feat: add rawOutput to tool call updates (#261)

## Summary
- Pass the raw tool result content as `rawOutput` in `tool_call_update`
notifications
- Allows ACP clients to access the unprocessed tool output alongside the
formatted content
- Adds tests using SDK types to document exact shapes for different tool
result types

## Test plan
- [x] `npm run build` passes
- [x] `npm test` passes (86 tests)
- [x] `npm run lint` passes
- [x] `npm run format:check` passes

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude <noreply@anthropic.com>

.github/workflows/publish.yml

@@ -32,5 +32,3 @@ jobs:
       - name: Create Release
         id: create_release
         uses: softprops/action-gh-release@6da8fa9354ddfdc4aeace5fc48d7f679b5214090
-        with:
-          draft: true

.gitignore

@@ -1,3 +1,5 @@
 node_modules
 dist
 .DS_Store
+.claude/*.local.*
+CLAUDE.local.md

CHANGELOG.md

@@ -1,5 +1,43 @@
 # Changelog
 
+## 0.13.2
+
+- Update to @anthropic-ai/claude-agent-sdk@0.2.22
+- Fix: return content from ACP write tool to help with issues with alternate providers.
+
+## 0.13.1
+
+- Update to @anthropic-ai/claude-agent-sdk@0.2.7
+- Add TypeScript declaration files for library users
+- Fixed error handling in custom ACP focused MCP tools
+
+## 0.13.0
+
+- Update to @anthropic-ai/claude-agent-sdk@0.2.6
+- Update to @agentclientprotocol/sdk@0.13.0
+
+## 0.12.6
+
+- Fix model selection
+
+## 0.12.5
+
+- Update to @anthropic-ai/claude-agent-sdk@v0.1.70
+- Unstable implementation of resuming sessions
+
+## 0.12.4
+
+- Update to @anthropic-ai/claude-agent-sdk@v0.1.67
+- Better respect permissions specified in settings files
+- Unstable implementation of forking
+
+## 0.12.3
+
+- Update to @anthropic-ai/claude-agent-sdk@v0.1.65
+- Update to @agentclientprotocol/sdk@0.9.0
+- Allow agent to write plans and todos to its config directory
+- Fix experimental resume ids
+
 ## 0.12.2
 
 - Fix duplicate tool use IDs error

README.md

@@ -4,7 +4,7 @@
 
 Use [Claude Code](https://www.anthropic.com/claude-code) from [ACP-compatible](https://agentclientprotocol.com) clients such as [Zed](https://zed.dev)!
 
-This tool implements an ACP agent by using the official [Claude Code SDK](https://docs.anthropic.com/en/docs/claude-code/sdk/sdk-overview), supporting:
+This tool implements an ACP agent by using the official [Claude Agent SDK](https://platform.claude.com/docs/en/agent-sdk/overview), supporting:
 
 - Context @-mentions
 - Images
@@ -32,20 +32,14 @@ Read the docs on [External Agent](https://zed.dev/docs/ai/external-agents) suppo
 
 ### Other clients
 
-- Emacs via [agent-shell.el](https://github.com/xenodium/agent-shell)
-- [marimo notebook](https://github.com/marimo-team/marimo)
-- Neovim
-  - via [CodeCompanion.nvim](https://codecompanion.olimorris.dev/configuration/adapters#setup-claude-code-via-acp)
-  - via [yetone/avante.nvim](https://github.com/yetone/avante.nvim)
-
-[Submit a PR](https://github.com/zed-industries/claude-code-acp/pulls) to add yours!
+Or try it with any of the other [ACP compatible clients](https://agentclientprotocol.com/overview/clients)!
 
 #### Installation
 
 Install the adapter from `npm`:
 
 ```bash
-npm install @zed-industries/claude-code-acp
+npm install -g @zed-industries/claude-code-acp
 ```
 
 You can then use `claude-code-acp` as a regular ACP agent:

package.json

@@ -3,15 +3,24 @@
   "publishConfig": {
     "access": "public"
   },
-  "version": "0.12.2",
+  "version": "0.13.2",
   "description": "An ACP-compatible coding agent powered by the Claude Code SDK (TypeScript)",
   "main": "dist/lib.js",
+  "types": "dist/lib.d.ts",
   "bin": {
     "claude-code-acp": "./dist/index.js"
   },
   "type": "module",
+  "exports": {
+    ".": {
+      "types": "./dist/lib.d.ts",
+      "import": "./dist/lib.js"
+    },
+    "./*": "./*"
+  },
   "files": [
     "dist/",
+    "!dist/tests/",
     "README.md",
     "LICENSE",
     "package.json"
@@ -51,22 +60,23 @@
   "author": "Zed Industries",
   "license": "Apache-2.0",
   "dependencies": {
-    "@agentclientprotocol/sdk": "0.8.0",
-    "@anthropic-ai/claude-agent-sdk": "0.1.61",
-    "@modelcontextprotocol/sdk": "1.24.3",
-    "diff": "8.0.2"
+    "@agentclientprotocol/sdk": "0.13.1",
+    "@anthropic-ai/claude-agent-sdk": "0.2.22",
+    "@modelcontextprotocol/sdk": "1.25.3",
+    "diff": "8.0.3",
+    "minimatch": "10.1.1"
   },
   "devDependencies": {
     "@anthropic-ai/sdk": "0.71.2",
-    "@types/node": "24.10.1",
-    "@typescript-eslint/eslint-plugin": "8.48.1",
-    "@typescript-eslint/parser": "8.48.1",
-    "eslint": "9.39.1",
+    "@types/node": "25.0.10",
+    "@typescript-eslint/eslint-plugin": "8.54.0",
+    "@typescript-eslint/parser": "8.54.0",
+    "eslint": "9.39.2",
     "eslint-config-prettier": "10.1.8",
-    "globals": "16.5.0",
-    "prettier": "3.7.4",
+    "globals": "17.2.0",
+    "prettier": "3.8.1",
     "ts-node": "10.9.2",
     "typescript": "5.9.3",
-    "vitest": "4.0.15"
+    "vitest": "4.0.18"
   }
 }

src/acp-agent.ts

@@ -5,6 +5,8 @@ import {
   AvailableCommand,
   CancelNotification,
   ClientCapabilities,
+  ForkSessionRequest,
+  ForkSessionResponse,
   InitializeRequest,
   InitializeResponse,
   ndJsonStream,
@@ -15,6 +17,8 @@ import {
   ReadTextFileRequest,
   ReadTextFileResponse,
   RequestError,
+  ResumeSessionRequest,
+  ResumeSessionResponse,
   SessionModelState,
   SessionNotification,
   SetSessionModelRequest,
@@ -26,6 +30,7 @@ import {
   WriteTextFileRequest,
   WriteTextFileResponse,
 } from "@agentclientprotocol/sdk";
+import { SettingsManager } from "./settings.js";
 import {
   CanUseTool,
   McpServerConfig,
@@ -40,7 +45,8 @@ import * as fs from "node:fs";
 import * as path from "node:path";
 import * as os from "node:os";
 import { nodeToWebReadable, nodeToWebWritable, Pushable, unreachable } from "./utils.js";
-import { createMcpServer, EDIT_TOOL_NAMES, toolNames } from "./mcp-server.js";
+import { createMcpServer } from "./mcp-server.js";
+import { EDIT_TOOL_NAMES, acpToolNames } from "./tools.js";
 import {
   toolInfoFromToolUse,
   planEntries,
@@ -48,11 +54,15 @@ import {
   ClaudePlanEntry,
   registerHookCallback,
   createPostToolUseHook,
+  createPreToolUseHook,
 } 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" };
 import { randomUUID } from "node:crypto";
+import { fileURLToPath } from "node:url";
+
+export const CLAUDE_CONFIG_DIR = process.env.CLAUDE ?? path.join(os.homedir(), ".claude");
 
 /**
  * Logger interface for customizing logging output
@@ -67,6 +77,7 @@ type Session = {
   input: Pushable<SDKUserMessage>;
   cancelled: boolean;
   permissionMode: PermissionMode;
+  settingsManager: SettingsManager;
 };
 
 type BackgroundTerminal =
@@ -114,12 +125,12 @@ export type ToolUpdateMeta = {
   };
 };
 
-type ToolUseCache = {
+export type ToolUseCache = {
   [key: string]: {
     type: "tool_use" | "server_tool_use" | "mcp_tool_use";
     id: string;
     name: string;
-    input: any;
+    input: unknown;
   };
 };
 
@@ -133,7 +144,6 @@ export class ClaudeAcpAgent implements Agent {
   };
   client: AgentSideConnection;
   toolUseCache: ToolUseCache;
-  fileContentCache: { [key: string]: string };
   backgroundTerminals: { [key: string]: BackgroundTerminal } = {};
   clientCapabilities?: ClientCapabilities;
   logger: Logger;
@@ -142,7 +152,6 @@ export class ClaudeAcpAgent implements Agent {
     this.sessions = {};
     this.client = client;
     this.toolUseCache = {};
-    this.fileContentCache = {};
     this.logger = logger ?? console;
   }
 
@@ -157,17 +166,17 @@ export class ClaudeAcpAgent implements Agent {
     };
 
