test(codemode): widen the test262 baseline to all implemented built-ins and expressions

2026-09-12 11:56:23 +00:00 · 2026-09-11 10:47:09 -05:00
197 changed files with 4358 additions and 3039 deletions
@@ -25,7 +25,7 @@ on:
        required: false
        type: string

-concurrency: ${{ github.workflow }}-${{ github.ref }}-${{ (github.ref_name == 'v2' && (inputs.version || inputs.bump) && 'release') || inputs.version || inputs.bump }}
+concurrency: ${{ github.workflow }}-${{ github.ref }}-${{ inputs.version || inputs.bump }}

 permissions:
  id-token: write
@@ -33,7 +33,7 @@ permissions:
  packages: write

 env:
-  OPENCODE_CHANNEL: ${{ (github.ref_name == 'v2' && !inputs.bump && !inputs.version && 'dev') || '' }}
+  OPENCODE_CHANNEL: ${{ (github.ref_name == 'v2' && 'dev') || '' }}

 jobs:
  version:
@@ -168,7 +168,7 @@ jobs:
          fi

          found=0
-          for file in packages/cli/dist/cli-darwin-*/bin/opencode; do
+          for file in packages/cli/dist/cli-darwin-*/bin/opencode2; do
            if [ ! -f "$file" ]; then
              continue
            fi
@@ -191,7 +191,7 @@ jobs:

      - uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
        with:
-          name: opencode-preview-cli-macos
+          name: opencode-preview-cli
          path: packages/cli/dist/cli-*
          if-no-files-found: error

@@ -199,7 +199,7 @@ jobs:
    needs: version
    runs-on: blacksmith-4vcpu-ubuntu-2404
    timeout-minutes: 30
-    if: github.repository == 'anomalyco/opencode' && !(github.ref_name == 'v2' && (inputs.bump || inputs.version))
+    if: github.repository == 'anomalyco/opencode'
    steps:
      - uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0

@@ -221,7 +221,7 @@ jobs:
    needs:
      - version
      - build-node-app-archive
-    if: github.repository == 'anomalyco/opencode' && !(github.ref_name == 'v2' && (inputs.bump || inputs.version))
+    if: github.repository == 'anomalyco/opencode'
    strategy:
      fail-fast: false
      matrix:
@@ -276,9 +276,10 @@ jobs:

  sign-cli-windows:
    needs:
-      - sign-cli-macos
+      - build-cli
+      - version
    runs-on: blacksmith-4vcpu-windows-2025
-    if: github.repository == 'anomalyco/opencode' && (github.ref_name == 'v2' || github.ref_name == 'beta')
+    if: github.repository == 'anomalyco/opencode' && github.ref_name != 'v2' && github.ref_name != 'beta'
    env:
      AZURE_CLIENT_ID: ${{ secrets.AZURE_CLIENT_ID }}
      AZURE_TENANT_ID: ${{ secrets.AZURE_TENANT_ID }}
@@ -291,8 +292,15 @@ jobs:

      - uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
        with:
-          name: opencode-preview-cli-macos
-          path: packages/cli/dist
+          name: opencode-cli-windows
+          path: packages/opencode/dist
+
+      - name: Setup git committer
+        id: committer
+        uses: ./.github/actions/setup-git-committer
+        with:
+          opencode-app-id: ${{ vars.OPENCODE_APP_ID }}
+          opencode-app-secret: ${{ secrets.OPENCODE_APP_SECRET }}

      - name: Azure login
        uses: azure/login@a457da9ea143d694b1b9c7c869ebb04ebe844ef5 # v2.3.0
@@ -307,9 +315,9 @@ jobs:
          signing-account-name: ${{ env.AZURE_TRUSTED_SIGNING_ACCOUNT_NAME }}
          certificate-profile-name: ${{ env.AZURE_TRUSTED_SIGNING_CERTIFICATE_PROFILE }}
          files: |
-            ${{ github.workspace }}\packages\cli\dist\cli-windows-arm64\bin\opencode.exe
-            ${{ github.workspace }}\packages\cli\dist\cli-windows-x64\bin\opencode.exe
-            ${{ github.workspace }}\packages\cli\dist\cli-windows-x64-baseline\bin\opencode.exe
+            ${{ github.workspace }}\packages\opencode\dist\opencode-windows-arm64\bin\opencode.exe
+            ${{ github.workspace }}\packages\opencode\dist\opencode-windows-x64\bin\opencode.exe
+            ${{ github.workspace }}\packages\opencode\dist\opencode-windows-x64-baseline\bin\opencode.exe
          exclude-environment-credential: true
          exclude-workload-identity-credential: true
          exclude-managed-identity-credential: true
@@ -325,9 +333,9 @@ jobs:
        shell: pwsh
        run: |
          $files = @(
-            "${{ github.workspace }}\packages\cli\dist\cli-windows-arm64\bin\opencode.exe",
-            "${{ github.workspace }}\packages\cli\dist\cli-windows-x64\bin\opencode.exe",
-            "${{ github.workspace }}\packages\cli\dist\cli-windows-x64-baseline\bin\opencode.exe"
+            "${{ github.workspace }}\packages\opencode\dist\opencode-windows-arm64\bin\opencode.exe",
+            "${{ github.workspace }}\packages\opencode\dist\opencode-windows-x64\bin\opencode.exe",
+            "${{ github.workspace }}\packages\opencode\dist\opencode-windows-x64-baseline\bin\opencode.exe"
          )

          foreach ($file in $files) {
@@ -337,17 +345,40 @@ jobs:
            }
          }

+      - name: Repack Windows CLI archives
+        working-directory: packages/opencode/dist
+        shell: pwsh
+        run: |
+          Compress-Archive -Path "opencode-windows-arm64\bin\*" -DestinationPath "opencode-windows-arm64.zip" -Force
+          Compress-Archive -Path "opencode-windows-x64\bin\*" -DestinationPath "opencode-windows-x64.zip" -Force
+          Compress-Archive -Path "opencode-windows-x64-baseline\bin\*" -DestinationPath "opencode-windows-x64-baseline.zip" -Force
+
+      - name: Upload signed Windows CLI release assets
+        if: needs.version.outputs.release != ''
+        shell: pwsh
+        env:
+          GH_TOKEN: ${{ steps.committer.outputs.token }}
+        run: |
+          gh release upload "v${{ needs.version.outputs.version }}" `
+            "${{ github.workspace }}\packages\opencode\dist\opencode-windows-arm64.zip" `
+            "${{ github.workspace }}\packages\opencode\dist\opencode-windows-x64.zip" `
+            "${{ github.workspace }}\packages\opencode\dist\opencode-windows-x64-baseline.zip" `
+            --clobber `
+            --repo "${{ needs.version.outputs.repo }}"
+
      - uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
        with:
-          name: opencode-preview-cli
-          path: packages/cli/dist/cli-*
-          if-no-files-found: error
+          name: opencode-cli-signed-windows
+          path: |
+            packages/opencode/dist/opencode-windows-arm64
+            packages/opencode/dist/opencode-windows-x64
+            packages/opencode/dist/opencode-windows-x64-baseline

  build-electron:
    needs:
      - version
-      - sign-cli-windows
-    if: github.repository == 'anomalyco/opencode' && (github.ref_name != 'v2' || needs.version.outputs.release != '')
+      - sign-cli-macos
+    if: github.repository == 'anomalyco/opencode' && github.ref_name != 'v2'
    continue-on-error: false
    env:
      AZURE_CLIENT_ID: ${{ secrets.AZURE_CLIENT_ID }}
@@ -8,9 +8,9 @@

 ## Live V2 TUI Testing

- Run `bun run dev:live` from a development worktree to test its TUI against the currently elected `opencode` background server and live sessions.
+- Run `bun run dev:live` from a development worktree to test its TUI against the currently elected `opencode2` background server and live sessions.
 - Pass a directory after the script when needed, for example `bun run dev:live /path/to/project`.
- The script discovers the server with `opencode service status`, injects its private local credential from `opencode service get password`, and uses the `dev` TUI storage channel so tabs and other client-local state match the installed client.
+- The script discovers the server with `opencode2 service status`, injects its private local credential from `opencode2 service get password`, and uses the `dev` TUI storage channel so tabs and other client-local state match the installed client.
 - Prefer `dev:live` over plain `bun run dev` for this workflow. An implicit managed-service connection may replace the live server when the worktree client version differs; explicit `--server` warns and continues without replacing it.

 ## V2 TUI Stories
@@ -31,7 +31,7 @@
    },
    "packages/ai": {
      "name": "@opencode/ai",
-      "version": "2.0.0",
+      "version": "1.17.20",
      "dependencies": {
        "@aws-sdk/credential-providers": "3.1057.0",
        "@opencode/schema": "workspace:*",
@@ -53,7 +53,7 @@
    },
    "packages/app": {
      "name": "@opencode/app",
-      "version": "2.0.0",
+      "version": "1.18.15",
      "dependencies": {
        "@corvu/drawer": "catalog:",
        "@dnd-kit/abstract": "0.5.0",
@@ -111,7 +111,7 @@
    },
    "packages/cli": {
      "name": "@opencode/cli",
-      "version": "2.0.0",
+      "version": "1.18.4",
      "bin": {
        "opencode2": "./bin/opencode2.cjs",
      },
@@ -175,7 +175,7 @@
    },
    "packages/client": {
      "name": "@opencode/client",
-      "version": "2.0.0",
+      "version": "1.17.13",
      "dependencies": {
        "@opencode/protocol": "workspace:*",
        "@opencode/schema": "workspace:*",
@@ -201,7 +201,7 @@
    },
    "packages/codemode": {
      "name": "@opencode/codemode",
-      "version": "2.0.0",
+      "version": "1.18.4",
      "dependencies": {
        "acorn": "8.15.0",
        "effect": "catalog:",
@@ -215,7 +215,7 @@
    },
    "packages/console/app": {
      "name": "@opencode/console-app",
-      "version": "2.0.0",
+      "version": "1.18.15",
      "dependencies": {
        "@cloudflare/vite-plugin": "1.15.2",
        "@ibm/plex": "6.4.1",
@@ -251,7 +251,7 @@
    },
    "packages/console/core": {
      "name": "@opencode/console-core",
-      "version": "2.0.0",
+      "version": "1.18.15",
      "dependencies": {
        "@aws-sdk/client-sts": "3.782.0",
        "@jsx-email/render": "1.1.1",
@@ -278,7 +278,7 @@
    },
    "packages/console/function": {
      "name": "@opencode/console-function",
-      "version": "2.0.0",
+      "version": "1.18.15",
      "dependencies": {
        "@openauthjs/openauth": "0.0.0-20250322224806",
        "@opencode/console-core": "workspace:*",
@@ -295,7 +295,7 @@
    },
    "packages/console/mail": {
      "name": "@opencode/console-mail",
-      "version": "2.0.0",
+      "version": "1.18.15",
      "dependencies": {
        "@jsx-email/all": "2.2.3",
        "@jsx-email/cli": "1.4.3",
@@ -319,7 +319,7 @@
    },
    "packages/console/support": {
      "name": "@opencode/console-support",
-      "version": "2.0.0",
+      "version": "1.18.15",
      "dependencies": {
        "@cloudflare/vite-plugin": "1.15.2",
        "@opencode/console-core": "workspace:*",
@@ -339,7 +339,7 @@
    },
    "packages/core": {
      "name": "@opencode/core",
-      "version": "2.0.0",
+      "version": "1.18.4",
      "dependencies": {
        "@ai-sdk/alibaba": "1.0.17",
        "@ai-sdk/anthropic": "3.0.82",
@@ -411,7 +411,7 @@
    },
    "packages/desktop": {
      "name": "@opencode/desktop",
-      "version": "2.0.0",
+      "version": "1.18.15",
      "dependencies": {
        "@zip.js/zip.js": "2.7.62",
        "electron-context-menu": "4.1.2",
@@ -463,7 +463,7 @@
    },
    "packages/enterprise": {
      "name": "@opencode/enterprise",
-      "version": "2.0.0",
+      "version": "1.18.15",
      "dependencies": {
        "@hono/standard-validator": "catalog:",
        "@opencode-ai/sdk": "1.18.21",
@@ -500,7 +500,7 @@
    },
    "packages/function": {
      "name": "@opencode/function",
-      "version": "2.0.0",
+      "version": "1.18.15",
      "dependencies": {
        "@octokit/auth-app": "8.0.1",
        "@octokit/rest": "catalog:",
@@ -516,7 +516,7 @@
    },
    "packages/http-recorder": {
      "name": "@opencode/http-recorder",
-      "version": "2.0.0",
+      "version": "1.18.15",
      "dependencies": {
        "@effect/platform-node-shared": "4.0.0-rc.112",
      },
@@ -535,7 +535,7 @@
    },
    "packages/httpapi-codegen": {
      "name": "@opencode/httpapi-codegen",
-      "version": "2.0.0",
+      "version": "0.0.0",
      "dependencies": {
        "effect": "catalog:",
        "prettier": "3.6.2",
@@ -548,7 +548,7 @@
    },
    "packages/latex": {
      "name": "@opencode/latex",
-      "version": "2.0.0",
+      "version": "0.0.0",
      "dependencies": {
        "@opencode/plugin": "workspace:*",
        "@opentui/core": "catalog:",
@@ -562,7 +562,7 @@
    },
    "packages/merman": {
      "name": "@opencode/merman",
-      "version": "2.0.0",
+      "version": "0.0.0",
      "dependencies": {
        "@opencode/plugin": "workspace:*",
        "@opentui/core": "catalog:",
@@ -577,7 +577,7 @@
    },
    "packages/plugin": {
      "name": "@opencode/plugin",
-      "version": "2.0.0",
+      "version": "1.18.15",
      "dependencies": {
        "@ai-sdk/provider": "3.0.8",
        "@opencode/ai": "workspace:*",
@@ -616,7 +616,7 @@
    },
    "packages/plugin-browser": {
      "name": "@opencode/plugin-browser",
-      "version": "2.0.0",
+      "version": "0.0.0",
      "dependencies": {
        "@opencode/plugin": "workspace:*",
        "@opencode/schema": "workspace:*",
@@ -646,7 +646,7 @@
    },
    "packages/protocol": {
      "name": "@opencode/protocol",
-      "version": "2.0.0",
+      "version": "1.17.11",
      "dependencies": {
        "@opencode/schema": "workspace:*",
        "effect": "catalog:",
@@ -661,7 +661,7 @@
    },
    "packages/schema": {
      "name": "@opencode/schema",
-      "version": "2.0.0",
+      "version": "1.17.11",
      "dependencies": {
        "@standard-schema/spec": "catalog:",
        "effect": "catalog:",
@@ -685,7 +685,7 @@
    },
    "packages/sdk": {
      "name": "@opencode/sdk",
-      "version": "2.0.0",
+      "version": "1.18.4",
      "dependencies": {
        "@opencode/client": "workspace:*",
        "@opencode/core": "workspace:*",
@@ -706,7 +706,7 @@
    },
    "packages/server": {
      "name": "@opencode/server",
-      "version": "2.0.0",
+      "version": "1.18.4",
      "dependencies": {
        "@effect/platform-node": "catalog:",
        "@effect/platform-node-shared": "catalog:",
@@ -728,7 +728,7 @@
    },
    "packages/session-ui": {
      "name": "@opencode/session-ui",
-      "version": "2.0.0",
+      "version": "1.18.15",
      "dependencies": {
        "@kobalte/core": "catalog:",
        "@opencode/client": "workspace:*",
@@ -763,7 +763,7 @@
    },
    "packages/simulation": {
      "name": "@opencode/simulation",
-      "version": "2.0.0",
+      "version": "1.17.13",
      "dependencies": {
        "@opencode/ai": "workspace:*",
        "@opencode/core": "workspace:*",
@@ -783,7 +783,7 @@
    },
    "packages/stats/app": {
      "name": "@opencode/stats-app",
-      "version": "2.0.0",
+      "version": "1.18.15",
      "dependencies": {
        "@ibm/plex": "6.4.1",
        "@kobalte/core": "catalog:",
@@ -817,7 +817,7 @@
    },
    "packages/stats/core": {
      "name": "@opencode/stats-core",
-      "version": "2.0.0",
+      "version": "1.18.15",
      "dependencies": {
        "@aws-sdk/client-athena": "3.933.0",
        "@planetscale/database": "1.19.0",
@@ -836,7 +836,7 @@
    },
    "packages/stats/server": {
      "name": "@opencode/stats-server",
-      "version": "2.0.0",
+      "version": "1.18.15",
      "dependencies": {
        "@aws-sdk/client-firehose": "3.933.0",
        "@effect/platform-node": "catalog:",
@@ -882,7 +882,7 @@
    },
    "packages/theme": {
      "name": "@opencode/theme",
-      "version": "2.0.0",
+      "version": "0.0.0",
      "dependencies": {
        "@opentui/core": "catalog:",
        "effect": "catalog:",
@@ -896,7 +896,7 @@
    },
    "packages/tui": {
      "name": "@opencode/tui",
-      "version": "2.0.0",
+      "version": "1.18.4",
      "dependencies": {
        "@opencode/client": "workspace:*",
        "@opencode/core": "workspace:*",
@@ -931,7 +931,7 @@
    },
    "packages/ui": {
      "name": "@opencode/ui",
-      "version": "2.0.0",
+      "version": "1.18.15",
      "dependencies": {
        "@kobalte/core": "catalog:",
        "@pierre/diffs": "catalog:",
@@ -966,7 +966,7 @@
    },
    "packages/util": {
      "name": "@opencode/util",
-      "version": "2.0.0",
+      "version": "1.18.3",
      "dependencies": {
        "@effect/opentelemetry": "catalog:",
        "@effect/platform-node": "catalog:",
@@ -999,7 +999,7 @@
    },
    "packages/web": {
      "name": "@opencode/web",
-      "version": "2.0.0",
+      "version": "1.18.15",
      "dependencies": {
        "@astrojs/cloudflare": "12.6.3",
        "@astrojs/markdown-remark": "6.3.1",
@@ -1040,7 +1040,7 @@
    },
    "services/update": {
      "name": "@opencode/update",
-      "version": "2.0.0",
+      "version": "1.18.4",
      "dependencies": {
        "jose": "6.0.11",
        "semver": "catalog:",
@@ -1,7 +1,6 @@
 #!/usr/bin/env bash
 set -euo pipefail
-APP=opencode
-SOURCE_APP=opencode
+APP=opencode2

 MUTED='\033[0;2m'
 RED='\033[0;31m'
@@ -23,7 +22,7 @@ Options:
 Examples:
    curl -fsSL https://opencode.ai/v2/install | bash
    curl -fsSL https://opencode.ai/v2/install | bash -s -- --version 0.0.0-beta-17236
-    ./install --binary /path/to/opencode
+    ./install --binary /path/to/opencode2
 EOF
 }

@@ -202,9 +201,9 @@ else

    filename="cli-$target-$specific_version.tgz"
    url="https://registry.npmjs.org/$package_name/-/$filename"
-    binary_name="$SOURCE_APP"
+    binary_name="$APP"
    if [ "$os" = "windows" ]; then
-        binary_name="$SOURCE_APP.exe"
+        binary_name="$APP.exe"
    fi
 fi

@@ -231,7 +230,12 @@ check_version() {
        installed_version="${installed_version##* }"
        installed_version="${installed_version#v}"

-        print_message info "${MUTED}Installed version: ${NC}$installed_version."
+        if [[ "$installed_version" != "$specific_version" ]]; then
+            print_message info "${MUTED}Installed version: ${NC}$installed_version."
+        else
+            print_message info "${MUTED}Version ${NC}$specific_version${MUTED} already installed"
+            exit 0
+        fi
    fi
 }

@@ -336,46 +340,15 @@ download_and_install() {
    fi

    tar -xzf "$tmp_dir/$filename" -C "$tmp_dir"
-    local installed_binary="$APP"
-    if [ "$os" = "windows" ]; then
-        installed_binary="$APP.exe"
-    fi
-    mv "$tmp_dir/package/bin/$binary_name" "$INSTALL_DIR/$installed_binary"
-    chmod 755 "$INSTALL_DIR/$installed_binary"
+    mv "$tmp_dir/package/bin/$binary_name" "$INSTALL_DIR"
+    chmod 755 "${INSTALL_DIR}/$binary_name"
    rm -rf "$tmp_dir"
 }

 install_from_binary() {
    print_message info "\n${MUTED}Installing ${NC}$APP ${MUTED}from: ${NC}$binary_path"
-    local installed_binary="$APP"
-    case "$(uname -s)" in
-        MINGW*|MSYS*|CYGWIN*) installed_binary="$APP.exe" ;;
-    esac
-    cp "$binary_path" "$INSTALL_DIR/$installed_binary"
-    chmod 755 "$INSTALL_DIR/$installed_binary"
-}
-
-install_legacy_shim() {
-    local shim_os="${os:-}"
-    if [[ -z "$shim_os" ]]; then
-        case "$(uname -s)" in
-            MINGW*|MSYS*|CYGWIN*) shim_os="windows" ;;
-        esac
-    fi
-    rm -f "$INSTALL_DIR/opencode2" "$INSTALL_DIR/opencode2.exe" "$INSTALL_DIR/opencode2.cmd"
-    if [[ "$shim_os" == "windows" ]]; then
-        cat > "$INSTALL_DIR/opencode2.cmd" <<'EOF'
-@echo off
-"%~dp0opencode.exe" %*
-exit /b %errorlevel%
-EOF
-        return
-    fi
-    cat > "$INSTALL_DIR/opencode2" <<'EOF'
-#!/bin/sh
-exec "$(dirname "$0")/opencode" "$@"
-EOF
-    chmod 755 "$INSTALL_DIR/opencode2"
+    cp "$binary_path" "${INSTALL_DIR}/$APP"
+    chmod 755 "${INSTALL_DIR}/$APP"
 }

 if [ -n "$binary_path" ]; then
@@ -384,7 +357,6 @@ else
    check_version
    download_and_install
 fi
-install_legacy_shim


 add_to_path() {
@@ -481,7 +453,7 @@ echo -e ""
 echo -e "${MUTED}OpenCode includes free models, to start:${NC}"
 echo -e ""
 echo -e "cd <project>  ${MUTED}# Open directory${NC}"
-echo -e "opencode      ${MUTED}# Run command${NC}"
+echo -e "opencode2     ${MUTED}# Run command${NC}"
 echo -e ""
 echo -e "${MUTED}For more information visit ${NC}https://opencode.ai/v2/docs"
 echo -e ""
@@ -2,15 +2,15 @@
  "$schema": "https://json.schemastore.org/package.json",
  "name": "opencode",
  "description": "AI-powered development tool",
-  "version": "2.0.0",
+  "version": "0.0.0",
  "private": true,
  "type": "module",
  "packageManager": "bun@1.4.2",
  "scripts": {
    "dev": "bun run --cwd packages/cli src/index.ts",
-    "dev:live": "sh -c 'OPENCODE_TUI_CHANNEL=dev OPENCODE_PASSWORD=\"$(opencode service get password)\" exec bun run dev \"$@\" --server \"$(opencode service status)\"' --",
+    "dev:live": "sh -c 'OPENCODE_TUI_CHANNEL=dev OPENCODE_PASSWORD=\"$(opencode2 service get password)\" exec bun run dev \"$@\" --server \"$(opencode2 service status)\"' --",
    "dev:vite": "bun run --cwd packages/cli --conditions=browser dev/vite.ts",
-    "dev:vite:live": "sh -c 'OPENCODE_TUI_CHANNEL=dev OPENCODE_PASSWORD=\"$(opencode service get password)\" exec bun run dev:vite \"$@\" --server \"$(opencode service status)\"' --",
+    "dev:vite:live": "sh -c 'OPENCODE_TUI_CHANNEL=dev OPENCODE_PASSWORD=\"$(opencode2 service get password)\" exec bun run dev:vite \"$@\" --server \"$(opencode2 service status)\"' --",
    "dev:desktop": "bun --cwd packages/desktop dev",
    "dev:web": "bun --cwd packages/app dev",
    "dev:console": "ulimit -n 10240 2>/dev/null; bun run --cwd packages/console/app dev",
@@ -122,14 +122,13 @@ Keep provider facades small and explicit:

 ### Provider Package Entrypoints

-Catalog-selected native providers use package-like export paths from `@opencode/ai`. They are internal entrypoints in one npm package, not separately published provider packages. Every entrypoint implements `ProviderPackage.Definition` and exposes `model(modelID, settings)`, where settings are one flat serializable object: the connection keys the entrypoint declares (`apiKey`, `baseURL`, `region`, …), the common `headers` and `body` overlays, and the protocol's request options (`reasoningEffort`, `thinking`, …) side by side. Each entrypoint destructures its own connection keys and passes the rest to the route as `providerOptions`; there is no nested `providerOptions` at the entrypoint.
+Catalog-selected native providers use package-like export paths from `@opencode/ai`. They are internal entrypoints in one npm package, not separately published provider packages. Every entrypoint implements `ProviderPackage.Definition` and exposes `model(modelID, settings)`, where settings are serializable provider configuration plus common `headers`, `body`, and `limits` overlays.

 ```ts
 import { model } from "@opencode/ai/providers/openai/responses"

 const selected = model("gpt-5", {
  apiKey,
-  reasoningEffort: "high",
 })
 ```

@@ -1,6 +1,6 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
-  "version": "2.0.0",
+  "version": "1.17.20",
  "name": "@opencode/ai",
  "type": "module",
  "license": "MIT",
@@ -1708,10 +1708,7 @@ export const transport = <
 }

 function requiredBetaHeaders(body: Pick<AnthropicMessagesBody, "messages" | "context_management" | "thinking">) {
-  // Always request interleaved thinking. The API accepts the header on any
-  // model and ignores it where unsupported, while manual-thinking models need
-  // it for thinking between tool calls.
-  const betas: string[] = ["interleaved-thinking-2025-05-14"]
+  const betas: string[] = []
  const requestsCompaction = (body.context_management?.edits.length ?? 0) > 0
  const replaysCompaction = body.messages.some((message) =>
    message.content.some((block) => block.type === "compaction"),
@@ -1,10 +1,6 @@
 import type { LanguageModel, ProviderOptions } from "./schema/index.js"
 import type { CompactionOperations } from "./route/client.js"

-/**
- * Flat, serializable settings for `model(modelID, settings)`. Each entrypoint declares the connection keys it
- * reads; every other key is a request option for the route's protocol.
- */
 export interface Settings extends Readonly<Record<string, unknown>> {
  readonly baseURL?: string
  readonly headers?: Readonly<Record<string, string>>
@@ -1,4 +1,3 @@
-import { Struct } from "effect"
 import type { ProviderPackage } from "../provider-package.js"
 import { AlibabaChat } from "../protocols/alibaba-chat.js"
 import { AlibabaMessages } from "../protocols/alibaba-messages.js"
@@ -35,9 +34,9 @@ export type Config = Location &
    readonly providerOptions?: ChatOptionsInput | MessagesOptionsInput | ResponsesOptionsInput
  }
 export type Settings<Options = ChatOptionsInput> = Location &
-  ProviderPackage.Settings &
-  Options & {
+  ProviderPackage.Settings & {
    readonly apiKey?: string
+    readonly providerOptions?: Options
  }

 const hosts = new Map<string, string>([
@@ -121,11 +120,7 @@ export const responsesModel: ProviderPackage.Definition<

 function fromSettings(input: Settings<Config["providerOptions"]>) {
  const { body, ...rest } = input
-  return configure({
-    ...rest,
-    http: body === undefined ? undefined : { body },
-    providerOptions: Struct.omit(rest, ["apiKey", "baseURL", "headers", "region", "workspaceID"]),
-  })
+  return configure({ ...rest, http: body === undefined ? undefined : { body } })
 }

 export const webSearch = () => hostedTool("web_search", "Search the web with Alibaba's hosted search tool.")
@@ -23,16 +23,16 @@ export type Config = RouteDefaultsInput & {
  readonly providerOptions?: OpenAIProviderOptionsInput
 }

-export type Settings = ProviderPackage.Settings &
-  OpenAIProviderOptionsInput & {
-    readonly apiKey?: string
-    readonly auth?: "bearer" | "sigv4"
-    readonly baseURL?: string
-    readonly credentials?: Credentials
-    readonly profile?: string
-    readonly region?: string
-    readonly topP?: number
-  }
+export interface Settings extends ProviderPackage.Settings {
+  readonly apiKey?: string
+  readonly auth?: "bearer" | "sigv4"
+  readonly baseURL?: string
+  readonly credentials?: Credentials
+  readonly profile?: string
+  readonly region?: string
+  readonly topP?: number
+  readonly providerOptions?: OpenAIProviderOptionsInput
+}

 const responsesRoute = Route.make({
  id: "bedrock-mantle-responses",
@@ -108,29 +108,18 @@ export const configure = (input: Config = {}) => {

 export const provider = configure()

