fix(core): preserve bounded tool receipts

packages/core/src/session/runner/llm.ts

@@ -172,17 +172,16 @@ const layer = Layer.effect(
                             callID: event.id,
                             output: update,
                           })
-                          if (
-                            typeof bounded.output.structured !== "object" ||
-                            bounded.output.structured === null ||
-                            Array.isArray(bounded.output.structured)
-                          )
-                            yield* Effect.die(new Error("Tool progress structured output must be an object"))
+                          const structured = bounded.output.structured
+                          const entries =
+                            typeof structured === "object" && structured !== null && !Array.isArray(structured)
+                              ? Object.entries(structured)
+                              : yield* Effect.die(new Error("Tool progress structured output must be an object"))
                           yield* events.publish(SessionEvent.Tool.Progress, {
                             sessionID: session.id,
                             assistantMessageID,
                             callID: event.id,
-                            structured: Object.fromEntries(Object.entries(bounded.output.structured)),
+                            structured: Object.fromEntries(entries),
                             content: [...bounded.output.content],
                           })
                         }).pipe(Effect.orDie),
@@ -275,6 +274,11 @@ const layer = Layer.effect(
             }
             yield* serialized(publisher.failAssistant(error))
           }
+          if (streamFailure instanceof ToolOutputStore.StorageError) {
+            const error = toSessionError(streamFailure)
+            yield* serialized(publisher.failUnsettledTools(error))
+            yield* serialized(publisher.failAssistant(error))
+          }
           // Provider error events only arrive from the stream, so the flag is final here.
           const providerFailed = publisher.hasProviderError()
 
@@ -301,8 +305,13 @@ const layer = Layer.effect(
           // settles so the model may recover. A typed infrastructure failure (tool output
           // could not be persisted) also fails the assistant and then fails the drain.
           const settledFailure = settledCauses.find((cause) => !Cause.hasInterrupts(cause) && !isUserDeclined(cause))
-          const infraError =
+          const typedError =
             settledFailure === undefined ? undefined : Option.getOrUndefined(Cause.findErrorOption(settledFailure))
+          const storageDefect = settledFailure?.reasons.find(
+            (reason) => Cause.isDieReason(reason) && reason.defect instanceof ToolOutputStore.StorageError,
+          )
+          const infraError =
+            typedError ?? (storageDefect && Cause.isDieReason(storageDefect) ? storageDefect.defect : undefined)
           if (settledFailure !== undefined) {
             const failure = infraError ?? Cause.squash(settledFailure)
             const error = toSessionError(failure)

packages/core/src/session/runner/publish-llm-event.ts

@@ -410,7 +410,6 @@ export const createLLMEventPublisher = (
           if (event.result.type === "error") return
           return yield* Effect.die(new Error(`Duplicate tool result: ${event.id}`))
         }
-        tool.settled = true
         const result = error ? { error } : settledOutput(event.output, event.result)
         const executed = event.providerExecuted === true || tool.providerExecuted
         const resultState = providerState(event.providerMetadata)
@@ -424,12 +423,13 @@ export const createLLMEventPublisher = (
             executed,
             resultState,
           })
+          tool.settled = true
           return
         }
         const bounded = yield* outputs.bound({
           sessionID: input.sessionID,
           callID: event.id,
-          output: result,
+          output: { ...result, structured: record(result.structured) },
         })
         yield* events.publish(SessionEvent.Tool.Success, {
           sessionID: input.sessionID,
@@ -437,10 +437,12 @@ export const createLLMEventPublisher = (
           callID: event.id,
           structured: record(bounded.output.structured),
           content: bounded.output.content,
+          // Provider-executed results remain verbatim for provider-history replay.
           ...(executed ? { result: event.result } : {}),
           executed,
           resultState,
         })
+        tool.settled = true
         return
       }
       case "tool-error": {

packages/core/src/tool/edit.ts

@@ -16,6 +16,7 @@ import { FSUtil } from "../fs-util"
 import { LocationMutation } from "../location-mutation"
 import { PermissionV2 } from "../permission"
 import { Tool } from "./tool"
+import { ToolStructured } from "./structured"
 
 export const name = "edit"
 
