Revert entrypoint changes (#127)

Also simplifies the permission mode workaround so we don't have to
change the profile immediately, which could have raced with client
changes anwyay.

.github/workflows/publish.yml

@@ -4,7 +4,7 @@ on:
     tags:
       - "v*.*.*"
 jobs:
-  build:
+  publish-npm:
     runs-on: ubuntu-latest
     environment: release # Optional: for enhanced security
     permissions:
@@ -22,3 +22,15 @@ jobs:
       - run: npm ci
       - run: npm run build
       - run: npm publish
+  release:
+    runs-on: ubuntu-latest
+    needs: [publish-npm]
+    permissions:
+      contents: write
+    steps:
+      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8
+      - name: Create Release
+        id: create_release
+        uses: softprops/action-gh-release@6da8fa9354ddfdc4aeace5fc48d7f679b5214090
+        with:
+          draft: true

CHANGELOG.md

@@ -1,5 +1,71 @@
 # Changelog
 
+## 0.8.0
+
+- Revert changes to filename for cli entrypoint
+- Provide library entrypoint via lib.ts
+
+## 0.7.0
+
+- Allow importing from this package as a library in addition to running it as a CLI. Allows for easier integration into existing node applications.
+- Update to @anthropic-ai/claude-agent-sdk@v0.1.27
+
+## 0.6.10
+
+- Provide `agentInfo` on initialization response.
+- Update to @agentclientprotocol/sdk@0.5.1
+- Fix crash when receiving a hook_response event
+- Fix for invalid locations when read call has no path
+
+## 0.6.9
+
+- Update to @anthropic-ai/claude-agent-sdk@v0.1.26
+- Update to @agentclientprotocol/sdk@0.5.0
+
+## 0.6.8
+
+- Fix for duplicate tokens appearing in thread with streaming enabled
+- Update to @anthropic-ai/claude-agent-sdk@v0.1.23
+- Update to @agentclientprotocol/sdk@0.4.9
+
+## 0.6.7
+
+- Fix for invalid plan input from the model introduced in latest agent-sdk
+
+## 0.6.6
+
+- Do not enable bypassPermissions mode if in root/sudo mode, because Claude Code will not start
+
+## 0.6.5
+
+- Fix for duplicated text content after streaming
+
+## 0.6.4
+
+- Support streaming partial messages!
+- Update to @anthropic-ai/claude-agent-sdk@v0.1.21
+
+## 0.6.3
+
+- Fix issue where slash commands were loaded before initialization was complete.
+
+## 0.6.2
+
+- Fix bug where mode selection would sometimes fire before initialization was complete.
+- Update to @anthropic-ai/claude-agent-sdk@v0.1.19
+
+## 0.6.1
+
+- Fix to allow bypassPermissions mode to be selected (it wasn't permitted previously)
+
+## 0.6.0
+
+- Provide a model selector. We use the "default" model by default, and the user can change it via the client.
+- Make sure writes require permissions when necessary: https://github.com/zed-industries/claude-code-acp/pull/92
+- Add support for appending or overriding the system prompt: https://github.com/zed-industries/claude-code-acp/pull/91
+- Update to @anthropic-ai/claude-agent-sdk@v0.1.15
+- Update to @agentclientprotocol/sdk@0.4.8
+
 ## 0.5.5
 