-const fromSettings = ({
-  apiKey,
-  auth,
-  baseURL,
-  body,
-  credentials,
-  headers,
-  profile,
-  region,
-  topP,
-  ...providerOptions
-}: Settings) =>
+const fromSettings = (settings: Settings) =>
  configure({
-    apiKey,
-    auth,
-    baseURL,
-    credentials,
-    generation: topP === undefined ? undefined : { topP },
-    headers: headers === undefined ? undefined : { ...headers },
-    http: body === undefined ? undefined : { body: { ...body } },
-    profile,
-    providerOptions,
-    region,
+    apiKey: settings.apiKey,
+    auth: settings.auth,
+    baseURL: settings.baseURL,
+    credentials: settings.credentials,
+    generation: settings.topP === undefined ? undefined : { topP: settings.topP },
+    headers: settings.headers === undefined ? undefined : { ...settings.headers },
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    profile: settings.profile,
+    providerOptions: settings.providerOptions,
+    region: settings.region,
  })

 export const chatModel: ProviderPackage.Definition<Settings, OpenAIProviderOptionsInput>["model"] = (
@@ -19,13 +19,13 @@ export type Config = RouteDefaultsInput &
  }

 export type Settings = ProviderPackage.Settings &
-  AnthropicMessages.ProviderOptionsInput &
  (
    | { readonly apiKey?: string; readonly authToken?: never }
    | { readonly apiKey?: never; readonly authToken?: string }
  ) & {
    readonly baseURL: string
    readonly provider?: string
+    readonly providerOptions?: AnthropicMessages.ProviderOptionsInput
  }

 export const routes = [AnthropicMessages.route]
@@ -63,20 +63,22 @@ export const provider = {

 export const model: ProviderPackage.Definition<Settings, AnthropicMessages.ProviderOptionsInput>["model"] = (
  modelID,
-  { apiKey, authToken, baseURL, body, headers, provider, ...providerOptions },
+  settings,
 ) => {
-  if (apiKey !== undefined && authToken !== undefined)
+  // Read before the exclusivity check narrows a conflicting settings object to `never`.
+  const provider = ProviderID.make(settings.provider ?? id)
+  if (settings.apiKey !== undefined && settings.authToken !== undefined)
    throw new ProviderConfigurationError({
-      provider: ProviderID.make(provider ?? id),
+      provider,
      message: "Anthropic-compatible apiKey cannot be combined with authToken",
    })
  return configure({
-    ...(authToken === undefined ? { apiKey: apiKey } : { auth: Auth.bearer(authToken) }),
-    baseURL,
-    headers: headers === undefined ? undefined : { ...headers },
-    http: body === undefined ? undefined : { body: { ...body } },
-    provider,
-    providerOptions,
+    ...(settings.authToken === undefined ? { apiKey: settings.apiKey } : { auth: Auth.bearer(settings.authToken) }),
+    baseURL: settings.baseURL,
+    headers: settings.headers === undefined ? undefined : { ...settings.headers },
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    provider: settings.provider,
+    providerOptions: settings.providerOptions,
  }).model(modelID)
 }

@@ -21,12 +21,12 @@ export type Config = RouteDefaultsInput &
  }

 export type Settings = ProviderPackage.Settings &
-  AnthropicMessages.ProviderOptionsInput &
  (
    | { readonly apiKey?: string; readonly authToken?: never }
    | { readonly apiKey?: never; readonly authToken?: string }
  ) & {
    readonly baseURL?: string
+    readonly providerOptions?: AnthropicMessages.ProviderOptionsInput
  }

 const auth = (options: ProviderAuthOption<"optional">) => {
@@ -54,18 +54,18 @@ export const configure = (input: Config = {}) => {
 export const provider = configure()
 export const model: ProviderPackage.Definition<Settings, AnthropicMessages.ProviderOptionsInput>["model"] = (
  modelID,
-  { apiKey, authToken, baseURL, body, headers, ...providerOptions },
+  settings,
 ) => {
-  if (apiKey !== undefined && authToken !== undefined)
+  if (settings.apiKey !== undefined && settings.authToken !== undefined)
    throw new ProviderConfigurationError({
      provider: id,
      message: "Anthropic apiKey cannot be combined with authToken",
    })
  return configure({
-    ...(authToken === undefined ? { apiKey: apiKey } : { auth: Auth.bearer(authToken) }),
-    baseURL,
-    headers: headers === undefined ? undefined : { ...headers },
-    http: body === undefined ? undefined : { body: { ...body } },
-    providerOptions,
+    ...(settings.authToken === undefined ? { apiKey: settings.apiKey } : { auth: Auth.bearer(settings.authToken) }),
+    baseURL: settings.baseURL,
+    headers: settings.headers === undefined ? undefined : { ...settings.headers },
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    providerOptions: settings.providerOptions,
  }).model(modelID)
 }
@@ -28,12 +28,12 @@ export type LanguageModelOptions = AzureURL &
 export type Config = LanguageModelOptions

 export type Settings = ProviderPackage.Settings &
-  OpenAIProviderOptionsInput &
  AzureURL & {
    readonly apiKey?: string
    readonly apiVersion?: string
    readonly queryParams?: Readonly<Record<string, string>>
    readonly useDeploymentBasedUrls?: boolean
+    readonly providerOptions?: OpenAIProviderOptionsInput
  }

 const resourceBaseURL = (resourceName: string) => `https://${resourceName.trim()}.openai.azure.com/openai`
@@ -151,28 +151,18 @@ export const provider = {
  configure,
 }

-const config = ({
-  apiKey,
-  apiVersion,
-  baseURL,
-  body,
-  headers,
-  queryParams,
-  resourceName,
-  useDeploymentBasedUrls,
-  ...providerOptions
-}: Settings): Config => {
+const config = (settings: Settings): Config => {
  const common = {
-    apiKey,
-    apiVersion,
-    headers: headers === undefined ? undefined : { ...headers },
-    http: body === undefined ? undefined : { body: { ...body } },
-    providerOptions,
-    queryParams: queryParams === undefined ? undefined : { ...queryParams },
-    useDeploymentBasedUrls,
+    apiKey: settings.apiKey,
+    apiVersion: settings.apiVersion,
+    headers: settings.headers === undefined ? undefined : { ...settings.headers },
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    providerOptions: settings.providerOptions,
+    queryParams: settings.queryParams === undefined ? undefined : { ...settings.queryParams },
+    useDeploymentBasedUrls: settings.useDeploymentBasedUrls,
  }
-  if (baseURL !== undefined) return { ...common, baseURL }
-  if (resourceName !== undefined) return { ...common, resourceName }
+  if (settings.baseURL !== undefined) return { ...common, baseURL: settings.baseURL }
+  if (settings.resourceName !== undefined) return { ...common, resourceName: settings.resourceName }
  throw new ProviderConfigurationError({ provider: id, message: "Azure requires resourceName or baseURL" })
 }

@@ -15,11 +15,11 @@ export type LanguageModelOptions = Omit<RouteDefaultsInput, "providerOptions"> &
    readonly providerOptions?: OpenAIProviderOptionsInput
  }

-export type Settings = ProviderPackage.Settings &
-  OpenAIProviderOptionsInput & {
-    readonly apiKey?: string
-    readonly baseURL?: string
-  }
+export interface Settings extends ProviderPackage.Settings {
+  readonly apiKey?: string
+  readonly baseURL?: string
+  readonly providerOptions?: OpenAIProviderOptionsInput
+}

 export const route = Route.make({
  id: "baseten-chat",
@@ -48,16 +48,13 @@ export const configure = (input: LanguageModelOptions = {}) => {

 export const provider = configure()

-export const model: ProviderPackage.Definition<Settings, OpenAIProviderOptionsInput>["model"] = (
-  modelID,
-  { apiKey, baseURL, body, headers, ...providerOptions },
-) =>
+export const model: ProviderPackage.Definition<Settings, OpenAIProviderOptionsInput>["model"] = (modelID, settings) =>
  configure({
-    apiKey,
-    baseURL,
-    headers: headers === undefined ? undefined : { ...headers },
-    http: body === undefined ? undefined : { body: { ...body } },
-    providerOptions,
+    apiKey: settings.apiKey,
+    baseURL: settings.baseURL,
+    headers: settings.headers === undefined ? undefined : { ...settings.headers },
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    providerOptions: settings.providerOptions,
  }).model(modelID)

 export * as Baseten from "./baseten.js"
@@ -15,11 +15,11 @@ export type LanguageModelOptions = Omit<RouteDefaultsInput, "providerOptions"> &
    readonly providerOptions?: OpenAIProviderOptionsInput
  }

-export type Settings = ProviderPackage.Settings &
-  OpenAIProviderOptionsInput & {
-    readonly apiKey?: string
-    readonly baseURL?: string
-  }
+export interface Settings extends ProviderPackage.Settings {
+  readonly apiKey?: string
+  readonly baseURL?: string
+  readonly providerOptions?: OpenAIProviderOptionsInput
+}

 export const route = Route.make({
  id: "cerebras-chat",
@@ -52,14 +52,11 @@ export const configure = (input: LanguageModelOptions = {}) => {

 export const provider = configure()

-export const model: ProviderPackage.Definition<Settings, OpenAIProviderOptionsInput>["model"] = (
-  modelID,
-  { apiKey, baseURL, body, headers, ...providerOptions },
-) =>
+export const model: ProviderPackage.Definition<Settings, OpenAIProviderOptionsInput>["model"] = (modelID, settings) =>
  configure({
-    apiKey,
-    baseURL,
-    headers: headers === undefined ? undefined : { ...headers },
-    http: body === undefined ? undefined : { body: { ...body } },
-    providerOptions,
+    apiKey: settings.apiKey,
+    baseURL: settings.baseURL,
+    headers: settings.headers === undefined ? undefined : { ...settings.headers },
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    providerOptions: settings.providerOptions,
  }).model(modelID)
@@ -27,10 +27,10 @@ export type LanguageModelOptions = GatewayURL &
  }

 export type Settings = ProviderPackage.Settings &
-  OpenAIProviderOptionsInput &
  GatewayURL & {
    readonly apiKey?: string
    readonly gatewayApiKey?: string
+    readonly providerOptions?: OpenAIProviderOptionsInput
  }

 export const baseURL = (input: GatewayURL) => {
@@ -89,25 +89,14 @@ export const configure = (input: LanguageModelOptions) => {

 export const provider = { id, configure }

-export const model: ProviderPackage.Definition<Settings, OpenAIProviderOptionsInput>["model"] = (modelID, settings) => {
-  const {
-    accountId: _,
-    apiKey,
-    baseURL: _url,
-    body,
-    gatewayApiKey,
-    gatewayId: _id,
-    headers,
-    ...providerOptions
-  } = settings
-  return configure({
-    apiKey,
-    gatewayApiKey,
+export const model: ProviderPackage.Definition<Settings, OpenAIProviderOptionsInput>["model"] = (modelID, settings) =>
+  configure({
+    apiKey: settings.apiKey,
+    gatewayApiKey: settings.gatewayApiKey,
    baseURL: baseURL(settings),
-    headers: headers === undefined ? undefined : { ...headers },
-    http: body === undefined ? undefined : { body: { ...body } },
-    providerOptions,
+    headers: settings.headers === undefined ? undefined : { ...settings.headers },
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    providerOptions: settings.providerOptions,
  }).model(modelID)
-}

 export * as CloudflareAIGateway from "./cloudflare-ai-gateway.js"
@@ -21,9 +21,9 @@ export type LanguageModelOptions = WorkersAIURL &
  }

 export type Settings = ProviderPackage.Settings &
-  OpenAIProviderOptionsInput &
  WorkersAIURL & {
    readonly apiKey?: string
+    readonly providerOptions?: OpenAIProviderOptionsInput
  }

 export const baseURL = (input: WorkersAIURL) => {
@@ -63,15 +63,13 @@ export const configure = (input: LanguageModelOptions) => {

 export const provider = { id, configure }

-export const model: ProviderPackage.Definition<Settings, OpenAIProviderOptionsInput>["model"] = (modelID, settings) => {
-  const { accountId: _, apiKey, baseURL: _url, body, headers, ...providerOptions } = settings
-  return configure({
-    apiKey,
+export const model: ProviderPackage.Definition<Settings, OpenAIProviderOptionsInput>["model"] = (modelID, settings) =>
+  configure({
+    apiKey: settings.apiKey,
    baseURL: baseURL(settings),
-    headers: headers === undefined ? undefined : { ...headers },
-    http: body === undefined ? undefined : { body: { ...body } },
-    providerOptions,
+    headers: settings.headers === undefined ? undefined : { ...settings.headers },
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    providerOptions: settings.providerOptions,
  }).model(modelID)
-}

 export * as CloudflareWorkersAI from "./cloudflare-workers-ai.js"
@@ -15,11 +15,11 @@ export type LanguageModelOptions = Omit<RouteDefaultsInput, "providerOptions"> &
    readonly providerOptions?: OpenAIProviderOptionsInput
  }

-export type Settings = ProviderPackage.Settings &
-  OpenAIProviderOptionsInput & {
-    readonly apiKey?: string
-    readonly baseURL?: string
-  }
+export interface Settings extends ProviderPackage.Settings {
+  readonly apiKey?: string
+  readonly baseURL?: string
+  readonly providerOptions?: OpenAIProviderOptionsInput
+}

 export const route = Route.make({
  id: "deepinfra-chat",
@@ -55,14 +55,11 @@ export const configure = (input: LanguageModelOptions = {}) => {

 export const provider = configure()

-export const model: ProviderPackage.Definition<Settings, OpenAIProviderOptionsInput>["model"] = (
-  modelID,
-  { apiKey, baseURL, body, headers, ...providerOptions },
-) =>
+export const model: ProviderPackage.Definition<Settings, OpenAIProviderOptionsInput>["model"] = (modelID, settings) =>
  configure({
-    apiKey,
-    baseURL,
-    headers: headers === undefined ? undefined : { ...headers },
-    http: body === undefined ? undefined : { body: { ...body } },
-    providerOptions,
+    apiKey: settings.apiKey,
+    baseURL: settings.baseURL,
+    headers: settings.headers === undefined ? undefined : { ...settings.headers },
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    providerOptions: settings.providerOptions,
  }).model(modelID)
@@ -15,11 +15,11 @@ export type LanguageModelOptions = Omit<RouteDefaultsInput, "providerOptions"> &
    readonly providerOptions?: OpenAIProviderOptionsInput
  }

-export type Settings = ProviderPackage.Settings &
-  OpenAIProviderOptionsInput & {
-    readonly apiKey?: string
-    readonly baseURL?: string
-  }
+export interface Settings extends ProviderPackage.Settings {
+  readonly apiKey?: string
+  readonly baseURL?: string
+  readonly providerOptions?: OpenAIProviderOptionsInput
+}

 export const route = Route.make({
  id: "deepseek-chat",
@@ -52,16 +52,13 @@ export const configure = (input: LanguageModelOptions = {}) => {

 export const provider = configure()

-export const model: ProviderPackage.Definition<Settings, OpenAIProviderOptionsInput>["model"] = (
-  modelID,
-  { apiKey, baseURL, body, headers, ...providerOptions },
-) =>
+export const model: ProviderPackage.Definition<Settings, OpenAIProviderOptionsInput>["model"] = (modelID, settings) =>
  configure({
-    apiKey,
-    baseURL,
-    headers: headers === undefined ? undefined : { ...headers },
-    http: body === undefined ? undefined : { body: { ...body } },
-    providerOptions,
+    apiKey: settings.apiKey,
+    baseURL: settings.baseURL,
+    headers: settings.headers === undefined ? undefined : { ...settings.headers },
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    providerOptions: settings.providerOptions,
  }).model(modelID)

 export * as DeepSeek from "./deepseek.js"
@@ -15,11 +15,11 @@ export type LanguageModelOptions = Omit<RouteDefaultsInput, "providerOptions"> &
    readonly providerOptions?: OpenAIProviderOptionsInput
  }

-export type Settings = ProviderPackage.Settings &
-  OpenAIProviderOptionsInput & {
-    readonly apiKey?: string
-    readonly baseURL?: string
-  }
+export interface Settings extends ProviderPackage.Settings {
+  readonly apiKey?: string
+  readonly baseURL?: string
+  readonly providerOptions?: OpenAIProviderOptionsInput
+}

 export const route = Route.make({
  id: "fireworks-chat",
@@ -48,16 +48,13 @@ export const configure = (input: LanguageModelOptions = {}) => {

 export const provider = configure()

-export const model: ProviderPackage.Definition<Settings, OpenAIProviderOptionsInput>["model"] = (
-  modelID,
-  { apiKey, baseURL, body, headers, ...providerOptions },
-) =>
+export const model: ProviderPackage.Definition<Settings, OpenAIProviderOptionsInput>["model"] = (modelID, settings) =>
  configure({
-    apiKey,
-    baseURL,
-    headers: headers === undefined ? undefined : { ...headers },
-    http: body === undefined ? undefined : { body: { ...body } },
-    providerOptions,
+    apiKey: settings.apiKey,
+    baseURL: settings.baseURL,
+    headers: settings.headers === undefined ? undefined : { ...settings.headers },
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    providerOptions: settings.providerOptions,
  }).model(modelID)

 export * as Fireworks from "./fireworks.js"
@@ -16,14 +16,14 @@ export type Config = RouteDefaultsInput &
    readonly providerOptions?: OpenAIProviderOptionsInput
  }

-export type Settings = ProviderPackage.Settings &
-  OpenAIProviderOptionsInput & {
-    readonly accessToken?: string
-    readonly apiKey?: never
-    readonly baseURL?: string
-    readonly location?: string
-    readonly project?: string
-  }
+export interface Settings extends ProviderPackage.Settings {
+  readonly accessToken?: string
+  readonly apiKey?: never
+  readonly baseURL?: string
+  readonly location?: string
+  readonly project?: string
+  readonly providerOptions?: OpenAIProviderOptionsInput
+}

 const route = Route.make({
  id: "google-vertex-chat",
@@ -74,19 +74,16 @@ export const provider = {
  configure,
 }

-export const model: ProviderPackage.Definition<Settings, OpenAIProviderOptionsInput>["model"] = (
-  modelID,
-  { accessToken, apiKey, baseURL, body, headers, location, project, ...providerOptions },
-) => {
-  if (apiKey !== undefined)
+export const model: ProviderPackage.Definition<Settings, OpenAIProviderOptionsInput>["model"] = (modelID, settings) => {
+  if (settings.apiKey !== undefined)
    throw new ProviderConfigurationError({ provider: id, message: "Google Vertex Chat does not support API keys" })
  return configure({
-    accessToken,
-    baseURL,
-    headers: headers === undefined ? undefined : { ...headers },
-    http: body === undefined ? undefined : { body: { ...body } },
-    location,
-    project,
-    providerOptions,
+    accessToken: settings.accessToken,
+    baseURL: settings.baseURL,
+    headers: settings.headers === undefined ? undefined : { ...settings.headers },
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    location: settings.location,
+    project: settings.project,
+    providerOptions: settings.providerOptions,
  }).model(modelID)
 }
@@ -25,14 +25,14 @@ export type Config = RouteDefaultsInput &
    readonly providerOptions?: AnthropicMessages.ProviderOptionsInput
  }

-export type Settings = ProviderPackage.Settings &
-  AnthropicMessages.ProviderOptionsInput & {
-    readonly accessToken?: string
-    readonly apiKey?: never
-    readonly baseURL?: string
-    readonly location?: string
-    readonly project?: string
-  }
+export interface Settings extends ProviderPackage.Settings {
+  readonly accessToken?: string
+  readonly apiKey?: never
+  readonly baseURL?: string
+  readonly location?: string
+  readonly project?: string
+  readonly providerOptions?: AnthropicMessages.ProviderOptionsInput
+}

 const route = Route.make({
  id: "google-vertex-messages",
@@ -105,17 +105,17 @@ export const provider = {

 export const model: ProviderPackage.Definition<Settings, AnthropicMessages.ProviderOptionsInput>["model"] = (
  modelID,
-  { accessToken, apiKey, baseURL, body, headers, location, project, ...providerOptions },
+  settings,
 ) => {
-  if (apiKey !== undefined)
+  if (settings.apiKey !== undefined)
    throw new ProviderConfigurationError({ provider: id, message: "Google Vertex Messages does not support API keys" })
  return configure({
-    accessToken,
-    baseURL,
-    headers: headers === undefined ? undefined : { ...headers },
-    http: body === undefined ? undefined : { body: { ...body } },
-    location,
-    project,
-    providerOptions,
+    accessToken: settings.accessToken,
+    baseURL: settings.baseURL,
+    headers: settings.headers === undefined ? undefined : { ...settings.headers },
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    location: settings.location,
+    project: settings.project,
+    providerOptions: settings.providerOptions,
  }).model(modelID)
 }
@@ -16,14 +16,14 @@ export type Config = RouteDefaultsInput &
    readonly providerOptions?: OpenResponsesProviderOptionsInput
  }

-export type Settings = ProviderPackage.Settings &
-  OpenResponsesProviderOptionsInput & {
-    readonly accessToken?: string
-    readonly apiKey?: never
-    readonly baseURL?: string
-    readonly location?: string
-    readonly project?: string
-  }
+export interface Settings extends ProviderPackage.Settings {
+  readonly accessToken?: string
+  readonly apiKey?: never
+  readonly baseURL?: string
+  readonly location?: string
+  readonly project?: string
+  readonly providerOptions?: OpenResponsesProviderOptionsInput
+}

 const route = Route.make({
  id: "google-vertex-responses",
@@ -77,17 +77,17 @@ export const provider = {

 export const model: ProviderPackage.Definition<Settings, OpenResponsesProviderOptionsInput>["model"] = (
  modelID,
-  { accessToken, apiKey, baseURL, body, headers, location, project, ...providerOptions },
+  settings,
 ) => {
-  if (apiKey !== undefined)
+  if (settings.apiKey !== undefined)
    throw new ProviderConfigurationError({ provider: id, message: "Google Vertex Responses does not support API keys" })
  return configure({
-    accessToken,
-    baseURL,
-    headers: headers === undefined ? undefined : { ...headers },
-    http: body === undefined ? undefined : { body: { ...body } },
-    location,
-    project,
-    providerOptions,
+    accessToken: settings.accessToken,
+    baseURL: settings.baseURL,
+    headers: settings.headers === undefined ? undefined : { ...settings.headers },
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    location: settings.location,
+    project: settings.project,
+    providerOptions: settings.providerOptions,
  }).model(modelID)
 }
@@ -26,7 +26,6 @@ export type Config = RouteDefaultsInput &
  }

 export type Settings = ProviderPackage.Settings &
-  GeminiProviderOptionsInput &
  (
    | { readonly accessToken?: string; readonly apiKey?: never }
    | { readonly accessToken?: never; readonly apiKey?: string }
@@ -34,6 +33,7 @@ export type Settings = ProviderPackage.Settings &
    readonly baseURL?: string
    readonly location?: string
    readonly project?: string
+    readonly providerOptions?: GeminiProviderOptionsInput
  }

 const fromRequest = Effect.fn("GoogleVertex.fromRequest")(function* (request: LLMRequest) {
@@ -124,22 +124,19 @@ export const provider = {
  id,
  configure,
 }
-export const model: ProviderPackage.Definition<Settings, GeminiProviderOptionsInput>["model"] = (
-  modelID,
-  { accessToken, apiKey, baseURL, body, headers, location, project, ...providerOptions },
-) => {
-  if (apiKey !== undefined && accessToken !== undefined)
+export const model: ProviderPackage.Definition<Settings, GeminiProviderOptionsInput>["model"] = (modelID, settings) => {
+  if (settings.apiKey !== undefined && settings.accessToken !== undefined)
    throw new ProviderConfigurationError({
      provider: id,
      message: "Google Vertex apiKey cannot be combined with accessToken or auth",
    })
  return configure({
-    ...(apiKey === undefined ? { accessToken: accessToken } : { apiKey: apiKey }),
-    baseURL,
-    headers: headers === undefined ? undefined : { ...headers },
-    http: body === undefined ? undefined : { body: { ...body } },
-    location,
-    project,
-    providerOptions,
+    ...(settings.apiKey === undefined ? { accessToken: settings.accessToken } : { apiKey: settings.apiKey }),
+    baseURL: settings.baseURL,
+    headers: settings.headers === undefined ? undefined : { ...settings.headers },
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    location: settings.location,
+    project: settings.project,
+    providerOptions: settings.providerOptions,
  }).model(modelID)
 }
@@ -20,11 +20,11 @@ export type Config = RouteDefaultsInput &
    readonly providerOptions?: Gemini.ProviderOptionsInput
  }

-export type Settings = ProviderPackage.Settings &
-  Gemini.ProviderOptionsInput & {
-    readonly apiKey?: string
-    readonly baseURL?: string
-  }
+export interface Settings extends ProviderPackage.Settings {
+  readonly apiKey?: string
+  readonly baseURL?: string
+  readonly providerOptions?: Gemini.ProviderOptionsInput
+}

 const auth = (options: ProviderAuthOption<"optional">) => {
  if ("auth" in options && options.auth) return options.auth
@@ -57,16 +57,13 @@ export const configure = (input: Config = {}) => {
 }

 export const provider = configure()
-export const model: ProviderPackage.Definition<Settings, Gemini.ProviderOptionsInput>["model"] = (
-  modelID,
-  { apiKey, baseURL, body, headers, ...providerOptions },
-) =>
+export const model: ProviderPackage.Definition<Settings, Gemini.ProviderOptionsInput>["model"] = (modelID, settings) =>
  configure({
-    apiKey,
-    baseURL,
-    headers: headers === undefined ? undefined : { ...headers },
-    http: body === undefined ? undefined : { body: { ...body } },
-    providerOptions,
+    apiKey: settings.apiKey,
+    baseURL: settings.baseURL,
+    headers: settings.headers === undefined ? undefined : { ...settings.headers },
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    providerOptions: settings.providerOptions,
  }).model(modelID)

 export const image = provider.image
@@ -26,11 +26,11 @@ export type LanguageModelOptions = Omit<RouteDefaultsInput, "providerOptions"> &
    readonly providerOptions?: ProviderOptions
  }

-export type Settings = ProviderPackage.Settings &
-  ProviderOptions & {
-    readonly apiKey?: string
-    readonly baseURL?: string
-  }
+export interface Settings extends ProviderPackage.Settings {
+  readonly apiKey?: string
+  readonly baseURL?: string
+  readonly providerOptions?: ProviderOptions
+}

 const Options = Schema.Struct({
  includeReasoning: Schema.optional(Schema.Boolean),
@@ -103,16 +103,13 @@ export const configure = (input: LanguageModelOptions = {}) => {

 export const provider = configure()

-export const model: ProviderPackage.Definition<Settings, ProviderOptions>["model"] = (
-  modelID,
-  { apiKey, baseURL, body, headers, ...providerOptions },
-) =>
+export const model: ProviderPackage.Definition<Settings, ProviderOptions>["model"] = (modelID, settings) =>
  configure({
-    apiKey,
-    baseURL,
-    headers: headers === undefined ? undefined : { ...headers },
-    http: body === undefined ? undefined : { body: { ...body } },
-    providerOptions,
+    apiKey: settings.apiKey,
+    baseURL: settings.baseURL,
+    headers: settings.headers === undefined ? undefined : { ...settings.headers },
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    providerOptions: settings.providerOptions,
  }).model(modelID)

 export * as Groq from "./groq.js"
@@ -79,11 +79,11 @@ export type LanguageModelOptions = Omit<RouteDefaultsInput, "providerOptions"> &
    readonly providerOptions?: ProviderOptionsInput
  }

-export type Settings = ProviderPackage.Settings &
-  ProviderOptionsInput & {
-    readonly apiKey?: string
-    readonly baseURL?: string
-  }
+export interface Settings extends ProviderPackage.Settings {
+  readonly apiKey?: string
+  readonly baseURL?: string
+  readonly providerOptions?: ProviderOptionsInput
+}

 const responsesRoute = Route.make({
  id: "meta-responses",
@@ -169,13 +169,13 @@ export const chatModel: ProviderPackage.Definition<Settings, OpenResponsesProvid
 export const messagesModel: ProviderPackage.Definition<Settings, MessagesOptionsInput>["model"] = (modelID, settings) =>
  fromSettings(settings).messages(modelID)

-function fromSettings({ apiKey, baseURL, body, headers, ...providerOptions }: Settings) {
+function fromSettings(settings: Settings) {
  return configure({
-    apiKey,
-    baseURL,
-    headers,
-    http: body === undefined ? undefined : { body: { ...body } },
-    providerOptions,
+    apiKey: settings.apiKey,
+    baseURL: settings.baseURL,
+    headers: settings.headers,
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    providerOptions: settings.providerOptions,
  })
 }

@@ -40,11 +40,11 @@ export type Config = Omit<RouteDefaultsInput, "providerOptions"> &
    readonly providerOptions?: ProviderOptionsInput
  }

-export type Settings<Options = MessagesOptionsInput> = ProviderPackage.Settings &
-  Options & {
-    readonly apiKey?: string
-    readonly baseURL?: string
-  }
+export interface Settings<Options = MessagesOptionsInput> extends ProviderPackage.Settings {
+  readonly apiKey?: string
+  readonly baseURL?: string
+  readonly providerOptions?: Options
+}

 const ChatOptions = Schema.Struct({
  thinking: Schema.optional(Schema.Struct({ type: Schema.String })),
@@ -127,14 +127,14 @@ export const provider = configure()

 export const model: ProviderPackage.Definition<Settings<MessagesOptionsInput>, MessagesOptionsInput>["model"] = (
  modelID,
-  { apiKey, baseURL, body, headers, ...providerOptions },
+  settings,
 ) =>
  configure({
-    apiKey,
-    baseURL,
-    headers,
-    http: body === undefined ? undefined : { body: { ...body } },
-    providerOptions,
+    apiKey: settings.apiKey,
+    baseURL: settings.baseURL,
+    headers: settings.headers,
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    providerOptions: settings.providerOptions,
  }).model(modelID)

 export const messages = provider.messages
@@ -3,14 +3,11 @@ import { MiniMax } from "../minimax.js"

 export type Settings = MiniMax.Settings<MiniMax.ChatOptionsInput>

-export const model: ProviderPackage.Definition<Settings, MiniMax.ChatOptionsInput>["model"] = (
-  modelID,
-  { apiKey, baseURL, body, headers, ...providerOptions },
-) =>
+export const model: ProviderPackage.Definition<Settings, MiniMax.ChatOptionsInput>["model"] = (modelID, settings) =>
  MiniMax.configure({
-    apiKey,
-    baseURL,
-    headers,
-    http: body === undefined ? undefined : { body: { ...body } },
-    providerOptions,
+    apiKey: settings.apiKey,
+    baseURL: settings.baseURL,
+    headers: settings.headers,
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    providerOptions: settings.providerOptions,
  }).chat(modelID)
@@ -5,12 +5,12 @@ export type Settings = MiniMax.Settings<MiniMax.ResponsesOptionsInput>

 export const model: ProviderPackage.Definition<Settings, MiniMax.ResponsesOptionsInput>["model"] = (
  modelID,
-  { apiKey, baseURL, body, headers, ...providerOptions },
+  settings,
 ) =>
  MiniMax.configure({
-    apiKey,
-    baseURL,
-    headers,
-    http: body === undefined ? undefined : { body: { ...body } },
-    providerOptions,
+    apiKey: settings.apiKey,
+    baseURL: settings.baseURL,
+    headers: settings.headers,
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    providerOptions: settings.providerOptions,
  }).responses(modelID)
@@ -14,11 +14,11 @@ export type LanguageModelOptions = Omit<RouteDefaultsInput, "providerOptions"> &
    readonly providerOptions?: ProviderOptions
  }