     // If client supports terminal-auth capability, use that instead.
-    // if (request.clientCapabilities?._meta?.["terminal-auth"] === true) {
-    //   const cliPath = fileURLToPath(import.meta.resolve("@anthropic-ai/claude-agent-sdk/cli.js"));
+    if (request.clientCapabilities?._meta?.["terminal-auth"] === true) {
+      const cliPath = fileURLToPath(import.meta.resolve("@anthropic-ai/claude-agent-sdk/cli.js"));
 
-    //   authMethod._meta = {
-    //     "terminal-auth": {
-    //       command: "node",
-    //       args: [cliPath, "/login"],
-    //       label: "Claude Code Login",
-    //     },
-    //   };
-    // }
+      authMethod._meta = {
+        "terminal-auth": {
+          command: "node",
+          args: [cliPath, "/login"],
+          label: "Claude Code Login",
+        },
+      };
+    }
 
     return {
       protocolVersion: 1,
@@ -180,6 +189,10 @@ export class ClaudeAcpAgent implements Agent {
           http: true,
           sse: true,
         },
+        sessionCapabilities: {
+          fork: {},
+          resume: {},
+        },
       },
       agentInfo: {
         name: packageJson.name,
@@ -189,6 +202,7 @@ export class ClaudeAcpAgent implements Agent {
       authMethods: [authMethod],
     };
   }
+
   async newSession(params: NewSessionRequest): Promise<NewSessionResponse> {
     if (
       fs.existsSync(path.resolve(os.homedir(), ".claude.json.backup")) &&
@@ -197,220 +211,39 @@ export class ClaudeAcpAgent implements Agent {
       throw RequestError.authRequired();
     }
 
-    const sessionId = randomUUID();
-    const input = new Pushable<SDKUserMessage>();
-
-    const mcpServers: Record<string, McpServerConfig> = {};
-    if (Array.isArray(params.mcpServers)) {
-      for (const server of params.mcpServers) {
-        if ("type" in server) {
-          mcpServers[server.name] = {
-            type: server.type,
-            url: server.url,
-            headers: server.headers
-              ? Object.fromEntries(server.headers.map((e) => [e.name, e.value]))
-              : undefined,
-          };
-        } else {
-          mcpServers[server.name] = {
-            type: "stdio",
-            command: server.command,
-            args: server.args,
-            env: server.env
-              ? Object.fromEntries(server.env.map((e) => [e.name, e.value]))
-              : undefined,
-          };
-        }
-      }
-    }
-
-    // Only add the acp MCP server if built-in tools are not disabled
-    if (!params._meta?.disableBuiltInTools) {
-      const server = createMcpServer(this, sessionId, this.clientCapabilities);
-      mcpServers["acp"] = {
-        type: "sdk",
-        name: "acp",
-        instance: server,
-      };
-    }
-
-    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";
-
-    // Extract options from _meta if provided
-    const userProvidedOptions = (params._meta as NewSessionMeta | undefined)?.claudeCode?.options;
-
-    const options: Options = {
-      systemPrompt,
-      settingSources: ["user", "project", "local"],
-      stderr: (err) => this.logger.error(err),
-      ...userProvidedOptions,
-      // Override certain fields that must be controlled by ACP
-      cwd: params.cwd,
-      includePartialMessages: true,
-      mcpServers: { ...(userProvidedOptions?.mcpServers || {}), ...mcpServers },
-      // Set our own session id
-      extraArgs: { ...userProvidedOptions?.extraArgs, "session-id": sessionId },
-      // 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,
-      canUseTool: this.canUseTool(sessionId),
-      // note: although not documented by the types, passing an absolute path
-      // here works to find zed's managed node version.
-      executable: process.execPath as any,
-      ...(process.env.CLAUDE_CODE_EXECUTABLE && {
-        pathToClaudeCodeExecutable: process.env.CLAUDE_CODE_EXECUTABLE,
-      }),
-      hooks: {
-        ...userProvidedOptions?.hooks,
-        PostToolUse: [
-          ...(userProvidedOptions?.hooks?.PostToolUse || []),
-          {
-            hooks: [createPostToolUseHook(this.logger)],
-          },
-        ],
-      },
-    };
-
-    const allowedTools = [];
-    const disallowedTools = [];
-
-    // Check if built-in tools should be disabled
-    const disableBuiltInTools = params._meta?.disableBuiltInTools === true;
-
-    if (!disableBuiltInTools) {
-      if (this.clientCapabilities?.fs?.readTextFile) {
-        allowedTools.push(toolNames.read);
-        disallowedTools.push("Read");
-      }
-      if (this.clientCapabilities?.fs?.writeTextFile) {
-        disallowedTools.push("Write", "Edit");
-      }
-      if (this.clientCapabilities?.terminal) {
-        allowedTools.push(toolNames.bashOutput, toolNames.killShell);
-        disallowedTools.push("Bash", "BashOutput", "KillShell");
-      }
-    } else {
-      // When built-in tools are disabled, explicitly disallow all of them
-      disallowedTools.push(
-        toolNames.read,
-        toolNames.write,
-        toolNames.edit,
-        toolNames.bash,
-        toolNames.bashOutput,
-        toolNames.killShell,
-        "Read",
-        "Write",
-        "Edit",
-        "Bash",
-        "BashOutput",
-        "KillShell",
-        "Glob",
-        "Grep",
-        "Task",
-        "TodoWrite",
-        "ExitPlanMode",
-        "WebSearch",
-        "WebFetch",
-        "AskUserQuestion",
-        "SlashCommand",
-        "Skill",
-        "NotebookEdit",
-      );
-    }
-
-    if (allowedTools.length > 0) {
-      options.allowedTools = allowedTools;
-    }
-    if (disallowedTools.length > 0) {
-      options.disallowedTools = disallowedTools;
-    }
-
-    // Handle abort controller from meta options
-    const abortController = userProvidedOptions?.abortController;
-    if (abortController?.signal.aborted) {
-      throw new Error("Cancelled");
-    }
-
-    const q = query({
-      prompt: input,
-      options,
+    return await this.createSession(params, {
+      // Revisit these meta values once we support resume
+      resume: (params._meta as NewSessionMeta | undefined)?.claudeCode?.options?.resume,
     });
+  }
 
-    this.sessions[sessionId] = {
-      query: q,
-      input: input,
-      cancelled: false,
-      permissionMode,
-    };
-
-    const availableCommands = await getAvailableSlashCommands(q);
-    const models = await getAvailableModels(q);
-
-    // Needs to happen after we return the session
-    setTimeout(() => {
-      this.client.sessionUpdate({
-        sessionId,
-        update: {
-          sessionUpdate: "available_commands_update",
-          availableCommands,
-        },
-      });
-    }, 0);
-
-    const availableModes = [
+  async unstable_forkSession(params: ForkSessionRequest): Promise<ForkSessionResponse> {
+    return await this.createSession(
       {
-        id: "default",
-        name: "Default",
-        description: "Standard behavior, prompts for dangerous operations",
+        cwd: params.cwd,
+        mcpServers: params.mcpServers ?? [],
+        _meta: params._meta,
       },
       {
-        id: "acceptEdits",
-        name: "Accept Edits",
-        description: "Auto-accept file edit operations",
+        resume: params.sessionId,
+        forkSession: true,
       },
-      {
-        id: "plan",
-        name: "Plan Mode",
-        description: "Planning mode, no actual tool execution",
-      },
-      {
-        id: "dontAsk",
-        name: "Don't Ask",
-        description: "Don't prompt for permissions, deny if not pre-approved",
-      },
-    ];
-    // Only works in non-root mode
-    if (!IS_ROOT) {
-      availableModes.push({
-        id: "bypassPermissions",
-        name: "Bypass Permissions",
-        description: "Bypass all permission checks",
-      });
-    }
+    );
+  }
 
-    return {
-      sessionId,
-      models,
-      modes: {
-        currentModeId: permissionMode,
-        availableModes,
+  async unstable_resumeSession(params: ResumeSessionRequest): Promise<ResumeSessionResponse> {
+    const response = await this.createSession(
+      {
+        cwd: params.cwd,
+        mcpServers: params.mcpServers ?? [],
+        _meta: params._meta,
       },
-    };
+      {
+        resume: params.sessionId,
+      },
+    );
+
+    return response;
   }
 
   async authenticate(_params: AuthenticateRequest): Promise<void> {
@@ -435,12 +268,16 @@ export class ClaudeAcpAgent implements Agent {
         }
         break;
       }
+
       switch (message.type) {
         case "system":
           switch (message.subtype) {
             case "init":
               break;
             case "compact_boundary":
+            case "hook_started":
+            case "task_notification":
+            case "hook_progress":
             case "hook_response":
             case "status":
               // Todo: process via status api: https://docs.claude.com/en/docs/claude-code/hooks#hook-output
@@ -494,7 +331,6 @@ export class ClaudeAcpAgent implements Agent {
             message,
             params.sessionId,
             this.toolUseCache,
-            this.fileContentCache,
             this.client,
             this.logger,
           )) {
@@ -558,7 +394,6 @@ export class ClaudeAcpAgent implements Agent {
             message.message.role,
             params.sessionId,
             this.toolUseCache,
-            this.fileContentCache,
             this.client,
             this.logger,
           )) {
@@ -567,6 +402,7 @@ export class ClaudeAcpAgent implements Agent {
           break;
         }
         case "tool_progress":
+        case "tool_use_summary":
           break;
         case "auth_status":
           break;
@@ -586,7 +422,9 @@ export class ClaudeAcpAgent implements Agent {
     await this.sessions[params.sessionId].query.interrupt();
   }
 