@@ -103,6 +104,15 @@ export const Plugin = {
                 "Replace exact text in one file. Relative paths resolve within the active Location. Absolute paths inside the Location are accepted. Explicit external absolute paths require external_directory approval before edit approval.",
               input: Input,
               output: Output,
+              structured: Output,
+              toStructuredOutput: ({ output }) =>
+                ToolStructured.fit((maximumBytes) => ({
+                  ...output,
+                  files: output.files.map((file) => ({
+                    ...file,
+                    patch: ToolStructured.truncate(file.patch, maximumBytes),
+                  })),
+                })),
               toModelOutput: ({ input, output }) => [
                 { type: "text", text: toModelOutput(output, input.oldString, input.newString) },
               ],

packages/core/src/tool/execute.ts

@@ -142,7 +142,7 @@ export const create = (registrations: ReadonlyMap<string, Registration>) => {
 }
 
 function codeModeTool(tool: AnyTool): AnyTool {
-  if ("jsonSchema" in tool) return tool
+  if ("jsonSchema" in tool || tool.codeModeOutput !== "output") return tool
   return { ...tool, structured: undefined }
 }
 

packages/core/src/tool/glob.ts

@@ -53,6 +53,7 @@ export const Plugin = {
             input: Input,
             output: Output,
             structured: StructuredOutput,
+            codeModeOutput: "output",
             toStructuredOutput: ({ output }) => ({ count: output.length }),
             toModelOutput: ({ output }) => [
               {

packages/core/src/tool/grep.ts

@@ -67,6 +67,7 @@ export const Plugin = {
             input: Input,
             output: Output,
             structured: StructuredOutput,
+            codeModeOutput: "output",
             toStructuredOutput: ({ output }) => ({ matches: output.length }),
             toModelOutput: ({ output }) => [
               {

packages/core/src/tool/patch.ts

@@ -11,6 +11,7 @@ import { LocationMutation } from "../location-mutation"
 import { Patch } from "../patch"
 import { PermissionV2 } from "../permission"
 import { Tool } from "./tool"
+import { ToolStructured } from "./structured"
 
 export const name = "patch"
 
@@ -72,6 +73,15 @@ export const Plugin = {
                 "Apply one patch containing add, update, and delete file operations. All targets are resolved and approved before target contents are read. Operations apply sequentially; if a later operation fails, earlier operations remain applied and the failure reports them explicitly. Moves and atomic rollback are not supported yet.",
               input: Input,
               output: Output,
+              structured: Output,
+              toStructuredOutput: ({ output }) =>
+                ToolStructured.fit((maximumBytes) => ({
+                  ...output,
+                  files: output.files.map((file) => ({
+                    ...file,
+                    patch: ToolStructured.truncate(file.patch, maximumBytes),
+                  })),
+                })),
               toModelOutput: ({ output }) => [{ type: "text", text: toModelOutput(output) }],
               execute: (input, context) => {
                 const applied: Array<typeof Applied.Type> = []

packages/core/src/tool/question.ts

@@ -7,6 +7,7 @@ import { Form } from "../form"
 import { PermissionV2 } from "../permission"
 import { QuestionV2 } from "../question"
 import { Tool } from "./tool"
+import { ToolStructured } from "./structured"
 
 export const name = "question"
 
@@ -63,6 +64,13 @@ export const Plugin = {
             description,
             input: Input,
             output: Output,
+            structured: Output,
+            toStructuredOutput: ({ output }) =>
+              ToolStructured.fit((maximumBytes) => ({
+                answers: output.answers.map((answers) =>
+                  answers.map((answer) => ToolStructured.truncate(answer, maximumBytes)),
+                ),
+              })),
             toModelOutput: ({ input, output }) => [
               { type: "text", text: toModelOutput(input.questions, output.answers) },
             ],

packages/core/src/tool/read.ts

@@ -74,6 +74,7 @@ export const Plugin = {
             input: Input,
             output: Output,
             structured: StructuredOutput,
+            codeModeOutput: "output",
             toStructuredOutput: ({ output }) => {
               if ("encoding" in output)
                 return {