-export type Settings = ProviderPackage.Settings &
-  ProviderOptions & {
-    readonly apiKey?: string
-    readonly baseURL?: string
-  }
+export interface Settings extends ProviderPackage.Settings {
+  readonly apiKey?: string
+  readonly baseURL?: string
+  readonly providerOptions?: ProviderOptions
+}

 export const route = MistralChat.route
 export const routes = [route]
@@ -39,16 +39,13 @@ export const configure = (input: LanguageModelOptions = {}) => {

 export const provider = configure()

-export const model: ProviderPackage.Definition<Settings, ProviderOptions>["model"] = (
-  modelID,
-  { apiKey, baseURL, body, headers, ...providerOptions },
-) =>
+export const model: ProviderPackage.Definition<Settings, ProviderOptions>["model"] = (modelID, settings) =>
  configure({
-    apiKey,
-    baseURL,
-    headers: headers === undefined ? undefined : { ...headers },
-    http: body === undefined ? undefined : { body: { ...body } },
-    providerOptions,
+    apiKey: settings.apiKey,
+    baseURL: settings.baseURL,
+    headers: settings.headers === undefined ? undefined : { ...settings.headers },
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    providerOptions: settings.providerOptions,
  }).model(modelID)

 export * as Mistral from "./mistral.js"
@@ -42,11 +42,11 @@ export type Config = Omit<RouteDefaultsInput, "providerOptions"> &
    readonly providerOptions?: ChatOptionsInput | MessagesOptionsInput | ResponsesOptionsInput
  }

-export type Settings<Options = ChatOptionsInput> = ProviderPackage.Settings &
-  Options & {
-    readonly apiKey?: string
-    readonly baseURL?: string
-  }
+export interface Settings<Options = ChatOptionsInput> extends ProviderPackage.Settings {
+  readonly apiKey?: string
+  readonly baseURL?: string
+  readonly providerOptions?: Options
+}

 const ChatOptions = Schema.Struct({
  reasoningEffort: Schema.optional(Schema.String),
@@ -133,16 +133,13 @@ export const chat = provider.chat
 export const messages = provider.messages
 export const responses = provider.responses

-export const model: ProviderPackage.Definition<Settings, ChatOptionsInput>["model"] = (
-  modelID,
-  { apiKey, baseURL, body, headers, ...providerOptions },
-) =>
+export const model: ProviderPackage.Definition<Settings, ChatOptionsInput>["model"] = (modelID, settings) =>
  configure({
-    apiKey,
-    baseURL,
-    headers,
-    http: body === undefined ? undefined : { body: { ...body } },
-    providerOptions,
+    apiKey: settings.apiKey,
+    baseURL: settings.baseURL,
+    headers: settings.headers,
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    providerOptions: settings.providerOptions,
  }).model(modelID)

 export * as Moonshot from "./moonshot.js"
@@ -5,12 +5,12 @@ export type Settings = Moonshot.Settings<Moonshot.MessagesOptionsInput>

 export const model: ProviderPackage.Definition<Settings, Moonshot.MessagesOptionsInput>["model"] = (
  modelID,
-  { apiKey, baseURL, body, headers, ...providerOptions },
+  settings,
 ) =>
  Moonshot.configure({
-    apiKey,
-    baseURL,
-    headers,
-    http: body === undefined ? undefined : { body: { ...body } },
-    providerOptions,
+    apiKey: settings.apiKey,
+    baseURL: settings.baseURL,
+    headers: settings.headers,
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    providerOptions: settings.providerOptions,
  }).messages(modelID)
@@ -5,12 +5,12 @@ export type Settings = Moonshot.Settings<Moonshot.ResponsesOptionsInput>

 export const model: ProviderPackage.Definition<Settings, Moonshot.ResponsesOptionsInput>["model"] = (
  modelID,
-  { apiKey, baseURL, body, headers, ...providerOptions },
+  settings,
 ) =>
  Moonshot.configure({
-    apiKey,
-    baseURL,
-    headers,
-    http: body === undefined ? undefined : { body: { ...body } },
-    providerOptions,
+    apiKey: settings.apiKey,
+    baseURL: settings.baseURL,
+    headers: settings.headers,
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    providerOptions: settings.providerOptions,
  }).responses(modelID)
@@ -16,12 +16,12 @@ export type Config = RouteDefaultsInput &
    readonly providerOptions?: OpenResponsesProviderOptionsInput
  }

-export type Settings = ProviderPackage.Settings &
-  OpenResponsesProviderOptionsInput & {
-    readonly apiKey?: string
-    readonly baseURL: string
-    readonly provider?: string
-  }
+export interface Settings extends ProviderPackage.Settings {
+  readonly apiKey?: string
+  readonly baseURL: string
+  readonly provider?: string
+  readonly providerOptions?: OpenResponsesProviderOptionsInput
+}

 export const routes = [OpenAICompatibleResponses.route]

@@ -48,13 +48,13 @@ export const provider = {

 export const model: ProviderPackage.Definition<Settings, OpenResponsesProviderOptionsInput>["model"] = (
  modelID,
-  { apiKey, baseURL, body, headers, provider, ...providerOptions },
+  settings,
 ) =>
  configure({
-    apiKey,
-    baseURL,
-    headers: headers === undefined ? undefined : { ...headers },
-    http: body === undefined ? undefined : { body: { ...body } },
-    provider,
-    providerOptions,
+    apiKey: settings.apiKey,
+    baseURL: settings.baseURL,
+    headers: settings.headers === undefined ? undefined : { ...settings.headers },
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    provider: settings.provider,
+    providerOptions: settings.providerOptions,
  }).model(modelID)
@@ -14,12 +14,12 @@ type GenericModelOptions = Omit<RouteDefaultsInput, "providerOptions"> &
    readonly providerOptions?: OpenAIProviderOptionsInput
  }

-export type Settings = ProviderPackage.Settings &
-  OpenAIProviderOptionsInput & {
-    readonly apiKey?: string
-    readonly baseURL: string
-    readonly provider?: string
-  }
+export interface Settings extends ProviderPackage.Settings {
+  readonly apiKey?: string
+  readonly baseURL: string
+  readonly provider?: string
+  readonly providerOptions?: OpenAIProviderOptionsInput
+}

 export const routes = [OpenAICompatibleChat.route]

@@ -45,17 +45,14 @@ export const provider = {
  configure,
 }

-export const model: ProviderPackage.Definition<Settings, OpenAIProviderOptionsInput>["model"] = (
-  modelID,
-  { apiKey, baseURL, body, headers, provider, ...providerOptions },
-) =>
+export const model: ProviderPackage.Definition<Settings, OpenAIProviderOptionsInput>["model"] = (modelID, settings) =>
  configure({
-    apiKey,
-    baseURL,
-    headers: headers === undefined ? undefined : { ...headers },
-    http: body === undefined ? undefined : { body: { ...body } },
-    provider,
-    providerOptions,
+    apiKey: settings.apiKey,
+    baseURL: settings.baseURL,
+    headers: settings.headers === undefined ? undefined : { ...settings.headers },
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    provider: settings.provider,
+    providerOptions: settings.providerOptions,
  }).model(modelID)

 export * as OpenAICompatible from "./openai-compatible.js"
@@ -57,14 +57,14 @@ export const imageGeneration = (options: ImageGenerationOptions = {}) =>
    },
  })

-export type Settings = ProviderPackage.Settings &
-  OpenAIProviderOptionsInput & {
-    readonly apiKey?: string
-    readonly baseURL?: string
-    readonly organization?: string
-    readonly project?: string
-    readonly queryParams?: Readonly<Record<string, string>>
-  }
+export interface Settings extends ProviderPackage.Settings {
+  readonly apiKey?: string
+  readonly baseURL?: string
+  readonly organization?: string
+  readonly project?: string
+  readonly queryParams?: Readonly<Record<string, string>>
+  readonly providerOptions?: OpenAIProviderOptionsInput
+}

 const auth = (options: ProviderAuthOption<"optional">) => AuthOptions.bearer(options, "OPENAI_API_KEY")

@@ -116,28 +116,19 @@ export const configure = (input: Config = {}) => {

 export const provider = configure()

-const config = ({
-  apiKey,
-  baseURL,
-  body,
-  headers: given,
-  organization,
-  project,
-  queryParams,
-  ...providerOptions
-}: Settings): Config => {
+const config = (settings: Settings): Config => {
  const headers = {
-    ...(organization === undefined ? {} : { "OpenAI-Organization": organization }),
-    ...(project === undefined ? {} : { "OpenAI-Project": project }),
-    ...given,
+    ...(settings.organization === undefined ? {} : { "OpenAI-Organization": settings.organization }),
+    ...(settings.project === undefined ? {} : { "OpenAI-Project": settings.project }),
+    ...settings.headers,
  }
  return {
-    apiKey,
-    baseURL,
+    apiKey: settings.apiKey,
+    baseURL: settings.baseURL,
    headers: Object.keys(headers).length === 0 ? undefined : headers,
-    http: body === undefined ? undefined : { body: { ...body } },
-    providerOptions,
-    queryParams: queryParams === undefined ? undefined : { ...queryParams },
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    providerOptions: settings.providerOptions,
+    queryParams: settings.queryParams === undefined ? undefined : { ...settings.queryParams },
  }
 }

@@ -77,11 +77,11 @@ export type LanguageModelOptions = Omit<RouteDefaultsInput, "providerOptions"> &
    readonly providerOptions?: OpenRouterProviderOptionsInput
  }

-export type Settings = ProviderPackage.Settings &
-  OpenRouterProviderOptionsInput & {
-    readonly apiKey?: string
-    readonly baseURL?: string
-  }
+export interface Settings extends ProviderPackage.Settings {
+  readonly apiKey?: string
+  readonly baseURL?: string
+  readonly providerOptions?: OpenRouterProviderOptionsInput
+}

 const OpenRouterBody = Schema.StructWithRest(Schema.Struct(OpenAIChat.bodyFields), [
  Schema.Record(Schema.String, Schema.Any),
@@ -191,12 +191,12 @@ export const configure = (input: LanguageModelOptions = {}) => {
 export const provider = configure()
 export const model: ProviderPackage.Definition<Settings, OpenRouterProviderOptionsInput>["model"] = (
  modelID,
-  { apiKey, baseURL, body, headers, ...providerOptions },
+  settings,
 ) =>
  configure({
-    apiKey,
-    baseURL,
-    headers,
-    http: body === undefined ? undefined : { body: { ...body } },
-    providerOptions,
+    apiKey: settings.apiKey,
+    baseURL: settings.baseURL,
+    headers: settings.headers,
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    providerOptions: settings.providerOptions,
  }).model(modelID)
@@ -15,11 +15,11 @@ export type LanguageModelOptions = Omit<RouteDefaultsInput, "providerOptions"> &
    readonly providerOptions?: OpenAIProviderOptionsInput
  }

-export type Settings = ProviderPackage.Settings &
-  OpenAIProviderOptionsInput & {
-    readonly apiKey?: string
-    readonly baseURL?: string
-  }
+export interface Settings extends ProviderPackage.Settings {
+  readonly apiKey?: string
+  readonly baseURL?: string
+  readonly providerOptions?: OpenAIProviderOptionsInput
+}

 export const route = Route.make({
  id: "togetherai-chat",
@@ -52,14 +52,11 @@ export const configure = (input: LanguageModelOptions = {}) => {

 export const provider = configure()

-export const model: ProviderPackage.Definition<Settings, OpenAIProviderOptionsInput>["model"] = (
-  modelID,
-  { apiKey, baseURL, body, headers, ...providerOptions },
-) =>
+export const model: ProviderPackage.Definition<Settings, OpenAIProviderOptionsInput>["model"] = (modelID, settings) =>
  configure({
-    apiKey,
-    baseURL,
-    headers: headers === undefined ? undefined : { ...headers },
-    http: body === undefined ? undefined : { body: { ...body } },
-    providerOptions,
+    apiKey: settings.apiKey,
+    baseURL: settings.baseURL,
+    headers: settings.headers === undefined ? undefined : { ...settings.headers },
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    providerOptions: settings.providerOptions,
  }).model(modelID)
@@ -20,11 +20,11 @@ export type LanguageModelOptions = Omit<RouteDefaultsInput, "providerOptions"> &
    readonly providerOptions?: XAIProviderOptionsInput
  }

-export type Settings = ProviderPackage.Settings &
-  XAIProviderOptionsInput & {
-    readonly apiKey?: string
-    readonly baseURL?: string
-  }
+export interface Settings extends ProviderPackage.Settings {
+  readonly apiKey?: string
+  readonly baseURL?: string
+  readonly providerOptions?: XAIProviderOptionsInput
+}

 export type { XAIImageOptions } from "../protocols/xai-images.js"

@@ -110,13 +110,13 @@ export const model: ProviderPackage.Definition<
  Settings,
  XAIProviderOptionsInput,
  typeof responsesRoute.compact
->["model"] = (modelID, { apiKey, baseURL, body, headers, ...providerOptions }) =>
+>["model"] = (modelID, settings) =>
  configure({
-    apiKey,
-    baseURL,
-    headers,
-    http: body === undefined ? undefined : { body: { ...body } },
-    providerOptions,
+    apiKey: settings.apiKey,
+    baseURL: settings.baseURL,
+    headers: settings.headers,
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    providerOptions: settings.providerOptions,
  }).model(modelID)
 export const responses = provider.responses
 export const chat = provider.chat
@@ -23,11 +23,11 @@ export type Config = Omit<RouteDefaultsInput, "providerOptions"> &
    readonly providerOptions?: ChatOptionsInput | MessagesOptionsInput | ResponsesOptionsInput
  }

-export type Settings<Options = ChatOptionsInput> = ProviderPackage.Settings &
-  Options & {
-    readonly apiKey?: string
-    readonly baseURL?: string
-  }
+export interface Settings<Options = ChatOptionsInput> extends ProviderPackage.Settings {
+  readonly apiKey?: string
+  readonly baseURL?: string
+  readonly providerOptions?: Options
+}

 const chatRoute = Route.make({
  id: "zai-coding-chat",
@@ -80,16 +80,13 @@ export const chat = provider.chat
 export const messages = provider.messages
 export const responses = provider.responses

-export const model: ProviderPackage.Definition<Settings, ChatOptionsInput>["model"] = (
-  modelID,
-  { apiKey, baseURL, body, headers, ...providerOptions },
-) =>
+export const model: ProviderPackage.Definition<Settings, ChatOptionsInput>["model"] = (modelID, settings) =>
  configure({
-    apiKey,
-    baseURL,
-    headers,
-    http: body === undefined ? undefined : { body: { ...body } },
-    providerOptions,
+    apiKey: settings.apiKey,
+    baseURL: settings.baseURL,
+    headers: settings.headers,
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    providerOptions: settings.providerOptions,
  }).model(modelID)

 export * as ZAICodingPlan from "./zai-coding-plan.js"
@@ -5,12 +5,12 @@ export type Settings = ZAICodingPlan.Settings<ZAICodingPlan.MessagesOptionsInput

 export const model: ProviderPackage.Definition<Settings, ZAICodingPlan.MessagesOptionsInput>["model"] = (
  modelID,
-  { apiKey, baseURL, body, headers, ...providerOptions },
+  settings,
 ) =>
  ZAICodingPlan.configure({
-    apiKey,
-    baseURL,
-    headers,
-    http: body === undefined ? undefined : { body: { ...body } },
-    providerOptions,
+    apiKey: settings.apiKey,
+    baseURL: settings.baseURL,
+    headers: settings.headers,
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    providerOptions: settings.providerOptions,
  }).messages(modelID)
@@ -5,12 +5,12 @@ export type Settings = ZAICodingPlan.Settings<ZAICodingPlan.ResponsesOptionsInpu

 export const model: ProviderPackage.Definition<Settings, ZAICodingPlan.ResponsesOptionsInput>["model"] = (
  modelID,
-  { apiKey, baseURL, body, headers, ...providerOptions },
+  settings,
 ) =>
  ZAICodingPlan.configure({
-    apiKey,
-    baseURL,
-    headers,
-    http: body === undefined ? undefined : { body: { ...body } },
-    providerOptions,
+    apiKey: settings.apiKey,
+    baseURL: settings.baseURL,
+    headers: settings.headers,
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    providerOptions: settings.providerOptions,
  }).responses(modelID)
@@ -17,11 +17,11 @@ export type Config = Omit<RouteDefaultsInput, "providerOptions"> &
    readonly providerOptions?: ChatOptionsInput
  }

-export type Settings = ProviderPackage.Settings &
-  ChatOptionsInput & {
-    readonly apiKey?: string
-    readonly baseURL?: string
-  }
+export interface Settings extends ProviderPackage.Settings {
+  readonly apiKey?: string
+  readonly baseURL?: string
+  readonly providerOptions?: ChatOptionsInput
+}

 export type { ZAIImageOptions } from "../protocols/zai-images.js"

@@ -70,16 +70,13 @@ export const provider = configure()
 export const image = provider.image
 export const chat = provider.chat

-export const model: ProviderPackage.Definition<Settings, ChatOptionsInput>["model"] = (
-  modelID,
-  { apiKey, baseURL, body, headers, ...providerOptions },
-) =>
+export const model: ProviderPackage.Definition<Settings, ChatOptionsInput>["model"] = (modelID, settings) =>
  configure({
-    apiKey,
-    baseURL,
-    headers,
-    http: body === undefined ? undefined : { body: { ...body } },
-    providerOptions,
+    apiKey: settings.apiKey,
+    baseURL: settings.baseURL,
+    headers: settings.headers,
+    http: settings.body === undefined ? undefined : { body: { ...settings.body } },
+    providerOptions: settings.providerOptions,
  }).model(modelID)

 export * as ZAI from "./zai.js"
@@ -188,13 +188,13 @@ describe("provider package entrypoints", () => {
      baseURL: "https://provider.example.test/v1/",
      headers: { "x-application": "opencode" },
      body: { service_tier: "priority" },
-      reasoningEffort: "high" as const,
+      providerOptions: { reasoningEffort: "high" as const },
    }
    const deepinfra = DeepInfra.model("google/gemma-3-27b-it", settings)

    expect(deepinfra.route.id).toBe("deepinfra-chat")
    expect(deepinfra.route.endpoint.baseURL).toBe("https://provider.example.test/v1/openai")
-    expect(deepinfra.route.defaults.providerOptions).toEqual({ reasoningEffort: "high" })
+    expect(deepinfra.route.defaults.providerOptions).toEqual(settings.providerOptions)
    expect(deepinfra.route.defaults.headers).toEqual(settings.headers)
    expect(deepinfra.route.defaults.http?.body).toEqual(settings.body)
  })
@@ -210,7 +210,7 @@ describe("provider package entrypoints", () => {
        apiKey: "fixture",
        headers: { "x-application": "opencode" },
        body: { custom: true },
-        reasoningEffort: "high",
+        providerOptions: { reasoningEffort: "high" },
      })
      expect(selected.provider).toBe(provider.id)
      expect(selected.route.endpoint.baseURL).toBe(provider.baseURL({ accountId: "account" }))
@@ -231,11 +231,11 @@ describe("provider package entrypoints", () => {
    }
    const openrouter = OpenRouter.model("anthropic/claude-sonnet-4", {
      ...settings,
-      usage: true,
+      providerOptions: { usage: true },
    })
    const xai = XAI.model("grok-4", {
      ...settings,
-      reasoningEffort: "high",
+      providerOptions: { reasoningEffort: "high" },
    })

    for (const selected of [openrouter, xai]) {
@@ -269,8 +269,7 @@ describe("provider package entrypoints", () => {
      provider: "example",
      headers: { "x-application": "opencode" },
      body: { service_tier: "priority" },
-      reasoningEffort: "low",
-      store: true,
+      providerOptions: { reasoningEffort: "low", store: true },
    })

    expect(String(selected.provider)).toBe("example")
@@ -296,7 +295,7 @@ describe("provider package entrypoints", () => {
      provider: "example",
      headers: { "x-application": "opencode" },
      body: { metadata: { user_id: "user_1" } },
-      effort: "low",
+      providerOptions: { effort: "low" },
    })

    expect(String(selected.provider)).toBe("example")
@@ -316,7 +315,7 @@ describe("provider package entrypoints", () => {
    const Anthropic = await import("@opencode/ai/providers/anthropic")
    const selected = Anthropic.model("claude-sonnet-4-6", {
      apiKey: "fixture",
-      thinking: { type: "adaptive" },
+      providerOptions: { thinking: { type: "adaptive" } },
    })

    expect(selected.route.defaults.providerOptions).toEqual({ thinking: { type: "adaptive" } })
@@ -410,7 +409,7 @@ describe("provider package entrypoints", () => {
      baseURL: "https://generativelanguage.test/v1beta",
      headers: { "x-application": "opencode" },
      body: { safetySettings: [] },
-      thinkingConfig: { thinkingBudget: 1_024 },
+      providerOptions: { thinkingConfig: { thinkingBudget: 1_024 } },
    })

    expect(selected.route.id).toBe("gemini")
@@ -69,9 +69,7 @@ for (const model of [
      dynamicResponse(({ request, text, respond }) =>
        Effect.sync(() => {
          const body = JSON.parse(text)
-          expect(request.headers["anthropic-beta"]).toBe(
-            "existing-beta,interleaved-thinking-2025-05-14,compact-2026-01-12",
-          )
+          expect(request.headers["anthropic-beta"]).toBe("existing-beta,compact-2026-01-12")
          if (body.messages.length === 1) {
            expect(body.context_management.edits).toEqual([
              {
@@ -32,9 +32,7 @@ for (const [id, enabled] of [
        enabled ? { type: "adaptive", block_binding: { prefix_mismatch_behavior: "drop_block" } } : undefined,
      )
      expect(prepared.request.headers["anthropic-beta"]).toBe(
-        enabled
-          ? "existing-beta,interleaved-thinking-2025-05-14,thinking-binding-controls-2026-08-01"
-          : "existing-beta,interleaved-thinking-2025-05-14",
+        enabled ? "existing-beta,thinking-binding-controls-2026-08-01" : "existing-beta",
      )
    }),
  )
@@ -55,9 +53,7 @@ it.effect("preserves explicit thinking settings and combines required beta heade
      const prepared = yield* AnthropicMessages.route.prepareTransport(compiled.body, request)
      expect(compiled.body.thinking).toEqual(thinking)
      expect(prepared.request.headers["anthropic-beta"]).toBe(
-        thinking.type === "disabled"
-          ? "interleaved-thinking-2025-05-14,compact-2026-01-12"
-          : "interleaved-thinking-2025-05-14,compact-2026-01-12,thinking-binding-controls-2026-08-01",
+        thinking.type === "disabled" ? "compact-2026-01-12" : "compact-2026-01-12,thinking-binding-controls-2026-08-01",
      )
    }
  }),
@@ -34,10 +34,12 @@ it.effect("Groq lowers its own options for custom catalog identities and endpoin
        baseURL: "https://gateway.example/v1",
        headers: { "x-client": "test" },
        body: { custom: "value" },
-        reasoningEffort: "default",
-        parallelToolCalls: true,
-        serviceTier: "flex",
-        user: "test-user",
+        providerOptions: {
+          reasoningEffort: "default",
+          parallelToolCalls: true,
+          serviceTier: "flex",
+          user: "test-user",
+        },
      }),
      { provider: "custom-groq" },
    )
@@ -87,7 +87,7 @@ it.effect("Meta package selectors preserve overrides and Chat token policy on cu
        baseURL: "https://gateway.example/v1",
        headers: { "x-client": "test" },
        body: { custom: "value" },
-        reasoningEffort: "future-effort",
+        providerOptions: { reasoningEffort: "future-effort" },
      })
      expect(model.route.endpoint.baseURL).toBe("https://gateway.example/v1")
      expect(model.route.defaults.headers).toEqual({ "x-client": "test" })
@@ -99,7 +99,7 @@ describe("native OpenAI-compatible providers", () => {
        const settings = {
          apiKey: "fixture",
          baseURL: "https://gateway.example/v1",
-          reasoningEffort: "high",
+          providerOptions: { reasoningEffort: "high" },
        }
        const selected = provider.configure(settings).model("test-model")
        expect(selected.provider).toBe(provider.id)
@@ -143,7 +143,7 @@ describe("native OpenAI-compatible providers", () => {
          tools: [
            ToolDefinition.make({ name: "lookup", description: "Look up data", inputSchema: { type: "object" } }),
          ],
-          store: true,
+          providerOptions: { store: true },
        }),
      )

@@ -168,7 +168,7 @@ describe("native OpenAI-compatible providers", () => {
            ]),
            Message.user("Continue."),
          ],
-          store: true,
+          providerOptions: { store: true },
        }),
      )

@@ -206,7 +206,7 @@ describe("native OpenAI-compatible providers", () => {
        baseURL: "https://gateway.example/v1",
        headers: { "x-application": "opencode" },
        body: { service_tier: "priority" },
-        reasoningEffort: "high",
+        providerOptions: { reasoningEffort: "high" },
      })

      expect(selected.route.endpoint.baseURL).toBe("https://gateway.example/v1")
@@ -1,6 +1,6 @@
 {
  "name": "@opencode/app",
-  "version": "2.0.0",
+  "version": "1.18.15",
  "description": "",
  "type": "module",
  "exports": {
@@ -285,7 +285,7 @@ export const DESKTOP_NATIVE_ENGLISH = {
  "desktop.updater.dialog.later": "Later",

  "desktop.cli.installed.title": "CLI Installed",
-  "desktop.cli.installed.message": "CLI installed to {{path}}\n\nRestart your terminal to use the 'opencode' command.",
+  "desktop.cli.installed.message": "CLI installed to {{path}}\n\nRestart your terminal to use the 'opencode2' command.",
  "desktop.cli.failed.title": "Installation Failed",
  "desktop.cli.failed.message": "Failed to install CLI: {{error}}",

@@ -1,16 +0,0 @@
-FROM alpine AS base
-
-ARG BUN_RUNTIME_TRANSPILER_CACHE_PATH=0
-ENV BUN_RUNTIME_TRANSPILER_CACHE_PATH=${BUN_RUNTIME_TRANSPILER_CACHE_PATH}
-RUN apk add --no-cache libgcc libstdc++ ripgrep
-
-FROM base AS build-amd64
-COPY dist/cli-linux-x64-baseline-musl/bin/opencode /usr/local/bin/opencode
-
-FROM base AS build-arm64
-COPY dist/cli-linux-arm64-musl/bin/opencode /usr/local/bin/opencode
-
-ARG TARGETARCH
-FROM build-${TARGETARCH}
-RUN ln -s opencode /usr/local/bin/opencode2 && opencode --version && opencode2 --version
-ENTRYPOINT ["opencode"]
@@ -1,135 +0,0 @@
-#!/usr/bin/env node
-
-const childProcess = require("child_process")
-const fs = require("fs")
-const path = require("path")
-const os = require("os")
-
-const forwardedSignals =
-  process.platform === "win32" ? ["SIGINT", "SIGTERM", "SIGHUP"] : ["SIGINT", "SIGTERM", "SIGHUP", "SIGUSR1"]
-
-function run(target) {
-  const child = childProcess.spawn(target, process.argv.slice(2), { stdio: "inherit" })
-  child.on("error", (error) => {
-    console.error(error.message)
-    process.exit(1)
-  })
-  const forwarders = {}
-  for (const signal of forwardedSignals) {
-    forwarders[signal] = () => {
-      try {
-        child.kill(signal)
-      } catch {}
-    }
-    process.on(signal, forwarders[signal])
-  }
-  child.on("exit", (code, signal) => {
-    for (const forwardedSignal of forwardedSignals) process.removeListener(forwardedSignal, forwarders[forwardedSignal])
-    if (signal) return process.kill(process.pid, signal)
-    process.exit(typeof code === "number" ? code : 0)
-  })
-}
-
-const envPath = process.env.OPENCODE_BIN_PATH
-const scriptDir = path.dirname(fs.realpathSync(__filename))
-const command = path.basename(__filename).replace(/\.cjs$/, "")
-const nodeBuild = command === "opencode-node"
-const sourceCommand = nodeBuild ? "opencode2-node" : "opencode"
-const cached = path.join(scriptDir, `.${command}`)
-const platform = { darwin: "darwin", linux: "linux", win32: "windows" }[os.platform()] || os.platform()
-const arch = { x64: "x64", arm64: "arm64", arm: "arm" }[os.arch()] || os.arch()
-const base = `@opencode/cli${nodeBuild ? "-node" : ""}-` + platform + "-" + arch
-const binary = platform === "windows" ? `${sourceCommand}.exe` : sourceCommand
-
-function supportsAvx2() {
-  if (arch !== "x64") return false
-  if (platform === "linux") {
-    try {
-      return /(^|\s)avx2(\s|$)/i.test(fs.readFileSync("/proc/cpuinfo", "utf8"))
-    } catch {
-      return false
-    }
-  }
-  if (platform === "darwin") {
-    try {
-      const result = childProcess.spawnSync("sysctl", ["-n", "hw.optional.avx2_0"], { encoding: "utf8", timeout: 1500 })
-      return result.status === 0 && (result.stdout || "").trim() === "1"
-    } catch {
-      return false
-    }
-  }
-  if (platform === "windows") {
-    const command =
-      '(Add-Type -MemberDefinition "[DllImport(""kernel32.dll"")] public static extern bool IsProcessorFeaturePresent(int ProcessorFeature);" -Name Kernel32 -Namespace Win32 -PassThru)::IsProcessorFeaturePresent(40)'
-    for (const executable of ["powershell.exe", "pwsh.exe", "pwsh", "powershell"]) {
-      try {
-        const result = childProcess.spawnSync(executable, ["-NoProfile", "-NonInteractive", "-Command", command], {
-          encoding: "utf8",
-          timeout: 3000,
-          windowsHide: true,
-        })
-        if (result.status !== 0) continue
-        const output = (result.stdout || "").trim().toLowerCase()
-        if (output === "true" || output === "1") return true
-        if (output === "false" || output === "0") return false
-      } catch {
-        continue
-      }
-    }
-  }
-  return false
-}
-
-const names = (() => {
-  if (nodeBuild) return [base]
-  const baseline = arch === "x64" && !supportsAvx2()
-  if (platform === "linux") {
-    const musl = (() => {
-      try {
-        if (fs.existsSync("/etc/alpine-release")) return true
-        const result = childProcess.spawnSync("ldd", ["--version"], { encoding: "utf8" })
-        return ((result.stdout || "") + (result.stderr || "")).toLowerCase().includes("musl")
-      } catch {
-        return false
-      }
-    })()
-    if (musl)
-      return arch === "x64"
-        ? baseline
-          ? [`${base}-baseline-musl`, `${base}-musl`, `${base}-baseline`, base]
-          : [`${base}-musl`, `${base}-baseline-musl`, base, `${base}-baseline`]
-        : [`${base}-musl`, base]
-    return arch === "x64"
-      ? baseline
-        ? [`${base}-baseline`, base, `${base}-baseline-musl`, `${base}-musl`]
-        : [base, `${base}-baseline`, `${base}-musl`, `${base}-baseline-musl`]
-      : [base, `${base}-musl`]
-  }
-  return arch === "x64" ? (baseline ? [`${base}-baseline`, base] : [base, `${base}-baseline`]) : [base]
-})()
-
-function findBinary(startDir) {
-  let current = startDir
-  for (;;) {
-    const modules = path.join(current, "node_modules")
-    if (fs.existsSync(modules))
-      for (const name of names) {
-        const candidate = path.join(modules, name, "bin", binary)
-        if (fs.existsSync(candidate)) return candidate
-      }
-    const parent = path.dirname(current)
-    if (parent === current) return
-    current = parent
-  }
-}
-
-const resolved = envPath || (fs.existsSync(cached) ? cached : findBinary(scriptDir))
-if (!resolved) {
-  console.error(
-    `It seems that your package manager failed to install the right ${command} CLI package. Try manually installing ` +
-      names.map((name) => `"${name}"`).join(" or ") +
-      " package",
-  )
-  process.exit(1)
-}
-run(resolved)
@@ -1,3 +1,134 @@
 #!/usr/bin/env node