-  async setSessionModel(params: SetSessionModelRequest): Promise<SetSessionModelResponse | void> {
+  async unstable_setSessionModel(
+    params: SetSessionModelRequest,
+  ): Promise<SetSessionModelResponse | void> {
     if (!this.sessions[params.sessionId]) {
       throw new Error("Session not found");
     }
@@ -621,15 +459,11 @@ export class ClaudeAcpAgent implements Agent {
 
   async readTextFile(params: ReadTextFileRequest): Promise<ReadTextFileResponse> {
     const response = await this.client.readTextFile(params);
-    if (!params.limit && !params.line) {
-      this.fileContentCache[params.path] = response.content;
-    }
     return response;
   }
 
   async writeTextFile(params: WriteTextFileRequest): Promise<WriteTextFileResponse> {
     const response = await this.client.writeTextFile(params);
-    this.fileContentCache[params.path] = params.content;
     return response;
   }
 
@@ -659,11 +493,7 @@ export class ClaudeAcpAgent implements Agent {
           toolCall: {
             toolCallId: toolUseID,
             rawInput: toolInput,
-            title: toolInfoFromToolUse(
-              { name: toolName, input: toolInput },
-              this.fileContentCache,
-              this.logger,
-            ).title,
+            title: toolInfoFromToolUse({ name: toolName, input: toolInput }).title,
           },
         });
 
@@ -726,11 +556,7 @@ export class ClaudeAcpAgent implements Agent {
         toolCall: {
           toolCallId: toolUseID,
           rawInput: toolInput,
-          title: toolInfoFromToolUse(
-            { name: toolName, input: toolInput },
-            this.fileContentCache,
-            this.logger,
-          ).title,
+          title: toolInfoFromToolUse({ name: toolName, input: toolInput }).title,
         },
       });
       if (signal.aborted || response.outcome?.outcome === "cancelled") {
@@ -768,6 +594,261 @@ export class ClaudeAcpAgent implements Agent {
       }
     };
   }
+
+  private async createSession(
+    params: NewSessionRequest,
+    creationOpts: { resume?: string; forkSession?: boolean } = {},
+  ): Promise<NewSessionResponse> {
+    // We want to create a new session id unless it is resume,
+    // but not resume + forkSession.
+    let sessionId;
+    if (creationOpts.forkSession) {
+      sessionId = randomUUID();
+    } else if (creationOpts.resume) {
+      sessionId = creationOpts.resume;
+    } else {
+      sessionId = randomUUID();
+    }
+
+    const input = new Pushable<SDKUserMessage>();
+
+    const settingsManager = new SettingsManager(params.cwd, {
+      logger: this.logger,
+    });
+    await settingsManager.initialize();
+
+    const mcpServers: Record<string, McpServerConfig> = {};
+    if (Array.isArray(params.mcpServers)) {
+      for (const server of params.mcpServers) {
+        if ("type" in server) {
+          mcpServers[server.name] = {
+            type: server.type,
+            url: server.url,
+            headers: server.headers
+              ? Object.fromEntries(server.headers.map((e) => [e.name, e.value]))
+              : undefined,
+          };
+        } else {
+          mcpServers[server.name] = {
+            type: "stdio",
+            command: server.command,
+            args: server.args,
+            env: server.env
+              ? Object.fromEntries(server.env.map((e) => [e.name, e.value]))
+              : undefined,
+          };
+        }
+      }
+    }
+
+    // Only add the acp MCP server if built-in tools are not disabled
+    if (!params._meta?.disableBuiltInTools) {
+      const server = createMcpServer(this, sessionId, this.clientCapabilities);
+      mcpServers["acp"] = {
+        type: "sdk",
+        name: "acp",
+        instance: server,
+      };
+    }
+
+    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";
+
+    // Extract options from _meta if provided
+    const userProvidedOptions = (params._meta as NewSessionMeta | undefined)?.claudeCode?.options;
+    const extraArgs = { ...userProvidedOptions?.extraArgs };
+    if (creationOpts?.resume === undefined || creationOpts?.forkSession) {
+      // Set our own session id if not resuming an existing session.
+      extraArgs["session-id"] = sessionId;
+    }
+
+    // Configure thinking tokens from environment variable
+    const maxThinkingTokens = process.env.MAX_THINKING_TOKENS
+      ? parseInt(process.env.MAX_THINKING_TOKENS, 10)
+      : undefined;
+
+    const options: Options = {
+      systemPrompt,
+      settingSources: ["user", "project", "local"],
+      stderr: (err) => this.logger.error(err),
+      ...(maxThinkingTokens !== undefined && { maxThinkingTokens }),
+      ...userProvidedOptions,
+      // Override certain fields that must be controlled by ACP
+      cwd: params.cwd,
+      includePartialMessages: true,
+      mcpServers: { ...(userProvidedOptions?.mcpServers || {}), ...mcpServers },
+      extraArgs,
+      // 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,
+      canUseTool: this.canUseTool(sessionId),
+      // note: although not documented by the types, passing an absolute path
+      // here works to find zed's managed node version.
+      executable: process.execPath as any,
+      ...(process.env.CLAUDE_CODE_EXECUTABLE && {
+        pathToClaudeCodeExecutable: process.env.CLAUDE_CODE_EXECUTABLE,
+      }),
+      tools: { type: "preset", preset: "claude_code" },
+      hooks: {
+        ...userProvidedOptions?.hooks,
+        PreToolUse: [
+          ...(userProvidedOptions?.hooks?.PreToolUse || []),
+          {
+            hooks: [createPreToolUseHook(settingsManager, this.logger)],
+          },
+        ],
+        PostToolUse: [
+          ...(userProvidedOptions?.hooks?.PostToolUse || []),
+          {
+            hooks: [createPostToolUseHook(this.logger)],
+          },
+        ],
+      },
+      ...creationOpts,
+    };
+
+    const allowedTools = [];
+    // Disable this for now, not a great way to expose this over ACP at the moment (in progress work so we can revisit)
+    const disallowedTools = ["AskUserQuestion"];
+
+    // Check if built-in tools should be disabled
+    const disableBuiltInTools = params._meta?.disableBuiltInTools === true;
+
+    if (!disableBuiltInTools) {
+      if (this.clientCapabilities?.fs?.readTextFile) {
+        allowedTools.push(acpToolNames.read);
+        disallowedTools.push("Read");
+      }
+      if (this.clientCapabilities?.fs?.writeTextFile) {
+        disallowedTools.push("Write", "Edit");
+      }
+      if (this.clientCapabilities?.terminal) {
+        allowedTools.push(acpToolNames.bashOutput, acpToolNames.killShell);
+        disallowedTools.push("Bash", "BashOutput", "KillShell");
+      }
+    } else {
+      // When built-in tools are disabled, explicitly disallow all of them
+      disallowedTools.push(
+        acpToolNames.read,
+        acpToolNames.write,
+        acpToolNames.edit,
+        acpToolNames.bash,
+        acpToolNames.bashOutput,
+        acpToolNames.killShell,
+        "Read",
+        "Write",
+        "Edit",
+        "Bash",
+        "BashOutput",
+        "KillShell",
+        "Glob",
+        "Grep",
+        "Task",
+        "TodoWrite",
+        "ExitPlanMode",
+        "WebSearch",
+        "WebFetch",
+        "AskUserQuestion",
+        "SlashCommand",
+        "Skill",
+        "NotebookEdit",
+      );
+    }
+
+    if (allowedTools.length > 0) {
+      options.allowedTools = allowedTools;
+    }
+    if (disallowedTools.length > 0) {
+      options.disallowedTools = disallowedTools;
+    }
+
+    // Handle abort controller from meta options
+    const abortController = userProvidedOptions?.abortController;
+    if (abortController?.signal.aborted) {
+      throw new Error("Cancelled");
+    }
+
+    const q = query({
+      prompt: input,
+      options,
+    });
+
+    this.sessions[sessionId] = {
+      query: q,
+      input: input,
+      cancelled: false,
+      permissionMode,
+      settingsManager,
+    };
+
+    const availableCommands = await getAvailableSlashCommands(q);
+    const models = await getAvailableModels(q);
+
+    // Needs to happen after we return the session
+    setTimeout(() => {
+      this.client.sessionUpdate({
+        sessionId,
+        update: {
+          sessionUpdate: "available_commands_update",
+          availableCommands,
+        },
+      });
+    }, 0);
+
+    const availableModes = [
+      {
+        id: "default",
+        name: "Default",
+        description: "Standard behavior, prompts for dangerous operations",
+      },
+      {
+        id: "acceptEdits",
+        name: "Accept Edits",
+        description: "Auto-accept file edit operations",
+      },
+      {
+        id: "plan",
+        name: "Plan Mode",
+        description: "Planning mode, no actual tool execution",
+      },
+      {
+        id: "dontAsk",
+        name: "Don't Ask",
+        description: "Don't prompt for permissions, deny if not pre-approved",
+      },
+    ];
+    // Only works in non-root mode
+    if (!IS_ROOT) {
+      availableModes.push({
+        id: "bypassPermissions",
+        name: "Bypass Permissions",
+        description: "Bypass all permission checks",
+      });
+    }
+
+    return {
+      sessionId,
+      models,
+      modes: {
+        currentModeId: permissionMode,
+        availableModes,
+      },
+    };
+  }
 }
 