 - Migrate to @agentclientprotocol/sdk@0.4.5

package.json

@@ -3,12 +3,12 @@
   "publishConfig": {
     "access": "public"
   },
+  "version": "0.8.0",
+  "description": "An ACP-compatible coding agent powered by the Claude Code SDK (TypeScript)",
+  "main": "dist/lib.js",
   "bin": {
     "claude-code-acp": "./dist/index.js"
   },
-  "version": "0.5.5",
-  "description": "An ACP-compatible coding agent powered by the Claude Code SDK (TypeScript)",
-  "main": "dist/index.js",
   "type": "module",
   "files": [
     "dist/",
@@ -51,30 +51,30 @@
   "author": "Zed Industries",
   "license": "Apache-2.0",
   "dependencies": {
-    "@agentclientprotocol/sdk": "0.4.5",
-    "@anthropic-ai/claude-agent-sdk": "0.1.13",
-    "@anthropic-ai/claude-code": "2.0.13",
-    "@modelcontextprotocol/sdk": "1.20.0",
+    "@agentclientprotocol/sdk": "0.5.1",
+    "@anthropic-ai/claude-agent-sdk": "0.1.27",
+    "@anthropic-ai/claude-code": "2.0.27",
+    "@modelcontextprotocol/sdk": "1.20.2",
     "diff": "8.0.2",
     "express": "5.1.0",
     "minimist": "1.2.8",
     "uuid": "13.0.0"
   },
   "devDependencies": {
-    "@anthropic-ai/sdk": "^0.65.0",
-    "@types/express": "5.0.3",
+    "@anthropic-ai/sdk": "0.67.0",
+    "@types/express": "5.0.4",
     "@types/minimist": "1.2.5",
-    "@types/node": "24.7.1",
+    "@types/node": "24.9.1",
     "@types/uuid": "10.0.0",
-    "@typescript-eslint/eslint-plugin": "8.46.0",
-    "@typescript-eslint/parser": "8.46.0",
-    "@vitest/ui": "3.2.4",
-    "eslint": "9.37.0",
+    "@typescript-eslint/eslint-plugin": "8.46.2",
+    "@typescript-eslint/parser": "8.46.2",
+    "@vitest/ui": "4.0.3",
+    "eslint": "9.38.0",
     "eslint-config-prettier": "10.1.8",
     "globals": "16.4.0",
     "prettier": "3.6.2",
     "ts-node": "10.9.2",
     "typescript": "5.9.3",
-    "vitest": "3.2.4"
+    "vitest": "4.0.3"
   }
 }

src/acp-agent.ts

@@ -15,6 +15,9 @@ import {
   ReadTextFileRequest,
   ReadTextFileResponse,
   RequestError,
+  SessionModelState,
+  SetSessionModelRequest,
+  SetSessionModelResponse,
   SetSessionModeRequest,
   SetSessionModeResponse,
   TerminalHandle,
@@ -28,9 +31,8 @@ import {
   PermissionMode,
   Query,
   query,
-  SDKAssistantMessage,
+  SDKPartialAssistantMessage,
   SDKUserMessage,
-  SDKUserMessageReplay,
 } from "@anthropic-ai/claude-agent-sdk";
 import * as fs from "node:fs";
 import * as path from "node:path";
@@ -51,6 +53,9 @@ import {
   toolUpdateFromToolResult,
   ClaudePlanEntry,
 } from "./tools.js";
+import { ContentBlockParam } from "@anthropic-ai/sdk/resources";
+import { BetaContentBlock, BetaRawContentBlockDelta } from "@anthropic-ai/sdk/resources/beta.mjs";
+import packageJson from "../package.json" with { type: "json" };
 
 type Session = {
   query: Query;
@@ -71,9 +76,19 @@ type BackgroundTerminal =
     };
 
 type ToolUseCache = {
-  [key: string]: { type: "tool_use"; id: string; name: string; input: any };
+  [key: string]: {
+    type: "tool_use" | "server_tool_use" | "mcp_tool_use";
+    id: string;
+    name: string;
+    input: any;
+  };
 };
 