-require("./opencode.cjs")
+const childProcess = require("child_process")
+const fs = require("fs")
+const path = require("path")
+const os = require("os")
+
+const forwardedSignals =
+  process.platform === "win32" ? ["SIGINT", "SIGTERM", "SIGHUP"] : ["SIGINT", "SIGTERM", "SIGHUP", "SIGUSR1"]
+
+function run(target) {
+  const child = childProcess.spawn(target, process.argv.slice(2), { stdio: "inherit" })
+  child.on("error", (error) => {
+    console.error(error.message)
+    process.exit(1)
+  })
+  const forwarders = {}
+  for (const signal of forwardedSignals) {
+    forwarders[signal] = () => {
+      try {
+        child.kill(signal)
+      } catch {}
+    }
+    process.on(signal, forwarders[signal])
+  }
+  child.on("exit", (code, signal) => {
+    for (const forwardedSignal of forwardedSignals) process.removeListener(forwardedSignal, forwarders[forwardedSignal])
+    if (signal) return process.kill(process.pid, signal)
+    process.exit(typeof code === "number" ? code : 0)
+  })
+}
+
+const envPath = process.env.OPENCODE_BIN_PATH
+const scriptDir = path.dirname(fs.realpathSync(__filename))
+const command = path.basename(__filename).replace(/\.cjs$/, "")
+const nodeBuild = command === "opencode2-node"
+const cached = path.join(scriptDir, `.${command}`)
+const platform = { darwin: "darwin", linux: "linux", win32: "windows" }[os.platform()] || os.platform()
+const arch = { x64: "x64", arm64: "arm64", arm: "arm" }[os.arch()] || os.arch()
+const base = `@opencode/cli${nodeBuild ? "-node" : ""}-` + platform + "-" + arch
+const binary = platform === "windows" ? `${command}.exe` : command
+
+function supportsAvx2() {
+  if (arch !== "x64") return false
+  if (platform === "linux") {
+    try {
+      return /(^|\s)avx2(\s|$)/i.test(fs.readFileSync("/proc/cpuinfo", "utf8"))
+    } catch {
+      return false
+    }
+  }
+  if (platform === "darwin") {
+    try {
+      const result = childProcess.spawnSync("sysctl", ["-n", "hw.optional.avx2_0"], { encoding: "utf8", timeout: 1500 })
+      return result.status === 0 && (result.stdout || "").trim() === "1"
+    } catch {
+      return false
+    }
+  }
+  if (platform === "windows") {
+    const command =
+      '(Add-Type -MemberDefinition "[DllImport(""kernel32.dll"")] public static extern bool IsProcessorFeaturePresent(int ProcessorFeature);" -Name Kernel32 -Namespace Win32 -PassThru)::IsProcessorFeaturePresent(40)'
+    for (const executable of ["powershell.exe", "pwsh.exe", "pwsh", "powershell"]) {
+      try {
+        const result = childProcess.spawnSync(executable, ["-NoProfile", "-NonInteractive", "-Command", command], {
+          encoding: "utf8",
+          timeout: 3000,
+          windowsHide: true,
+        })
+        if (result.status !== 0) continue
+        const output = (result.stdout || "").trim().toLowerCase()
+        if (output === "true" || output === "1") return true
+        if (output === "false" || output === "0") return false
+      } catch {
+        continue
+      }
+    }
+  }
+  return false
+}
+
+const names = (() => {
+  if (nodeBuild) return [base]
+  const baseline = arch === "x64" && !supportsAvx2()
+  if (platform === "linux") {
+    const musl = (() => {
+      try {
+        if (fs.existsSync("/etc/alpine-release")) return true
+        const result = childProcess.spawnSync("ldd", ["--version"], { encoding: "utf8" })
+        return ((result.stdout || "") + (result.stderr || "")).toLowerCase().includes("musl")
+      } catch {
+        return false
+      }
+    })()
+    if (musl)
+      return arch === "x64"
+        ? baseline
+          ? [`${base}-baseline-musl`, `${base}-musl`, `${base}-baseline`, base]
+          : [`${base}-musl`, `${base}-baseline-musl`, base, `${base}-baseline`]
+        : [`${base}-musl`, base]
+    return arch === "x64"
+      ? baseline
+        ? [`${base}-baseline`, base, `${base}-baseline-musl`, `${base}-musl`]
+        : [base, `${base}-baseline`, `${base}-musl`, `${base}-baseline-musl`]
+      : [base, `${base}-musl`]
+  }
+  return arch === "x64" ? (baseline ? [`${base}-baseline`, base] : [base, `${base}-baseline`]) : [base]
+})()
+
+function findBinary(startDir) {
+  let current = startDir
+  for (;;) {
+    const modules = path.join(current, "node_modules")
+    if (fs.existsSync(modules))
+      for (const name of names) {
+        const candidate = path.join(modules, name, "bin", binary)
+        if (fs.existsSync(candidate)) return candidate
+      }
+    const parent = path.dirname(current)
+    if (parent === current) return
+    current = parent
+  }
+}
+
+const resolved = envPath || (fs.existsSync(cached) ? cached : findBinary(scriptDir))
+if (!resolved) {
+  console.error(
+    `It seems that your package manager failed to install the right ${command} CLI package. Try manually installing ` +
+      names.map((name) => `"${name}"`).join(" or ") +
+      " package",
+  )
+  process.exit(1)
+}
+run(resolved)
@@ -1,11 +1,10 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/cli",
-  "version": "2.0.0",
+  "version": "1.18.4",
  "type": "module",
  "license": "MIT",
  "bin": {
-    "opencode": "./bin/opencode.cjs",
    "opencode2": "./bin/opencode2.cjs"
  },
  "files": [
@@ -12,7 +12,7 @@ import { verifyArtifact, verifySimulationGraph } from "./verify-artifact"
 import { resolveOpencodePty } from "./opencode-pty"

 const dir = path.resolve(import.meta.dirname, "..")
-const binary = "opencode"
+const binary = "opencode2"
 const outdir = path.resolve(
  dir,
  process.argv.find((arg) => arg.startsWith("--outdir="))?.slice("--outdir=".length) ?? "dist",
@@ -149,7 +149,7 @@ export default { path: file, version: ${JSON.stringify(opencodePty.version)}, sh
    },
    define: {
      OPENCODE_VERSION: `'${Script.version}'`,
-      OPENCODE_CLI_NAME: "'opencode'",
+      OPENCODE_CLI_NAME: `'${binary}'`,
      OPENCODE_CHANNEL: `'${Script.channel}'`,
      OPENCODE_ARTIFACT: `'cli'`,
      OPENCODE_LIBC: item.os === "linux" ? `'${item.abi ?? "glibc"}'` : "undefined",
@@ -12,11 +12,10 @@ const require = createRequire(import.meta.url)
 const packageJson = JSON.parse(fs.readFileSync(path.join(directory, "package.json"), "utf8"))
 const command = Object.keys(packageJson.bin ?? {})[0]
 if (!command) throw new Error("OpenCode package does not declare a binary")
-const sourceCommand = packageJson.opencodeSourceBinary ?? command

 const platform = { darwin: "darwin", linux: "linux", win32: "windows" }[os.platform()] ?? os.platform()
 const arch = { x64: "x64", arm64: "arm64", arm: "arm" }[os.arch()] ?? os.arch()
-const sourceBinary = platform === "windows" ? `${sourceCommand}.exe` : sourceCommand
+const sourceBinary = platform === "windows" ? `${command}.exe` : command
 const targetBinary = path.resolve(directory, packageJson.bin[command])
 const dependencies = packageJson.optionalDependencies ?? {}
 const base = Object.keys(dependencies).find((name) => name.endsWith(`-${platform}-${arch}`))
@@ -6,10 +6,15 @@ import path from "node:path"
 import { fileURLToPath } from "node:url"
 import { UpdateArtifact } from "../../../script/update-artifact"

-if (Script.channel !== "beta") throw new Error("AUR publishing requires the beta channel")
-const name = "opencode-beta"
-const command = "opencode"
-if (!/^\d+\.\d+\.\d+-beta[.-]\d+(?:\.\d+)?$/.test(Script.version)) throw new Error("Expected a beta release version")
+if (Script.channel !== "beta" && Script.channel !== "latest") {
+  throw new Error("AUR publishing requires the beta or latest channel")
+}
+const beta = Script.channel === "beta"
+const name = beta ? "opencode-beta" : "opencode-bin"
+const command = beta ? "opencode2" : "opencode"
+if (!(beta ? /^\d+\.\d+\.\d+-beta[.-]\d+(?:\.\d+)?$/ : /^\d+\.\d+\.\d+$/).test(Script.version)) {
+  throw new Error(`Expected a ${Script.channel} release version`)
+}

 const dir = fileURLToPath(new URL("..", import.meta.url))
 const root = path.resolve(process.env.OPENCODE_CLI_DIST ?? path.join(dir, "dist"))
@@ -17,9 +22,6 @@ const outdir = path.join(root, `aur-${name}`)
 const dryRun = process.argv.includes("--dry-run")
 const pkgver = Script.version.replaceAll("-", ".")
 const license = Bun.file(path.join(dir, "..", "..", "LICENSE"))
-const shim = `#!/bin/sh
-exec "$(dirname "$0")/opencode" "$@"
-`

 await rm(outdir, { recursive: true, force: true })
 await mkdir(path.dirname(outdir), { recursive: true })
@@ -46,7 +48,6 @@ const sources = await Promise.all(
 )

 await Bun.write(path.join(outdir, "LICENSE"), license)
-await Bun.write(path.join(outdir, "opencode2"), shim)
 await Bun.write(
  path.join(outdir, "PKGBUILD"),
  [
@@ -54,22 +55,21 @@ await Bun.write(
    `pkgname=${name}`,
    `pkgver=${pkgver}`,
    "pkgrel=1",
-    "pkgdesc='OpenCode beta - the AI coding agent for the terminal'",
+    `pkgdesc='OpenCode${beta ? " V2 beta" : ""} - the AI coding agent for the terminal'`,
    "url='https://github.com/anomalyco/opencode'",
    "arch=('x86_64' 'aarch64')",
    "license=('MIT')",
    "depends=('glibc' 'gcc-libs' 'ripgrep')",
-    `provides=('${command}' 'opencode2')`,
-    `conflicts=('${command}' 'opencode2')`,
+    `provides=('${command}')`,
+    `conflicts=('${command}')`,
    // Stripping a compiled Bun executable can damage its embedded application.
    "options=('!strip' '!debug')",
-    "source=('LICENSE' 'opencode2')",
-    `sha256sums=('${new Bun.CryptoHasher("sha256").update(await license.arrayBuffer()).digest("hex")}' '${new Bun.CryptoHasher("sha256").update(shim).digest("hex")}')`,
+    "source=('LICENSE')",
+    `sha256sums=('${new Bun.CryptoHasher("sha256").update(await license.arrayBuffer()).digest("hex")}')`,
    ...sources,
    "",
    "package() {",
-    `  install -Dm755 "$srcdir/package/bin/opencode" "$pkgdir/usr/bin/${command}"`,
-    '  install -Dm755 "$srcdir/opencode2" "$pkgdir/usr/bin/opencode2"',
+    `  install -Dm755 "$srcdir/package/bin/opencode2" "$pkgdir/usr/bin/${command}"`,
    '  install -Dm644 "$srcdir/LICENSE" "$pkgdir/usr/share/licenses/$pkgname/LICENSE"',
    "}",
    "",
@@ -79,7 +79,7 @@ await Bun.write(path.join(outdir, ".SRCINFO"), await $`makepkg --printsrcinfo`.c
 console.log(`Prepared ${name} ${pkgver} in ${outdir}`)
 if (dryRun) process.exit(0)

-await $`git add PKGBUILD .SRCINFO LICENSE opencode2`.cwd(outdir)
+await $`git add PKGBUILD .SRCINFO LICENSE`.cwd(outdir)
 if ((await $`git diff --cached --quiet`.cwd(outdir).nothrow()).exitCode !== 0) {
  await $`git commit -m ${`chore: update ${name} to ${pkgver}`}`.cwd(outdir)
  await $`git push origin master`.cwd(outdir)
@@ -29,8 +29,6 @@ async function publish(dir: string, name: string, version: string) {
 async function publishDistribution(input: {
  root: string
  name: string
-  command: string
-  legacyCommand?: string
  binary: string
  packagePrefix: string
  artifact: string
@@ -50,7 +48,7 @@ async function publishDistribution(input: {

  await $`mkdir -p ${input.root}/${input.name}/bin`
  await $`cp ./script/postinstall.mjs ${input.root}/${input.name}/postinstall.mjs`
-  await Bun.file(`${input.root}/${input.name}/bin/${input.command}.exe`).write(
+  await Bun.file(`${input.root}/${input.name}/bin/${input.binary}.exe`).write(
    [
      `echo "Error: ${input.name}'s postinstall script was not run." >&2`,
      'echo "" >&2',
@@ -64,11 +62,7 @@ async function publishDistribution(input: {
    JSON.stringify(
      {
        name: input.name,
-        bin: {
-          [input.command]: `./bin/${input.command}.exe`,
-          ...(input.legacyCommand ? { [input.legacyCommand]: `./bin/${input.command}.exe` } : {}),
-        },
-        ...(input.command !== input.binary ? { opencodeSourceBinary: input.binary } : {}),
+        bin: { [input.binary]: `./bin/${input.binary}.exe` },
        scripts: { postinstall: "node ./postinstall.mjs" },
        version,
        license: pkg.license,
@@ -126,28 +120,21 @@ async function publishDistribution(input: {
 await publishDistribution({
  root,
  name: pkg.name,
-  command: "opencode",
-  legacyCommand: "opencode2",
-  binary: "opencode",
+  binary: "opencode2",
  packagePrefix: "@opencode/cli-",
  artifact: "cli",
 })
-if (Script.channel !== "latest" && existsSync(path.join(root, "node"))) {
+if (existsSync(path.join(root, "node"))) {
  await publishDistribution({
    root: path.join(root, "node"),
    name: "@opencode/cli-node",
-    command: "opencode2-node",
    binary: "opencode2-node",
    packagePrefix: "@opencode/cli-node-",
    artifact: "cli-node",
  })
 }

-if (Script.channel === "latest" && Script.release && !dryRun) {
-  await $`docker buildx build --platform linux/amd64,linux/arm64 --tag ghcr.io/anomalyco/opencode:${Script.version} --push .`
-}
-
-if (Script.channel === "beta" && Script.release) {
+if ((Script.channel === "beta" || Script.channel === "latest") && Script.release) {
  await $`bun ./script/publish-aur.ts ${dryRun ? ["--dry-run"] : []}`.env({ ...process.env, OPENCODE_CLI_DIST: root })
 }

@@ -11,10 +11,7 @@ import path from "node:path"
 const nodeBuild = process.argv.includes("--node")
 const target = `cli${nodeBuild ? "-node" : ""}-${process.platform === "win32" ? "windows" : process.platform}-${process.arch}`
 const directory = path.join(import.meta.dir, "..", "dist", ...(nodeBuild ? ["node"] : []), target, "bin")
-const binary = path.join(
-  directory,
-  `${nodeBuild ? "opencode2-node" : "opencode"}${process.platform === "win32" ? ".exe" : ""}`,
-)
+const binary = path.join(directory, `opencode2${nodeBuild ? "-node" : ""}${process.platform === "win32" ? ".exe" : ""}`)
 if (!(await Bun.file(binary).exists())) throw new Error(`Missing compiled CLI in ${directory}`)

 const root = await fs.realpath(await fs.mkdtemp(path.join(os.tmpdir(), "opencode-service-smoke-")))
@@ -36,7 +36,7 @@ const PermissionParams = {
 }

 const Root = Spec.make(typeof OPENCODE_CLI_NAME === "string" ? OPENCODE_CLI_NAME : "opencode", {
-  description: "OpenCode command line interface",
+  description: "OpenCode 2.0 preview command line interface",
  params: {
    ...ServerParams,
    ...PermissionParams,
@@ -105,7 +105,7 @@ const make = Effect.gen(function* () {
      global.home,
      ".opencode",
      "bin",
-      process.platform === "win32" ? "opencode.exe" : "opencode",
+      process.platform === "win32" ? "opencode2.exe" : "opencode2",
    )
    if (path.resolve(process.execPath) === path.resolve(binary)) return "curl"
    if (!installedPackage) return
@@ -186,10 +186,7 @@ const make = Effect.gen(function* () {
        "npm",
        "install",
        "--global",
-        ...((OPENCODE_ARTIFACT === "cli" && !installedPackage?.endsWith("/cli-node")) ||
-        (installedPackage && packageName !== installedPackage)
-          ? ["--force"]
-          : []),
+        ...(installedPackage && packageName !== installedPackage ? ["--force"] : []),
        target,
      ],
      pnpm: ["pnpm", "add", "--global", `--allow-build=${packageName}`, target],
@@ -423,24 +423,24 @@ test("updates effective duplicate canonical keybinds", async () => {
  const file = path.join(directory.path, "cli.json")
  await Bun.write(
    file,
-    `{"keybinds":{"session.delete":"first","session.delete":"last","opencode.settings":"off","opencode.settings":"on"}}`,
+    `{"keybinds":{"session.delete":"first","session.delete":"last","permission.mode":"off","permission.mode":"on"}}`,
  )

  const config = await run(
    directory.path,
    Effect.gen(function* () {
      const service = yield* Config.Service
-      expect((yield* service.get()).keybinds).toEqual({ "session.delete": "last", "opencode.settings": "on" })
+      expect((yield* service.get()).keybinds).toEqual({ "session.delete": "last", "permission.mode": "on" })
      return yield* service.update((draft) => {
-        draft.keybinds = { ...draft.keybinds, "session.delete": "changed", "opencode.settings": "changed" }
+        draft.keybinds = { ...draft.keybinds, "session.delete": "changed", "permission.mode": "changed" }
      })
    }),
  )

-  expect(config.keybinds).toEqual({ "session.delete": "changed", "opencode.settings": "changed" })
+  expect(config.keybinds).toEqual({ "session.delete": "changed", "permission.mode": "changed" })
  expect(parse(await Bun.file(file).text()).keybinds).toEqual({
    "session.delete": "changed",
-    "opencode.settings": "changed",
+    "permission.mode": "changed",
  })
 })

@@ -100,7 +100,7 @@ function fixture(
 }

 const installs = [
-  { method: "npm", command: ["npm", "install", "--global", "--force", "@opencode/cli@2.3.4-beta.1"] },
+  { method: "npm", command: ["npm", "install", "--global", "@opencode/cli@2.3.4-beta.1"] },
  {
    method: "pnpm",
    command: ["pnpm", "add", "--global", "--allow-build=@opencode/cli", "@opencode/cli@2.3.4-beta.1"],
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/client",
-  "version": "2.0.0",
+  "version": "1.17.13",
  "type": "module",
  "license": "MIT",
  "repository": {
@@ -74,6 +74,7 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
 - [ ] Destructuring a key that member access resolves through the owning built-in, such as
      `const { constructor } = error`, reads `undefined`.
 - [ ] Member expressions as `for...in` targets (`for (x.y in obj)`).
+- [ ] `IteratorClose` during destructuring should throw a `TypeError` when `return()` yields a non-object.

 ## Statements and control flow

@@ -121,15 +122,12 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
 - [ ] User-defined constructor calls.
 - [ ] `Function.prototype.call`, `apply`, and `bind` for CodeMode functions.
 - [ ] Classes and private fields.
- [x] Functions are objects: they hold own properties (`fn.count = 1`), enumerate them, and expose read-only `name`
-      and `length`. Names follow JavaScript's NamedEvaluation: declarations, named expressions, bindings,
-      assignments, object literal keys, and destructuring or parameter defaults.
- [ ] `name` and `length` of built-in functions such as `Math.max` or `"a".includes`.
+- [ ] `name` and `length` properties of functions, including names inferred from bindings and destructuring defaults.
 - [ ] A named function expression's name is not bound inside its own body.
 - [ ] Redeclaring a function in the same scope is rejected; in JavaScript the last declaration wins.
 - [ ] A line terminator between `async function` and the function name.
- [ ] Async generator functions evaluate parameter defaults and destructuring at the first `next()` rather than at the
-      call, so their errors are not thrown synchronously.
+- [ ] Generator and async generator functions evaluate parameter defaults and destructuring at the first `next()`
+      rather than at the call, so their errors are not thrown synchronously.
 - [x] Synchronous and async generator declarations/expressions, `yield`, and `yield*`, including lazy bodies,
      `next(value)`, `return(value)`, `throw(value)`, exhaustion, promise adoption, async request ordering,
      `try`/`catch`/`finally`, and sync/async iterator symbols. Async `yield*` awaits values while adapting a sync
@@ -173,8 +171,12 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
 - [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.
- [ ] Operators, `switch` discriminants, and coercion helpers such as `String` and `isNaN` applied to functions and
-      namespaces; JavaScript coerces them, the interpreter rejects non-data operands.
+- [ ] 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.
+- [ ] ToPrimitive on object operands: operators, `Error(message)`, `Date` arguments, and `parseInt` radix should call
+      `valueOf`/`toString` in spec order and surface their throws.
+- [ ] Property keys follow ToPropertyKey: `x[null]`, `x[true]`, and objects (via `toString`) become string keys; only
+      strings and numbers are accepted.

 ## Promises and tools

@@ -246,8 +248,9 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
 - [x] Circular references are rejected when created (`o.self = o`, `array.push(array)`), not at serialization as in JS.
 - [x] `Object.is` for supported data values.
 - [x] `Object.groupBy` over finite collections and custom synchronous iterators/generators, with string-key coercion
-      and plain-object results.
- [ ] `Object.prototype` methods on values: `toString`, `toLocaleString`, `valueOf`, and `hasOwnProperty`.
+      and null-prototype results.
+- [ ] `Object.prototype` methods on values: `toString`, `toLocaleString`, `valueOf`, `hasOwnProperty`, and
+      `propertyIsEnumerable`.

 ## Arrays

@@ -267,13 +270,12 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
 - [x] `length`, numeric indexing, index assignment, spread, and `for...of`.
 - [x] The `thisArg` argument of `Array.from` is accepted and ignored, like JS arrows.
 - [x] `Array.prototype.toSpliced`.
- [x] Canonical array/string index parsing: keys such as `"01"` are ordinary properties rather than aliases of index
-      `1`.
+- [x] Canonical array/string index parsing: keys such as `"01"` remain non-index properties rather than aliasing index
+      `1`; arbitrary array-property assignment remains unsupported.
 - [x] `Array.prototype.sort` preserves trailing holes, while `toSorted` densifies holes into `undefined` elements,
      like JavaScript.
- [x] Assigning `length` to truncate or extend an array; invalid lengths throw `RangeError`.
- [x] Non-index own properties on arrays (`arr.foo = 1`, `arr.constructor = null`). They are excluded from the JSON
-      form, like `JSON.stringify`.
+- [ ] Assigning `length` to truncate or extend an array.
+- [ ] Non-index own properties on arrays (`arr.foo = 1`, `arr.constructor = null`).
 - [ ] Argument coercion for `indexOf`, `lastIndexOf`, `includes`, `fill`, `flat`, `copyWithin`, and the `join`
      separator: JavaScript applies ToIntegerOrInfinity/ToString (including `valueOf`, strings, and `undefined`), the
      interpreter requires numbers and strings; `includes()`/`indexOf()` with no argument should search for
@@ -298,6 +300,8 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
      `repeat` still requires a finite non-negative count.
 - [x] Native no-argument parity for `match()`, `matchAll()`, and `search()`; all behave as an empty pattern. Present
      arguments must still be a regular expression or string pattern.
+- [ ] `String.raw`.
+- [ ] `match`, `search`, and `split` accept any value and coerce it (objects via `toString`), like JavaScript.