 async function getAvailableModels(query: Query): Promise<SessionModelState> {
@@ -803,7 +884,13 @@ async function getAvailableSlashCommands(query: Query): Promise<AvailableCommand
 
   return commands
     .map((command) => {
-      const input = command.argumentHint ? { hint: command.argumentHint } : null;
+      const input = command.argumentHint
+        ? {
+            hint: Array.isArray(command.argumentHint)
+              ? command.argumentHint.join(" ")
+              : command.argumentHint,
+          }
+        : null;
       let name = command.name;
       if (command.name.endsWith(" (MCP)")) {
         name = `mcp:${name.replace(" (MCP)", "")}`;
@@ -922,7 +1009,6 @@ export function toAcpNotifications(
   role: "assistant" | "user",
   sessionId: string,
   toolUseCache: ToolUseCache,
-  fileContentCache: { [key: string]: string },
   client: AgentSideConnection,
   logger: Logger,
 ): SessionNotification[] {
@@ -1033,7 +1119,7 @@ export function toAcpNotifications(
             sessionUpdate: "tool_call",
             rawInput,
             status: "pending",
-            ...toolInfoFromToolUse(chunk, fileContentCache, logger),
+            ...toolInfoFromToolUse(chunk),
           };
         }
         break;
@@ -1065,6 +1151,7 @@ export function toAcpNotifications(
             toolCallId: chunk.tool_use_id,
             sessionUpdate: "tool_call_update",
             status: "is_error" in chunk && chunk.is_error ? "failed" : "completed",
+            rawOutput: chunk.content,
             ...toolUpdateFromToolResult(chunk, toolUseCache[chunk.tool_use_id]),
           };
         }
@@ -1096,7 +1183,6 @@ export function streamEventToAcpNotifications(
   message: SDKPartialAssistantMessage,
   sessionId: string,
   toolUseCache: ToolUseCache,
-  fileContentCache: { [key: string]: string },
   client: AgentSideConnection,
   logger: Logger,
 ): SessionNotification[] {
@@ -1108,7 +1194,6 @@ export function streamEventToAcpNotifications(
         "assistant",
         sessionId,
         toolUseCache,
-        fileContentCache,
         client,
         logger,
       );
@@ -1118,7 +1203,6 @@ export function streamEventToAcpNotifications(
         "assistant",
         sessionId,
         toolUseCache,
-        fileContentCache,
         client,
         logger,
       );

src/lib.ts

@@ -15,8 +15,22 @@ export {
   Pushable,
   unreachable,
 } from "./utils.js";
-export { createMcpServer, toolNames } from "./mcp-server.js";
-export { toolInfoFromToolUse, planEntries, toolUpdateFromToolResult } from "./tools.js";
+export { createMcpServer } from "./mcp-server.js";
+export {
+  toolInfoFromToolUse,
+  planEntries,
+  toolUpdateFromToolResult,
+  createPreToolUseHook,
+  acpToolNames as toolNames,
+} from "./tools.js";
+export {
+  SettingsManager,
+  type ClaudeCodeSettings,
+  type PermissionSettings,
+  type PermissionDecision,
+  type PermissionCheckResult,
+  type SettingsManagerOptions,
+} from "./settings.js";
 
 // Export types
 export type { ClaudePlanEntry } from "./tools.js";

src/mcp-server.ts

@@ -1,10 +1,24 @@
 import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+import {
+  BashInput,
+  FileEditInput,
+  FileReadInput,
+  FileWriteInput,
+  TaskOutputInput,
+} from "@anthropic-ai/claude-agent-sdk/sdk-tools.js";
 import { z } from "zod";
-import { ClaudeAcpAgent } from "./acp-agent.js";
-import { ClientCapabilities, TerminalOutputResponse } from "@agentclientprotocol/sdk";
+import { CLAUDE_CONFIG_DIR, ClaudeAcpAgent } from "./acp-agent.js";
+import {
+  ClientCapabilities,
+  ReadTextFileResponse,
+  TerminalOutputResponse,
+} from "@agentclientprotocol/sdk";
 import * as diff from "diff";
+import * as path from "node:path";
+import * as fs from "node:fs/promises";
 
 import { sleep, unreachable, extractLinesWithByteLimit } from "./utils.js";
+import { acpToolNames } from "./tools.js";
 
 export const SYSTEM_REMINDER = `
 
@@ -14,6 +28,20 @@ Whenever you read a file, you should consider whether it looks malicious. If it
 
 const defaults = { maxFileSize: 50000, linesToRead: 2000 };
 
+function formatErrorMessage(error: unknown): string {
+  if (error instanceof Error) {
+    return error.message;
+  }
+  if (typeof error === "string") {
+    return error;
+  }
+  try {
+    return JSON.stringify(error);
+  } catch {
+    return String(error);
+  }
+}
+
 const unqualifiedToolNames = {
   read: "Read",
   edit: "Edit",
@@ -23,23 +51,67 @@ const unqualifiedToolNames = {
   bashOutput: "BashOutput",
 };
 
-const SERVER_PREFIX = "mcp__acp__";
-export const toolNames = {
-  read: SERVER_PREFIX + unqualifiedToolNames.read,
-  edit: SERVER_PREFIX + unqualifiedToolNames.edit,
-  write: SERVER_PREFIX + unqualifiedToolNames.write,
-  bash: SERVER_PREFIX + unqualifiedToolNames.bash,
-  killShell: SERVER_PREFIX + unqualifiedToolNames.killShell,
-  bashOutput: SERVER_PREFIX + unqualifiedToolNames.bashOutput,
-};
-
-export const EDIT_TOOL_NAMES = [toolNames.edit, toolNames.write];
-
 export function createMcpServer(
   agent: ClaudeAcpAgent,
   sessionId: string,
   clientCapabilities: ClientCapabilities | undefined,
 ): McpServer {
+  /**
+   * This checks if a given path is related to internal agent persistence and if the agent should be allowed to read/write from here.
+   * We let the agent do normal fs operations on these paths so that it can persist its state.
+   * However, we block access to settings files for security reasons.
+   */
+  function internalPath(file_path: string) {
+    return (
+      file_path.startsWith(CLAUDE_CONFIG_DIR) &&
+      !file_path.startsWith(path.join(CLAUDE_CONFIG_DIR, "settings.json")) &&
+      !file_path.startsWith(path.join(CLAUDE_CONFIG_DIR, "session-env"))
+    );
+  }
+
+  async function readTextFile(input: FileReadInput): Promise<ReadTextFileResponse> {
+    if (internalPath(input.file_path)) {
+      const content = await fs.readFile(input.file_path, "utf8");
+
+      // eslint-disable-next-line eqeqeq
+      if (input.offset != null || input.limit != null) {
+        const lines = content.split("\n");
+
+        // Apply offset and limit if provided
+        const offset = input.offset ?? 1;
+        const limit = input.limit ?? lines.length;
+
+        // Extract the requested lines (offset is 1-based)
+        const startIndex = Math.max(0, offset - 1);
+        const endIndex = Math.min(lines.length, startIndex + limit);
+        const selectedLines = lines.slice(startIndex, endIndex);
+
+        return { content: selectedLines.join("\n") };
+      } else {
+        return { content };
+      }
+    }
+
+    return agent.readTextFile({
+      sessionId,
+      path: input.file_path,
+      line: input.offset,
+      limit: input.limit,
+    });
+  }
+
+  async function writeTextFile(input: FileWriteInput): Promise<void> {
+    if (internalPath(input.file_path)) {
+      await fs.writeFile(input.file_path, input.content, "utf8");
+    } else {
+      await agent.writeTextFile({
+        sessionId,
+        path: input.file_path,
+        content: input.content,
+      });
+    }
+  }
+
   // Create MCP server
   const server = new McpServer({ name: "acp", version: "1.0.0" }, { capabilities: { tools: {} } });
 
@@ -50,7 +122,7 @@ export function createMcpServer(
         title: unqualifiedToolNames.read,
         description: `Reads the content of the given file in the project.
 
-In sessions with ${toolNames.read} always use it instead of Read as it contains the most up-to-date contents.
+In sessions with ${acpToolNames.read} always use it instead of Read as it contains the most up-to-date contents.
 
 Reads a file from the local filesystem. If the User provides a path to a file assume that path is valid. It is okay to read a file that does not exist; an error will be returned.
 
