () => {
       execute: () => Effect.never,
     })
     const result = await Effect.runPromise(
-      CodeMode.make({
-        tools: { host: { call } },
-        limits: { timeoutMs: 10 },
-        onToolCallEnd: (call) => Effect.sync(() => outcomes.push(call.outcome)),
-      }).execute("return await tools.host.call({})"),
+      CodeMode.make({ tools: { host: { call } }, limits: { timeoutMs: 10 }, hooks: observe(events) }).execute(
+        "return await tools.host.call({})",
+      ),
     )
 
     expect(result).toMatchObject({ ok: false, error: { kind: "TimeoutExceeded" } })
-    expect(outcomes).toEqual(["interrupted"])
+    expect(events).toEqual(['tool.before {"name":"host.call","input":{}}', "tool.after host.call interrupted"])
   })
 })
 
@@ -840,20 +889,17 @@ describe("CodeMode public contract", () => {
     }
   })
 
-  test("search is a counted tool call: it burns maxToolCalls and fires the hooks", async () => {
-    const started: Array<string> = []
-    const ended: Array<string> = []
+  test("search is a counted tool call: it burns maxToolCalls and is observed", async () => {
+    const observed: Array<CodeMode.ToolInvocation> = []
     const limited = CodeMode.make({
       tools,
       limits: { maxToolCalls: 1 },
-      onToolCallStart: (call) => Effect.sync(() => void started.push(call.name)),
-      onToolCallEnd: (call) => Effect.sync(() => void ended.push(`${call.name}:${call.outcome}`)),
+      hooks: { "tool.before": (call) => Effect.sync(() => void observed.push(call)) },
     })
     const result = await Effect.runPromise(limited.execute(`search({}); return search({})`))
     expect(result.ok).toBe(false)
     if (!result.ok) expect(result.error.kind).toBe("ToolCallLimitExceeded")
-    expect(started).toEqual(["search"])
-    expect(ended).toEqual(["search:success"])
+    expect(observed).toEqual([{ name: "search", input: {} }])
   })
 
   test("search is an opaque, shadowable global like other built-ins", async () => {
@@ -863,10 +909,9 @@ describe("CodeMode public contract", () => {
     const shadowed = await Effect.runPromise(runtime.execute(`const search = () => "local"; return search()`))
     expect(shadowed.ok).toBe(true)
     if (shadowed.ok) expect(shadowed.value).toBe("local")
-    // The reference itself cannot cross the data boundary.
+    // The reference itself vanishes at the data boundary, as functions do in JSON.stringify.
     const escaped = await Effect.runPromise(runtime.execute(`return { search }`))
-    expect(escaped.ok).toBe(false)
-    if (!escaped.ok) expect(escaped.error.kind).toBe("InvalidDataValue")
+    expect(escaped).toMatchObject({ ok: true, value: {} })
   })
 
   test("search defaults to 10 results and resolves exact tool paths", async () => {
@@ -1090,7 +1135,7 @@ describe("CodeMode public contract", () => {
     })
     const runtime = CodeMode.make({
       tools: { math: { double: transformed } },
-      onToolCallStart: (call) => Effect.sync(() => observed.push(call.input)),
+      hooks: { "tool.before": (call) => Effect.sync(() => void observed.push(call.input)) },
     })
 
     const success = await Effect.runPromise(runtime.execute(`return await tools.math.double({ value: "21" })`))
@@ -1104,7 +1149,7 @@ describe("CodeMode public contract", () => {
     expect(observed).toStrictEqual([{ value: 21 }, 21])
   })
 
-  test("returns JSON-safe data and normalizes undefined to null", async () => {
+  test("returns JSON-safe data: undefined vanishes as in JSON.stringify, and a bare undefined is null", async () => {
     const result = await Effect.runPromise(
       CodeMode.execute({
         code: `return { top: undefined, nested: [1, undefined] }`,
@@ -1112,9 +1157,10 @@ describe("CodeMode public contract", () => {
     )
     expect(result).toStrictEqual({
       ok: true,
-      value: { top: null, nested: [1, null] },
+      value: { nested: [1, null] },
       toolCalls: [],
     })
+    expect(await Effect.runPromise(CodeMode.execute({ code: `return undefined` }))).toMatchObject({ value: null })
     expect(Schema.decodeUnknownSync(CodeMode.Result)(JSON.parse(JSON.stringify(result)))).toStrictEqual(result)
   })
 

packages/codemode/test/extensions.test.ts

@@ -2,67 +2,12 @@ import { describe, expect, test } from "bun:test"
 import { Effect, Schema } from "effect"
 import { CodeMode, Extension, Tool } from "../src/index.js"
 