 ## Numbers and Math

@@ -352,6 +356,8 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
 - [x] `Date.prototype.toUTCString` and its `toGMTString` alias.
 - [x] `toDateString` and `toTimeString` in the host's local timezone.
 - [x] Native one-argument Date coercion for supported values, including booleans, null, arrays, and plain objects.
+- [ ] Date setters and multi-argument construction coerce object arguments through `valueOf`/`toString` and surface
+      their throws.
 - [x] Native Date loose-equality and default primitive-coercion semantics, using CodeMode's deterministic ISO string
      representation for the string primitive.
 - [x] Native `RangeError` branding for invalid `toISOString()` calls.
@@ -362,7 +368,7 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
 - [x] `test`, `exec`, and `toString`.
 - [x] Readable `source`, `flags`, `lastIndex`, `hasIndices`, `global`, `ignoreCase`, `multiline`, `sticky`, `unicode`,
      `unicodeSets`, and `dotAll`.
- [x] Captures, named groups, match `.index` and `.input`, and stateful global matching.
+- [x] Captures, named groups, match `.index`, and stateful global matching.
 - [x] Integration with supported String methods, including function replacers.
 - [x] Writable `lastIndex`.
 - [x] Match `indices` metadata for the `d` flag, including named groups on `exec`, `match`, and `matchAll` results.
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/codemode",
-  "version": "2.0.0",
+  "version": "1.18.4",
  "description": "Effect-native confined code execution over schema-described tools",
  "type": "module",
  "license": "MIT",
@@ -1,16 +1,11 @@
 export * as Data from "./data.js"

 import type { DiagnosticKind } from "./codemode.js"
-import {
-  ownEntries,
-  parseArrayIndex,
-  ProgramArray,
-  ProgramFunction,
-  ProgramObject,
-  set,
-} from "./interpreter/objects.js"
 import { Values } from "./values.js"

+/** A null-prototype object owned by the program. */
+export type SafeObject = Record<string, unknown>
+
 const MAX_VALUE_DEPTH = 32

 export class ToolRuntimeError extends Error {
@@ -28,15 +23,15 @@ export class ToolRuntimeError extends Error {
 }

 /**
- * Brings a host-produced value into the program: program and runtime values pass through, their
- * host counterparts (Date, RegExp, Map, Set, URL, URLSearchParams) are wrapped, and host objects
- * and arrays are copied.
+ * Brings a host-produced runtime value into the program: runtime values pass through, their host
+ * counterparts (Date, RegExp, Map, Set, URL, URLSearchParams) are wrapped, and objects become
+ * null-prototype copies. Arrays keep extra enumerable properties such as `index` and `groups`.
 */
 export const toProgram = (value: unknown, label: string): unknown => copy(value, label, "program", 0, new Set())

 /**
 * 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.
+ * empty objects, and objects become null-prototype copies. Used for tool results and parsed JSON.
 */
 export const fromData = (value: unknown, label: string): unknown => copy(value, label, "data", 0, new Set())

@@ -49,7 +44,8 @@ export const fromData = (value: unknown, label: string): unknown => copy(value,
 export const toData = (value: unknown, label: string, undefinedAs: "json" | "result" = "json"): unknown =>
  copy(value, label, undefinedAs, 0, new Set())

-// "program" and "data" build program objects; "json" and "result" build ordinary objects for the host.
+// "program" and "data" build program-owned null-prototype objects; "json" and "result" build
+// ordinary objects for the host.
 type Mode = "program" | "data" | "json" | "result"

 const copy = (value: unknown, label: string, mode: Mode, depth: number, seen: Set<object>): unknown => {
@@ -68,13 +64,9 @@ const copy = (value: unknown, label: string, mode: Mode, depth: number, seen: Se
      `${label} contains an un-awaited Promise; await tool calls (e.g. \`const result = await tools.ns.tool(...)\`) before using their results.`,
    )
  }
-  if (value instanceof ProgramFunction && mode !== "program") {
-    throw new ToolRuntimeError("InvalidDataValue", `${label} must contain data only.`)
-  }

-  const plain = mode === "program" || mode === "data"
  if (mode === "program") {
-    if (value instanceof ProgramObject || Values.isValue(value)) return value
+    if (Values.isValue(value)) return value
    if (value instanceof Date) return new Values.Date(value.getTime())
    if (value instanceof RegExp) return new Values.RegExp(value.source, value.flags)
    if (value instanceof Map) {
@@ -93,6 +85,7 @@ const copy = (value: unknown, label: string, mode: Mode, depth: number, seen: Se
    if (value instanceof URLSearchParams) return new Values.URLSearchParams(new URLSearchParams(value))
  }

+  const plain = mode === "program" || mode === "data"
  if (value instanceof Values.Date) 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 Values.URL) return value.url.href
@@ -105,7 +98,7 @@ const copy = (value: unknown, label: string, mode: Mode, depth: number, seen: Se
    value instanceof Set ||
    value instanceof URLSearchParams
  ) {
-    return plain ? new ProgramObject() : {}
+    return plain ? (Object.create(null) as SafeObject) : {}
  }

  if (seen.has(value)) {
@@ -113,32 +106,17 @@ const copy = (value: unknown, label: string, mode: Mode, depth: number, seen: Se
  }
  seen.add(value)

-  if (value instanceof ProgramArray) {
-    const copied = Array.from(value.items, (item) => copy(item, label, mode, depth + 1, seen) ?? null)
-    seen.delete(value)
-    return copied
-  }
-  if (value instanceof ProgramObject) {
-    const copied: Record<string, unknown> = {}
-    for (const [key, item] of ownEntries(value)) {
-      const next = copy(item, label, mode, depth + 1, seen)
-      if (next === undefined && mode === "json") continue
-      define(copied, key, next)
-    }
-    seen.delete(value)
-    return copied
-  }
-
  if (Array.isArray(value)) {
-    if (plain) {
-      const copied = new ProgramArray(value.map((item) => copy(item, label, mode, depth + 1, seen)))
+    // Host output densifies holes to null like JSON; program copies keep them.
+    const copied = plain
+      ? value.map((item) => copy(item, label, mode, depth + 1, seen))
+      : Array.from(value, (item) => copy(item, label, mode, depth + 1, seen) ?? null)
+    if (mode === "program") {
      for (const [key, item] of Object.entries(value)) {
-        if (parseArrayIndex(key) === undefined) set(copied, key, copy(item, label, mode, depth + 1, seen))
+        if (Object.hasOwn(copied, key)) continue
+        define(copied, key, copy(item, label, mode, depth + 1, seen))
      }
-      seen.delete(value)
-      return copied
    }
-    const copied = Array.from(value, (item) => copy(item, label, mode, depth + 1, seen) ?? null)
    seen.delete(value)
    return copied
  }
@@ -148,13 +126,7 @@ const copy = (value: unknown, label: string, mode: Mode, depth: number, seen: Se
    throw new ToolRuntimeError("InvalidDataValue", `${label} must contain plain objects only.`)
  }

-  if (plain) {
-    const copied = new ProgramObject()
-    for (const [key, item] of Object.entries(value)) set(copied, key, copy(item, label, mode, depth + 1, seen))
-    seen.delete(value)
-    return copied
-  }
-  const copied: Record<string, unknown> = {}
+  const copied: SafeObject = plain ? (Object.create(null) as SafeObject) : {}
  for (const [key, item] of Object.entries(value)) {
    const next = copy(item, label, mode, depth + 1, seen)
    if (next === undefined && mode === "json") continue
@@ -164,8 +136,8 @@ const copy = (value: unknown, label: string, mode: Mode, depth: number, seen: Se
  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.
+// Own data property regardless of the target's prototype, so a "__proto__" key on a host object or
+// array never reaches the Object.prototype setter.
 const define = (target: object, key: string, value: unknown): void => {
  Object.defineProperty(target, key, { value, enumerable: true, writable: true, configurable: true })
 }
@@ -1,11 +1,10 @@
 import { Effect } from "effect"
 import type { Diagnostic } from "../codemode.js"
 import { ToolError } from "../tool-error.js"
-import { toData, ToolRuntimeError } from "../data.js"
+import { type SafeObject, toData, ToolRuntimeError } from "../data.js"
 import { type AstNode, formatLocation, InterpreterRuntimeError, ProgramThrow, sourceLocation } from "./model.js"
 import { containsRuntimeReference } from "./references.js"
 import { type HostCall, HostFunction } from "./host.js"
-import { get, ProgramError, ProgramObject } from "./objects.js"
 import { type Runner } from "./runner.js"
 import {
  coerceToString,
@@ -45,8 +44,12 @@ export const normalizeError = (error: unknown): Diagnostic => {
      message = "a non-data value"
    } else if (typeof value === "string") {
      message = value
-    } else if (value instanceof ProgramObject && typeof get(value, "message") === "string") {
-      message = get(value, "message") as string
+    } else if (
+      value !== null &&
+      typeof value === "object" &&
+      typeof (value as { message?: unknown }).message === "string"
+    ) {
+      message = (value as { message: string }).message
    } else {
      try {
        message = JSON.stringify(toData(value, "Thrown value")) ?? String(value)
@@ -84,14 +87,14 @@ export const caughtErrorValue = (thrown: unknown): unknown => {
  return createErrorValue(name, normalizeError(thrown).message)
 }

-const constructErrorValue = (name: string, args: Array<unknown>): ProgramError =>
+const constructErrorValue = (name: string, args: Array<unknown>): SafeObject =>
  createErrorValue(name, args[0] === undefined ? "" : coerceToString(args[0]))

 const constructAggregateErrorValue = <R>(
  runner: Runner<R>,
  args: Array<unknown>,
  node: AstNode,
-): Effect.Effect<ProgramError, unknown, R> =>
+): Effect.Effect<SafeObject, unknown, R> =>
  Effect.gen(function* () {
    const cursor = yield* runner.syncIterator(args[0], node)
    if (cursor === undefined) {
@@ -1,14 +1,13 @@
 import { Effect } from "effect"
-import { toProgram } from "../data.js"
+import { type SafeObject, toProgram } from "../data.js"
 import { dateSetterArgumentCount, invokeDateMethod } from "../stdlib/date.js"
 import { invokeNumberMethod } from "../stdlib/number.js"
 import { invokeRegExpMethod, matchToValue, toHostRegex } from "../stdlib/regexp.js"
 import { invokeURLMethod, uriArgument } from "../stdlib/url.js"
-import { coerceToNumber, coerceToString } from "../stdlib/value.js"
+import { coerceToNumber, coerceToString, errorBrandName } from "../stdlib/value.js"
 import { compareText } from "../tool-runtime.js"
 import { Values } from "../values.js"
 import { type AstNode, IntrinsicReference, InterpreterRuntimeError } from "./model.js"
-import { get, ProgramArray, ProgramObject, record } from "./objects.js"
 import { containsOpaqueReference, rejectCircularInsertion, typeofValue } from "./references.js"
 import { applyCollectionCallback, isSupportedCallback, type Runner, toPrimitive } from "./runner.js"

@@ -17,14 +16,6 @@ export const invokeIntrinsic = <R>(
  ref: IntrinsicReference,
  args: Array<unknown>,
  node: AstNode,
-): Effect.Effect<unknown, unknown, R> =>
-  Effect.map(invoke(runner, ref, args, node), (result) => (Array.isArray(result) ? new ProgramArray(result) : result))
-
-const invoke = <R>(
-  runner: Runner<R>,
-  ref: IntrinsicReference,
-  args: Array<unknown>,
-  node: AstNode,
 ): Effect.Effect<unknown, unknown, R> => {
  if (typeof ref.receiver === "string") {
    if (ref.name === "replace" || ref.name === "replaceAll") {
@@ -41,7 +32,7 @@ const invoke = <R>(
  if (typeof ref.receiver === "number") {
    return Effect.succeed(invokeNumberMethod(ref.receiver, ref.name, args, node))
  }
-  if (ref.receiver instanceof ProgramArray) {
+  if (Array.isArray(ref.receiver)) {
    return invokeArrayMethod(runner, ref.receiver, ref.name, args, node)
  }
  if (ref.receiver instanceof Values.Date) {
@@ -224,7 +215,7 @@ const invokeStringMethod = (value: string, name: string, args: Array<unknown>, n
          node,
        )
      }
-      return new ProgramArray(Array.from(value.matchAll(pattern), matchToValue))
+      return Array.from(value.matchAll(pattern), matchToValue)
    }
    case "search": {
      result = value.search(toHostRegex(args[0], name, node))
@@ -297,7 +288,13 @@ const invokeStringReplacer = <R>(
    if (typeof match !== "string" || typeof offset !== "number") {
      throw new InterpreterRuntimeError(`String.${name} produced an invalid replacement match.`, node)
    }
-    if (hasGroups) callbackArgs[callbackArgs.length - 1] = record(groups as Record<string, unknown>)
+    if (hasGroups) {
+      const safeGroups: SafeObject = Object.create(null) as SafeObject
+      for (const [key, group] of Object.entries(groups)) {
+        safeGroups[key] = group
+      }
+      callbackArgs[callbackArgs.length - 1] = safeGroups
+    }
    matches.push({ match, offset, args: callbackArgs })
    return match
  }
@@ -323,11 +320,14 @@ const invokeStringReplacer = <R>(
    let end = 0
    for (const match of matches) {
      const replacement = yield* apply(match.args)
+      // Error values are branded plain objects; toProgram would strip the brand before coercion.
      output.push(
        value.slice(end, match.offset),
        replacement instanceof Values.Promise
          ? "[object Promise]"
-          : coerceToString(toProgram(replacement, `String.${name} replacer result`)),
+          : errorBrandName(replacement)
+            ? coerceToString(replacement)
+            : coerceToString(toProgram(replacement, `String.${name} replacer result`)),
      )
      end = match.offset + match.match.length
    }
@@ -365,7 +365,7 @@ const invokeMapMethod = <R>(
    case "values":
      return Effect.sync(() => Array.from(target.map.values()))
    case "entries":
-      return Effect.sync(() => Array.from(target.map.entries(), ([key, item]) => new ProgramArray([key, item])))
+      return Effect.sync(() => Array.from(target.map.entries(), ([key, item]): Array<unknown> => [key, item]))
    case "forEach": {
      const apply = applyCollectionCallback(runner, args[0], "Map.forEach", node)
      return Effect.gen(function* () {
@@ -404,7 +404,7 @@ const invokeSetMethod = <R>(
    case "values":
      return Effect.sync(() => Array.from(target.set.values()))
    case "entries":
-      return Effect.sync(() => Array.from(target.set.values(), (item) => new ProgramArray([item, item])))
+      return Effect.sync(() => Array.from(target.set.values(), (item): Array<unknown> => [item, item]))
    case "forEach": {
      const apply = applyCollectionCallback(runner, args[0], "Set.forEach", node)
      return Effect.gen(function* () {
@@ -518,27 +518,28 @@ const loadSetRecord = <R>(runner: Runner<R>, source: unknown, name: string, node
      keys: () => Effect.succeed(source.map.keys()),
    })
  }
-  if (!(source instanceof ProgramObject)) {
+  if (source === null || typeof source !== "object" || Values.isValue(source)) {
    throw new InterpreterRuntimeError(`Set.${name} expects a Set-like object.`, node).as("TypeError")
  }
+  const object = source as Record<string, unknown>
  return Effect.gen(function* () {
-    const size = yield* coerceNumericArgument(runner, get(source, "size"), node)
+    const size = yield* coerceNumericArgument(runner, object.size, node)
    if (Number.isNaN(size)) {
      throw new InterpreterRuntimeError(`Set.${name} received a Set-like object with an invalid size.`, node).as(
        "TypeError",
      )
    }
-    const has = get(source, "has")
-    const keys = get(source, "keys")
-    if (!isSupportedCallback(has) || !isSupportedCallback(keys)) {
+    if (!isSupportedCallback(object.has) || !isSupportedCallback(object.keys)) {
      throw new InterpreterRuntimeError(`Set.${name} expects callable 'has' and 'keys' methods.`, node).as("TypeError")
    }
+    const has = object.has
+    const keys = object.keys
    return {
      size: Math.max(Math.trunc(size), 0),
      has: (item: unknown) => Effect.map(runner.invokeCallable(has, [item], node), Boolean),
      keys: () =>
        Effect.flatMap(runner.invokeCallable(keys, [], node), (result) => {
-          if (result instanceof ProgramArray) return Effect.succeed(result.items)
+          if (Array.isArray(result)) return Effect.succeed(result)
          throw new InterpreterRuntimeError(`Set.${name} expected 'keys' to return an iterator.`, node).as("TypeError")
        }),
    }
@@ -603,7 +604,7 @@ const invokeURLSearchParamsMethod = <R>(
    case "values":
      return Effect.sync(() => Array.from(target.params.values()))
    case "entries":
-      return Effect.sync(() => Array.from(target.params.entries(), ([key, value]) => new ProgramArray([key, value])))
+      return Effect.sync(() => Array.from(target.params.entries(), ([key, value]): Array<unknown> => [key, value]))
    case "toString":
      return Effect.sync(() => target.params.toString())
    case "forEach": {
@@ -621,12 +622,11 @@ const invokeURLSearchParamsMethod = <R>(

 const invokeArrayMethod = <R>(
  runner: Runner<R>,
-  receiver: ProgramArray,
+  target: Array<unknown>,
  name: string,
  args: Array<unknown>,
  node: AstNode,
 ): Effect.Effect<unknown, unknown, R> => {
-  const target = receiver.items
  const optNumber = (value: unknown, label: string): number | undefined => {
    if (value === undefined) return undefined
    if (typeof value !== "number")
@@ -638,8 +638,9 @@ const invokeArrayMethod = <R>(
      if (args.length > 1 || (args.length === 1 && typeof args[0] !== "string")) {
        throw new InterpreterRuntimeError("Array.join expects zero arguments or one string separator.", node)
      }
+      const input = toProgram(target, "Array.join input") as Array<unknown>
      return Effect.succeed(
-        target.map((item) => coerceToString(item ?? "")).join(args.length === 0 ? "," : (args[0] as string)),
+        input.map((item) => coerceToString(item ?? "")).join(args.length === 0 ? "," : (args[0] as string)),
      )
    }
    case "includes":
@@ -659,15 +660,11 @@ const invokeArrayMethod = <R>(
    case "slice":
      return Effect.succeed(target.slice(optNumber(args[0], "start"), optNumber(args[1], "end")))
    case "concat":
-      return Effect.succeed(target.concat(...args.map((item) => (item instanceof ProgramArray ? item.items : item))))
-    case "flat": {
-      const flatten = (items: Array<unknown>, depth: number): Array<unknown> =>
-        items.flatMap((item) => (item instanceof ProgramArray && depth > 0 ? flatten(item.items, depth - 1) : [item]))
-      return Effect.succeed(flatten(target, optNumber(args[0], "depth") ?? 1))
-    }
+      return Effect.succeed(target.concat(...args))
+    case "flat":
+      return Effect.succeed(target.flat(optNumber(args[0], "depth") ?? 1))
    case "reverse":
-      target.reverse()
-      return Effect.succeed(receiver)
+      return Effect.succeed(target.reverse())
    case "sort": {
      const length = target.length
      const holeCount = Array.from({ length }, (_, index) => Object.hasOwn(target, index)).filter((own) => !own).length
@@ -679,7 +676,7 @@ const invokeArrayMethod = <R>(
        Array.from({ length: holeCount }, (_, index) => itemCount + index).forEach((index) => {
          Reflect.deleteProperty(target, index)
        })
-        return receiver
+        return target
      })
    }
    case "toSorted":
@@ -698,12 +695,12 @@ const invokeArrayMethod = <R>(
    }
    case "push": {
      // Validate all insertions before mutating to avoid partial cyclic updates.
-      for (const item of args) rejectCircularInsertion(receiver, item, "Array.push result", node)
+      for (const item of args) rejectCircularInsertion(target, item, "Array.push result", node)
      target.push(...args)
      return Effect.succeed(target.length)
    }
    case "unshift": {
-      for (const item of args) rejectCircularInsertion(receiver, item, "Array.unshift result", node)
+      for (const item of args) rejectCircularInsertion(target, item, "Array.unshift result", node)
      target.unshift(...args)
      return Effect.succeed(target.length)
    }
@@ -717,7 +714,7 @@ const invokeArrayMethod = <R>(
      if (args.length === 1) return Effect.succeed(target.splice(start))
      const deleteCount = optNumber(args[1], "delete count") ?? 0
      const inserted = args.slice(2)
-      for (const item of inserted) rejectCircularInsertion(receiver, item, "Array.splice result", node)
+      for (const item of inserted) rejectCircularInsertion(target, item, "Array.splice result", node)
      return Effect.succeed(target.splice(start, deleteCount, ...inserted))
    }
    case "toSpliced": {
@@ -734,23 +731,23 @@ const invokeArrayMethod = <R>(
      return Effect.succeed(copied)
    }
    case "fill": {
-      rejectCircularInsertion(receiver, args[0], "Array.fill result", node)
-      target.fill(args[0], optNumber(args[1], "start"), optNumber(args[2], "end"))
-      return Effect.succeed(receiver)
+      rejectCircularInsertion(target, args[0], "Array.fill result", node)
+      return Effect.succeed(target.fill(args[0], optNumber(args[1], "start"), optNumber(args[2], "end")))
    }
    case "copyWithin":
-      target.copyWithin(
-        optNumber(args[0], "target index") ?? 0,
-        optNumber(args[1], "start") ?? 0,
-        optNumber(args[2], "end"),
+      return Effect.succeed(
+        target.copyWithin(
+          optNumber(args[0], "target index") ?? 0,
+          optNumber(args[1], "start") ?? 0,
+          optNumber(args[2], "end"),
+        ),
      )
-      return Effect.succeed(receiver)
    case "keys":
      return Effect.succeed(Array.from(target.keys()))
    case "values":
      return Effect.succeed([...target])
    case "entries":
-      return Effect.succeed(Array.from(target.entries(), ([index, item]) => new ProgramArray([index, item])))
+      return Effect.succeed(Array.from(target.entries(), ([index, item]): Array<unknown> => [index, item]))
  }

  const apply = applyCollectionCallback(runner, args[0], `Array.${name}`, node)
@@ -763,7 +760,7 @@ const invokeArrayMethod = <R>(
        values.length = length
        for (let index = 0; index < length; index += 1) {
          if (!(index in target)) continue
-          values[index] = yield* apply([target[index], index, receiver])
+          values[index] = yield* apply([target[index], index, target])
        }
        return values
      }
@@ -771,8 +768,8 @@ const invokeArrayMethod = <R>(
        const values: Array<unknown> = []
        for (let index = 0; index < length; index += 1) {
          if (!(index in target)) continue
-          const mapped = yield* apply([target[index], index, receiver])
-          if (mapped instanceof ProgramArray) values.push(...mapped.items)
+          const mapped = yield* apply([target[index], index, target])
+          if (Array.isArray(mapped)) values.push(...mapped)
          else values.push(mapped)
        }
        return values
@@ -782,36 +779,36 @@ const invokeArrayMethod = <R>(
        for (let index = 0; index < length; index += 1) {
          if (!(index in target)) continue
          const item = target[index]
-          if (yield* apply([item, index, receiver])) values.push(item)
+          if (yield* apply([item, index, target])) values.push(item)
        }
        return values
      }
      case "find":
        for (let index = 0; index < length; index += 1) {
          const item = target[index]
-          if (yield* apply([item, index, receiver])) return item
+          if (yield* apply([item, index, target])) return item
        }
        return undefined
      case "findIndex":
        for (let index = 0; index < length; index += 1) {
-          if (yield* apply([target[index], index, receiver])) return index
+          if (yield* apply([target[index], index, target])) return index
        }
        return -1
      case "some":
        for (let index = 0; index < length; index += 1) {
          if (!(index in target)) continue
-          if (yield* apply([target[index], index, receiver])) return true
+          if (yield* apply([target[index], index, target])) return true
        }
        return false
      case "every":
        for (let index = 0; index < length; index += 1) {
          if (!(index in target)) continue
-          if (!(yield* apply([target[index], index, receiver]))) return false
+          if (!(yield* apply([target[index], index, target]))) return false
        }
        return true
      case "forEach":
        for (let index = 0; index < length; index += 1) {
-          if (index in target) yield* apply([target[index], index, receiver])
+          if (index in target) yield* apply([target[index], index, target])
        }
        return undefined
      case "reduce": {
@@ -828,7 +825,7 @@ const invokeArrayMethod = <R>(
        }
        for (let index = start; index < length; index += 1) {
          if (!(index in target)) continue
-          accumulator = yield* apply([accumulator, target[index], index, receiver])
+          accumulator = yield* apply([accumulator, target[index], index, target])
        }
        return accumulator
      }
@@ -846,19 +843,19 @@ const invokeArrayMethod = <R>(
        }
        for (let index = start; index >= 0; index -= 1) {
          if (!(index in target)) continue
-          accumulator = yield* apply([accumulator, target[index], index, receiver])
+          accumulator = yield* apply([accumulator, target[index], index, target])
        }
        return accumulator
      }
      case "findLast":
        for (let index = length - 1; index >= 0; index -= 1) {
          const item = target[index]
-          if (yield* apply([item, index, receiver])) return item
+          if (yield* apply([item, index, target])) return item
        }
        return undefined
      case "findLastIndex":
        for (let index = length - 1; index >= 0; index -= 1) {
-          if (yield* apply([target[index], index, receiver])) return index
+          if (yield* apply([target[index], index, target])) return index
        }
        return -1
    }
@@ -1,7 +1,7 @@
-import type { Node } from "acorn"
+import type { BlockStatement, Expression, Node, Pattern } from "acorn"
 import type { Effect } from "effect"
 import type { DiagnosticKind } from "../codemode.js"
-import type { ProgramObject } from "./objects.js"
+import type { SafeObject } from "../data.js"
 import type { Values } from "../values.js"

 /** Any parsed node; the interpreter narrows on `type` and reads `loc` for diagnostics. */
@@ -20,10 +20,20 @@ export type StatementResult =
  | { kind: "continue"; label?: string }

 export type MemberReference = {
-  target: ProgramObject | Values.RegExp | Values.URL
+  target: SafeObject | Array<unknown> | Values.RegExp | Values.URL
  key: PropertyKey
 }

+export class CodeModeFunction {
+  constructor(
+    readonly parameters: ReadonlyArray<Pattern>,
+    readonly body: BlockStatement | Expression,
+    readonly capturedScopes: ReadonlyArray<Map<string, Binding>>,
+    readonly async: boolean,
+    readonly generator: boolean,
+  ) {}
+}
+
 export type GeneratorRequestKind = "next" | "return" | "throw"

 export class CodeModeGenerator {
@@ -1,145 +0,0 @@
-import type { BlockStatement, Expression, Pattern } from "acorn"
-import { AsyncIteratorSymbol, type Binding, IteratorSymbol } from "./model.js"
-
-/** An object owned by the program: own properties plus a prototype link. */
-export class ProgramObject {
-  readonly props = new Map<PropertyKey, unknown>()
-  constructor(public proto: ProgramObject | null = null) {}
-}
-
-export class ProgramArray extends ProgramObject {
-  constructor(readonly items: Array<unknown> = []) {
-    super()
-  }
-}
-
-export class ProgramError extends ProgramObject {
-  constructor(readonly errorName: string) {
-    super()
-  }
-}
-
-export class ProgramFunction extends ProgramObject {
-  readonly length: number
-  constructor(
-    readonly name: string,
-    readonly parameters: ReadonlyArray<Pattern>,
-    readonly body: BlockStatement | Expression,
-    readonly capturedScopes: ReadonlyArray<Map<string, Binding>>,
-    readonly async: boolean,
-    readonly generator: boolean,
-  ) {
-    super()
-    const optional = parameters.findIndex((p) => p.type === "AssignmentPattern" || p.type === "RestElement")
-    this.length = optional === -1 ? parameters.length : optional
-  }
-}
-
-const MAX_ARRAY_LENGTH = 4_294_967_295
-
-export const parseArrayIndex = (key: string | number): number | undefined => {
-  const property = String(key)
-  if (!/^(0|[1-9]\d*)$/.test(property)) return undefined
-  const index = Number(property)
-  return index < MAX_ARRAY_LENGTH ? index : undefined
-}
-
-const canonical = (key: PropertyKey): string | symbol => (typeof key === "symbol" ? key : String(key))
-
-const index = (target: ProgramObject, key: string | symbol): number | undefined =>
-  target instanceof ProgramArray && typeof key === "string" ? parseArrayIndex(key) : undefined
-
-// Non-enumerable built-in properties: array length, function name and length.
-const builtin = (target: ProgramObject, name: string | symbol): boolean =>
-  (name === "length" && target instanceof ProgramArray) ||
-  ((name === "name" || name === "length") && target instanceof ProgramFunction)
-
-export const hasOwn = (target: ProgramObject, key: PropertyKey): boolean => {
-  const name = canonical(key)
-  const at = index(target, name)
-  if (at !== undefined) return at in (target as ProgramArray).items
-  return builtin(target, name) || target.props.has(name)
-}
-
-export const getOwn = (target: ProgramObject, key: PropertyKey): unknown => {
-  const name = canonical(key)
-  const at = index(target, name)
-  if (at !== undefined) return (target as ProgramArray).items[at]
-  if (target instanceof ProgramArray && name === "length") return target.items.length
-  if (target instanceof ProgramFunction && name === "name") return target.name
-  if (target instanceof ProgramFunction && name === "length") return target.length
-  return target.props.get(name)
-}
-
-export const get = (target: ProgramObject, key: PropertyKey): unknown => {
-  for (let current: ProgramObject | null = target; current !== null; current = current.proto) {
-    if (hasOwn(current, key)) return getOwn(current, key)
-  }
-  return undefined
-}
-
-export const has = (target: ProgramObject, key: PropertyKey): boolean => {
-  for (let current: ProgramObject | null = target; current !== null; current = current.proto) {
-    if (hasOwn(current, key)) return true
-  }
-  return false
-}
-
-export const set = (target: ProgramObject, key: PropertyKey, value: unknown): boolean => {
-  const name = canonical(key)
-  const at = index(target, name)
-  if (at !== undefined) {
-    ;(target as ProgramArray).items[at] = value
-    return true
-  }
-  if (name === "length" && target instanceof ProgramArray) {
-    const length = typeof value === "number" ? value : Number(value)
-    if (!Number.isInteger(length) || length < 0 || length > 4_294_967_295) return false
-    target.items.length = length
-    return true
-  }
-  if (builtin(target, name)) return false
-  target.props.set(name, value)
-  return true
-}
-
-export const remove = (target: ProgramObject, key: PropertyKey): boolean => {
-  const name = canonical(key)
-  const at = index(target, name)
-  if (at !== undefined) return delete (target as ProgramArray).items[at]
-  if (name === "length" && target instanceof ProgramArray) return false
-  if (builtin(target, name)) return true
-  target.props.delete(name)
-  return true
-}
-
-// JS order: array indexes, integer-like keys ascending, other strings, then symbols.
-export const ownKeys = (target: ProgramObject): Array<string | symbol> => {
-  const strings = [...target.props.keys()].filter((key): key is string => typeof key === "string")
-  const symbols = [...target.props.keys()].filter((key): key is symbol => typeof key === "symbol")
-  return [
-    ...(target instanceof ProgramArray ? Object.keys(target.items) : []),
-    ...strings.filter((key) => parseArrayIndex(key) !== undefined).sort((a, b) => Number(a) - Number(b)),
-    ...strings.filter((key) => parseArrayIndex(key) === undefined),
-    ...symbols,
-  ]
-}
-
-export const ownEntries = (target: ProgramObject): Array<[string, unknown]> =>
-  ownKeys(target)
-    .filter((key): key is string => typeof key === "string")
-    .map((key) => [key, getOwn(target, key)])
-
-export const record = (entries: Record<string, unknown>): ProgramObject => {
-  const target = new ProgramObject()
-  for (const [key, value] of Object.entries(entries)) set(target, key, value)
-  return target
-}
-
-export const assign = (target: ProgramObject, source: ProgramObject, skip?: ReadonlySet<PropertyKey>): void => {
-  for (const key of ownKeys(source)) {
-    if (skip?.has(key)) continue
-    if (typeof key === "symbol" && key !== IteratorSymbol && key !== AsyncIteratorSymbol) continue
-    set(target, key, getOwn(source, key))
-  }
-}
@@ -1,7 +1,13 @@
 import { Cause, Deferred, Effect, Exit, Fiber, Scope } from "effect"
 import type { Diagnostic } from "../codemode.js"
-import { type AstNode, InterpreterRuntimeError, ProgramThrow, PromiseInstanceMethodReference } from "./model.js"
-import { get, ProgramArray, ProgramFunction, ProgramObject, record } from "./objects.js"
+import type { SafeObject } from "../data.js"
+import {
+  type AstNode,
+  CodeModeFunction,
+  InterpreterRuntimeError,
+  ProgramThrow,
+  PromiseInstanceMethodReference,
+} from "./model.js"
 import { HostFunction, requiresNew, sync } from "./host.js"
 import { caughtErrorValue, normalizeError } from "./errors.js"
 import { typeofValue } from "./references.js"
@@ -105,8 +111,8 @@ export const resolvePromiseValue = <R>(
 ): Effect.Effect<unknown, unknown, R> => {
  if (own?.promise !== undefined && value === own.promise) return Effect.fail(selfResolutionError(node))
  if (value instanceof Values.Promise) return runner.settlePromise(value)
-  if (!(value instanceof ProgramObject)) return Effect.succeed(value)
-  const then = get(value, "then")
+  if (value === null || typeof value !== "object" || !Object.hasOwn(value, "then")) return Effect.succeed(value)
+  const then = (value as SafeObject).then
  if (typeofValue(then) !== "function") return Effect.succeed(value)

  return Effect.gen(function* () {
@@ -168,12 +174,10 @@ const invokePromiseMethod = <R>(
      }

      if (name === "all") {
-        return new ProgramArray(
-          yield* settleAfterTurn(
-            Effect.all(
-              items.map((item) => Effect.flatten(promises.await(item))),
-              { concurrency: "unbounded" },
-            ),
+        return yield* settleAfterTurn(
+          Effect.all(
+            items.map((item) => Effect.flatten(promises.await(item))),
+            { concurrency: "unbounded" },
          ),
        )
      }
@@ -182,14 +186,19 @@ const invokePromiseMethod = <R>(
        for (const item of items) {
          const exit = yield* promises.await(item)
          if (Exit.isSuccess(exit)) {
-            outcomes.push(record({ status: "fulfilled", value: exit.value }))
+            outcomes.push(Object.assign(Object.create(null) as SafeObject, { status: "fulfilled", value: exit.value }))
            continue
          }
          if (Cause.hasInterruptsOnly(exit.cause)) return yield* Effect.failCause(exit.cause)
-          outcomes.push(record({ status: "rejected", reason: caughtErrorValue(Cause.squash(exit.cause)) }))
+          outcomes.push(
+            Object.assign(Object.create(null) as SafeObject, {
+              status: "rejected",
+              reason: caughtErrorValue(Cause.squash(exit.cause)),
+            }),
+          )
        }
        yield* Effect.yieldNow
-        return new ProgramArray(outcomes)
+        return outcomes
      }
      if (name === "race") {
        if (items.length === 0) {
@@ -244,7 +253,7 @@ const constructPromise = <R>(
  executor: unknown,
  node: AstNode,
 ): Effect.Effect<Values.Promise, unknown, R> => {
-  if (!(executor instanceof ProgramFunction)) {
+  if (!(executor instanceof CodeModeFunction)) {
    throw new InterpreterRuntimeError(
      "new Promise(...) expects an executor function (e.g. new Promise((resolve, reject) => { ... })).",
      node,
@@ -3,18 +3,20 @@ import { Values } from "../values.js"
 import { HostFunction, HostNamespace } from "./host.js"
 import {
  type AstNode,
+  AsyncIteratorSymbol,
+  CodeModeFunction,
  CodeModeGenerator,
  GeneratorMethodReference,
  InterpreterRuntimeError,
  IntrinsicReference,
+  IteratorSymbol,
  PromiseInstanceMethodReference,
 } from "./model.js"
-import { getOwn, ownKeys, ProgramArray, ProgramFunction, ProgramObject } from "./objects.js"

 export const isRuntimeReference = (value: unknown): boolean =>
  value instanceof HostFunction ||
  value instanceof HostNamespace ||
-  value instanceof ProgramFunction ||
+  value instanceof CodeModeFunction ||
  value instanceof CodeModeGenerator ||
  value instanceof GeneratorMethodReference ||
  value instanceof ToolReference ||
@@ -24,8 +26,11 @@ export const isRuntimeReference = (value: unknown): boolean =>
  Values.isValue(value)

 function* childValues(value: object): Generator {
-  if (!(value instanceof ProgramObject)) return
-  for (const key of ownKeys(value)) yield getOwn(value, key)
+  for (const key of Reflect.ownKeys(value)) {
+    if (!Object.prototype.propertyIsEnumerable.call(value, key)) continue
+    if (typeof key === "symbol" && key !== AsyncIteratorSymbol && key !== IteratorSymbol) continue
+    yield Reflect.get(value, key)
+  }
 }