packages/core/src/tool/registry.ts

@@ -118,8 +118,7 @@ const registryLayer = Layer.effect(
 
     const settleTool = Effect.fn("ToolRegistry.settleTool")(function* (input: ExecuteInput, tool: AnyTool) {
       // Hooks fire only for hosted/local tools; provider-executed calls never reach settleTool.
-      const propagateTruncation =
-        !("jsonSchema" in tool) && tool.structured !== undefined && tool.toStructuredOutput !== undefined
+      const propagateTruncation = !("jsonSchema" in tool) && tool.contentTruncation === true
       const beforeEvent: ToolHooks.BeforeEvent = {
         tool: input.call.name,
         sessionID: input.sessionID,
@@ -200,7 +199,6 @@ const registryLayer = Layer.effect(
             sessionID: input.sessionID,
             callID: input.call.id,
             output: afterEvent.output,
-            propagateTruncation,
           })
         : undefined
       const outputPaths = [

packages/core/src/tool/shell.ts

@@ -148,6 +148,7 @@ export const Plugin = {
             input: Input,
             output: Output,
             structured: StructuredOutput,
+            codeModeOutput: "output",
             toStructuredOutput: ({ output }) => ({
               truncated: output.truncated,
               ...(output.exit === undefined ? {} : { exit: output.exit }),

packages/core/src/tool/skill.ts

@@ -74,6 +74,8 @@ export const Plugin = {
             input: Input,
             output: Output,
             structured: StructuredOutput,
+            codeModeOutput: "output",
+            contentTruncation: true,
             toStructuredOutput: ({ output }) => ({
               name: output.name,
               directory: output.directory,

packages/core/src/tool/structured.ts

@@ -0,0 +1,39 @@
+export * as ToolStructured from "./structured"
+
+import { ToolOutputStore } from "../tool-output-store"
+
+export function fit<A>(project: (maxStringBytes: number) => A) {
+  const full = project(ToolOutputStore.MAX_STRUCTURED_BYTES)
+  if (Buffer.byteLength(JSON.stringify(full), "utf-8") <= ToolOutputStore.MAX_STRUCTURED_BYTES) return full
+
+  let minimum = 0
+  let maximum = ToolOutputStore.MAX_STRUCTURED_BYTES
+  let result = project(0)
+  while (minimum <= maximum) {
+    const middle = Math.floor((minimum + maximum) / 2)
+    const candidate = project(middle)
+    if (Buffer.byteLength(JSON.stringify(candidate), "utf-8") <= ToolOutputStore.MAX_STRUCTURED_BYTES) {
+      result = candidate
+      minimum = middle + 1
+      continue
+    }
+    maximum = middle - 1
+  }
+  return result
+}
+
+export function truncate(input: string, maximumBytes: number) {
+  if (Buffer.byteLength(input, "utf-8") <= maximumBytes) return input
+  const marker = " ... truncated ..."
+  const markerBytes = Buffer.byteLength(marker, "utf-8")
+  const available = Math.max(0, maximumBytes - markerBytes)
+  let bytes = 0
+  let end = 0
+  for (const char of input) {
+    const size = Buffer.byteLength(char, "utf-8")
+    if (bytes + size > available) break
+    bytes += size
+    end += char.length
+  }
+  return input.slice(0, end).replace(/\r?\n$/, "") + (maximumBytes >= markerBytes ? marker : "")
+}

packages/core/src/tool/subagent.ts

@@ -123,6 +123,7 @@ export const Plugin = {
             input: Input,
             output: Output,
             structured: StructuredOutput,
+            contentTruncation: true,
             toStructuredOutput: ({ output }) => ({
               sessionID: output.sessionID,
               status: output.status,

packages/core/src/tool/webfetch.ts

@@ -135,6 +135,8 @@ export const Plugin = {
             input: Input,
             output: Output,
             structured: StructuredOutput,
+            codeModeOutput: "output",
+            contentTruncation: true,
             toStructuredOutput: ({ input, output }) => ({
               url: output.url,
               contentType: output.contentType,