-class Bag {
-  static made = 0
-  static of(...items: Array<string>) {
-    return new this(items)
-  }
-  constructor(readonly items: Array<string> = []) {
-    Bag.made++
-  }
-  get size() {
-    return this.items.length
-  }
-  set size(length: number) {
-    this.items.length = length
-  }
-  add(item: string) {
-    this.items.push(item)
-    return this
-  }
-  toArray() {
-    return [...this.items]
-  }
-  pair() {
-    return { self: this, list: [this, new Bag()] }
-  }
-  async later<T>(value: T) {
-    return value
-  }
-  async reject(reason: unknown) {
-    throw reason
-  }
-  fail() {
-    throw new RangeError("boom")
-  }
-  get lazy() {
-    return Promise.resolve(1)
-  }
-  detached() {
-    return new Other()
-  }
-}
-class Other {}
-class Big extends Bag {
-  double() {
-    return this.items.length * 2
-  }
-}
-class Vault {
-  secrets = new Map<string, string>()
-  set(key: string, value: string) {
-    this.secrets.set(key, value)
-  }
-}
-
 const held: Array<unknown> = []
 const config = { retries: 3, nested: { deep: true } }
+const requests: Array<unknown> = []
 const extension = Extension.make({
-  name: "bag",
+  name: "web",
   globals: {
-    Bag,
-    Big,
-    Vault,
     keep: (value: unknown) => {
       held.push(value)
       return value
@@ -70,6 +15,19 @@ const extension = Extension.make({
     settings: () => config,
     later: async (value: number) => value + 1,
     first: (map: Map<unknown, unknown>) => map.get("k"),
+    fetch: async (url: string, init?: { method?: string }) => {
+      requests.push([url, init])
+      const bytes = new TextEncoder().encode(`{"url":"${url}"}`)
+      return {
+        status: 200,
+        ok: true,
+        headers: { get: (name: string) => (name === "content-type" ? "application/json" : null) },
+        text: () => new TextDecoder().decode(bytes),
+        json: () => JSON.parse(new TextDecoder().decode(bytes)),
+        bytes: () => bytes,
+        handlers: [(step: number) => step + 1],
+      }
+    },
   },
 })
 
@@ -87,66 +45,61 @@ const failure = async (code: string, target = runtime) => {
   return result.error
 }
 
-describe("extension classes behave like JS", () => {
-  test("construct, call methods, read and write accessors", async () => {
-    expect(await value(`const b = new Bag(["a"]); b.add("b"); return [b.size, b.toArray()]`)).toEqual([2, ["a", "b"]])
-    expect(await value(`const b = new Bag(["a", "b"]); b.size = 1; return b.toArray()`)).toEqual(["a"])
-  })
-
-  test("instanceof, constructor, typeof, and prototype identity", async () => {
-    expect(
-      await value(
-        `const b = new Bag(); return [b instanceof Bag, b.constructor === Bag, typeof Bag, Bag.prototype.constructor === Bag]`,
-      ),
-    ).toEqual([true, true, "function", true])
-  })
-
-  test("statics, including `new this()` through an exposed subclass", async () => {
-    expect(await value(`return [Bag.of("x", "y").toArray(), Big.of("q") instanceof Big, Big.of === Bag.of]`)).toEqual([
-      ["x", "y"],
-      true,
-      true,
-    ])
-  })
-
-  test("data properties are invisible, so a program write never reaches the host class", async () => {
-    Bag.made = 0
-    expect(await value(`Bag.made = 999; return Bag.made`)).toBe(999)
-    expect(Bag.made).toBe(0)
-    expect(await value(`return [Bag.made, new Bag(["a"]).items]`)).toEqual([null, null])
-  })
-
-  test("inheritance chains to the exposed ancestor", async () => {
-    expect(
-      await value(`const b = new Big(["a"]); return [b.double(), b.add("b").size, b instanceof Bag, b instanceof Big]`),
-    ).toEqual([2, 2, true, true])
-  })
-
-  test("calling a class without new throws the host TypeError", async () => {
-    const error = await failure(`Bag()`)
-    expect(error.message).toStartWith("TypeError: ")
-    expect(error.message).toContain("new")
-  })
-
-  test("a function global is callable, awaitable, and not constructible", async () => {
+describe("extension functions", () => {
+  test("a global is callable, awaitable, and not constructible", async () => {
     expect(await value(`return await later(1)`)).toBe(2)
+    expect(await value(`return [typeof later, later.name, later.length]`)).toEqual(["function", "later", 1])
     expect((await failure(`new later()`)).message).toContain("new later(...) is not supported")
   })
 