 // Depth-first search over a value tree. `match` stops the walk; `skip` prunes a subtree without matching it.
@@ -74,7 +79,7 @@ export const rejectCircularInsertion = (

 export const describeValue = (value: unknown): string => {
  if (value === null) return "null"
-  if (value instanceof ProgramArray) return "an array"
+  if (Array.isArray(value)) return "an array"
  if (value instanceof Values.Promise) return "an un-awaited Promise"
  if (value instanceof ToolReference) return "a tool reference"
  if (value instanceof Values.Date) return "a Date"
@@ -92,7 +97,7 @@ export const describeValue = (value: unknown): string => {
 export const typeofValue = (value: unknown): string => {
  if (
    value instanceof HostFunction ||
-    value instanceof ProgramFunction ||
+    value instanceof CodeModeFunction ||
    value instanceof GeneratorMethodReference ||
    value instanceof IntrinsicReference ||
    value instanceof PromiseInstanceMethodReference
@@ -103,3 +108,12 @@ export const typeofValue = (value: unknown): string => {
  if (value instanceof ToolReference) return value.path.length > 0 ? "function" : "object"
  return typeof value
 }
+
+const MAX_ARRAY_LENGTH = 4_294_967_295
+
+export const parseArrayIndex = (key: string | number): number | undefined => {
+  const property = String(key)
+  if (!/^(0|[1-9]\d*)$/.test(property)) return undefined
+  const index = Number(property)
+  return index < MAX_ARRAY_LENGTH ? index : undefined
+}
@@ -2,8 +2,7 @@ import { Effect, Exit } from "effect"
 import { Values } from "../values.js"
 import { coerceToString } from "../stdlib/value.js"
 import { HostFunction } from "./host.js"
-import { type AstNode, InterpreterRuntimeError, IntrinsicReference } from "./model.js"
-import { get, has, ProgramFunction, ProgramObject } from "./objects.js"
+import { type AstNode, CodeModeFunction, InterpreterRuntimeError, IntrinsicReference } from "./model.js"
 import { typeofValue } from "./references.js"

 export type IteratorCursor<R> = {
@@ -13,7 +12,7 @@ export type IteratorCursor<R> = {

 /** Everything a host function needs to call back into the program. */
 export type Runner<R> = {
-  readonly invokeFunction: (fn: ProgramFunction, args: Array<unknown>) => Effect.Effect<unknown, unknown, R>
+  readonly invokeFunction: (fn: CodeModeFunction, args: Array<unknown>) => Effect.Effect<unknown, unknown, R>
  readonly invokeCallable: (
    callable: unknown,
    args: Array<unknown>,
@@ -43,14 +42,13 @@ export const toPrimitive = <R>(
  if (Values.isValue(value)) {
    return Effect.succeed(value instanceof Values.Date && hint === "number" ? value.time : coerceToString(value))
  }
-  if (!(value instanceof ProgramObject)) return Effect.succeed(value)
+  const object = value as Record<string, unknown>
  const order = hint === "number" ? ["valueOf", "toString"] : ["toString", "valueOf"]
  return Effect.gen(function* () {
    for (const method of order) {
-      if (method === "toString" && !has(value, "toString")) return coerceToString(value)
-      const callable = get(value, method)
-      if (typeofValue(callable) !== "function") continue
-      const result = yield* runner.invokeCallable(callable, [], node)
+      if (method === "toString" && !Object.hasOwn(object, "toString")) return coerceToString(value)
+      if (!Object.hasOwn(object, method) || typeofValue(object[method]) !== "function") continue
+      const result = yield* runner.invokeCallable(object[method], [], node)
      if (result === null || (typeof result !== "object" && typeof result !== "function")) return result
    }
    throw new InterpreterRuntimeError("Cannot convert object to primitive value.", node).as("TypeError")
@@ -61,10 +59,10 @@ export const toPrimitive = <R>(
 // Array.from mappers, and promise reactions all admit exactly these callables.
 // Admission means dispatchable, not necessarily invocable: new-requiring
 // constructors pass the gate and throw a TypeError on call, like JS.
-export type SupportedCallback = ProgramFunction | HostFunction<unknown> | IntrinsicReference
+export type SupportedCallback = CodeModeFunction | HostFunction<unknown> | IntrinsicReference

 export const isSupportedCallback = (value: unknown): value is SupportedCallback =>
-  value instanceof ProgramFunction ||
+  value instanceof CodeModeFunction ||
  (value instanceof HostFunction && value.callback) ||
  value instanceof IntrinsicReference

@@ -1,7 +1,6 @@
 import type {
  ArrayExpression,
  ArrayPattern,
-  AssignmentPattern,
  ArrowFunctionExpression,
  AssignmentExpression,
  AssignmentProperty,
@@ -42,12 +41,13 @@ import type {
  YieldExpression,
 } from "acorn"
 import { Cause, Deferred, Effect, Exit } from "effect"
-import { ToolRuntimeError, toProgram } from "../data.js"
+import { ToolRuntimeError, type SafeObject, toProgram } from "../data.js"
 import { ToolReference } from "../tool-runtime.js"
 import {
  type AstNode,
  AsyncIteratorSymbol,
  type Binding,
+  CodeModeFunction,
  CodeModeGenerator,
  ComputedValue,
  GeneratorMethodReference,
@@ -55,7 +55,9 @@ import {
  type GeneratorRequestKind,
  IntrinsicReference,
  InterpreterRuntimeError,
+  isRecord,
  IteratorSymbol,
+  IteratorSymbols,
  type MemberReference,
  OptionalShortCircuit,
  PromiseInstanceMethodReference,
@@ -67,25 +69,13 @@ import { caughtErrorValue } from "./errors.js"
 import { globals, type Host } from "./globals.js"
 import { HostFunction, HostNamespace } from "./host.js"
 import { invokeIntrinsic } from "./methods.js"
-import {
-  assign,
-  get,
-  has,
-  ownKeys,
-  parseArrayIndex,
-  ProgramArray,
-  ProgramFunction,
-  ProgramObject,
-  record,
-  remove,
-  set,
-} from "./objects.js"
 import { preserveConsumerError, type Runner } from "./runner.js"
 import { invokePromiseInstanceMethod, PromiseRuntime, resolvePromise, resolvePromiseValue } from "./promises.js"
 import {
  containsOpaqueReference,
  describeValue,
  isRuntimeReference,
+  parseArrayIndex,
  rejectCircularInsertion,
  typeofValue,
 } from "./references.js"
@@ -128,11 +118,14 @@ const calleeDescription = (callee: Expression | Super | undefined): string => {
  return "The called value"
 }

+const hasOwn = (value: unknown, key: PropertyKey): boolean =>
+  value !== null && typeof value === "object" && Object.hasOwn(value, key)
+
 const constructorName = (value: unknown): string | undefined => {
  if (typeof value === "string") return "String"
  if (typeof value === "number") return "Number"
  if (typeof value === "boolean") return "Boolean"
-  if (value instanceof ProgramArray) return "Array"
+  if (Array.isArray(value)) return "Array"
  if (value instanceof Values.Date) return "Date"
  if (value instanceof Values.RegExp) return "RegExp"
  if (value instanceof Values.Map) return "Map"
@@ -140,7 +133,7 @@ const constructorName = (value: unknown): string | undefined => {
  if (value instanceof Values.URL) return "URL"
  if (value instanceof Values.URLSearchParams) return "URLSearchParams"
  if (value instanceof Values.Promise) return "Promise"
-  if (!(value instanceof ProgramObject) || value instanceof ProgramFunction) return undefined
+  if (value === null || typeof value !== "object" || isRuntimeReference(value)) return undefined
  return errorBrandName(value) ?? "Object"
 }

@@ -237,7 +230,7 @@ const loopDeclaration = (left: VariableDeclaration | Pattern, statement: "for...
 }

 type CustomIterator = {
-  iterator: ProgramObject | CodeModeGenerator
+  iterator: SafeObject | CodeModeGenerator
  next: unknown
  asynchronous: boolean
 }
@@ -254,6 +247,13 @@ const isOpaqueMemberReference = (value: unknown): value is OpaqueMemberReference
  value instanceof IntrinsicReference ||
  value instanceof GeneratorMethodReference

+const copyIteratorSymbols = (source: object, target: object, consumed?: ReadonlySet<PropertyKey>): void => {
+  for (const symbol of IteratorSymbols) {
+    if (!consumed?.has(symbol) && Object.hasOwn(source, symbol))
+      Reflect.set(target, symbol, Reflect.get(source, symbol))
+  }
+}
+
 type GeneratorRequest = {
  kind: GeneratorRequestKind
  value: unknown
@@ -435,19 +435,8 @@ class Frame<R> {
    }).pipe(Effect.ensuring(Effect.sync(() => self.scopes.pop())))
  }

-  private createFunction(
-    node: FunctionDeclaration | FunctionExpression | ArrowFunctionExpression,
-    name = node.type === "ArrowFunctionExpression" ? "" : (node.id?.name ?? ""),
-  ): ProgramFunction {
-    return new ProgramFunction(name, node.params, node.body, this.scopes.capture(), node.async, node.generator)
-  }
-
-  // NamedEvaluation: an anonymous function definition takes the name of what it is assigned to.
-  private evaluateNamed(node: Expression, name: string): Effect.Effect<unknown, unknown, R> {
-    if (node.type === "ArrowFunctionExpression" || (node.type === "FunctionExpression" && !node.id)) {
-      return Effect.sync(() => this.createFunction(node, name))
-    }
-    return this.evaluateExpression(node)
+  private createFunction(node: FunctionDeclaration | FunctionExpression | ArrowFunctionExpression): CodeModeFunction {
+    return new CodeModeFunction(node.params, node.body, this.scopes.capture(), node.async, node.generator)
  }

  private hoistFunctions(statements: ReadonlyArray<Statement | ModuleDeclaration>): void {
@@ -734,26 +723,22 @@ class Frame<R> {
  }

  syncIterator(value: unknown, node: AstNode) {
-    const iterator =
-      value instanceof ProgramArray
-        ? value.items[Symbol.iterator]()
-        : typeof value === "string"
-          ? value[Symbol.iterator]()
-          : value instanceof Values.Map
-            ? value.map.entries()
-            : value instanceof Values.Set
-              ? value.set.values()
-              : value instanceof Values.URLSearchParams
-                ? value.params.entries()
-                : undefined
+    const iterator = Array.isArray(value)
+      ? value[Symbol.iterator]()
+      : typeof value === "string"
+        ? value[Symbol.iterator]()
+        : value instanceof Values.Map
+          ? value.map.entries()
+          : value instanceof Values.Set
+            ? value.set.values()
+            : value instanceof Values.URLSearchParams
+              ? value.params.entries()
+              : undefined
    if (iterator !== undefined) {
      return Effect.succeed({
        next: Effect.sync(() => {
          const step = iterator.next()
-          return {
-            done: Boolean(step.done),
-            value: Array.isArray(step.value) ? new ProgramArray(step.value) : step.value,
-          }
+          return { done: Boolean(step.done), value: step.value }
        }),
        close: Effect.void,
      })
@@ -778,9 +763,9 @@ class Frame<R> {
        asynchronous: value.asynchronous,
      })
    }
-    if (!(value instanceof ProgramObject)) return Effect.undefined
-    const asyncMethod = allowAsync ? get(value, AsyncIteratorSymbol) : undefined
-    const method = asyncMethod ?? get(value, IteratorSymbol)
+    if (!isRecord(value) || isRuntimeReference(value)) return Effect.undefined
+    const asyncMethod = allowAsync ? Reflect.get(value, AsyncIteratorSymbol) : undefined
+    const method = asyncMethod ?? Reflect.get(value, IteratorSymbol)
    if (method === undefined || method === null) return Effect.undefined
    const self = this
    return Effect.map(
@@ -792,7 +777,7 @@ class Frame<R> {
          next:
            object instanceof CodeModeGenerator
              ? new GeneratorMethodReference(object, "next")
-              : self.requireIteratorMethod(get(object, "next"), "Iterator next", node),
+              : self.requireIteratorMethod(object.next, "Iterator next", node),
          asynchronous: asyncMethod !== undefined && asyncMethod !== null,
        }
      },
@@ -808,7 +793,7 @@ class Frame<R> {
          "Iterator next() result",
          node,
        )
-        return { done: Boolean(get(object, "done")), value: get(object, "value") }
+        return { done: Boolean(object.done), value: object.value }
      }

      const called = yield* Effect.exit(self.invokeCallable(iterator.next, [], node))
@@ -819,7 +804,7 @@ class Frame<R> {
      const captured = yield* Effect.exit(
        Effect.sync(() => {
          const object = self.requireIteratorObject(called.value, "Iterator next() result", node)
-          return { done: Boolean(get(object, "done")), value: get(object, "value") }
+          return { done: Boolean(object.done), value: object.value }
        }),
      )
      if (!Exit.isSuccess(captured)) {
@@ -839,7 +824,7 @@ class Frame<R> {
    const close =
      iterator.iterator instanceof CodeModeGenerator
        ? new GeneratorMethodReference(iterator.iterator, "return")
-        : get(iterator.iterator, "return")
+        : iterator.iterator.return
    if (close === undefined || close === null) return iterator.asynchronous || !awaiting ? Effect.void : Effect.yieldNow
    const self = this
    return Effect.gen(function* () {
@@ -859,7 +844,7 @@ class Frame<R> {
        return yield* Effect.failCause(called.cause)
      }
      const captured = yield* Effect.exit(
-        Effect.sync(() => get(self.requireIteratorObject(called.value, "Iterator return() result", node), "value")),
+        Effect.sync(() => self.requireIteratorObject(called.value, "Iterator return() result", node).value),
      )
      if (!Exit.isSuccess(captured)) {
        if (awaiting) yield* Effect.yieldNow
@@ -869,12 +854,12 @@ class Frame<R> {
    })
  }

-  private requireIteratorObject(value: unknown, context: string, node: AstNode): ProgramObject {
-    if (value instanceof ProgramObject) return value
+  private requireIteratorObject(value: unknown, context: string, node: AstNode): SafeObject {
+    if (isRecord(value) && !isRuntimeReference(value)) return value
    throw new InterpreterRuntimeError(`${context} must be an object.`, node).as("TypeError")
  }

-  private requireIterator(value: unknown, node: AstNode): ProgramObject | CodeModeGenerator {
+  private requireIterator(value: unknown, node: AstNode): SafeObject | CodeModeGenerator {
    return value instanceof CodeModeGenerator
      ? value
      : this.requireIteratorObject(value, "Iterator method result", node)
@@ -889,7 +874,7 @@ class Frame<R> {
  private enumerableKeys(value: unknown, node: AstNode): Array<string> {
    if (value instanceof ToolReference) return [...this.runtime.toolKeys(value.path)]
    if (value === null || value === undefined) return []
-    return ownKeys(enumerableSource("for...in", value, node)).filter((key): key is string => typeof key === "string")
+    return Object.keys(enumerableSource("for...in", value, node))
  }

  private evaluateForInStatement(
@@ -1035,14 +1020,11 @@ class Frame<R> {

        const init = declaration.init
        // `var x` alone is a no-op: the binding was hoisted on function entry.
-        const id = declaration.id
-        const evaluate = (init: Expression) =>
-          id.type === "Identifier" ? self.evaluateNamed(init, id.name) : self.evaluateExpression(init)
        if (kind === "var") {
-          if (init) yield* self.assignPattern(id, yield* evaluate(init), declaration)
+          if (init) yield* self.assignPattern(declaration.id, yield* self.evaluateExpression(init), declaration)
          continue
        }
-        const value = init ? yield* evaluate(init) : undefined
+        const value = init ? yield* self.evaluateExpression(init) : undefined
        yield* self.declarePattern(declaration.id, value, kind !== "const", declaration, true)
      }
    })
@@ -1065,13 +1047,13 @@ class Frame<R> {
      }

      if (pattern.type === "AssignmentPattern") {
-        const resolved = value === undefined ? yield* self.evaluateDefault(pattern) : value
+        const resolved = value === undefined ? yield* self.evaluateExpression(pattern.right) : value
        yield* self.declarePattern(pattern.left, resolved, mutable, node, initialize)
        return
      }

      if (pattern.type === "ObjectPattern") {
-        if (!(value instanceof ProgramObject)) {
+        if (value === null || typeof value !== "object" || isRuntimeReference(value)) {
          throw new InterpreterRuntimeError(
            `Object destructuring requires a data object or array value, received ${describeValue(value)}.`,
            pattern,
@@ -1082,8 +1064,11 @@ class Frame<R> {
        const consumed = new Set<PropertyKey>()
        for (const property of pattern.properties) {
          if (property.type === "RestElement") {
-            const rest = new ProgramObject()
-            assign(rest, value, consumed)
+            const rest: SafeObject = Object.create(null) as SafeObject
+            for (const [key, item] of Object.entries(value as SafeObject)) {
+              if (!consumed.has(key)) rest[key] = item
+            }
+            copyIteratorSymbols(value, rest, consumed)
            yield* self.declarePattern(property.argument, rest, mutable, property, initialize)
            continue
          }
@@ -1092,7 +1077,7 @@ class Frame<R> {
          consumed.add(typeof key === "symbol" ? key : String(key))
          yield* self.declarePattern(
            property.value,
-            self.destructuringPropertyValue(value, key),
+            self.destructuringPropertyValue(value as SafeObject | Array<unknown>, key),
            mutable,
            property,
            initialize,
@@ -1125,13 +1110,13 @@ class Frame<R> {
      }

      if (pattern.type === "AssignmentPattern") {
-        const resolved = value === undefined ? yield* self.evaluateDefault(pattern) : value
+        const resolved = value === undefined ? yield* self.evaluateExpression(pattern.right) : value
        yield* self.assignPattern(pattern.left, resolved, node)
        return
      }

      if (pattern.type === "ObjectPattern") {
-        if (!(value instanceof ProgramObject)) {
+        if (value === null || typeof value !== "object" || isRuntimeReference(value)) {
          throw new InterpreterRuntimeError(
            `Object destructuring requires a data object or array value, received ${describeValue(value)}.`,
            pattern,
@@ -1139,17 +1124,21 @@ class Frame<R> {
          )
        }

+        const source = value as SafeObject | Array<unknown>
        const consumed = new Set<PropertyKey>()
        for (const property of pattern.properties) {
          if (property.type === "RestElement") {
-            const rest = new ProgramObject()
-            assign(rest, value, consumed)
+            const rest: SafeObject = Object.create(null) as SafeObject
+            for (const [key, item] of Object.entries(source)) {
+              if (!consumed.has(key)) rest[key] = item
+            }
+            copyIteratorSymbols(source, rest, consumed)
            yield* self.assignPattern(property.argument, rest, property)
            continue
          }
          const key = yield* self.destructuringPropertyKey(property)
          consumed.add(typeof key === "symbol" ? key : String(key))
-          yield* self.assignPattern(property.value, self.destructuringPropertyValue(value, key), property)
+          yield* self.assignPattern(property.value, self.destructuringPropertyValue(source, key), property)
        }
        return
      }
@@ -1164,12 +1153,6 @@ class Frame<R> {
    })
  }

-  private evaluateDefault(pattern: AssignmentPattern): Effect.Effect<unknown, unknown, R> {
-    return pattern.left.type === "Identifier"
-      ? this.evaluateNamed(pattern.right, pattern.left.name)
-      : this.evaluateExpression(pattern.right)
-  }
-
  private destructureArrayPattern(
    pattern: ArrayPattern,
    value: unknown,
@@ -1189,7 +1172,7 @@ class Frame<R> {
          if (element === null) continue
          yield* consume(
            element.type === "RestElement" ? element.argument : element,
-            element.type === "RestElement" ? new ProgramArray() : undefined,
+            element.type === "RestElement" ? [] : undefined,
            element,
          )
          if (element.type === "RestElement") return
@@ -1206,7 +1189,7 @@ class Frame<R> {
            done = next.done
            if (!done) rest.push(next.value)
          }
-          yield* consume(element.argument, new ProgramArray(rest), element)
+          yield* consume(element.argument, rest, element)
          return
        }
        const consumed = consume(element, step.done ? undefined : step.value, pattern)
@@ -1229,9 +1212,11 @@ class Frame<R> {
    throw unsupportedSyntax(keyNode.type, keyNode)
  }

-  private destructuringPropertyValue(source: ProgramObject, key: PropertyKey): unknown {
-    if (!(source instanceof ProgramArray)) return get(source, key)
-    if (has(source, key)) return get(source, key)
+  private destructuringPropertyValue(source: SafeObject | Array<unknown>, key: PropertyKey): unknown {
+    if (!Array.isArray(source)) return Reflect.get(source, key)
+    if (key === "length") return source.length
+    if (typeof key === "number") return source[key]
+    if (Object.hasOwn(source, key)) return Reflect.get(source, key)
    if (typeof key === "string" && arrayMethods.has(key)) return new IntrinsicReference(source, key)
    return undefined
  }
@@ -1309,7 +1294,7 @@ class Frame<R> {
        // otherwise; say `new` is unsupported for them and point at the plain call.
        const name = calleeDescription(node.callee)
        const message =
-          callee instanceof ProgramFunction
+          callee instanceof CodeModeFunction
            ? `${name} cannot be constructed: user-defined constructors and classes are not supported. Call it as a function that returns a plain object instead.`
            : callee instanceof HostFunction
              ? `new ${name}(...) is not supported; call ${name}(...) without new instead.`
@@ -1337,9 +1322,6 @@ class Frame<R> {
  private applyBinaryOperator(operator: string, lhs: unknown, rhs: unknown, node: AstNode): unknown {
    if (operator === "===") return lhs === rhs
    if (operator === "!==") return lhs !== rhs
-    if (operator === "in" && rhs instanceof ProgramObject && !containsOpaqueReference(lhs)) {
-      return has(rhs, lhs !== null && typeof lhs === "object" ? coerceToString(lhs) : (lhs as PropertyKey))
-    }
    if (containsOpaqueReference(lhs) || containsOpaqueReference(rhs)) {
      throw new InterpreterRuntimeError("Binary operators require data values.", node, "InvalidDataValue")
    }
@@ -1392,10 +1374,11 @@ class Frame<R> {
      case ">>>":
        return (l as number) >>> (r as number)
      case "in":
-        if (!(rhs instanceof ProgramObject)) {
+        if (rhs === null || typeof rhs !== "object") {
          throw new InterpreterRuntimeError("The 'in' operator requires a data object on the right-hand side.", node)
        }
-        return has(rhs, coerceOperand(lhs) as PropertyKey)
+        // Never expose properties inherited from host prototypes.
+        return Object.hasOwn(rhs as object, coerceOperand(lhs) as PropertyKey)
      default:
        throw new InterpreterRuntimeError(`Unsupported binary operator '${operator}'.`, node)
    }
@@ -1472,7 +1455,7 @@ class Frame<R> {
          const next = toProgram(self.applyCompoundAssignment(operator, current, rightValue, node), "Assignment result")
          return self.scopes.set(name, next, left)
        }
-        const rightValue = yield* self.evaluateNamed(node.right, name)
+        const rightValue = yield* self.evaluateExpression(node.right)
        return self.scopes.set(name, rightValue, left)
      }
      if (left.type === "MemberExpression") {
@@ -1504,7 +1487,7 @@ class Frame<R> {
      return Effect.gen(function* () {
        const current = self.scopes.get(name, left)
        if (!shouldAssign(current)) return current
-        const rightValue = yield* self.evaluateNamed(node.right, name)
+        const rightValue = yield* self.evaluateExpression(node.right)
        return self.scopes.set(name, rightValue, left)
      })
    }
@@ -1593,7 +1576,7 @@ class Frame<R> {
        }
        return yield* self.createToolCallPromise(callable.path, args)
      }
-      if (callable instanceof ProgramFunction) {
+      if (callable instanceof CodeModeFunction) {
        return yield* self.invokeFunction(callable, args)
      }
      if (callable instanceof GeneratorMethodReference) {
@@ -1644,7 +1627,7 @@ class Frame<R> {
    })
  }

-  invokeFunction(fn: ProgramFunction, args: Array<unknown>): Effect.Effect<unknown, unknown, R> {
+  invokeFunction(fn: CodeModeFunction, args: Array<unknown>): Effect.Effect<unknown, unknown, R> {
    const invocation = new Frame(this.runtime, new ScopeStack([...fn.capturedScopes, new Map()]))
    const run = Effect.gen(function* () {
      // Seed all parameters first so defaults cannot fall through to same-named outer bindings.
@@ -1656,13 +1639,7 @@ class Frame<R> {
      }
      for (const [index, parameter] of fn.parameters.entries()) {
        if (parameter.type === "RestElement") {
-          yield* invocation.declarePattern(
-            parameter.argument,
-            new ProgramArray(args.slice(index)),
-            true,
-            parameter,
-            true,
-          )
+          yield* invocation.declarePattern(parameter.argument, args.slice(index), true, parameter, true)
          break
        }
        yield* invocation.declarePattern(parameter, args[index], true, parameter, true)
@@ -1714,12 +1691,12 @@ class Frame<R> {
      }
      if (state.completed) {
        if (kind === "throw") return Effect.fail(new ProgramThrow(value))
-        return Effect.succeed(record({ value: kind === "return" ? value : undefined, done: true }))
+        return Effect.succeed({ value: kind === "return" ? value : undefined, done: true })
      }
      if (!state.started && kind !== "next") {
        state.completed = true
        if (kind === "throw") return Effect.fail(new ProgramThrow(value))
-        return Effect.succeed(record({ value, done: true }))
+        return Effect.succeed({ value, done: true })
      }

      state.pending.push(request)
@@ -1749,7 +1726,7 @@ class Frame<R> {
          if (active) {
            Deferred.doneUnsafe(
              active.response,
-              Exit.isSuccess(exit) ? Exit.succeed(record({ value: exit.value, done: true })) : exit,
+              Exit.isSuccess(exit) ? Exit.succeed({ value: exit.value, done: true }) : exit,
            )
          }
          yield* invocation.completeGeneratorRequests(state, asynchronous)
@@ -1776,13 +1753,13 @@ class Frame<R> {
          const resolved = yield* Effect.exit(self.awaitValue(pending.value))
          Deferred.doneUnsafe(
            pending.response,
-            Exit.isSuccess(resolved) ? Exit.succeed(record({ value: resolved.value, done: true })) : resolved,
+            Exit.isSuccess(resolved) ? Exit.succeed({ value: resolved.value, done: true }) : resolved,
          )
          continue
        }
        Deferred.doneUnsafe(
          pending.response,
-          Exit.succeed(record({ value: pending.kind === "return" ? pending.value : undefined, done: true })),
+          Exit.succeed({ value: pending.kind === "return" ? pending.value : undefined, done: true }),
        )
      }
    })
@@ -1827,7 +1804,7 @@ class Frame<R> {
  private suspendGenerator(value: unknown, node: AstNode): Effect.Effect<unknown, unknown, R> {
    const state = this.generatorState
    if (!state?.active) throw new InterpreterRuntimeError("Generator has no active request.", node)
-    Deferred.doneUnsafe(state.active.response, Exit.succeed(record({ value, done: false })))
+    Deferred.doneUnsafe(state.active.response, Exit.succeed({ value, done: false }))
    state.active = undefined
    return Effect.flatMap(this.takeGeneratorRequest(state), (request) => {
      state.active = request
@@ -1843,7 +1820,7 @@ class Frame<R> {
    const self = this
    return Effect.gen(function* () {
      if (
-        value instanceof ProgramArray ||
+        Array.isArray(value) ||
        typeof value === "string" ||
        value instanceof Values.Map ||
        value instanceof Values.Set ||
@@ -1884,7 +1861,7 @@ class Frame<R> {
            ? iterator.next
            : iterator.iterator instanceof CodeModeGenerator
              ? new GeneratorMethodReference(iterator.iterator, kind)
-              : get(iterator.iterator, kind)
+              : iterator.iterator[kind]
        if (method === undefined || method === null) {
          if (kind === "return") return yield* Effect.fail(new GeneratorReturn(input))
          yield* self.closeIterator(iterator, node, self.generatorAsync)
@@ -1902,11 +1879,11 @@ class Frame<R> {
          `Iterator ${kind}() result`,
          node,
        )
-        const done = Boolean(get(result, "done"))
+        const done = Boolean(result.done)
        const resultValue: unknown =
          self.generatorAsync && !iterator.asynchronous
-            ? yield* self.awaitAsyncFromSyncValue(iterator, get(result, "value"), node, kind !== "return" && !done)
-            : get(result, "value")
+            ? yield* self.awaitAsyncFromSyncValue(iterator, result.value, node, kind !== "return" && !done)
+            : result.value
        if (done) {
          if (kind === "return") return yield* Effect.fail(new GeneratorReturn(resultValue))
          return resultValue
@@ -1928,15 +1905,17 @@ class Frame<R> {
    })
  }