packages/core/src/tool/websearch.ts

@@ -209,6 +209,8 @@ export const Plugin = {
             input: Input,
             output: Output,
             structured: StructuredOutput,
+            codeModeOutput: "output",
+            contentTruncation: true,
             toStructuredOutput: ({ output }) => ({
               provider: output.provider,
               bytes: Buffer.byteLength(output.text, "utf-8"),

packages/core/test/session-runner-tool-events.test.ts

@@ -122,6 +122,45 @@ test("provider-executed success bounds output before durable publication", async
   })
 })
 
+test("normalizes structured output to its durable record shape before bounding", async () => {
+  const guarded: ToolOutputStore.BoundInput[] = []
+  const outputStore: Pick<ToolOutputStore.Interface, "bound"> = {
+    bound: (input) => Effect.sync(() => guarded.push(input)).pipe(Effect.as({ output: input.output, outputPaths: [] })),
+  }
+  const { publisher } = capture("anthropic", outputStore)
+  await Effect.runPromise(publisher.publish(call))
+  await Effect.runPromise(
+    publisher.publish(
+      LLMEvent.toolResult({
+        ...result,
+        output: { structured: "x".repeat(ToolOutputStore.MAX_STRUCTURED_BYTES - 2), content: [] },
+      }),
+    ),
+  )
+
+  expect(guarded[0]?.output.structured).toEqual({
+    value: "x".repeat(ToolOutputStore.MAX_STRUCTURED_BYTES - 2),
+  })
+})
+
+test("a bounding failure leaves the tool eligible for durable failure", async () => {
+  const storage = new ToolOutputStore.StorageError({ operation: "write", cause: new Error("disk full") })
+  const outputStore: Pick<ToolOutputStore.Interface, "bound"> = {
+    bound: () => Effect.fail(storage),
+  }
+  const { published, publisher } = capture("anthropic", outputStore)
+  await Effect.runPromise(publisher.publish(call))
+  const exit = await Effect.runPromiseExit(publisher.publish(result))
+  expect(exit._tag).toBe("Failure")
+
+  await Effect.runPromise(publisher.failUnsettledTools({ type: "unknown", message: storage.message }))
+  expect(published.some((event) => event.type === "session.tool.success.1")).toBe(false)
+  expect(published.find((event) => event.type === "session.tool.failed.1")?.data).toMatchObject({
+    callID: call.id,
+    error: { type: "unknown", message: storage.message },
+  })
+})
+
 test("provider metadata is flattened using the route key", async () => {
   const { published, publisher } = capture()
   await Effect.runPromise(

packages/core/test/tool-edit.test.ts

@@ -2,7 +2,8 @@ import fs from "fs/promises"
 import path from "path"
 import { fileURLToPath } from "url"
 import { describe, expect, test } from "bun:test"
-import { Effect, Layer } from "effect"
+import { Effect, Layer, Schema } from "effect"
+import { parsePatch } from "diff"
 import { AppNodeBuilder } from "@opencode-ai/core/effect/app-node-builder"
 import { LayerNode } from "@opencode-ai/core/effect/layer-node"
 import { FileMutation } from "@opencode-ai/core/file-mutation"
@@ -174,6 +175,45 @@ describe("EditTool", () => {
     ),
   )
 