-  test("a program can patch a prototype for its own run only", async () => {
-    expect(await value(`Bag.prototype.add = () => "patched"; return new Bag().add("x")`)).toBe("patched")
-    expect(await value(`return new Bag().add("x").toArray()`)).toEqual(["x"])
+  test("a function inside a result is callable and crosses the same way", async () => {
+    requests.length = 0
+    expect(
+      await value(
+        `const res = await fetch("https://a.test/", { method: "GET" }); return [res.status, res.ok, res.headers.get("content-type"), res.text(), res.json(), [...res.bytes()].length, typeof res.json, res.json.name, res.handlers[0](1)]`,
+      ),
+    ).toEqual([
+      200,
+      true,
+      "application/json",
+      '{"url":"https://a.test/"}',
+      { url: "https://a.test/" },
+      25,
+      "function",
+      "json",
+      2,
+    ])
+    expect(requests).toEqual([["https://a.test/", { method: "GET" }]])
+  })
+
+  test("a function inside a result is named by its path in diagnostics", async () => {
+    expect((await failure(`const res = await fetch("https://a.test/"); res.handlers[0](() => 1)`)).message).toContain(
+      "Argument 1 to fetch.handlers[0] contains a function",
+    )
+    const target = CodeMode.make({
+      extensions: [Extension.make({ name: "odd", globals: { make: () => ({ sym: () => Symbol("s") }) } })],
+    })
+    expect((await failure(`make().sym()`, target)).message).toContain("make.sym produced a symbol")
+  })
+
+  test("a function is invisible to the data boundary like any program function", async () => {
+    expect(await value(`return await fetch("https://a.test/")`)).toEqual({
+      status: 200,
+      ok: true,
+      headers: {},
+      handlers: [null],
+    })
+    expect(await value(`return JSON.stringify((await fetch("https://a.test/")).headers)`)).toBe("{}")
+  })
+
+  test("a class global is only a function; calling it throws the host TypeError", async () => {
+    const target = CodeMode.make({ extensions: [Extension.make({ name: "cls", globals: { Bag: class Bag {} } })] })
+    expect((await failure(`Bag()`, target)).message).toContain("without")
+    expect((await failure(`new Bag()`, target)).message).toContain("new Bag(...) is not supported")
   })
 })
 
 describe("values are converted at the boundary, never shared", () => {
-  test("the same host instance is the same handle", async () => {
-    expect(
-      await value(`const b = new Bag(); const p = b.pair(); return [p.self === b, p.list[0] === b, keep(b) === b]`),
-    ).toEqual([true, true, true])
-    expect(await value(`const p = new Bag().pair(); return p.list[1] instanceof Bag`)).toBe(true)
-  })
-
   test("plain data passed in is a copy the program cannot change afterwards", async () => {
     held.length = 0
     await value(
@@ -163,8 +116,12 @@ describe("values are converted at the boundary, never shared", () => {
     expect(config).toEqual({ retries: 3, nested: { deep: true } })
   })
 
-  test("Map and Set contents are converted element-wise, so handles unwrap inside them", async () => {
-    expect(await value(`const b = new Bag(); return first(new Map([["k", b]])) === b`)).toBe(true)
+  test("the same host value returned twice is two program values", async () => {
+    expect(await value(`return settings() === settings()`)).toBe(false)
+    expect(await value(`return keep(settings()) === settings()`)).toBe(false)
+  })
+
+  test("Map and Set contents are converted element-wise", async () => {
     expect(await value(`return first(new Map([["k", { z: 1 }]]))`)).toEqual({ z: 1 })
     held.length = 0
     await value(`const inner = { z: 1 }; keep(new Set([inner])); inner.z = 2`)
@@ -214,6 +171,13 @@ describe("values are converted at the boundary, never shared", () => {
     expect(Object.keys(held[0] as object)).toEqual([])
   })
 