-  private evaluateObjectExpression(node: ObjectExpression): Effect.Effect<ProgramObject, unknown, R> {
-    const objectValue = new ProgramObject()
+  private evaluateObjectExpression(node: ObjectExpression): Effect.Effect<Record<string, unknown>, unknown, R> {
+    const objectValue: Record<string, unknown> = Object.create(null) as Record<string, unknown>
    const self = this
    return Effect.gen(function* () {
      for (const property of node.properties) {
        if (property.type === "SpreadElement") {
          const spread = yield* self.evaluateExpression(property.argument)
          if (spread === null || spread === undefined) continue
-          assign(objectValue, enumerableSource("Object spread", spread, property))
+          const from = enumerableSource("Object spread", spread, property)
+          for (const [key, value] of Object.entries(from)) objectValue[key] = value
+          if (typeof from === "object") copyIteratorSymbols(from, objectValue)
          continue
        }

@@ -1958,20 +1937,14 @@ class Frame<R> {
          throw new InterpreterRuntimeError("Unsupported object property key shape.", keyNode)
        }

-        const name =
-          key === IteratorSymbol
-            ? "[Symbol.iterator]"
-            : key === AsyncIteratorSymbol
-              ? "[Symbol.asyncIterator]"
-              : String(key)
-        set(objectValue, key, yield* self.evaluateNamed(property.value, name))
+        Reflect.set(objectValue, key, yield* self.evaluateExpression(property.value))
      }

      return objectValue
    })
  }

-  private evaluateArrayExpression(node: ArrayExpression): Effect.Effect<ProgramArray, unknown, R> {
+  private evaluateArrayExpression(node: ArrayExpression): Effect.Effect<Array<unknown>, unknown, R> {
    const values: Array<unknown> = []

    const self = this
@@ -1996,7 +1969,7 @@ class Frame<R> {
          values.push(yield* self.evaluateExpression(element))
        }
      }
-      return new ProgramArray(values)
+      return values
    })
  }

@@ -2083,11 +2056,7 @@ class Frame<R> {
      }

      // Values have no prototype chain, so `.constructor` resolves to the owning built-in directly.
-      if (
-        operation === "read" &&
-        key === "constructor" &&
-        !(objectValue instanceof ProgramObject && has(objectValue, key))
-      ) {
+      if (operation === "read" && key === "constructor" && !hasOwn(objectValue, key)) {
        const name = constructorName(objectValue)
        if (name !== undefined) return new ComputedValue(self.runtime.builtins.get(name))
      }
@@ -2168,8 +2137,6 @@ class Frame<R> {
        return new ComputedValue(undefined)
      }

-      if (objectValue instanceof ProgramObject) return { target: objectValue, key }
-
      if (isRuntimeReference(objectValue)) {
        throw new InterpreterRuntimeError(
          `Cannot read properties of ${describeValue(objectValue)}; only data values expose properties.`,
@@ -2177,27 +2144,42 @@ class Frame<R> {
          "InvalidDataValue",
        )
      }
-      throw new InterpreterRuntimeError("Cannot access a property on a non-object value.", objectNode)
+
+      if (typeof objectValue !== "object" || objectValue === null) {
+        throw new InterpreterRuntimeError("Cannot access a property on a non-object value.", objectNode)
+      }
+
+      if (Array.isArray(objectValue)) {
+        if (operation === "delete") return { target: objectValue, key }
+        const index = typeof key === "symbol" ? undefined : parseArrayIndex(key)
+        if (key !== "length" && !(typeof key === "string" && arrayMethods.has(key)) && index === undefined) {
+          if (typeof key === "string" && Object.hasOwn(objectValue, key)) {
+            return new ComputedValue((objectValue as Record<string, unknown> & Array<unknown>)[key])
+          }
+          return new ComputedValue(undefined)
+        }
+        return { target: objectValue, key: index ?? key }
+      }
+
+      return { target: objectValue as SafeObject, key }
    })
  }

  private readMember(node: MemberExpression): Effect.Effect<unknown, unknown, R> {
-    const self = this
    return Effect.map(this.getMemberReference(node), (reference) => {
      if (reference === OptionalShortCircuit) return OptionalShortCircuit
      if (reference instanceof ComputedValue) return reference.value
      if (reference === undefined || isOpaqueMemberReference(reference)) return reference
-      const value = self.readReferenceValue(reference, reference.key)
-      if (
-        value === undefined &&
-        reference.target instanceof ProgramArray &&
-        typeof reference.key === "string" &&
-        arrayMethods.has(reference.key) &&
-        !has(reference.target, reference.key)
-      ) {
-        return new IntrinsicReference(reference.target, reference.key)
+      if (Array.isArray(reference.target)) {
+        if (reference.key === "length") return reference.target.length
+        if (typeof reference.key === "string") return new IntrinsicReference(reference.target, reference.key)
+        return Reflect.get(reference.target, reference.key)
      }
-      return value
+      if (reference.target instanceof Values.RegExp) return reference.target.lastIndex
+      if (reference.target instanceof Values.URL) {
+        return Reflect.get(reference.target.url, reference.key)
+      }
+      return Reflect.get(reference.target, reference.key)
    })
  }

@@ -2223,7 +2205,7 @@ class Frame<R> {
      if (reference.target instanceof Values.RegExp) {
        return Reflect.deleteProperty(reference.target.regex, reference.key)
      }
-      return remove(reference.target, reference.key)
+      return Reflect.deleteProperty(reference.target, reference.key)
    })
  }

@@ -2243,6 +2225,12 @@ class Frame<R> {
      ) {
        throw new InterpreterRuntimeError("Only data fields may be assigned.", node)
      }
+      if (Array.isArray(reference.target)) {
+        if (reference.key === "length") throw new InterpreterRuntimeError("Array length cannot be assigned.", node)
+        if (typeof reference.key === "string" && arrayMethods.has(reference.key)) {
+          throw new InterpreterRuntimeError("Array methods cannot be assigned.", node)
+        }
+      }
      const key = reference.key
      const { write, next, result } = yield* compute(self.readReferenceValue(reference, key))
      if (write) self.assignToReference(reference, key, next, node)
@@ -2255,10 +2243,23 @@ class Frame<R> {
      return Reflect.get(reference.target.url, key)
    }
    if (reference.target instanceof Values.RegExp) return reference.target.lastIndex
-    return get(reference.target, key)
+    return Reflect.get(reference.target, key)
  }

  private assignToReference(reference: MemberReference, key: PropertyKey, next: unknown, node: AstNode): void {
+    if (Array.isArray(reference.target)) {
+      const target = reference.target
+      if (typeof key !== "number" || parseArrayIndex(key) === undefined) {
+        throw new InterpreterRuntimeError(
+          "Array assignment index must be a valid array index.",
+          node,
+          "InvalidDataValue",
+        )
+      }
+      rejectCircularInsertion(target, next, "Array assignment result", node)
+      target[key] = next
+      return
+    }
    if (reference.target instanceof Values.URL) {
      const property = key as string
      if (!urlWritableProperties.has(property)) {
@@ -2277,16 +2278,9 @@ class Frame<R> {
      reference.target.lastIndex = next
      return
    }
-    const target = reference.target
-    rejectCircularInsertion(
-      target,
-      next,
-      target instanceof ProgramArray ? "Array assignment result" : "Object assignment result",
-      node,
-    )
-    if (set(target, key, next)) return
-    if (target instanceof ProgramArray) throw new InterpreterRuntimeError("Invalid array length", node).as("RangeError")
-    throw new InterpreterRuntimeError(`Cannot assign to read only property '${String(key)}'.`, node).as("TypeError")
+    const target = reference.target as SafeObject
+    rejectCircularInsertion(target, next, "Object assignment result", node)
+    Reflect.set(target, key, next)
  }

  private toPropertyKey(value: unknown, node: AstNode): PropertyKey {
@@ -1,27 +1,28 @@
 import { Effect } from "effect"
 import { HostFunction, sync, syncCall } from "../interpreter/host.js"
 import { type AstNode, CodeModeGenerator, InterpreterRuntimeError } from "../interpreter/model.js"
-import { get, ProgramArray, ProgramObject } from "../interpreter/objects.js"
 import { describeValue } from "../interpreter/references.js"
 import { applyCollectionCallback, preserveConsumerError, type Runner } from "../interpreter/runner.js"

-const constructArray = (args: Array<unknown>, node: AstNode): ProgramArray => {
-  if (args.length !== 1) return new ProgramArray([...args])
+const constructArray = (args: Array<unknown>, node: AstNode): Array<unknown> => {
+  if (args.length !== 1) return [...args]
  const first = args[0]
-  if (typeof first !== "number") return new ProgramArray([first])
+  if (typeof first !== "number") return [first]
  if (!Number.isInteger(first) || first < 0 || first > 4294967295) {
    throw new InterpreterRuntimeError("Invalid array length.", node).as("RangeError")
  }
  // Sparse like JS: Array(3) has holes, and combinator loops already skip them.
-  return new ProgramArray(new Array(first))
+  return new Array(first)
 }

-const arrayLikeSource = (
-  source: unknown,
-  node: AstNode,
-): { readonly length: number; readonly source: ProgramObject } => {
-  if (source instanceof ProgramObject && typeof get(source, "length") === "number") {
-    const length = get(source, "length") as number
+const arrayLikeSource = (source: unknown, node: AstNode): { readonly length: number; readonly source: object } => {
+  if (
+    source !== null &&
+    typeof source === "object" &&
+    (Object.getPrototypeOf(source) === Object.prototype || Object.getPrototypeOf(source) === null) &&
+    typeof (source as { length?: unknown }).length === "number"
+  ) {
+    const length = (source as { length: number }).length
    const normalized = Number.isNaN(length) || length <= 0 ? 0 : Math.trunc(length)
    if (normalized > 4_294_967_295) throw new RangeError("Invalid array length")
    return { length: normalized, source }
@@ -48,16 +49,16 @@ const arrayFrom = <R>(runner: Runner<R>, args: Array<unknown>, node: AstNode): E
      const arrayLike = arrayLikeSource(source, node)
      const values: Array<unknown> = []
      for (let index = 0; index < arrayLike.length; index += 1) {
-        const item = get(arrayLike.source, index)
+        const item = Reflect.get(arrayLike.source, index)
        values.push(apply === undefined ? item : yield* apply([item, index]))
      }
-      return new ProgramArray(values)
+      return values
    }
    const values: Array<unknown> = []
    let index = 0
    while (true) {
      const step = yield* cursor.next
-      if (step.done) return new ProgramArray(values)
+      if (step.done) return values
      values.push(apply === undefined ? step.value : yield* preserveConsumerError(cursor, apply([step.value, index])))
      index += 1
    }
@@ -70,10 +71,10 @@ export const arrayGlobal = <R>(runner: Runner<R>) =>
    name: "Array",
    call: syncCall(constructArray),
    construct: syncCall(constructArray),
-    instanceOf: (value) => value instanceof ProgramArray,
+    instanceOf: (value) => Array.isArray(value),
    members: {
-      isArray: sync("Array.isArray", (args) => args[0] instanceof ProgramArray),
-      of: sync("Array.of", (args) => new ProgramArray([...args])),
+      isArray: sync("Array.isArray", (args) => Array.isArray(args[0])),
+      of: sync("Array.of", (args) => [...args]),
      from: new HostFunction<R>({ name: "Array.from", call: (args, node) => arrayFrom(runner, args, node) }),
    },
  })
@@ -1,7 +1,7 @@
 import { Effect } from "effect"
+import type { SafeObject } from "../data.js"
 import { HostFunction, requiresNew } from "../interpreter/host.js"
-import { type AstNode, InterpreterRuntimeError } from "../interpreter/model.js"
-import { getOwn, ProgramArray, ProgramObject, set } from "../interpreter/objects.js"
+import { type AstNode, InterpreterRuntimeError, isRecord } from "../interpreter/model.js"
 import { describeValue, isRuntimeReference } from "../interpreter/references.js"
 import { applyCollectionCallback, preserveConsumerError, type Runner, toPrimitive } from "../interpreter/runner.js"
 import { Values } from "../values.js"
@@ -108,13 +108,13 @@ export const groupBy = <R>(runner: Runner<R>, namespace: "Map" | "Object") =>
            const item = step.value
            const key = yield* preserveConsumerError(cursor, apply([item, index]))
            const group = result.map.get(key)
-            if (group === undefined) result.map.set(key, new ProgramArray([item]))
-            else (group as ProgramArray).items.push(item)
+            if (group === undefined) result.map.set(key, [item])
+            else (group as Array<unknown>).push(item)
            index += 1
          }
        }

-        const result = new ProgramObject()
+        const result: SafeObject = Object.create(null) as SafeObject
        let index = 0
        while (true) {
          const step = yield* cursor.next
@@ -124,9 +124,9 @@ export const groupBy = <R>(runner: Runner<R>, namespace: "Map" | "Object") =>
            cursor,
            Effect.flatMap(apply([item, index]), (value) => coerceGroupByPropertyKey(runner, value, node)),
          )
-          const group = getOwn(result, key)
-          if (group === undefined) set(result, key, new ProgramArray([item]))
-          else (group as ProgramArray).items.push(item)
+          const group = result[key]
+          if (group === undefined) result[key] = [item]
+          else (group as Array<unknown>).push(item)
          index += 1
        }
      })
@@ -150,12 +150,12 @@ const constructMap = <R>(runner: Runner<R>, init: unknown, node: AstNode) => {
      yield* preserveConsumerError(
        cursor,
        Effect.sync(() => {
-          if (!(step.value instanceof ProgramObject)) {
+          if (!isRecord(step.value) || isRuntimeReference(step.value)) {
            throw new InterpreterRuntimeError("new Map(...) expects [key, value] pairs as entry objects.", node).as(
              "TypeError",
            )
          }
-          target.map.set(getOwn(step.value, 0), getOwn(step.value, 1))
+          target.map.set(step.value[0], step.value[1])
        }),
      )
    }
@@ -1,6 +1,5 @@
 import { toData, toProgram } from "../data.js"
 import { HostNamespace, sync } from "../interpreter/host.js"
-import { get, ownEntries, ProgramArray, ProgramObject } from "../interpreter/objects.js"
 import { containsOpaqueReference, containsRuntimeReference, isRuntimeReference } from "../interpreter/references.js"
 import { Values } from "../values.js"
 import { coerceToString } from "./value.js"
@@ -52,8 +51,8 @@ const formatConsoleValue = (value: unknown, seen: Set<object>, depth: number): s
  if (value instanceof Values.Map) {
    seen.add(value)
    try {
-      const entries = Array.from(value.map.entries(), ([key, item]) => new ProgramArray([key, item]))
-      return `Map(${value.map.size}) ${formatConsoleValue(new ProgramArray(entries), seen, depth + 1)}`
+      const entries = Array.from(value.map.entries(), ([key, item]): Array<unknown> => [key, item])
+      return `Map(${value.map.size}) ${formatConsoleValue(entries, seen, depth + 1)}`
    } finally {
      seen.delete(value)
    }
@@ -61,7 +60,7 @@ const formatConsoleValue = (value: unknown, seen: Set<object>, depth: number): s
  if (value instanceof Values.Set) {
    seen.add(value)
    try {
-      return `Set(${value.set.size}) ${formatConsoleValue(new ProgramArray([...value.set.values()]), seen, depth + 1)}`
+      return `Set(${value.set.size}) ${formatConsoleValue(Array.from(value.set.values()), seen, depth + 1)}`
    } finally {
      seen.delete(value)
    }
@@ -69,11 +68,10 @@ const formatConsoleValue = (value: unknown, seen: Set<object>, depth: number): s
  if (isRuntimeReference(value)) return "[opaque reference]"
  seen.add(value)
  try {
-    if (value instanceof ProgramArray) {
-      return `[${value.items.map((item) => formatConsoleValue(item, seen, depth + 1)).join(",")}]`
+    if (Array.isArray(value)) {
+      return `[${value.map((item) => formatConsoleValue(item, seen, depth + 1)).join(",")}]`
    }
-    if (!(value instanceof ProgramObject)) return "[object Object]"
-    return `{${ownEntries(value)
+    return `{${Object.entries(value)
      .map(([key, item]) => `${JSON.stringify(key)}:${formatConsoleValue(item, seen, depth + 1)}`)
      .join(",")}}`
  } finally {
@@ -106,19 +104,20 @@ const consoleTableRows = (
  data: unknown,
  columns: ReadonlyArray<string> | undefined,
 ): Array<{ readonly index: string; readonly values: Record<string, unknown> }> => {
-  if (data instanceof ProgramArray) {
-    return data.items.map((item, index) => ({ index: String(index), values: consoleTableValues(item, columns) }))
+  if (Array.isArray(data)) {
+    return data.map((item, index) => ({ index: String(index), values: consoleTableValues(item, columns) }))
  }
-  if (data instanceof ProgramObject) {
-    return ownEntries(data).map(([index, item]) => ({ index, values: consoleTableValues(item, columns) }))
+  if (data !== null && typeof data === "object" && !Values.isValue(data)) {
+    return Object.entries(data).map(([index, item]) => ({ index, values: consoleTableValues(item, columns) }))
  }
  return [{ index: "0", values: { Value: data } }]
 }

 const consoleTableValues = (value: unknown, columns: ReadonlyArray<string> | undefined): Record<string, unknown> => {
-  if (value instanceof ProgramObject && !(value instanceof ProgramArray)) {
-    if (columns !== undefined) return Object.fromEntries(columns.map((column) => [column, get(value, column)]))
-    return Object.fromEntries(ownEntries(value))
+  if (value !== null && typeof value === "object" && !Array.isArray(value) && !Values.isValue(value)) {
+    const source = value as Record<string, unknown>
+    if (columns !== undefined) return Object.fromEntries(columns.map((column) => [column, source[column]]))
+    return Object.fromEntries(Object.entries(source))
  }
  return { Value: value }
 }
@@ -3,8 +3,7 @@ import { HostFunction, HostNamespace } from "../interpreter/host.js"
 import { applyCollectionCallback, type Runner } from "../interpreter/runner.js"
 import { type AstNode, InterpreterRuntimeError } from "../interpreter/model.js"
 import { typeofValue } from "../interpreter/references.js"
-import { fromData, toData, toProgram } from "../data.js"
-import { get, ownKeys, ProgramArray, ProgramObject, record, remove, set } from "../interpreter/objects.js"
+import { fromData, type SafeObject, toData, toProgram } from "../data.js"
 import { Values } from "../values.js"

 export const jsonGlobal = <R>(runner: Runner<R>) =>
@@ -30,19 +29,28 @@ const parse = <R>(runner: Runner<R>, args: Array<unknown>, node: AstNode): Effec
  if (typeofValue(args[1]) !== "function") return Effect.succeed(parsed)

  const apply = applyCollectionCallback(runner, args[1], "JSON.parse", node)
-  const visit = (holder: ProgramObject, key: string): Effect.Effect<unknown, unknown, R> =>
+  const root: SafeObject = Object.create(null) as SafeObject
+  root[""] = parsed
+  const visit = (holder: SafeObject | Array<unknown>, key: string): Effect.Effect<unknown, unknown, R> =>
    Effect.gen(function* () {
-      const value = get(holder, key)
-      if (value instanceof ProgramObject) {
-        for (const name of ownKeys(value)) {
-          const revived = yield* visit(value, name as string)
-          if (revived === undefined) remove(value, name)
-          else set(value, name, revived)
+      const value = holder[key as keyof typeof holder]
+      if (Array.isArray(value)) {
+        const length = value.length
+        for (let index = 0; index < length; index += 1) {
+          const revived = yield* visit(value, String(index))
+          if (revived === undefined) Reflect.deleteProperty(value, index)
+          else value[index] = revived
+        }
+      } else if (isPlainObject(value)) {
+        for (const name of Object.keys(value)) {
+          const revived = yield* visit(value, name)
+          if (revived === undefined) Reflect.deleteProperty(value, name)
+          else value[name] = revived
        }
      }
      return yield* apply([key, value])
    })
-  return visit(record({ "": parsed }), "")
+  return visit(root, "")
 }

 const stringify = <R>(runner: Runner<R>, args: Array<unknown>, node: AstNode): Effect.Effect<unknown, unknown, R> => {
@@ -51,41 +59,44 @@ const stringify = <R>(runner: Runner<R>, args: Array<unknown>, node: AstNode): E
  const replacer = args[1]

  if (typeofValue(replacer) !== "function") {
-    const properties =
-      replacer instanceof ProgramArray
-        ? replacer.items
-            .filter((item): item is string | number => typeof item === "string" || typeof item === "number")
-            .map(String)
-        : null
+    const properties = Array.isArray(replacer)
+      ? replacer
+          .filter((item): item is string | number => typeof item === "string" || typeof item === "number")
+          .map(String)
+      : null
    return Effect.succeed(JSON.stringify(toData(args[0], "JSON.stringify value"), properties, indent))
  }

  // Validate up front; the replacer walk below reads the original value.
  toProgram(args[0], "JSON.stringify value")
  const apply = applyCollectionCallback(runner, replacer, "JSON.stringify", node)
+  const root: SafeObject = Object.create(null) as SafeObject
+  root[""] = args[0]
  const stack = new Set<object>()
-  const visit = (holder: ProgramObject, key: string): Effect.Effect<unknown, unknown, R> =>
+  const visit = (holder: SafeObject | Array<unknown>, key: string): Effect.Effect<unknown, unknown, R> =>
    Effect.gen(function* () {
-      const value = yield* apply([key, toJSONValue(get(holder, key))])
+      const value = yield* apply([key, toJSONValue(holder[key as keyof typeof holder])])
      if (value === undefined || typeofValue(value) === "function") return undefined
      toProgram(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 ProgramObject)) return {}
-      if (stack.has(value))
-        throw new InterpreterRuntimeError("Converting circular structure to JSON.", node).as("TypeError")
-      stack.add(value)
-      if (value instanceof ProgramArray) {
+      if (Array.isArray(value)) {
+        if (stack.has(value))
+          throw new InterpreterRuntimeError("Converting circular structure to JSON.", node).as("TypeError")
+        stack.add(value)
        const result: Array<unknown> = []
-        for (let index = 0; index < value.items.length; index += 1) {
+        for (let index = 0; index < value.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 ownKeys(value)) {
-        if (typeof name !== "string") continue
+      if (!isPlainObject(value)) return {}
+      if (stack.has(value))
+        throw new InterpreterRuntimeError("Converting circular structure to JSON.", node).as("TypeError")
+      stack.add(value)
+      const result: SafeObject = Object.create(null) as SafeObject
+      for (const name of Object.keys(value)) {
        const item = yield* visit(value, name)
        if (item !== undefined) result[name] = item
      }
@@ -93,7 +104,7 @@ const stringify = <R>(runner: Runner<R>, args: Array<unknown>, node: AstNode): E
      return result
    })

-  return Effect.map(visit(record({ "": args[0] }), ""), (value) => JSON.stringify(value, null, indent))
+  return Effect.map(visit(root, ""), (value) => JSON.stringify(value, null, indent))
 }

 const toJSONValue = (value: unknown): unknown => {
@@ -103,3 +114,6 @@ const toJSONValue = (value: unknown): unknown => {
  if (value instanceof Values.URL) return value.url.href
  return value
 }
+
+const isPlainObject = (value: unknown): value is SafeObject =>
+  value !== null && typeof value === "object" && !Values.isValue(value)
@@ -2,10 +2,11 @@ import { Effect } from "effect"
 import { toProgram } from "../data.js"
 import { HostFunction, sync, syncCall } from "../interpreter/host.js"
 import { type AstNode, AsyncIteratorSymbol, InterpreterRuntimeError, IteratorSymbol } from "../interpreter/model.js"
-import { getOwn, hasOwn, ownEntries, ownKeys, ProgramArray, ProgramObject, set } from "../interpreter/objects.js"
 import {
  containsOpaqueReference,
  describeValue,
+  isRuntimeReference,
+  parseArrayIndex,
  rejectCircularInsertion,
  typeofValue,
 } from "../interpreter/references.js"
@@ -15,8 +16,9 @@ import { Values } from "../values.js"
 import { groupBy } from "./collections.js"
 import { coerceToString } from "./value.js"

-// ToObject for enumeration.
-export const enumerableSource = (label: string, value: unknown, node: AstNode): ProgramObject => {
+// ToObject for enumeration. Strings return themselves: the host's Object.keys/entries/hasOwn index a
+// primitive string directly. Numbers, booleans, wrappers, and functions have no own enumerable keys.
+export const enumerableSource = (label: string, value: unknown, node: AstNode): Record<string, unknown> => {
  if (value === null || value === undefined) {
    throw new InterpreterRuntimeError(`${label} cannot convert ${describeValue(value)} to an object.`, node).as(
      "TypeError",
@@ -36,41 +38,58 @@ export const enumerableSource = (label: string, value: unknown, node: AstNode):
      "InvalidDataValue",
    )
  }
-  if (typeof value === "string") return new ProgramArray([...value])
-  if (value instanceof ProgramObject) return value
-  return new ProgramObject()
+  if (typeof value === "string") return value as unknown as Record<string, unknown>
+  if (typeof value !== "object" || Values.isValue(value) || isRuntimeReference(value)) return {}
+  return value as Record<string, unknown>
 }

 export const objectAssign = (args: Array<unknown>, node: AstNode): unknown => {
  const target = args[0]
  // JS would box a primitive target; wrappers and primitives cannot hold fields here.
-  if (!(target instanceof ProgramObject)) {
+  if (target === null || typeof target !== "object" || Values.isValue(target) || isRuntimeReference(target)) {
    throw new InterpreterRuntimeError(
      `Object.assign expects a data object or array target, received ${describeValue(target)}.`,
      node,
    ).as("TypeError")
  }
+  const out = target as Record<string, unknown>
  const seen = new Set<object>()
+  const guardedSet = (key: PropertyKey, item: unknown): void => {
+    // Arrays hold only indexed elements, as with direct assignment; Reflect.set would otherwise
+    // reach Array's length and Object.prototype's __proto__ setter.
+    if (Array.isArray(out) && (typeof key === "symbol" || parseArrayIndex(key) === undefined)) {
+      throw new InterpreterRuntimeError(
+        `Object.assign cannot assign '${String(key)}' to an array: only array indexes may be assigned.`,
+        node,
+      ).as("TypeError")
+    }
+    rejectCircularInsertion(out, item, "Object.assign result", node, seen)
+    if (!Reflect.set(out, key, item))
+      throw new InterpreterRuntimeError(`Object.assign could not assign property '${String(key)}'.`, node).as(
+        "TypeError",
+      )
+  }
  for (const source of args.slice(1)) {
    if (source === null || source === undefined) continue
    const from = enumerableSource("Object.assign(...)", source, node)
-    for (const key of ownKeys(from)) {
+    if (typeof from !== "object") {
+      for (const [key, item] of Object.entries(from)) guardedSet(key, item)
+      continue
+    }
+    for (const key of Reflect.ownKeys(from)) {
      if (typeof key === "symbol" && key !== AsyncIteratorSymbol && key !== IteratorSymbol) continue
-      rejectCircularInsertion(target, getOwn(from, key), "Object.assign result", node, seen)
-      if (!set(target, key, getOwn(from, key))) {
-        throw new InterpreterRuntimeError("Invalid array length", node).as("RangeError")
-      }
+      if (Object.prototype.propertyIsEnumerable.call(from, key)) guardedSet(key, Reflect.get(from, key))
    }
  }
-  return target
+  return out
 }

 const objectFromEntries = <R>(
  runner: Runner<R>,
  source: unknown,
  node: AstNode,
-): Effect.Effect<ProgramObject, unknown, R> => {
-  const out = new ProgramObject()
+): Effect.Effect<Record<string, unknown>, unknown, R> => {
+  const out: Record<string, unknown> = Object.create(null)
  return Effect.gen(function* () {
    const cursor = yield* runner.syncIterator(source, node)
    if (cursor === undefined) {
@@ -84,12 +103,21 @@ const objectFromEntries = <R>(
      yield* preserveConsumerError(
        cursor,
        Effect.sync(() => {
-          if (!(step.value instanceof ProgramObject) || containsOpaqueReference(step.value)) {
+          if (
+            step.value === null ||
+            typeof step.value !== "object" ||
+            Values.isValue(step.value) ||
+            containsOpaqueReference(step.value)
+          ) {
            throw new InterpreterRuntimeError("Object.fromEntries expects [key, value] entry objects.", node).as(
              "TypeError",
            )
          }
-          set(out, coerceToString(getOwn(step.value, 0)), getOwn(step.value, 1))
+          const entry = step.value as Record<string, unknown>
+          toProgram(entry[0], "Object.fromEntries key")
+          toProgram(entry[1], "Object.fromEntries value")
+          const key = coerceToString(entry[0])
+          out[key] = entry[1]
        }),
      )
    }
@@ -98,7 +126,7 @@ const objectFromEntries = <R>(

 const constructObject = (args: Array<unknown>, node: AstNode): unknown => {
  const first = args[0]
-  if (first === null || first === undefined) return new ProgramObject()
+  if (first === null || first === undefined) return Object.create(null)
  if (typeof first === "object") return first
  throw new InterpreterRuntimeError(
    `Object(${typeof first}) wrapper objects are not supported; use the primitive value directly.`,
@@ -119,24 +147,18 @@ export const objectGlobal = <R>(runner: Runner<R>, toolKeys: (path: ReadonlyArra
        toProgram(
          args[0] instanceof ToolReference
            ? [...toolKeys(args[0].path)]
-            : ownKeys(enumerableSource("Object.keys(...)", args[0], node)).filter((key) => typeof key === "string"),
+            : Object.keys(enumerableSource("Object.keys(...)", args[0], node)),
          "Object.keys result",
        ),
      ),
-      values: sync(
-        "Object.values",
-        (args, node) =>
-          new ProgramArray(ownEntries(enumerableSource("Object.values(...)", args[0], node)).map((entry) => entry[1])),
+      values: sync("Object.values", (args, node) =>
+        Object.values(enumerableSource("Object.values(...)", args[0], node)),
      ),
-      entries: sync(
-        "Object.entries",
-        (args, node) =>
-          new ProgramArray(
-            ownEntries(enumerableSource("Object.entries(...)", args[0], node)).map((entry) => new ProgramArray(entry)),
-          ),
+      entries: sync("Object.entries", (args, node) =>
+        Object.entries(enumerableSource("Object.entries(...)", args[0], node)).map(([key, item]) => [key, item]),
      ),
      hasOwn: sync("Object.hasOwn", (args, node) =>
-        hasOwn(
+        Object.hasOwn(
          enumerableSource("Object.hasOwn(...)", args[0], node),
          args[1] === AsyncIteratorSymbol || args[1] === IteratorSymbol ? args[1] : String(args[1]),
        ),
@@ -1,9 +1,19 @@
 import { sync, syncCall } from "../interpreter/host.js"
 import { type AstNode, InterpreterRuntimeError } from "../interpreter/model.js"
-import { ProgramArray, record, set } from "../interpreter/objects.js"
+import type { SafeObject } from "../data.js"
 import { Values } from "../values.js"
 import { coerceToNumber, coerceToString } from "./value.js"