+const DEFAULT_MODEL_ID = "default";
+
+// Bypass Permissions doesn't work if we are a root/sudo user
+const IS_ROOT = (process.geteuid?.() ?? process.getuid?.()) === 0;
+
 // Implement the ACP Agent interface
 export class ClaudeAcpAgent implements Agent {
   sessions: {
@@ -96,7 +111,6 @@ export class ClaudeAcpAgent implements Agent {
     this.clientCapabilities = request.clientCapabilities;
     return {
       protocolVersion: 1,
-      // todo!()
       agentCapabilities: {
         promptCapabilities: {
           image: true,
@@ -107,6 +121,11 @@ export class ClaudeAcpAgent implements Agent {
           sse: true,
         },
       },
+      agentInfo: {
+        name: packageJson.name,
+        title: "Claude Code",
+        version: packageJson.version,
+      },
       authMethods: [
         {
           description: "Run `claude /login` in the terminal",
@@ -169,11 +188,32 @@ export class ClaudeAcpAgent implements Agent {
       },
     };
 
+    let systemPrompt: Options["systemPrompt"] = { type: "preset", preset: "claude_code" };
+    if (params._meta?.systemPrompt) {
+      const customPrompt = params._meta.systemPrompt;
+      if (typeof customPrompt === "string") {
+        systemPrompt = customPrompt;
+      } else if (
+        typeof customPrompt === "object" &&
+        "append" in customPrompt &&
+        typeof customPrompt.append === "string"
+      ) {
+        systemPrompt.append = customPrompt.append;
+      }
+    }
+
+    const permissionMode = "default";
+
     const options: Options = {
       cwd: params.cwd,
+      includePartialMessages: true,
       mcpServers,
-      systemPrompt: { type: "preset", preset: "claude_code" },
+      systemPrompt,
       settingSources: ["user", "project", "local"],
+      // If we want bypassPermissions to be an option, we have to allow it here.
+      // But it doesn't work in root mode, so we only activate it if it will work.
+      allowDangerouslySkipPermissions: !IS_ROOT,
+      permissionMode,
       permissionPromptToolName: PERMISSION_TOOL_NAME,
       stderr: (err) => console.error(err),
       // note: although not documented by the types, passing an absolute path
@@ -191,7 +231,6 @@ export class ClaudeAcpAgent implements Agent {
       disallowedTools.push("Read");
     }
     if (this.clientCapabilities?.fs?.writeTextFile) {
-      allowedTools.push(toolNames.write);
       disallowedTools.push("Write", "Edit");
     }
     if (this.clientCapabilities?.terminal) {
@@ -210,14 +249,19 @@ export class ClaudeAcpAgent implements Agent {
       prompt: input,
       options,
     });
+
     this.sessions[sessionId] = {
       query: q,
       input: input,
       cancelled: false,
-      permissionMode: "default",
+      permissionMode,
     };
 
-    getAvailableSlashCommands(q).then((availableCommands) => {
+    const availableCommands = await getAvailableSlashCommands(q);
+    const models = await getAvailableModels(q);
+
+    // Needs to happen after we return the session
+    setTimeout(() => {
       this.client.sessionUpdate({
         sessionId,
         update: {
@@ -225,34 +269,40 @@ export class ClaudeAcpAgent implements Agent {
           availableCommands,
         },
       });
-    });
+    }, 0);
+
+    const availableModes = [
+      {
+        id: "default",
+        name: "Always Ask",
+        description: "Prompts for permission on first use of each tool",
+      },
+      {
+        id: "acceptEdits",
+        name: "Accept Edits",
+        description: "Automatically accepts file edit permissions for the session",
+      },
+      {
+        id: "plan",
+        name: "Plan Mode",
+        description: "Claude can analyze but not modify files or execute commands",
+      },
+    ];
+    // Only works in non-root mode
+    if (!IS_ROOT) {
+      availableModes.push({
+        id: "bypassPermissions",
+        name: "Bypass Permissions",
+        description: "Skips all permission prompts",
+      });
+    }
 