@@ -60,7 +132,7 @@ Usage:
 - You can optionally specify a line offset and limit (especially handy for long files), but it's recommended to read the whole file by not providing these parameters
 - Any files larger than ${defaults.maxFileSize} bytes will be truncated
 - This tool allows Claude Code to read images (eg PNG, JPG, etc). When reading an image file the contents are presented visually as Claude Code is a multimodal LLM.
-- This tool can only read files, not directories. To read a directory, use an ls command via the ${toolNames.bash} tool.
+- This tool can only read files, not directories. To read a directory, use an ls command via the ${acpToolNames.bash} tool.
 - You have the capability to call multiple tools in a single response. It is always better to speculatively read multiple files as a batch that are potentially useful.`,
         inputSchema: {
           file_path: z.string().describe("The absolute path to the file to read"),
@@ -87,7 +159,7 @@ Usage:
           idempotentHint: false,
         },
       },
-      async (input) => {
+      async (input: FileReadInput) => {
         try {
           const session = agent.sessions[sessionId];
           if (!session) {
@@ -101,12 +173,7 @@ Usage:
             };
           }
 
-          const readResponse = await agent.readTextFile({
-            sessionId,
-            path: input.file_path,
-            line: input.offset,
-            limit: input.limit,
-          });
+          const readResponse = await readTextFile(input);
 
           if (typeof readResponse?.content !== "string") {
             throw new Error(`No file contents for ${input.file_path}.`);
@@ -117,13 +184,13 @@ Usage:
 
           // Construct informative message about what was read
           let readInfo = "";
-          if (input.offset > 1 || result.wasLimited) {
+          if ((input.offset && input.offset > 1) || result.wasLimited) {
             readInfo = "\n\n<file-read-info>";
 
             if (result.wasLimited) {
               readInfo += `Read ${result.linesRead} lines (hit 50KB limit). `;
-            } else {
-              readInfo += `Read lines ${input.offset}-${result.linesRead}. `;
+            } else if (input.offset && input.offset > 1) {
+              readInfo += `Read lines ${input.offset}-${input.offset + result.linesRead}.`;
             }
 
             if (result.wasLimited) {
@@ -141,12 +208,13 @@ Usage:
               },
             ],
           };
-        } catch (error: any) {
+        } catch (error) {
           return {
+            isError: true,
             content: [
               {
                 type: "text",
-                text: "Reading file failed: " + error.message,
+                text: "Reading file failed: " + formatErrorMessage(error),
               },
             ],
           };
@@ -162,12 +230,12 @@ Usage:
         title: unqualifiedToolNames.write,
         description: `Writes a file to the local filesystem..
 
-In sessions with ${toolNames.write} always use it instead of Write as it will
+In sessions with ${acpToolNames.write} always use it instead of Write as it will
 allow the user to conveniently review changes.
 
 Usage:
 - This tool will overwrite the existing file if there is one at the provided path.
-- If this is an existing file, you MUST use the ${toolNames.read} tool first to read the file's contents. This tool will fail if you did not read the file first.
+- If this is an existing file, you MUST use the ${acpToolNames.read} tool first to read the file's contents. This tool will fail if you did not read the file first.
 - ALWAYS prefer editing existing files in the codebase. NEVER write new files unless explicitly required.
 - NEVER proactively create documentation files (*.md) or README files. Only create documentation files if explicitly requested by the User.
 - Only use emojis if the user explicitly requests it. Avoid writing emojis to files unless asked.`,
@@ -185,7 +253,7 @@ Usage:
           idempotentHint: false,
         },
       },
-      async (input) => {
+      async (input: FileWriteInput) => {
         try {
           const session = agent.sessions[sessionId];
           if (!session) {
@@ -198,21 +266,23 @@ Usage:
               ],
             };
           }
-          await agent.writeTextFile({
-            sessionId,
-            path: input.file_path,
-            content: input.content,
-          });
+          await writeTextFile(input);
 
-          return {
-            content: [],
-          };
-        } catch (error: any) {
           return {
             content: [
               {
                 type: "text",
-                text: "Writing file failed: " + error.message,
+                text: `The file ${input.file_path} has been updated successfully.`,
+              },
+            ],
+          };
+        } catch (error) {
+          return {
+            isError: true,
+            content: [
+              {
+                type: "text",
+                text: "Writing file failed: " + formatErrorMessage(error),
               },
             ],
           };
@@ -226,11 +296,11 @@ Usage:
         title: unqualifiedToolNames.edit,
         description: `Performs exact string replacements in files.
 
-In sessions with ${toolNames.edit} always use it instead of Edit as it will
+In sessions with ${acpToolNames.edit} always use it instead of Edit as it will
 allow the user to conveniently review changes.
 
 Usage:
-- You must use your \`${toolNames.read}\` tool at least once in the conversation before editing. This tool will error if you attempt an edit without reading the file.
+- You must use your \`${acpToolNames.read}\` tool at least once in the conversation before editing. This tool will error if you attempt an edit without reading the file.
 - When editing text from Read tool output, ensure you preserve the exact indentation (tabs/spaces) as it appears.
 - ALWAYS prefer editing existing files in the codebase. NEVER write new files unless explicitly required.
 - Only use emojis if the user explicitly requests it. Avoid adding emojis to files unless asked.
@@ -246,7 +316,7 @@ Usage:
             .boolean()
             .default(false)
             .optional()
-            .describe("Replace all occurences of old_string (default false)"),
+            .describe("Replace all occurrences of old_string (default false)"),
         },
         annotations: {
           title: "Edit file",
@@ -256,7 +326,7 @@ Usage:
           idempotentHint: false,
         },
       },
-      async (input) => {
+      async (input: FileEditInput) => {
         try {
           const session = agent.sessions[sessionId];
           if (!session) {
@@ -270,9 +340,8 @@ Usage:
             };
           }
 
-          const readResponse = await agent.readTextFile({
-            sessionId,
-            path: input.file_path,
+          const readResponse = await readTextFile({
+            file_path: input.file_path,
           });
 
           if (typeof readResponse?.content !== "string") {
@@ -289,11 +358,7 @@ Usage:
 
           const patch = diff.createPatch(input.file_path, readResponse.content, newContent);
 
-          await agent.writeTextFile({
-            sessionId,
-            path: input.file_path,
-            content: newContent,
-          });
+          await writeTextFile({ file_path: input.file_path, content: newContent });
 
           return {
             content: [
@@ -303,12 +368,13 @@ Usage:
               },
             ],
           };
-        } catch (error: any) {
+        } catch (error) {
           return {
+            isError: true,
             content: [
               {
                 type: "text",
-                text: "Editing file failed: " + (error?.message ?? String(error)),
+                text: "Editing file failed: " + formatErrorMessage(error),
               },
             ],
           };
@@ -324,13 +390,10 @@ Usage:
         title: unqualifiedToolNames.bash,
         description: `Executes a bash command
 
-In sessions with ${toolNames.bash} always use it instead of Bash`,
+In sessions with ${acpToolNames.bash} always use it instead of Bash`,
         inputSchema: {
           command: z.string().describe("The command to execute"),
-          timeout: z
-            .number()
-            .default(2 * 60 * 1000)
-            .describe(`Optional timeout in milliseconds (max ${2 * 60 * 1000})`),
+          timeout: z.number().describe(`Optional timeout in milliseconds (max ${2 * 60 * 1000})`),
           description: z.string().optional()
             .describe(`Clear, concise description of what this command does in 5-10 words, in active voice. Examples:
 Input: ls
@@ -348,125 +411,137 @@ Output: Create directory 'foo'`),
             .boolean()
             .default(false)
             .describe(
-              `Set to true to run this command in the background. The tool returns an \`id\` that can be used with the \`${toolNames.bashOutput}\` tool to retrieve the current output, or the \`${toolNames.killShell}\` tool to stop it early.`,
+              `Set to true to run this command in the background. The tool returns an \`id\` that can be used with the \`${acpToolNames.bashOutput}\` tool to retrieve the current output, or the \`${acpToolNames.killShell}\` tool to stop it early.`,
             ),
         },
       },
-      async (input, extra) => {
-        const session = agent.sessions[sessionId];
-        if (!session) {
-          return {
-            content: [
-              {
-                type: "text",
-                text: "The user has left the building",
-              },
-            ],
-          };
-        }
-
-        const toolCallId = extra._meta?.["claudecode/toolUseId"];
-
-        if (typeof toolCallId !== "string") {
-          throw new Error("No tool call ID found");
-        }
-
-        if (!agent.clientCapabilities?.terminal || !agent.client.createTerminal) {
-          throw new Error("unreachable");
-        }
-
-        const handle = await agent.client.createTerminal({
-          command: input.command,
-          env: [{ name: "CLAUDECODE", value: "1" }],
-          sessionId,
-          outputByteLimit: 32_000,
-        });
-
-        await agent.client.sessionUpdate({
-          sessionId,
-          update: {
-            sessionUpdate: "tool_call_update",
-            toolCallId,
-            status: "in_progress",
-            title: input.description,
-            content: [{ type: "terminal", terminalId: handle.id }],
-          },
-        });
-
-        const abortPromise = new Promise((resolve) => {
-          if (extra.signal.aborted) {
-            resolve(null);
-          } else {
-            extra.signal.addEventListener("abort", () => {
-              resolve(null);
-            });
-          }
-        });
-
-        const statusPromise = Promise.race([
-          handle.waitForExit().then((exitStatus) => ({ status: "exited" as const, exitStatus })),
-          abortPromise.then(() => ({ status: "aborted" as const, exitStatus: null })),
-          sleep(input.timeout).then(async () => {
-            if (agent.backgroundTerminals[handle.id]?.status === "started") {
-              await handle.kill();
-            }
-            return { status: "timedOut" as const, exitStatus: null };
-          }),
-        ]);
-
-        if (input.run_in_background) {
-          agent.backgroundTerminals[handle.id] = {
-            handle,
-            lastOutput: null,
-            status: "started",
-          };
-
-          statusPromise.then(async ({ status, exitStatus }) => {
-            const bgTerm = agent.backgroundTerminals[handle.id];
-
-            if (bgTerm.status !== "started") {
-              return;
-            }
-
-            const currentOutput = await handle.currentOutput();
-
-            agent.backgroundTerminals[handle.id] = {
-              status,
-              pendingOutput: {
-                ...currentOutput,
-                output: stripCommonPrefix(bgTerm.lastOutput?.output ?? "", currentOutput.output),
-                exitStatus: exitStatus ?? currentOutput.exitStatus,
-              },
+      async (input: BashInput, extra) => {
+        try {
+          const session = agent.sessions[sessionId];
+          if (!session) {
+            return {
+              content: [
+                {
+                  type: "text",
+                  text: "The user has left the building",
+                },
+              ],
             };
+          }
 