+  it.live("retains a bounded patch for large edits", () =>
+    Effect.acquireUseRelease(
+      Effect.promise(() => tmpdir()),
+      (tmp) => {
+        reset()
+        const target = path.join(tmp.path, "large.txt")
+        const before = "x".repeat(9_000)
+        const after = "y".repeat(9_000)
+        return Effect.promise(() => fs.writeFile(target, before)).pipe(
+          Effect.andThen(
+            withTool(tmp.path, (registry) =>
+              Effect.gen(function* () {
+                const settled = yield* settleTool(
+                  registry,
+                  call({ path: "large.txt", oldString: before, newString: after }),
+                )
+                const structured = Schema.decodeUnknownSync(EditTool.Output)(settled.output?.structured)
+                expect(Buffer.byteLength(JSON.stringify(structured))).toBeLessThanOrEqual(
+                  ToolOutputStore.MAX_STRUCTURED_BYTES,
+                )
+                expect(() => parsePatch(structured.files[0]?.patch ?? "")).not.toThrow()
+                expect(structured).toMatchObject({
+                  replacements: 1,
+                  files: [
+                    {
+                      file: "large.txt",
+                      patch: expect.stringContaining("... truncated ..."),
+                    },
+                  ],
+                })
+              }),
+            ),
+          ),
+        )
+      },
+      (tmp) => Effect.promise(() => tmp[Symbol.asyncDispose]()),
+    ),
+  )
+
   it.live("accepts an absolute file path inside the active Location", () =>
     Effect.acquireUseRelease(
       Effect.promise(() => tmpdir()),

packages/core/test/tool-execute.test.ts

@@ -100,6 +100,7 @@ test("execute exposes typed internal output instead of the persisted receipt", a
     input: Schema.Struct({}),
     output: Schema.Struct({ content: Schema.String, bytes: Schema.Number }),
     structured: Schema.Struct({ bytes: Schema.Number }),
+    codeModeOutput: "output",
     toStructuredOutput: ({ output }) => ({ bytes: output.bytes }),
     toModelOutput: ({ output }) => [{ type: "text", text: output.content }],
     execute: () => Effect.succeed({ content: "full payload", bytes: 12 }),
@@ -127,3 +128,35 @@ test("execute exposes typed internal output instead of the persisted receipt", a
   expect(result.structured).toEqual({ toolCalls: [{ tool: "fetch", status: "completed" }] })
   expect(result.content).toEqual([{ type: "text", text: "full payload" }])
 })
+
+test("execute keeps the structured projection unless a tool opts into internal output", async () => {
+  const child = Tool.make({
+    description: "Fetch content",
+    input: Schema.Struct({}),
+    output: Schema.Struct({ content: Schema.String, bytes: Schema.Number }),
+    structured: Schema.Struct({ bytes: Schema.Number }),
+    toStructuredOutput: ({ output }) => ({ bytes: output.bytes }),
+    execute: () => Effect.succeed({ content: "internal", bytes: 8 }),
+  })
+  const execute = ExecuteTool.create(new Map([["fetch", { tool: child, name: "fetch" }]]))
+  const result = await Effect.runPromise(
+    Tool.settle(
+      execute,
+      {
+        type: "tool-call",
+        id: "call_execute",
+        name: "execute",
+        input: { code: "return await tools.fetch({})" },
+      },
+      {
+        sessionID: Session.ID.make("ses_execute"),
+        agent: Agent.ID.make("build"),
+        messageID: SessionMessage.ID.make("msg_execute"),
+        callID: "call_execute",
+        progress: () => Effect.void,
+      },
+    ),
+  )
+
+  expect(result.content).toEqual([{ type: "text", text: '{\n  "bytes": 8\n}' }])
+})

packages/core/test/tool-patch.test.ts

@@ -1,7 +1,8 @@
 import fs from "fs/promises"
 import path from "path"
 import { describe, expect } from "bun:test"
-import { Deferred, Effect, Exit, Fiber, Layer } from "effect"
+import { Deferred, Effect, Exit, Fiber, Layer, Schema } from "effect"
+import { parsePatch } from "diff"
 import { AppNodeBuilder } from "@opencode-ai/core/effect/app-node-builder"
 import { LayerNode } from "@opencode-ai/core/effect/layer-node"
 import { FileMutation } from "@opencode-ai/core/file-mutation"
@@ -217,6 +218,40 @@ describe("PatchTool", () => {
     ),
   )
 