     return {
       sessionId,
+      models,
       modes: {
-        currentModeId: "default",
-        availableModes: [
-          {
-            id: "default",
-            name: "Always Ask",
-            description: "Prompts for permission on first use of each tool",
-          },
-          {
-            id: "acceptEdits",
-            name: "Accept Edits",
-            description: "Automatically accepts file edit permissions for the session",
-          },
-          {
-            id: "bypassPermissions",
-            name: "Bypass Permissions",
-            description: "Skips all permission prompts",
-          },
-          {
-            id: "plan",
-            name: "Plan Mode",
-            description: "Claude can analyze but not modify files or execute commands",
-          },
-        ],
+        currentModeId: permissionMode,
+        availableModes,
       },
     };
   }
@@ -286,8 +336,11 @@ export class ClaudeAcpAgent implements Agent {
               break;
             case "compact_boundary":
               break;
+            case "hook_response":
+              // Todo: process via status api: https://docs.claude.com/en/docs/claude-code/hooks#hook-output
+              break;
             default:
-              unreachable(message as never);
+              unreachable(message);
           }
           break;
         case "result": {
@@ -311,6 +364,17 @@ export class ClaudeAcpAgent implements Agent {
               return { stopReason: "refusal" };
           }
         }
+        case "stream_event": {
+          for (const notification of streamEventToAcpNotifications(
+            message,
+            params.sessionId,
+            this.toolUseCache,
+            this.fileContentCache,
+          )) {
+            await this.client.sessionUpdate(notification);
+          }
+          break;
+        }
         case "user":
         case "assistant": {
           if (this.sessions[params.sessionId].cancelled) {
@@ -350,8 +414,15 @@ export class ClaudeAcpAgent implements Agent {
             throw RequestError.authRequired();
           }
 
+          const content =
+            message.type === "assistant"
+              ? // Handled by stream events above
+                message.message.content.filter((item) => !["text", "thinking"].includes(item.type))
+              : message.message.content;
+
           for (const notification of toAcpNotifications(
-            message,
+            content,
+            message.message.role,
             params.sessionId,
             this.toolUseCache,
             this.fileContentCache,
@@ -361,7 +432,7 @@ export class ClaudeAcpAgent implements Agent {
           break;
         }
         default:
-          unreachable(message as never);
+          unreachable(message);
       }
     }
     throw new Error("Session did not end in result");
@@ -375,6 +446,13 @@ export class ClaudeAcpAgent implements Agent {
     await this.sessions[params.sessionId].query.interrupt();
   }
 
+  async setSessionModel(params: SetSessionModelRequest): Promise<SetSessionModelResponse | void> {
+    if (!this.sessions[params.sessionId]) {
+      throw new Error("Session not found");
+    }
+    await this.sessions[params.sessionId].query.setModel(params.modelId);
+  }
+
   async setSessionMode(params: SetSessionModeRequest): Promise<SetSessionModeResponse> {
     if (!this.sessions[params.sessionId]) {
       throw new Error("Session not found");
@@ -415,6 +493,26 @@ export class ClaudeAcpAgent implements Agent {
   }
 }
 