+type MatchValue = Array<unknown> & {
+  index?: number
+  groups?: SafeObject
+  indices?: IndicesValue
+}
+
+type IndicesValue = Array<unknown> & {
+  groups?: SafeObject
+}
+
 export const regexpMethods = new Set(["test", "exec", "toString"])

 export const regexpProperties = new Set([
@@ -46,12 +56,17 @@ export const toHostRegex = (arg: unknown, method: string, node: AstNode, extraFl
  )
 }

-export const matchToValue = (match: RegExpMatchArray): ProgramArray => {
-  const result = new ProgramArray(Array.from(match, (group) => group))
-  if (match.index !== undefined) set(result, "index", match.index)
-  if (match.input !== undefined) set(result, "input", match.input)
-  if (match.groups) set(result, "groups", record(match.groups))
-  if (match.indices) set(result, "indices", indicesToValue(match.indices))
+export const matchToValue = (match: RegExpMatchArray): Array<unknown> => {
+  const result: MatchValue = Array.from(match, (group) => group)
+  if (match.index !== undefined) result.index = match.index
+  if (match.groups) {
+    const groups: SafeObject = Object.create(null) as SafeObject
+    for (const [key, group] of Object.entries(match.groups)) {
+      groups[key] = group
+    }
+    result.groups = groups
+  }
+  if (match.indices) result.indices = indicesToValue(match.indices)
  return result
 }

@@ -128,16 +143,16 @@ const toLength = (value: unknown): number => {
  return Math.min(Math.floor(number), Number.MAX_SAFE_INTEGER)
 }

-const indicesToValue = (indices: RegExpIndicesArray): ProgramArray => {
-  const range = (pair: [number, number] | undefined) => (pair === undefined ? undefined : new ProgramArray([...pair]))
-  const result = new ProgramArray(Array.from(indices, range))
-  const groups = indices.groups
-  set(
-    result,
-    "groups",
-    groups === undefined
-      ? undefined
-      : record(Object.fromEntries(Object.entries(groups).map(([key, pair]) => [key, range(pair)]))),
-  )
+const indicesToValue = (indices: RegExpIndicesArray): IndicesValue => {
+  const result: IndicesValue = Array.from(indices, (range) => (range === undefined ? undefined : [...range]))
+  if (indices.groups) {
+    const groups: SafeObject = Object.create(null) as SafeObject
+    for (const [key, range] of Object.entries(indices.groups)) {
+      groups[key] = range === undefined ? undefined : [...range]
+    }
+    result.groups = groups
+    return result
+  }
+  result.groups = undefined
  return result
 }
@@ -2,7 +2,6 @@ import { Effect } from "effect"
 import { toProgram } from "../data.js"
 import { HostFunction, requiresNew, sync, syncCall } from "../interpreter/host.js"
 import { type AstNode, InterpreterRuntimeError } from "../interpreter/model.js"
-import { ownEntries, ProgramObject } from "../interpreter/objects.js"
 import { isRuntimeReference } from "../interpreter/references.js"
 import { preserveConsumerError, type Runner } from "../interpreter/runner.js"
 import { Values } from "../values.js"
@@ -184,14 +183,15 @@ const constructURLSearchParams = <R>(
      ).as("TypeError")
    }
    if (Values.isValue(init)) return new Values.URLSearchParams(new URLSearchParams())
-    if (!(init instanceof ProgramObject)) {
+    const data = toProgram(init, "new URLSearchParams input")
+    if (data === null || typeof data !== "object") {
      throw new InterpreterRuntimeError(
        "new URLSearchParams(...) expects a query string, data object, iterable pairs, or URLSearchParams.",
        node,
      ).as("TypeError")
    }
    return new Values.URLSearchParams(
-      new URLSearchParams(Object.fromEntries(ownEntries(init).map(([key, value]) => [key, coerceToString(value)]))),
+      new URLSearchParams(Object.fromEntries(Object.entries(data).map(([key, value]) => [key, coerceToString(value)]))),
    )
  })
 }
@@ -1,7 +1,6 @@
 import { type HostFunction, sync, type SyncOptions } from "../interpreter/host.js"
 import { type AstNode, InterpreterRuntimeError } from "../interpreter/model.js"
-import { toProgram } from "../data.js"
-import { get, ProgramArray, ProgramError, set } from "../interpreter/objects.js"
+import { type SafeObject, toProgram } from "../data.js"
 import { Values } from "../values.js"

 export const errorConstructors = new Set([
@@ -17,21 +16,21 @@ export const errorConstructors = new Set([

 export const compoundOperators = new Set(["+=", "-=", "*=", "/=", "%=", "**=", "&=", "|=", "^=", "<<=", ">>=", ">>>="])

-export const createErrorValue = (name: string, message: string): ProgramError => {
-  const value = new ProgramError(name)
-  set(value, "name", name)
-  set(value, "message", message)
+const ErrorBrand: unique symbol = Symbol("codemode.error")
+
+export const createErrorValue = (name: string, message: string): SafeObject => {
+  const value = Object.assign(Object.create(null) as SafeObject, { name, message })
+  Object.defineProperty(value, ErrorBrand, { value: name })
  return value
 }

-export const createAggregateErrorValue = (errors: Array<unknown>, message: string): ProgramError => {
-  const value = createErrorValue("AggregateError", message)
-  set(value, "errors", new ProgramArray(errors))
-  return value
-}
+export const createAggregateErrorValue = (errors: Array<unknown>, message: string): SafeObject =>
+  Object.assign(createErrorValue("AggregateError", message), { errors })

 export const errorBrandName = (value: unknown): string | undefined =>
-  value instanceof ProgramError ? value.errorName : undefined
+  value !== null && typeof value === "object"
+    ? ((value as Record<PropertyKey, unknown>)[ErrorBrand] as string | undefined)
+    : undefined

 export const coerceToString = (value: unknown): string => {
  if (value === null) return "null"
@@ -43,27 +42,29 @@ export const coerceToString = (value: unknown): string => {
  if (value instanceof Values.Set) return "[object Set]"
  if (value instanceof Values.URL) return value.url.href
  if (value instanceof Values.URLSearchParams) return value.params.toString()
-  if (value instanceof ProgramError) {
+  if (errorBrandName(value) !== undefined) {
    // Match Error.prototype.toString: "name: message", or just one when the other is empty.
-    const name = get(value, "name")
-    const message = get(value, "message")
-    const shownName = typeof name === "string" ? name : "Error"
-    const shownMessage = typeof message === "string" ? message : ""
-    if (shownMessage === "") return shownName
-    if (shownName === "") return shownMessage
-    return `${shownName}: ${shownMessage}`
+    const error = value as { name?: unknown; message?: unknown }
+    const name = typeof error.name === "string" ? error.name : "Error"
+    const message = typeof error.message === "string" ? error.message : ""
+    if (message === "") return name
+    if (name === "") return message
+    return `${name}: ${message}`
  }
-  if (value instanceof ProgramArray) {
-    return value.items.map((item) => (item === null || item === undefined ? "" : coerceToString(item))).join(",")
+  if (typeof value === "object") {
+    return Array.isArray(value)
+      ? value.map((item) => (item === null || item === undefined ? "" : coerceToString(item))).join(",")
+      : "[object Object]"
  }
-  if (typeof value === "object") return "[object Object]"
  return String(value)
 }

 export const coerceToNumber = (value: unknown): number => {
  if (value instanceof Values.Date) return value.time
  if (Values.isValue(value)) return Number.NaN
-  if (value instanceof ProgramArray) return Number(coerceToString(value))
+  // Arrays coerce through our own string coercion: host Number(array) joins with host
+  // ToPrimitive, which throws on the null-prototype objects the interpreter produces.
+  if (Array.isArray(value)) return Number(coerceToString(value))
  return value !== null && typeof value === "object" ? Number.NaN : Number(value)
 }

@@ -77,6 +78,8 @@ const coerce = (name: Coercion, args: Array<unknown>, node: AstNode): unknown =>
    if (name === "String") return ""
  }
  const raw = args[0]
+  // Error values are plain SafeObjects; the toProgram path below would strip their brand.
+  if (name === "String" && errorBrandName(raw) !== undefined) return coerceToString(raw)
  if (Values.isValue(raw)) {
    if (name === "Boolean") return true
    if (name === "Number") return coerceToNumber(raw)
@@ -98,7 +98,7 @@ describe("Object.keys over arrays", () => {
    )
    expect((await error(`const { a } = new Map(); return a`)).message).toContain("received a Map.")
    expect((await error(`return Array.from(7)`)).message).toContain("received a number.")
-    expect(await value(`return [(() => 1).x, Object.keys(() => 1)]`)).toEqual([null, []])
+    expect((await error(`return (() => 1).x`)).message).toContain("Cannot read properties of a function")
  })
 })

@@ -167,14 +167,17 @@ describe("Object.assign Test262 parity", () => {
    ).toEqual([true, [1, 8, 9], true, [1, 8, 3], true, 5, true, 0])
  })

-  test("test/built-ins/Object/assign/target-Array.js", async () => {
+  test("array targets accept only array indexes (deviation from target-Array.js)", async () => {
    expect(
      await value(`
        const target = [7]
-        for (const source of [{ x: 1 }, { "1.5": 1 }, { "-0": 1 }, { 1: 8 }, { length: 1 }]) Object.assign(target, source)
-        return [[...target], target.length, Object.keys(target), target.x]
+        const out = []
+        for (const source of [{ length: 0 }, { x: 1 }, { "1.5": 1 }, { "-0": 1 }, { ["__proto__"]: null }]) {
+          try { Object.assign(target, source) } catch (error) { out.push(error.name) }
+        }
+        return [out, [...target], target.length, Object.keys(target)]
      `),
-    ).toEqual([[7], 1, ["0", "x", "1.5", "-0"], 1])
+    ).toEqual([["TypeError", "TypeError", "TypeError", "TypeError", "TypeError"], [7], 1, ["0"]])
  })

  test("test/built-ins/Object/assign/Target-{Null,Undefined}.js", async () => {
@@ -81,26 +81,27 @@ describe("H3: array property access reads as undefined (not a throw)", () => {
    ).toEqual(["b", "b", null, null, "a", null])
  })

-  test("noncanonical keys are ordinary properties that never alias an element", async () => {
+  test("noncanonical keys cannot mutate or delete an aliased element", async () => {
    expect(
      await value(`
        const values = ["a", "b"]
-        values["01"] = "c"
-        const before = [values["01"], values[1], values.length]
+        let writes = 0
+        try { values["01"] = ++writes } catch {}
        const removed = delete values["01"]
-        return [before, removed, values["01"], values]
+        return [writes, removed, values]
      `),
-    ).toEqual([["c", "b", 2], true, null, ["a", "b"]])
+    ).toEqual([0, true, ["a", "b"]])
  })

-  test("the maximum array length is a property, not an index", async () => {
+  test("the maximum array length is not accepted as an array index", async () => {
    expect(
      await value(`
        const values = []
-        values["4294967295"] = 1
-        return [values["4294967295"], values.length]
+        let writes = 0
+        try { values["4294967295"] = ++writes } catch {}
+        return [writes, values.length]
      `),
-    ).toEqual([1, 0])
+    ).toEqual([0, 0])
  })
 })

@@ -245,14 +246,16 @@ describe("property deletion", () => {
    expect(await value(`const values = [1, 2]; return [delete values.length, values.length]`)).toEqual([false, 2])
  })

-  test("arrays accept named properties like JS, and they stay out of the JSON form", async () => {
+  test("does not broaden unsupported array property assignment", async () => {
    expect(
      await value(`
-        const values = [1]
-        values.field = 2
-        return [values.field, Object.keys(values), values]
+        const values = []
+        let rightHandSideRuns = 0
+        function next() { rightHandSideRuns++; return 1 }
+        try { values.field = next() } catch {}
+        return rightHandSideRuns
      `),
-    ).toEqual([2, ["0", "field"], [1]])
+    ).toBe(0)
  })

  test("optional deletion short-circuits without evaluating the key", async () => {
@@ -913,48 +916,3 @@ describe("coercion parity: unknown static members read as undefined", () => {
    ])
  })
 })
-
-describe("functions are objects", () => {
-  test("name follows NamedEvaluation and length counts required parameters", async () => {
-    expect(
-      await value(`
-        function decl(a, b = 1, ...rest) {}
-        const arrow = () => {}
-        const named = function inner() {}
-        let assigned
-        assigned = (a, b) => {}
-        const { fromDefault = () => {} } = {}
-        const [fromArray = function () {}] = []
-        const obj = { method() {}, key: () => {}, [Symbol.iterator]: () => {} }
-        const passthrough = (0, () => {})
-        return [
-          [decl.name, decl.length],
-          [arrow.name, named.name, assigned.name, assigned.length],
-          [fromDefault.name, fromArray.name],
-          [obj.method.name, obj.key.name, obj[Symbol.iterator].name],
-          passthrough.name,
-        ]
-      `),
-    ).toEqual([
-      ["decl", 1],
-      ["arrow", "inner", "assigned", 2],
-      ["fromDefault", "fromArray"],
-      ["method", "key", "[Symbol.iterator]"],
-      "",
-    ])
-  })
-
-  test("functions hold own properties; name and length are read-only", async () => {
-    expect(
-      await value(`
-        const fn = () => 1
-        fn.count = 2
-        fn.count += 1
-        let renamed = false
-        try { fn.name = "other" } catch (error) { renamed = error instanceof TypeError }
-        const { name, count } = fn
-        return [fn.count, Object.keys(fn), "count" in fn, "name" in fn, name, count, renamed, delete fn.count, fn.count]
-      `),
-    ).toEqual([3, ["count"], true, true, "fn", 3, true, true, null])
-  })
-})
@@ -17,6 +17,8 @@
 import { describe, expect, test } from "bun:test"
 import { Effect, Schema } from "effect"
 import { CodeMode, Tool } from "../src/index.js"
+import { AsyncIteratorSymbol, IteratorSymbol } from "../src/interpreter/model.js"
+import { objectAssign } from "../src/stdlib/object.js"

 // Standard-library value types: Date, RegExp, Map, Set. Programs use them as ordinary JS;
 // intra-CodeMode checkpoints (Object.* helpers, spread, coercion inputs) preserve the live
@@ -768,18 +770,13 @@ describe("stdlib integration", () => {
      ],
    ])
    expect(await value(`const match = /a/.exec("ba"); return [Object.values(match), Object.entries(match)]`)).toEqual([
-      ["a", 1, "ba"],
+      ["a", 1],
      [
        ["0", "a"],
        ["index", 1],
-        ["input", "ba"],
      ],
    ])
-    expect(await value(`return Object.keys(Object.values({ match: /a/.exec("ba") })[0])`)).toEqual([
-      "0",
-      "index",
-      "input",
-    ])
+    expect(await value(`return Object.keys(Object.values({ match: /a/.exec("ba") })[0])`)).toEqual(["0", "index"])
  })

  test("Object.fromEntries accepts every supported entry collection", async () => {
@@ -852,6 +849,86 @@ describe("stdlib integration", () => {
    expect(await value(`try { Object.assign(null, { a: 1 }); return false } catch { return true }`)).toBe(true)
  })

+  test("Object.assign ignores non-enumerable supported symbols without reading them", () => {
+    const target = {}
+    const reads: Array<boolean> = []
+    const source = Object.defineProperty({}, IteratorSymbol, {
+      get() {
+        reads.push(true)
+        return target
+      },
+    })
+    expect(objectAssign([target, source], { type: "CallExpression", start: 0, end: 0 })).toBe(target)
+    expect(reads).toEqual([])
+    expect(Object.hasOwn(target, IteratorSymbol)).toBe(false)
+  })
+
+  test("Object.assign ignores nested non-enumerable supported symbols during cycle checks", () => {
+    const target = {}
+    const reads: Array<boolean> = []
+    const nested = Object.defineProperty({}, IteratorSymbol, {
+      get() {
+        reads.push(true)
+        return target
+      },
+    })
+    expect(objectAssign([target, { nested }], { type: "CallExpression", start: 0, end: 0 })).toBe(target)
+    expect(reads).toEqual([])
+    expect(target).toEqual({ nested })
+  })
+
+  test("Object.assign rejects cycles through supported symbols on nested arrays", () => {
+    const target = {}
+    const nested = Object.defineProperty([], IteratorSymbol, { enumerable: true, value: target })
+    expect(() => objectAssign([target, { nested }], { type: "CallExpression", start: 0, end: 0 })).toThrow(
+      "Object.assign result contains a circular value.",
+    )
+    expect(Object.hasOwn(target, "nested")).toBe(false)
+  })
+
+  test("Object.assign cycle checks traverse sparse keys lazily", () => {
+    const target = {}
+    const reads: Array<boolean> = []
+    const nested = Object.defineProperties([], {
+      4294967294: { enumerable: true, value: target },
+      later: {
+        enumerable: true,
+        get() {
+          reads.push(true)
+          return null
+        },
+      },
+    })
+    expect(() => objectAssign([target, { nested }], { type: "CallExpression", start: 0, end: 0 })).toThrow(
+      "Object.assign result contains a circular value.",
+    )
+    expect(reads).toEqual([])
+  })
+
+  test("Object.assign stops after a supported symbol write fails", () => {
+    const previous = () => ({ done: true })
+    const target = Object.defineProperty({}, IteratorSymbol, { value: previous })
+    const reads: Array<boolean> = []
+    const source = Object.defineProperties(
+      {},
+      {
+        [IteratorSymbol]: { enumerable: true, value: () => ({ done: false }) },
+        [AsyncIteratorSymbol]: {
+          enumerable: true,
+          get() {
+            reads.push(true)
+            return () => ({ done: true })
+          },
+        },
+      },
+    )
+    expect(() => objectAssign([target, source], { type: "CallExpression", start: 0, end: 0 })).toThrow(
+      "Object.assign could not assign property",
+    )
+    expect(Reflect.get(target, IteratorSymbol)).toBe(previous)
+    expect(reads).toEqual([])
+  })
+
  test("Object.assign rejects direct and nested cycles", async () => {
    expect(
      await value(`
@@ -923,6 +1000,27 @@ describe("stdlib integration", () => {
    ).toEqual([true, true, true, 2])
  })

+  test("Object.assign traverses shared aliases once", () => {
+    const reads: Array<boolean> = []
+    const shared = Object.defineProperty({}, "value", {
+      enumerable: true,
+      get() {
+        reads.push(true)
+        return 1
+      },
+    })
+    const target = {}
+    expect(
+      objectAssign([target, { left: shared, right: shared }], {
+        type: "CallExpression",
+        start: 0,
+        end: 0,
+      }),
+    ).toBe(target)
+    expect(target).toEqual({ left: shared, right: shared })
+    expect(reads).toEqual([true])
+  })
+
  test("assignment resolves and reads its left side before evaluating the right side", async () => {
    expect(await value(`let x = 1; x += (x = 5); return x`)).toBe(6)
    expect(await value(`let i = 0; const values = [9]; values[i++] = i; return [values, i]`)).toEqual([[1], 1])
@@ -1101,7 +1199,7 @@ describe("CodeMode values at intra-CodeMode checkpoints", () => {
    const diagnostic = await error(`return Array.from(Promise.resolve([1]))`)
    expect(diagnostic.kind).toBe("InvalidDataValue")
    expect(diagnostic.message).toContain("await")
-    expect(await value(`return Array.from((a, b) => 1)`)).toEqual([null, null])
+    expect((await error(`return Array.from(() => 1)`)).kind).toBe("InvalidDataValue")
  })

  test("regexes stay callable through Object.values", async () => {
@@ -24,7 +24,7 @@ Without them the runner registers no tests, so CI is unaffected. Licensed under

 `script/sync-test262.ts` skips a file when its frontmatter declares a `flags`, `features`, or `includes` value the
 manifest marks unsupported, or when its code matches one of the manifest's `boundaries` patterns. The sync checks the
-checkout is at the pinned revision, so every machine runs the same 3993 files. Boundaries are
+checkout is at the pinned revision, so every machine runs the same files. Boundaries are
 intentional limits of the interpreter, not compatibility work: classes, `this`, `arguments`, prototype objects,
 property descriptors, accessors, boxed primitives, sloppy mode, `eval`, `Symbol()`, and the `$262` host API. If one
 of those decisions changes, delete its entry and re-sync; the tests are upstream, not lost.
@@ -1,6 +1,35 @@
 {
  "revision": "250f204f23a9249ff204be2baec29600faae7b75",
-  "directories": ["built-ins/Array/prototype", "language/statements"],
+  "directories": [
+    "built-ins/Array",
+    "built-ins/Object",
+    "built-ins/JSON",
+    "built-ins/String",
+    "built-ins/Number",
+    "built-ins/Math",
+    "built-ins/Boolean",
+    "built-ins/Date",
+    "built-ins/Map",
+    "built-ins/Set",
+    "built-ins/Promise",
+    "built-ins/RegExp",
+    "built-ins/Error",
+    "built-ins/NativeErrors",
+    "built-ins/AggregateError",
+    "built-ins/parseInt",
+    "built-ins/parseFloat",
+    "built-ins/isNaN",
+    "built-ins/isFinite",
+    "built-ins/encodeURI",
+    "built-ins/encodeURIComponent",
+    "built-ins/decodeURI",
+    "built-ins/decodeURIComponent",
+    "built-ins/undefined",
+    "built-ins/NaN",
+    "built-ins/Infinity",
+    "language/statements",
+    "language/expressions"
+  ],
  "harness": ["assert.js", "sta.js", "compareArray.js", "doneprintHandle.js"],
  "flags": ["module", "raw", "noStrict"],
  "boundaries": {
@@ -11,7 +40,7 @@
    "prototype objects": "\\.prototype\\b",
    "accessor properties": "\\b(get|set)\\s+[\\w$\\[][^\\n(]*\\(",
    "property descriptors": "Object\\.(defineProperty|defineProperties|getOwnPropertyDescriptors?|getOwnPropertyNames|create|getPrototypeOf|setPrototypeOf|freeze|seal|preventExtensions|isFrozen|isSealed|isExtensible)\\b",
-    "boxed primitives": "\\bnew\\s+(String|Number|Boolean)\\s*\\(",
+    "boxed primitives": "\\bnew\\s+(String|Number|Boolean)\\s*\\(|\\bObject\\s*\\(\\s*(-?\\d|[\"'`]|true\\b|false\\b|NaN\\b|Infinity\\b)",
    "sloppy mode": "\\bwith\\s*\\(",
    "eval": "\\b(eval|Function)\\b",
    "new.target": "\\bnew\\.target\\b",
@@ -7,8 +7,7 @@ import { caughtErrorValue } from "../../src/interpreter/errors.js"
 import { executeProgram } from "../../src/interpreter/execute.js"
 import type { Host } from "../../src/interpreter/globals.js"
 import { HostFunction } from "../../src/interpreter/host.js"
-import { ProgramThrow } from "../../src/interpreter/model.js"
-import { get, ProgramArray, ProgramObject } from "../../src/interpreter/objects.js"
+import { CodeModeFunction, ProgramThrow } from "../../src/interpreter/model.js"
 import { createErrorValue, errorBrandName } from "../../src/stdlib/value.js"
 import { ToolRuntime } from "../../src/tool-runtime.js"

@@ -68,10 +67,7 @@ const harness = <R>(host: Host<R>, onDone: (error: unknown) => void): ReadonlyAr
  const fail = (message: string) => Effect.fail(new ProgramThrow(createErrorValue("Test262Error", message)))
  const prefix = (message: unknown) => (message === undefined ? "" : `${String(message)} `)
  const compare = (a: unknown, b: unknown) =>
-    a instanceof ProgramArray &&
-    b instanceof ProgramArray &&
-    a.items.length === b.items.length &&
-    a.items.every((value, i) => Object.is(value, b.items[i]))
+    Array.isArray(a) && Array.isArray(b) && a.length === b.length && a.every((value, i) => Object.is(value, b[i]))
  const test262Error = new HostFunction<R>({
    name: "Test262Error",
    call: (args) => Effect.succeed(createErrorValue("Test262Error", args[0] === undefined ? "" : String(args[0]))),
@@ -158,9 +154,10 @@ const harness = <R>(host: Host<R>, onDone: (error: unknown) => void): ReadonlyAr
 const show = (value: unknown): string => {
  if (typeof value === "string") return JSON.stringify(value)
  if (Object.is(value, -0)) return "-0"
-  if (value instanceof ProgramArray) return `[${value.items.map(show).join(", ")}]`
+  if (Array.isArray(value)) return `[${value.map(show).join(", ")}]`
  if (value instanceof HostFunction) return value.name
-  if (!(value instanceof ProgramObject)) return String(value)
-  const message = get(value, "message")
+  if (value instanceof CodeModeFunction) return "program function"
+  if (value === null || typeof value !== "object") return String(value)
+  const message = (value as { message?: unknown }).message
  return typeof message === "string" ? `${errorBrandName(value) ?? "object"}: ${message}` : "object"
 }
@@ -192,10 +192,9 @@ describe("blocked member names on tool paths", () => {
      `,
      ),
    ).toEqual([true, true, true, null, true, null, null, null, true, null, null, "undefined"])
-    expect(await value(runtime, `return [(() => 1).constructor, typeof (() => 1).__proto__]`)).toEqual([
-      null,
-      "undefined",
-    ])
+    expect((await failure(runtime, `return (() => 1).constructor`)).message).toContain(
+      "Cannot read properties of a function",
+    )
    const escape = await failure(runtime, `return ({}).constructor.constructor.constructor("return 1")()`)
    expect(escape.message).toContain("Cannot access a property on a non-object value")
    const poisoned = await failure(runtime, `const o = {}; o.__proto__.constructor("return 1")`)
@@ -1,6 +1,6 @@
 {
  "name": "@opencode/console-app",
-  "version": "2.0.0",
+  "version": "1.18.15",
  "type": "module",
  "license": "MIT",
  "scripts": {
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/console-core",
-  "version": "2.0.0",
+  "version": "1.18.15",
  "private": true,
  "type": "module",
  "license": "MIT",
@@ -1,6 +1,6 @@
 {
  "name": "@opencode/console-function",
-  "version": "2.0.0",
+  "version": "1.18.15",
  "$schema": "https://json.schemastore.org/package.json",
  "private": true,
  "type": "module",
@@ -1,6 +1,6 @@
 {
  "name": "@opencode/console-mail",
-  "version": "2.0.0",
+  "version": "1.18.15",
  "dependencies": {
    "@jsx-email/all": "2.2.3",
    "@jsx-email/cli": "1.4.3",
@@ -1,6 +1,6 @@
 {
  "name": "@opencode/console-support",
-  "version": "2.0.0",
+  "version": "1.18.15",
  "type": "module",
  "license": "MIT",
  "scripts": {
--- a/Show More
+++ b/Show More