+  it.live("retains a bounded patch for large changes", () =>
+    Effect.acquireUseRelease(
+      Effect.promise(() => tmpdir()),
+      (tmp) => {
+        reset()
+        const target = path.join(tmp.path, "large.txt")
+        const before = "x".repeat(9_000)
+        const after = "y".repeat(9_000)
+        return Effect.promise(() => fs.writeFile(target, `${before}\n`)).pipe(
+          Effect.andThen(
+            withTool(tmp.path, (registry) =>
+              Effect.gen(function* () {
+                const settled = yield* settleTool(
+                  registry,
+                  call(`*** Begin Patch\n*** Update File: large.txt\n@@\n-${before}\n+${after}\n*** End Patch`),
+                )
+                const structured = Schema.decodeUnknownSync(PatchTool.Output)(settled.output?.structured)
+                expect(Buffer.byteLength(JSON.stringify(structured))).toBeLessThanOrEqual(
+                  ToolOutputStore.MAX_STRUCTURED_BYTES,
+                )
+                expect(() => parsePatch(structured.files[0]?.patch ?? "")).not.toThrow()
+                expect(structured).toMatchObject({
+                  applied: [{ type: "update", resource: "large.txt" }],
+                  files: [{ file: "large.txt", patch: expect.stringContaining("... truncated ...") }],
+                })
+              }),
+            ),
+          ),
+        )
+      },
+      (tmp) => Effect.promise(() => tmp[Symbol.asyncDispose]()),
+    ),
+  )
+
   it.live("rejects moves before applying any hunk", () =>
     Effect.acquireUseRelease(
       Effect.promise(() => tmpdir()),

packages/core/test/tool-question.test.ts

@@ -19,6 +19,7 @@ const assertions: PermissionV2.AssertInput[] = []
 let captured: Form.CreateInput | undefined
 let reject = false
 let deny = false
+let firstAnswer = "Build"
 const capturedInput = () => captured
 const questionInput = {
   questions: [
@@ -63,7 +64,7 @@ const form = Layer.succeed(
         Effect.andThen(
           Effect.sync(
             (): Form.TerminalState =>
-              reject ? { status: "cancelled" } : { status: "answered", answer: { q0: "Build", q1: ["Dev"] } },
+              reject ? { status: "cancelled" } : { status: "answered", answer: { q0: firstAnswer, q1: ["Dev"] } },
           ),
         ),
       ),
@@ -122,6 +123,7 @@ describe("QuestionTool", () => {
       captured = undefined
       reject = false
       deny = false
+      firstAnswer = "Build"
       const registry = yield* ToolRegistry.Service
       const questions = [
         {
@@ -200,6 +202,27 @@ describe("QuestionTool", () => {
     }),
   )
 
+  it.effect("retains bounded answers for long custom responses", () =>
+    Effect.gen(function* () {
+      reject = false
+      deny = false
+      firstAnswer = "x".repeat(ToolOutputStore.MAX_STRUCTURED_BYTES)
+      const registry = yield* ToolRegistry.Service
+      const settled = yield* settleTool(registry, {
+        sessionID,
+        ...toolIdentity,
+        call: { type: "tool-call", id: "call-question-large", name: "question", input: questionInput },
+      })
+
+      expect(Buffer.byteLength(JSON.stringify(settled.output?.structured))).toBeLessThanOrEqual(
+        ToolOutputStore.MAX_STRUCTURED_BYTES,
+      )
+      expect(settled.output?.structured).toMatchObject({
+        answers: [[expect.stringContaining("... truncated ...")]],
+      })
+    }).pipe(Effect.ensuring(Effect.sync(() => (firstAnswer = "Build")))),
+  )
+
   it.effect("does not invent tool ownership metadata without a durable registry source", () =>
     Effect.gen(function* () {
       captured = undefined

packages/plugin/src/v2/effect/tool.ts

@@ -97,6 +97,10 @@ export type Definition<
   readonly input: Input
   readonly output: Output
   readonly structured?: Structured
+  /** Expose encoded output to CodeMode instead of the persisted structured projection. */
+  readonly codeModeOutput?: "output"
+  /** Mark a receipt's `truncated` field when its model-facing text is bounded. */
+  readonly contentTruncation?: true
   readonly permission?: string
   readonly toStructuredOutput?: (input: {
     readonly input: InputValue<Input>