+  test("an Error with an unknown name crosses as a plain Error", async () => {
+    held.length = 0
+    await value(`const e = new Error("x"); e.name = "constructor"; keep(e); e.name = "__proto__"; keep(e)`)
+    expect(held[0]).toBeInstanceOf(Error)
+    expect(held[1]).toBeInstanceOf(Error)
+  })
+
   test("functions, promises, and symbols cannot be passed in", async () => {
     expect((await failure(`keep(() => 1)`)).message).toContain("Argument 1 to keep contains a function")
     expect((await failure(`keep(later(1))`)).message).toContain("un-awaited Promise")
@@ -228,82 +192,55 @@ describe("values are converted at the boundary, never shared", () => {
     expect((await failure(`big()`, target)).message).toContain("big produced a bigint")
   })
 
-  test("an instance of an unexposed class cannot come out", async () => {
-    expect((await failure(`new Bag().detached()`)).message).toContain("produced a Other, which the program cannot hold")
-  })
-
-  test("a getter must be synchronous", async () => {
-    expect((await failure(`new Bag().lazy`)).message).toContain("Bag.prototype.lazy returned a Promise")
-  })
-})
-
-describe("the host object behind a handle is unreachable", () => {
-  test("enumeration, spread, and JSON see no own properties", async () => {
-    expect(
-      await value(`const b = new Bag(["a"]); return [Object.keys(b), Object.entries({ ...b }), String(b)]`),
-    ).toEqual([[], [], "[object Object]"])
-  })
-
-  test("a handle cannot be returned, stringified, or handed to a tool", async () => {
-    expect(await failure(`return new Bag()`)).toMatchObject({ kind: "InvalidDataValue" })
-    expect((await failure(`return JSON.stringify(new Bag())`)).message).toContain("contains a Bag")
-    const tools = CodeMode.make({
-      extensions: [extension],
-      tools: {
-        echo: Tool.make({
-          description: "Echo",
-          input: Schema.Struct({ v: Schema.Unknown }),
-          output: Schema.Unknown,
-          execute: (input) => Effect.succeed(input.v),
-        }),
-      },
-    })
-    expect((await failure(`return await tools.echo({ v: new Bag() })`, tools)).message).toContain("contains a Bag")
-  })
-
-  test("a method only runs on a handle of its own class", async () => {
-    expect((await failure(`const add = new Bag().add; add("x")`)).message).toContain(
-      "Illegal invocation: Bag.prototype.add called on undefined",
-    )
-    expect((await failure(`const o = { add: Bag.prototype.add }; o.add("x")`)).message).toContain(
-      "called on a data object",
-    )
-    const vault = new Vault()
+  test("a value that cannot come out carries a location like any built-in error, sync or async", async () => {
     const target = CodeMode.make({
-      extensions: [Extension.make({ name: "vault", globals: { Bag, Vault, vault: () => vault } })],
+      extensions: [
+        Extension.make({ name: "odd", globals: { sym: () => Symbol("s"), later: async () => Symbol("s") } }),
+      ],
     })
-    expect((await failure(`const v = vault(); v.add = Bag.prototype.add; v.add("x")`, target)).message).toContain(
-      "Illegal invocation: Bag.prototype.add called on a Vault",
-    )
-    expect(vault.secrets.size).toBe(0)
+    expect((await failure(`sym()`, target)).location).toEqual((await failure(`JSON.parse("{")`, target)).location)
+    expect((await failure(`await later()`, target)).location).toBeDefined()
   })
 