-            return handle.release();
+          const toolCallId = extra._meta?.["claudecode/toolUseId"];
+
+          if (typeof toolCallId !== "string") {
+            throw new Error("No tool call ID found");
+          }
+
+          if (!agent.clientCapabilities?.terminal || !agent.client.createTerminal) {
+            throw new Error("unreachable");
+          }
+
+          const handle = await agent.client.createTerminal({
+            command: input.command,
+            env: [{ name: "CLAUDECODE", value: "1" }],
+            sessionId,
+            outputByteLimit: 32_000,
           });
 
+          await agent.client.sessionUpdate({
+            sessionId,
+            update: {
+              sessionUpdate: "tool_call_update",
+              toolCallId,
+              status: "in_progress",
+              title: input.description,
+              content: [{ type: "terminal", terminalId: handle.id }],
+            },
+          });
+
+          const abortPromise = new Promise((resolve) => {
+            if (extra.signal.aborted) {
+              resolve(null);
+            } else {
+              extra.signal.addEventListener("abort", () => {
+                resolve(null);
+              });
+            }
+          });
+
+          const statusPromise = Promise.race([
+            handle.waitForExit().then((exitStatus) => ({ status: "exited" as const, exitStatus })),
+            abortPromise.then(() => ({ status: "aborted" as const, exitStatus: null })),
+            sleep(input.timeout ?? 2 * 60 * 1000).then(async () => {
+              if (agent.backgroundTerminals[handle.id]?.status === "started") {
+                await handle.kill();
+              }
+              return { status: "timedOut" as const, exitStatus: null };
+            }),
+          ]);
+
+          if (input.run_in_background) {
+            agent.backgroundTerminals[handle.id] = {
+              handle,
+              lastOutput: null,
+              status: "started",
+            };
+
+            statusPromise.then(async ({ status, exitStatus }) => {
+              const bgTerm = agent.backgroundTerminals[handle.id];
+
+              if (bgTerm.status !== "started") {
+                return;
+              }
+
+              const currentOutput = await handle.currentOutput();
+
+              agent.backgroundTerminals[handle.id] = {
+                status,
+                pendingOutput: {
+                  ...currentOutput,
+                  output: stripCommonPrefix(bgTerm.lastOutput?.output ?? "", currentOutput.output),
+                  exitStatus: exitStatus ?? currentOutput.exitStatus,
+                },
+              };
+
+              return handle.release();
+            });
+
+            return {
+              content: [
+                {
+                  type: "text",
+                  text: `Command started in background with id: ${handle.id}`,
+                },
+              ],
+            };
+          }
+
+          await using terminal = handle;
+
+          const { status } = await statusPromise;
+
+          if (status === "aborted") {
+            return {
+              content: [{ type: "text", text: "Tool cancelled by user" }],
+            };
+          }
+
+          const output = await terminal.currentOutput();
+
           return {
+            content: [{ type: "text", text: toolCommandOutput(status, output) }],
+          };
+        } catch (error) {
+          return {
+            isError: true,
             content: [
               {
                 type: "text",
-                text: `Command started in background with id: ${handle.id}`,
+                text: "Running bash command failed: " + formatErrorMessage(error),
               },
             ],
           };
         }
-
-        await using terminal = handle;
-
-        const { status } = await statusPromise;
-
-        if (status === "aborted") {
-          return {
-            content: [{ type: "text", text: "Tool cancelled by user" }],
-          };
-        }
-
-        const output = await terminal.currentOutput();
-
-        return {
-          content: [{ type: "text", text: toolCommandOutput(status, output) }],
-        };
       },
     );
 
@@ -475,50 +550,111 @@ Output: Create directory 'foo'`),
       {
         title: unqualifiedToolNames.bashOutput,
         description: `- Retrieves output from a running or completed background bash shell
-- Takes a shell_id parameter identifying the shell
+- Takes a bash_id parameter identifying the shell
 - Always returns only new output since the last check
 - Returns stdout and stderr output along with shell status
 - Use this tool when you need to monitor or check the output of a long-running shell
 
-In sessions with ${toolNames.bashOutput} always use it instead of BashOutput.`,
+In sessions with ${acpToolNames.bashOutput} always use it for output from Bash commands instead of TaskOutput.`,
         inputSchema: {
-          shell_id: z
+          task_id: z
             .string()
-            .describe(`The id of the background bash command as returned by \`${toolNames.bash}\``),
+            .describe(
+              `The id of the background bash command as returned by \`${acpToolNames.bash}\``,
+            ),
+          block: z.boolean().describe("Whether to wait for completion"),
+          timeout: z.number().describe("Max wait time in ms"),
         },
       },
-      async (input) => {
-        const bgTerm = agent.backgroundTerminals[input.shell_id];
+      async (input: TaskOutputInput) => {
+        try {
+          const bgTerm = agent.backgroundTerminals[input.task_id];
 
-        if (!bgTerm) {
-          throw new Error(`Unknown shell ${input.shell_id}`);
-        }
+          if (!bgTerm) {
+            throw new Error(`Unknown shell ${input.task_id}`);
+          }
 
-        if (bgTerm.status === "started") {
-          const newOutput = await bgTerm.handle.currentOutput();
-          const strippedOutput = stripCommonPrefix(
-            bgTerm.lastOutput?.output ?? "",
-            newOutput.output,
-          );
-          bgTerm.lastOutput = newOutput;
+          if (input.block && bgTerm.status === "started") {
+            const statusPromise = Promise.race([
+              bgTerm.handle
+                .waitForExit()
+                .then((exitStatus) => ({ status: "exited" as const, exitStatus })),
+              sleep(input.timeout ?? 2 * 60 * 1000).then(async () => {
+                if (bgTerm.status === "started") {
+                  await bgTerm.handle.kill();
+                }
+                return { status: "timedOut" as const, exitStatus: null };
+              }),
+            ]);
 
-          return {
-            content: [
-              {
-                type: "text",
-                text: toolCommandOutput(bgTerm.status, {
-                  ...newOutput,
-                  output: strippedOutput,
-                }),
+            const { status, exitStatus } = await statusPromise;
+            const currentOutput = await bgTerm.handle.currentOutput();
+            const strippedOutput = stripCommonPrefix(
+              bgTerm.lastOutput?.output ?? "",
+              currentOutput.output,
+            );
+
+            agent.backgroundTerminals[input.task_id] = {
+              status,
+              pendingOutput: {
+                ...currentOutput,
+                output: strippedOutput,
+                exitStatus: exitStatus ?? currentOutput.exitStatus,
               },
-            ],
-          };
-        } else {
+            };
+
+            await bgTerm.handle.release();
+
+            return {
+              content: [
+                {
+                  type: "text",
+                  text: toolCommandOutput(status, {
+                    ...currentOutput,
+                    output: strippedOutput,
+                    exitStatus: exitStatus ?? currentOutput.exitStatus,
+                  }),
+                },
+              ],
+            };
+          }
+
+          if (bgTerm.status === "started") {
+            const newOutput = await bgTerm.handle.currentOutput();
+            const strippedOutput = stripCommonPrefix(
+              bgTerm.lastOutput?.output ?? "",
+              newOutput.output,
+            );
+            bgTerm.lastOutput = newOutput;
+
+            return {
+              content: [
+                {
+                  type: "text",
+                  text: toolCommandOutput(bgTerm.status, {
+                    ...newOutput,
+                    output: strippedOutput,
+                  }),
+                },
+              ],
+            };
+          } else {
+            return {
+              content: [
+                {
+                  type: "text",
+                  text: toolCommandOutput(bgTerm.status, bgTerm.pendingOutput),
+                },
+              ],
+            };
+          }
+        } catch (error) {
           return {
+            isError: true,
             content: [
               {
                 type: "text",
-                text: toolCommandOutput(bgTerm.status, bgTerm.pendingOutput),
+                text: "Retrieving bash output failed: " + formatErrorMessage(error),
               },
             ],
           };
@@ -535,57 +671,71 @@ In sessions with ${toolNames.bashOutput} always use it instead of BashOutput.`,
 - Returns a success or failure status
 - Use this tool when you need to terminate a long-running shell
 