+async function getAvailableModels(query: Query): Promise<SessionModelState> {
+  const models = await query.supportedModels();
+
+  // Query doesn't give us access to the currently selected model, so we default to "default" if it is there,
+  // otherwise we just choose the first model in the list.
+  const currentModel = models.find((model) => model.value === DEFAULT_MODEL_ID) || models[0];
+  await query.setModel(currentModel.value);
+
+  const availableModels = models.map((model) => ({
+    modelId: model.value,
+    name: model.displayName,
+    description: model.description,
+  }));
+
+  return {
+    availableModels,
+    currentModelId: currentModel.value,
+  };
+}
+
 async function getAvailableSlashCommands(query: Query): Promise<AvailableCommand[]> {
   const UNSUPPORTED_COMMANDS = [
     "add-dir",
@@ -560,20 +658,18 @@ function promptToClaude(prompt: PromptRequest): SDKUserMessage {
  * Only handles text, image, and thinking chunks for now.
  */
 export function toAcpNotifications(
-  message: SDKAssistantMessage | SDKUserMessage | SDKUserMessageReplay,
+  content: string | ContentBlockParam[] | BetaContentBlock[] | BetaRawContentBlockDelta[],
+  role: "assistant" | "user",
   sessionId: string,
   toolUseCache: ToolUseCache,
   fileContentCache: { [key: string]: string },
 ): SessionNotification[] {
-  const content = message.message.content;
-
   if (typeof content === "string") {
     return [
       {
         sessionId,
         update: {
-          sessionUpdate:
-            message.type === "assistant" ? "agent_message_chunk" : "user_message_chunk",
+          sessionUpdate: role === "assistant" ? "agent_message_chunk" : "user_message_chunk",
           content: {
             type: "text",
             text: content,
@@ -589,9 +685,9 @@ export function toAcpNotifications(
     let update: SessionNotification["update"] | null = null;
     switch (chunk.type) {
       case "text":
+      case "text_delta":
         update = {
-          sessionUpdate:
-            message.type === "assistant" ? "agent_message_chunk" : "user_message_chunk",
+          sessionUpdate: role === "assistant" ? "agent_message_chunk" : "user_message_chunk",
           content: {
             type: "text",
             text: chunk.text,
@@ -600,8 +696,7 @@ export function toAcpNotifications(
         break;
       case "image":
         update = {
-          sessionUpdate:
-            message.type === "assistant" ? "agent_message_chunk" : "user_message_chunk",
+          sessionUpdate: role === "assistant" ? "agent_message_chunk" : "user_message_chunk",
           content: {
             type: "image",
             data: chunk.source.type === "base64" ? chunk.source.data : "",
@@ -611,6 +706,7 @@ export function toAcpNotifications(
         };
         break;
       case "thinking":
+      case "thinking_delta":
         update = {
           sessionUpdate: "agent_thought_chunk",
           content: {
@@ -620,12 +716,17 @@ export function toAcpNotifications(
         };
         break;
       case "tool_use":
+      case "server_tool_use":
+      case "mcp_tool_use": {
         toolUseCache[chunk.id] = chunk;
         if (chunk.name === "TodoWrite") {
-          update = {
-            sessionUpdate: "plan",
-            entries: planEntries(chunk.input as { todos: ClaudePlanEntry[] }),
-          };
+          // @ts-expect-error - sometimes input is empty object
+          if (Array.isArray(chunk.input.todos)) {
+            update = {
+              sessionUpdate: "plan",
+              entries: planEntries(chunk.input as { todos: ClaudePlanEntry[] }),
+            };
+          }
         } else {
           let rawInput;
           try {
@@ -642,8 +743,15 @@ export function toAcpNotifications(
           };
         }
         break;
+      }
 
-      case "tool_result": {
+      case "tool_result":
+      case "web_fetch_tool_result":
+      case "web_search_tool_result":
+      case "code_execution_tool_result":
+      case "bash_code_execution_tool_result":
+      case "text_editor_code_execution_tool_result":
+      case "mcp_tool_result": {
         const toolUse = toolUseCache[chunk.tool_use_id];
         if (!toolUse) {
           console.error(
@@ -656,15 +764,24 @@ export function toAcpNotifications(
           update = {
             toolCallId: chunk.tool_use_id,
             sessionUpdate: "tool_call_update",
-            status: chunk.is_error ? "failed" : "completed",
+            status: "is_error" in chunk && chunk.is_error ? "failed" : "completed",
             ...toolUpdateFromToolResult(chunk, toolUseCache[chunk.tool_use_id]),
           };
         }
         break;
       }
 
+      case "document":
+      case "search_result":
+      case "redacted_thinking":
+      case "input_json_delta":
+      case "citations_delta":
+      case "signature_delta":
+      case "container_upload":
+        break;
+
       default:
-        throw new Error("unhandled chunk type: " + chunk.type);
+        unreachable(chunk);
     }
     if (update) {
       output.push({ sessionId, update });
@@ -674,6 +791,42 @@ export function toAcpNotifications(
   return output;
 }
 