-  test("reading an accessor off the prototype itself is an illegal invocation", async () => {
-    expect((await failure(`Bag.prototype.size`)).message).toContain("Illegal invocation")
+  test("a class instance cannot come out", async () => {
+    class Other {}
+    const target = CodeMode.make({
+      extensions: [Extension.make({ name: "odd", globals: { detached: () => new Other() } })],
+    })
+    expect((await failure(`detached()`, target)).message).toContain("produced a Other, which the program cannot hold")
   })
 })
 
 describe("host errors", () => {
   test("a synchronous throw becomes the matching program error", async () => {
-    expect(await value(`try { new Bag().fail() } catch (e) { return [e instanceof RangeError, e.message] }`)).toEqual([
+    const target = CodeMode.make({
+      extensions: [
+        Extension.make({
+          name: "odd",
+          globals: {
+            fail: () => {
+              throw new RangeError("boom")
+            },
+          },
+        }),
+      ],
+    })
+    expect(await value(`try { fail() } catch (e) { return [e instanceof RangeError, e.message] }`, target)).toEqual([
       true,
       "boom",
     ])
   })
 
   test("a thrown or rejected value crosses like a return, so the program catches what was thrown", async () => {
-    expect(
-      await value(
-        `try { await new Bag().reject(new TypeError("bad")) } catch (e) { return [e instanceof TypeError, e.message] }`,
-      ),
-    ).toEqual([true, "bad"])
-    expect(await value(`try { await new Bag().reject("plain") } catch (e) { return e }`)).toBe("plain")
     const reason = { status: 404, nested: { a: 1 } }
     const target = CodeMode.make({
       extensions: [
         Extension.make({
           name: "api",
           globals: {
+            reject: async (reason: unknown) => {
+              throw reason
+            },
             get: async () => Promise.reject(reason),
             boom: () => {
               throw reason
@@ -312,6 +249,13 @@ describe("host errors", () => {
         }),
       ],
     })
+    expect(
+      await value(
+        `try { await reject(new TypeError("bad")) } catch (e) { return [e instanceof TypeError, e.message] }`,
+        target,
+      ),
+    ).toEqual([true, "bad"])
+    expect(await value(`try { await reject("plain") } catch (e) { return e }`, target)).toBe("plain")
     expect(await value(`try { await get() } catch (e) { e.status = 0; return e }`, target)).toEqual({
       status: 0,
       nested: { a: 1 },
@@ -325,23 +269,45 @@ describe("host errors", () => {
 describe("configuration", () => {
   test("extension calls are not tool calls", async () => {
     const limited = CodeMode.make({ extensions: [extension], limits: { maxToolCalls: 0 } })
-    const result = await Effect.runPromise(limited.execute(`new Bag().add("x"); return await later(1)`))
+    const result = await Effect.runPromise(
+      limited.execute(`(await fetch("https://a.test/")).json(); return await later(1)`),
+    )
     expect(result.ok).toBe(true)
     expect(result.toolCalls).toEqual([])
   })
 
-  test("a global must be a class or a function", () => {
+  test("a result handed to a tool is plain data", async () => {
+    const tools = CodeMode.make({
+      extensions: [extension],
+      tools: {
+        echo: Tool.make({
+          description: "Echo",
+          input: Schema.Struct({ v: Schema.Unknown }),
+          output: Schema.Unknown,
+          execute: (input) => Effect.succeed(input.v),
+        }),
+      },
+    })
+    expect(await value(`return await tools.echo({ v: await fetch("https://a.test/") })`, tools)).toEqual({
+      status: 200,
+      ok: true,
+      headers: {},
+      handlers: [null],
+    })
+  })
+
+  test("a global must be a function", () => {
     expect(() => Extension.make({ name: "bad", globals: { n: 1 as never } })).toThrow(
-      'Extension "bad" global "n" must be a class or a function.',
+      'Extension "bad" global "n" must be a function.',
     )
   })
 
   test("a global may not shadow a built-in or another extension", () => {
-    expect(() => CodeMode.make({ extensions: [Extension.make({ name: "web", globals: { URL: class {} } })] })).toThrow(
+    expect(() => CodeMode.make({ extensions: [Extension.make({ name: "web", globals: { URL: () => 1 } })] })).toThrow(
       'Extension "web" global "URL" is already defined.',
     )
     expect(() =>
-      CodeMode.make({ extensions: [extension, Extension.make({ name: "again", globals: { Bag: class {} } })] }),
-    ).toThrow('Extension "again" global "Bag" is already defined.')
+      CodeMode.make({ extensions: [extension, Extension.make({ name: "again", globals: { fetch: () => 1 } })] }),
+    ).toThrow('Extension "again" global "fetch" is already defined.')
   })
 })

packages/codemode/test/generator-test262.test.ts

@@ -47,7 +47,7 @@ describe("confined generators", () => {
       { value: 2, done: false },
       { value: 4, done: false },
       { value: 7, done: true },
-      { value: null, done: true },
+      { done: true },
     ])
   })
 