-In sessions with ${toolNames.killShell} always use it instead of KillShell.`,
+In sessions with ${acpToolNames.killShell} always use it instead of KillShell.`,
         inputSchema: {
           shell_id: z
             .string()
-            .describe(`The id of the background bash command as returned by \`${toolNames.bash}\``),
+            .describe(
+              `The id of the background bash command as returned by \`${acpToolNames.bash}\``,
+            ),
         },
       },
       async (input) => {
-        const bgTerm = agent.backgroundTerminals[input.shell_id];
+        try {
+          const bgTerm = agent.backgroundTerminals[input.shell_id];
 
-        if (!bgTerm) {
-          throw new Error(`Unknown shell ${input.shell_id}`);
-        }
+          if (!bgTerm) {
+            throw new Error(`Unknown shell ${input.shell_id}`);
+          }
 
-        switch (bgTerm.status) {
-          case "started": {
-            await bgTerm.handle.kill();
-            const currentOutput = await bgTerm.handle.currentOutput();
-            agent.backgroundTerminals[bgTerm.handle.id] = {
-              status: "killed",
-              pendingOutput: {
-                ...currentOutput,
-                output: stripCommonPrefix(bgTerm.lastOutput?.output ?? "", currentOutput.output),
+          switch (bgTerm.status) {
+            case "started": {
+              await bgTerm.handle.kill();
+              const currentOutput = await bgTerm.handle.currentOutput();
+              agent.backgroundTerminals[bgTerm.handle.id] = {
+                status: "killed",
+                pendingOutput: {
+                  ...currentOutput,
+                  output: stripCommonPrefix(bgTerm.lastOutput?.output ?? "", currentOutput.output),
+                },
+              };
+              await bgTerm.handle.release();
+
+              return {
+                content: [{ type: "text", text: "Command killed successfully." }],
+              };
+            }
+            case "aborted":
+              return {
+                content: [{ type: "text", text: "Command aborted by user." }],
+              };
+            case "exited":
+              return {
+                content: [{ type: "text", text: "Command had already exited." }],
+              };
+            case "killed":
+              return {
+                content: [{ type: "text", text: "Command was already killed." }],
+              };
+            case "timedOut":
+              return {
+                content: [{ type: "text", text: "Command killed by timeout." }],
+              };
+            default: {
+              unreachable(bgTerm);
+              throw new Error("Unexpected background terminal status");
+            }
+          }
+        } catch (error) {
+          return {
+            isError: true,
+            content: [
+              {
+                type: "text",
+                text: "Killing shell failed: " + formatErrorMessage(error),
               },
-            };
-            await bgTerm.handle.release();
-
-            return {
-              content: [{ type: "text", text: "Command killed successfully." }],
-            };
-          }
-          case "aborted":
-            return {
-              content: [{ type: "text", text: "Command aborted by user." }],
-            };
-          case "exited":
-            return {
-              content: [{ type: "text", text: "Command had already exited." }],
-            };
-          case "killed":
-            return {
-              content: [{ type: "text", text: "Command was already killed." }],
-            };
-          case "timedOut":
-            return {
-              content: [{ type: "text", text: "Command killed by timeout." }],
-            };
-          default: {
-            unreachable(bgTerm);
-            throw new Error("Unexpected background terminal status");
-          }
+            ],
+          };
         }
       },
     );