+export function streamEventToAcpNotifications(
+  message: SDKPartialAssistantMessage,
+  sessionId: string,
+  toolUseCache: ToolUseCache,
+  fileContentCache: { [key: string]: string },
+): SessionNotification[] {
+  const event = message.event;
+  switch (event.type) {
+    case "content_block_start":
+      return toAcpNotifications(
+        [event.content_block],
+        "assistant",
+        sessionId,
+        toolUseCache,
+        fileContentCache,
+      );
+    case "content_block_delta":
+      return toAcpNotifications(
+        [event.delta],
+        "assistant",
+        sessionId,
+        toolUseCache,
+        fileContentCache,
+      );
+    // No content
+    case "message_start":
+    case "message_delta":
+    case "message_stop":
+    case "content_block_stop":
+      return [];
+
+    default:
+      unreachable(event);
+  }
+}
+
 export function runAcp() {
   const input = nodeToWebWritable(process.stdout);
   const output = nodeToWebReadable(process.stdin);

src/index.ts

@@ -19,7 +19,7 @@ process.on("unhandledRejection", (reason, promise) => {
   console.error("Unhandled Rejection at:", promise, "reason:", reason);
 });
 
-import { runAcp as runAcp } from "./acp-agent.js";
+import { runAcp } from "./acp-agent.js";
 runAcp();
 
 // Keep process alive

src/lib.ts

@@ -0,0 +1,25 @@
+// Export the main agent class and utilities for library usage
+export {
+  ClaudeAcpAgent,
+  runAcp,
+  toAcpNotifications,
+  streamEventToAcpNotifications,
+} from "./acp-agent.js";
+export {
+  loadManagedSettings,
+  applyEnvironmentSettings,
+  nodeToWebReadable,
+  nodeToWebWritable,
+  Pushable,
+  unreachable,
+} from "./utils.js";
+export {
+  createMcpServer,
+  createPermissionMcpServer,
+  PERMISSION_TOOL_NAME,
+  toolNames,
+} from "./mcp-server.js";
+export { toolInfoFromToolUse, planEntries, toolUpdateFromToolResult } from "./tools.js";
+
+// Export types
+export type { ClaudePlanEntry } from "./tools.js";

src/tests/acp-agent.test.ts

@@ -18,7 +18,7 @@ import {
 import { nodeToWebWritable, nodeToWebReadable } from "../utils.js";
 import { markdownEscape, toolInfoFromToolUse, toolUpdateFromToolResult } from "../tools.js";
 import { toAcpNotifications } from "../acp-agent.js";
-import { SDKAssistantMessage } from "@anthropic-ai/claude-agent-sdk";
+import { query, SDKAssistantMessage } from "@anthropic-ai/claude-agent-sdk";
 
 describe.skipIf(!process.env.RUN_INTEGRATION_TESTS)("ACP subprocess integration", () => {
   let child: ReturnType<typeof spawn>;
@@ -649,7 +649,9 @@ describe("tool conversions", () => {
       session_id: "d056596f-e328-41e9-badd-b07122ae5227",
       uuid: "b7c3330c-de8f-4bba-ac53-68c7f76ffeb5",
     };
-    expect(toAcpNotifications(received, "test", {}, {})).toStrictEqual([
+    expect(
+      toAcpNotifications(received.message.content, received.message.role, "test", {}, {}),
+    ).toStrictEqual([
       {
         sessionId: "test",
         update: {
@@ -780,3 +782,16 @@ describe("escape markdown", () => {
     expect(escaped).toEqual("````\nfor example:\n```markdown\nHello *world*!\n```\n````");
   });
 });
+
+describe("SDK behavior", () => {
+  it.skipIf(!process.env.RUN_INTEGRATION_TESTS)(
+    "query has a 'default' model",
+    async () => {
+      const q = query({ prompt: "hi" });
+      const models = await q.supportedModels();
+      const defaultModel = models.find((m) => m.value === "default");
+      expect(defaultModel).toBeDefined();
+    },
+    10000,
+  );
+});