@@ -84,7 +84,7 @@ describe("confined generators", () => {
         try { iterator.throw("second") } catch (error) { exhausted = error }
         return [suspended, exhausted, iterator.next()]
       `),
-    ).toEqual(["first", "second", { value: null, done: true }])
+    ).toEqual(["first", "second", { done: true }])
   })
 
   test("rejects synchronous generator reentry", async () => {
@@ -236,11 +236,7 @@ describe("confined generators", () => {
       `),
     ).toEqual([
       [true, true, true],
-      [
-        { value: 1, done: false },
-        { value: 3, done: true },
-        { value: null, done: true },
-      ],
+      [{ value: 1, done: false }, { value: 3, done: true }, { done: true }],
       ["start", "received 2"],
     ])
   })
@@ -339,7 +335,7 @@ describe("confined generators", () => {
       { value: 1, done: false },
       { value: "recovered", done: false },
       ["caught bad"],
-      { value: null, done: true },
+      { done: true },
       ["caught bad", "finally"],
     ])
   })
@@ -391,11 +387,8 @@ describe("confined generators", () => {
     ).toEqual([[1, 2], "TypeError"])
   })
 
-  test("keeps generator references opaque at the data boundary", async () => {
-    const result = await execute(`function* generate() { yield 1 } return generate()`)
-    expect(result.ok).toBe(false)
-    if (result.ok) return
-    expect(result.error.kind).toBe("InvalidDataValue")
+  test("a returned generator serializes as {} like JSON.stringify", async () => {
+    expect(await value(`function* generate() { yield 1 } return generate()`)).toEqual({})
   })
 
   // test/built-ins/GeneratorPrototype/return/from-state-suspended-start.js
@@ -421,14 +414,7 @@ describe("confined generators", () => {
 
         return [startReturn, afterReturn, startThrow, afterThrow, completedThrow, events]
       `),
-    ).toEqual([
-      { value: 7, done: true },
-      { value: null, done: true },
-      "start",
-      { value: null, done: true },
-      "completed",
-      [],
-    ])
+    ).toEqual([{ value: 7, done: true }, { done: true }, "start", { done: true }, "completed", []])
   })
 
   // test/built-ins/AsyncGeneratorPrototype/return/return-suspendedStart-promise.js
@@ -454,14 +440,7 @@ describe("confined generators", () => {
 
         return [startReturn, afterReturn, startThrow, afterThrow, completedThrow, events]
       `),
-    ).toEqual([
-      { value: 7, done: true },
-      { value: null, done: true },
-      "start",
-      { value: null, done: true },
-      "completed",
-      [],
-    ])
+    ).toEqual([{ value: 7, done: true }, { done: true }, "start", { done: true }, "completed", []])
   })
 
   // test/built-ins/AsyncGeneratorPrototype/return/return-suspendedYield-try-finally.js
@@ -512,7 +491,7 @@ describe("confined generators", () => {
         }
         return results
       `),
-    ).toEqual(["direct", { value: null, done: true }, "delegated", { value: null, done: true }])
+    ).toEqual(["direct", { done: true }, "delegated", { done: true }])
   })
 
   // test/built-ins/AsyncFromSyncIteratorPrototype/next/for-await-iterator-next-rejected-promise-close.js
@@ -1033,7 +1012,7 @@ describe("confined generators", () => {
     ).toBe("a=1")
   })
 
-  test("converts URLSearchParams pair elements before requesting the next", async () => {
+  test("coerces URLSearchParams pair elements like JS and closes both generators", async () => {
     expect(
       await value(`
         const events = []
@@ -1048,11 +1027,10 @@ describe("confined generators", () => {
         function* entries() {
           try { yield pair() } finally { events.push("outer close") }
         }
-        let name
-        try { new URLSearchParams(entries()) } catch (error) { name = error.name }
-        return [events, name]
+        const params = new URLSearchParams(entries())
+        return [events, params.toString()]
       `),
-    ).toEqual([["first", "pair close", "outer close"], "Error"])
+    ).toEqual([["first", "second", "pair close", "outer close"], "%5Bobject+Object%5D=2"])
   })
 
   test("validates URLSearchParams pair lengths after converting the outer sequence", async () => {