src/tools.ts

@@ -1,6 +1,14 @@
 import { PlanEntry, ToolCallContent, ToolCallLocation, ToolKind } from "@agentclientprotocol/sdk";
 import { replaceAndCalculateLocation, SYSTEM_REMINDER, toolNames } from "./mcp-server.js";
-import { ToolResultBlockParam } from "@anthropic-ai/sdk/resources";
+import { ToolResultBlockParam, WebSearchToolResultBlockParam } from "@anthropic-ai/sdk/resources";
+import {
+  BetaBashCodeExecutionToolResultBlockParam,
+  BetaCodeExecutionToolResultBlockParam,
+  BetaRequestMCPToolResultBlockParam,
+  BetaTextEditorCodeExecutionToolResultBlockParam,
+  BetaWebFetchToolResultBlockParam,
+  BetaWebSearchToolResultBlockParam,
+} from "@anthropic-ai/sdk/resources/beta.mjs";
 
 interface ToolInfo {
   title: string;
@@ -105,12 +113,14 @@ export function toolInfoFromToolUse(
       return {
         title: "Read " + (input.file_path ?? "File") + limit,
         kind: "read",
-        locations: [
-          {
-            path: input.file_path,
-            line: input.offset ?? 0,
-          },
-        ],
+        locations: input.file_path
+          ? [
+              {
+                path: input.file_path,
+                line: input.offset ?? 0,
+              },
+            ]
+          : [],
         content: [],
       };
     }
@@ -336,7 +346,7 @@ export function toolInfoFromToolUse(
 
     case "TodoWrite":
       return {
-        title: input?.todos
+        title: Array.isArray(input?.todos)
           ? `Update TODOs: ${input.todos.map((todo: any) => todo.content).join(", ")}`
           : "Update TODOs",
         kind: "think",
@@ -385,7 +395,15 @@ export function toolInfoFromToolUse(
 }
 
 export function toolUpdateFromToolResult(
-  toolResult: ToolResultBlockParam,
+  toolResult:
+    | ToolResultBlockParam
+    | BetaWebSearchToolResultBlockParam
+    | BetaWebFetchToolResultBlockParam
+    | WebSearchToolResultBlockParam
+    | BetaCodeExecutionToolResultBlockParam
+    | BetaBashCodeExecutionToolResultBlockParam
+    | BetaTextEditorCodeExecutionToolResultBlockParam
+    | BetaRequestMCPToolResultBlockParam,
   toolUse: any | undefined,
 ): ToolUpdate {
   switch (toolUse?.name) {
@@ -425,7 +443,12 @@ export function toolUpdateFromToolResult(
     case toolNames.edit:
     case toolNames.write:
     case "Write": {
-      if (toolResult.is_error && toolResult.content && toolResult.content.length > 0) {
+      if (
+        "is_error" in toolResult &&
+        toolResult.is_error &&
+        toolResult.content &&
+        toolResult.content.length > 0
+      ) {
         // Only return errors
         return toAcpContentUpdate(toolResult.content, true);
       }
@@ -451,7 +474,10 @@ export function toolUpdateFromToolResult(
     case "WebSearch":
     case "Other":
     default: {
-      return toAcpContentUpdate(toolResult.content, toolResult.is_error);
+      return toAcpContentUpdate(
+        toolResult.content,
+        "is_error" in toolResult ? toolResult.is_error : false,
+      );
     }
   }
 }

src/utils.ts

@@ -76,7 +76,13 @@ export function nodeToWebReadable(nodeStream: Readable): ReadableStream<Uint8Arr
 }
 
 export function unreachable(value: never): never {
-  throw new Error(`Unexpected case: ${value}`);
+  let valueAsString;
+  try {
+    valueAsString = JSON.stringify(value);
+  } catch {
+    valueAsString = value;
+  }
+  throw new Error(`Unexpected case: ${valueAsString}`);
 }
 
 export function sleep(time: number): Promise<void> {