src/settings.ts

@@ -0,0 +1,522 @@
+import * as fs from "node:fs";
+import * as path from "node:path";
+import * as os from "node:os";
+import { minimatch } from "minimatch";
+import { ACP_TOOL_NAME_PREFIX, acpToolNames } from "./tools.js";
+import { CLAUDE_CONFIG_DIR } from "./acp-agent.js";
+
+/**
+ * Permission rule format examples:
+ * - "Read" - matches all Read tool calls
+ * - "Read(./.env)" - matches specific path
+ * - "Read(./.env.*)" - glob pattern
+ * - "Read(./secrets/**)" - recursive glob
+ * - "Bash(npm run lint)" - exact command prefix
+ * - "Bash(npm run:*)" - command prefix with wildcard
+ *
+ * Docs: https://code.claude.com/docs/en/iam#tool-specific-permission-rules
+ */
+
+export interface PermissionSettings {
+  allow?: string[];
+  deny?: string[];
+  ask?: string[];
+  additionalDirectories?: string[];
+  defaultMode?: string;
+}
+
+export interface ClaudeCodeSettings {
+  permissions?: PermissionSettings;
+  env?: Record<string, string>;
+}
+
+export type PermissionDecision = "allow" | "deny" | "ask";
+
+export interface PermissionCheckResult {
+  decision: PermissionDecision;
+  rule?: string;
+  source?: "allow" | "deny" | "ask";
+}
+
+interface ParsedRule {
+  toolName: string;
+  argument?: string;
+  isWildcard?: boolean;
+}
+
+/**
+ * Shell operators that can be used for command chaining/injection
+ * These should cause a prefix match to fail to prevent bypasses like:
+ * - "safe-cmd && malicious-cmd"
+ * - "safe-cmd; malicious-cmd"
+ * - "safe-cmd | malicious-cmd"
+ * - "safe-cmd || malicious-cmd"
+ * - "$(malicious-cmd)"
+ * - "`malicious-cmd`"
+ */
+const SHELL_OPERATORS = ["&&", "||", ";", "|", "$(", "`", "\n"];
+
+/**
+ * Checks if a string contains shell operators that could allow command chaining
+ */
+function containsShellOperator(str: string): boolean {
+  return SHELL_OPERATORS.some((op) => str.includes(op));
+}
+
+/*
+ * Tools that modify files. Per Claude Code docs:
+ * "Edit rules apply to all built-in tools that edit files."
+ * This means an Edit(...) rule should match Write, MultiEdit, etc.
+ */
+const FILE_EDITING_TOOLS = [acpToolNames.edit, acpToolNames.write];
+
+/**
+ * Tools that read files. Per Claude Code docs:
+ * "Claude will make a best-effort attempt to apply Read rules to all built-in tools
+ * that read files like Grep and Glob."
+ * This means a Read(...) rule should match Grep, Glob, etc.
+ */
+const FILE_READING_TOOLS = [acpToolNames.read];
+
+/**
+ * Functions to extract the relevant argument from tool input for permission matching
+ */
+const TOOL_ARG_ACCESSORS: Record<string, (input: unknown) => string | undefined> = {
+  mcp__acp__Read: (input) => (input as { file_path?: string })?.file_path,
+  mcp__acp__Edit: (input) => (input as { file_path?: string })?.file_path,
+  mcp__acp__Write: (input) => (input as { file_path?: string })?.file_path,
+  mcp__acp__Bash: (input) => (input as { command?: string })?.command,
+};
+
+/**
+ * Parses a permission rule string into its components
+ * Examples:
+ *   "Read" -> { toolName: "Read" }
+ *   "Read(./.env)" -> { toolName: "Read", argument: "./.env" }
+ *   "Bash(npm run:*)" -> { toolName: "Bash", argument: "npm run", isWildcard: true }
+ */
+function parseRule(rule: string): ParsedRule {
+  const match = rule.match(/^(\w+)(?:\((.+)\))?$/);
+  if (!match) {
+    return { toolName: rule };
+  }
+
+  const [, toolName, argument] = match;
+
+  if (argument && argument.endsWith(":*")) {
+    return {
+      toolName,
+      argument: argument.slice(0, -2),
+      isWildcard: true,
+    };
+  }
+
+  return { toolName, argument };
+}
+
+/**
+ * Normalizes a path for comparison:
+ * - Expands ~ to home directory
+ * - Resolves relative paths against cwd
+ * - Normalizes path separators
+ */
+function normalizePath(filePath: string, cwd: string): string {
+  if (filePath.startsWith("~/")) {
+    filePath = path.join(os.homedir(), filePath.slice(2));
+  } else if (filePath.startsWith("./")) {
+    filePath = path.join(cwd, filePath.slice(2));
+  } else if (!path.isAbsolute(filePath)) {
+    filePath = path.join(cwd, filePath);
+  }
+  return path.normalize(filePath);
+}
+
+/**
+ * Checks if a file path matches a glob pattern
+ */
+function matchesGlob(pattern: string, filePath: string, cwd: string): boolean {
+  const normalizedPattern = normalizePath(pattern, cwd);
+  const normalizedPath = normalizePath(filePath, cwd);
+
+  return minimatch(normalizedPath, normalizedPattern, {
+    dot: true,
+    matchBase: false,
+    nocase: process.platform === "win32",
+  });
+}
+
+/**
+ * Checks if a tool invocation matches a parsed permission rule
+ */
+function matchesRule(rule: ParsedRule, toolName: string, toolInput: unknown, cwd: string): boolean {
+  // Per Claude Code docs:
+  // - "Edit rules apply to all built-in tools that edit files."
+  // - "Claude will make a best-effort attempt to apply Read rules to all built-in tools
+  //    that read files like Grep, Glob, and LS."
+  const ruleAppliesToTool =
+    rule.toolName === "Bash" ||
+    (rule.toolName === "Edit" && FILE_EDITING_TOOLS.includes(toolName)) ||
+    (rule.toolName === "Read" && FILE_READING_TOOLS.includes(toolName));
+
+  if (!ruleAppliesToTool) {
+    return false;
+  }
+
+  if (!rule.argument) {
+    return true;
+  }
+
+  const argAccessor = TOOL_ARG_ACCESSORS[toolName];
+  if (!argAccessor) {
+    return true;
+  }
+
+  const actualArg = argAccessor(toolInput);
+  if (!actualArg) {
+    return false;
+  }
+
+  if (toolName === acpToolNames.bash) {
+    // Per Claude Code docs: https://code.claude.com/docs/en/iam#tool-specific-permission-rules
+    // - Bash(npm run build) matches the EXACT command "npm run build"
+    // - Bash(npm run test:*) matches commands STARTING WITH "npm run test"
+    // The :* suffix enables prefix matching, without it the match is exact
+    //
+    // Also from docs: "Claude Code is aware of shell operators (like &&) so a prefix match
+    // rule like Bash(safe-cmd:*) won't give it permission to run the command safe-cmd && other-cmd"
+    if (rule.isWildcard) {
+      if (!actualArg.startsWith(rule.argument)) {
+        return false;
+      }
+      // Check that the matched prefix isn't followed by shell operators that could
+      // allow command chaining/injection
+      const remainder = actualArg.slice(rule.argument.length);
+      if (containsShellOperator(remainder)) {
+        return false;
+      }
+      return true;
+    }
+    return actualArg === rule.argument;
+  }
+
+  // For file-based tools (Read, Edit, Write), use glob matching
+  return matchesGlob(rule.argument, actualArg, cwd);
+}
+
+/**
+ * Reads and parses a JSON settings file, returning an empty object if not found or invalid
+ */
+async function loadSettingsFile(filePath: string | null): Promise<ClaudeCodeSettings> {
+  if (!filePath) {
+    return {};
+  }
+
+  try {
+    const content = await fs.promises.readFile(filePath, "utf-8");
+    return JSON.parse(content) as ClaudeCodeSettings;
+  } catch {
+    return {};
+  }
+}
+
+/**
+ * Gets the enterprise settings path based on the current platform
+ */
+export function getManagedSettingsPath(): string {
+  switch (process.platform) {
+    case "darwin":
+      return "/Library/Application Support/ClaudeCode/managed-settings.json";
+    case "linux":
+      return "/etc/claude-code/managed-settings.json";
+    case "win32":
+      return "C:\\Program Files\\ClaudeCode\\managed-settings.json";
+    default:
+      return "/etc/claude-code/managed-settings.json";
+  }
+}
+
+export interface SettingsManagerOptions {
+  onChange?: () => void;
+  logger?: { log: (...args: any[]) => void; error: (...args: any[]) => void };
+}
+
+/**
+ * Manages Claude Code settings from multiple sources with proper precedence.
+ *
+ * Settings are loaded from (in order of increasing precedence):
+ * 1. User settings (~/.claude/settings.json)
+ * 2. Project settings (<cwd>/.claude/settings.json)
+ * 3. Local project settings (<cwd>/.claude/settings.local.json)
+ * 4. Enterprise managed settings (platform-specific path)
+ *
+ * The manager watches all settings files for changes and automatically reloads.
+ */
+export class SettingsManager {
+  private cwd: string;
+  private userSettings: ClaudeCodeSettings = {};
+  private projectSettings: ClaudeCodeSettings = {};
+  private localSettings: ClaudeCodeSettings = {};
+  private enterpriseSettings: ClaudeCodeSettings = {};
+  private mergedSettings: ClaudeCodeSettings = {};
+  private watchers: fs.FSWatcher[] = [];
+  private onChange?: () => void;
+  private logger: { log: (...args: any[]) => void; error: (...args: any[]) => void };
+  private initialized = false;
+  private debounceTimer: ReturnType<typeof setTimeout> | null = null;
+
+  constructor(cwd: string, options?: SettingsManagerOptions) {
+    this.cwd = cwd;
+    this.onChange = options?.onChange;
+    this.logger = options?.logger ?? console;
+  }
+
+  /**
+   * Initialize the settings manager by loading all settings and setting up file watchers
+   */
+  async initialize(): Promise<void> {
+    if (this.initialized) {
+      return;
+    }
+
+    await this.loadAllSettings();
+    this.setupWatchers();
+    this.initialized = true;
+  }
+
+  /**
+   * Returns the path to the user settings file
+   */
+  private getUserSettingsPath(): string {
+    return path.join(CLAUDE_CONFIG_DIR, "settings.json");
+  }
+
+  /**
+   * Returns the path to the project settings file
+   */
+  private getProjectSettingsPath(): string {
+    return path.join(this.cwd, ".claude", "settings.json");
+  }
+
+  /**
+   * Returns the path to the local project settings file
+   */
+  private getLocalSettingsPath(): string {
+    return path.join(this.cwd, ".claude", "settings.local.json");
+  }
+
+  /**
+   * Loads settings from all sources
+   */
+  private async loadAllSettings(): Promise<void> {
+    const [userSettings, projectSettings, localSettings, enterpriseSettings] = await Promise.all([
+      loadSettingsFile(this.getUserSettingsPath()),
+      loadSettingsFile(this.getProjectSettingsPath()),
+      loadSettingsFile(this.getLocalSettingsPath()),
+      loadSettingsFile(getManagedSettingsPath()),
+    ]);
+
+    this.userSettings = userSettings;
+    this.projectSettings = projectSettings;
+    this.localSettings = localSettings;
+    this.enterpriseSettings = enterpriseSettings;
+
+    this.mergeSettings();
+  }
+
+  /**
+   * Merges all settings sources with proper precedence.
+   * For permissions, rules from all sources are combined.
+   * Deny rules always take precedence during permission checks.
+   */
+  private mergeSettings(): void {
+    const allSettings = [
+      this.userSettings,
+      this.projectSettings,
+      this.localSettings,
+      this.enterpriseSettings,
+    ];
+
+    const merged: ClaudeCodeSettings = {
+      permissions: {
+        allow: [],
+        deny: [],
+        ask: [],
+      },
+    };
+
+    for (const settings of allSettings) {
+      if (settings.permissions) {
+        if (settings.permissions.allow) {
+          merged.permissions!.allow!.push(...settings.permissions.allow);
+        }
+        if (settings.permissions.deny) {
+          merged.permissions!.deny!.push(...settings.permissions.deny);
+        }
+        if (settings.permissions.ask) {
+          merged.permissions!.ask!.push(...settings.permissions.ask);
+        }
+        if (settings.permissions.additionalDirectories) {
+          merged.permissions!.additionalDirectories = [
+            ...(merged.permissions!.additionalDirectories || []),
+            ...settings.permissions.additionalDirectories,
+          ];
+        }
+        if (settings.permissions.defaultMode) {
+          merged.permissions!.defaultMode = settings.permissions.defaultMode;
+        }
+      }
+
+      if (settings.env) {
+        merged.env = { ...merged.env, ...settings.env };
+      }
+    }
+
+    this.mergedSettings = merged;
+  }
+
+  /**
+   * Sets up file watchers for all settings files
+   */
+  private setupWatchers(): void {
+    const paths = [
+      this.getUserSettingsPath(),
+      this.getProjectSettingsPath(),
+      this.getLocalSettingsPath(),
+      getManagedSettingsPath(),
+    ];
+
+    for (const filePath of paths) {
+      if (!filePath) continue;
+
+      try {
+        const dir = path.dirname(filePath);
+        const filename = path.basename(filePath);
+
+        if (fs.existsSync(dir)) {
+          const watcher = fs.watch(dir, (eventType, changedFilename) => {
+            if (changedFilename === filename) {
+              this.handleSettingsChange();
+            }
+          });
+
+          watcher.on("error", (error) => {
+            this.logger.error(`Settings watcher error for ${filePath}:`, error);
+          });
+
+          this.watchers.push(watcher);
+        }
+      } catch (error) {
+        this.logger.error(`Failed to set up watcher for ${filePath}:`, error);
+      }
+    }
+  }
+
+  /**
+   * Handles settings file changes with debouncing to avoid rapid reloads
+   */
+  private handleSettingsChange(): void {
+    if (this.debounceTimer) {
+      clearTimeout(this.debounceTimer);
+    }
+
+    this.debounceTimer = setTimeout(async () => {
+      this.debounceTimer = null;
+      try {
+        await this.loadAllSettings();
+        this.onChange?.();
+      } catch (error) {
+        this.logger.error("Failed to reload settings:", error);
+      }
+    }, 100);
+  }
+
+  /**
+   * Checks if a tool invocation is allowed based on the loaded settings.
+   *
+   * @param toolName - The tool name (can be ACP-prefixed like mcp__acp__Read or plain like Read)
+   * @param toolInput - The tool input object
+   * @returns The permission decision and matching rule info
+   */
+  checkPermission(toolName: string, toolInput: unknown): PermissionCheckResult {
+    if (!toolName.startsWith(ACP_TOOL_NAME_PREFIX)) {
+      return { decision: "ask" };
+    }
+
+    const permissions = this.mergedSettings.permissions;
+
+    if (!permissions) {
+      return { decision: "ask" };
+    }
+
+    // Check deny rules first (highest priority)
+    for (const rule of permissions.deny || []) {
+      const parsed = parseRule(rule);
+      if (matchesRule(parsed, toolName, toolInput, this.cwd)) {
+        return { decision: "deny", rule, source: "deny" };
+      }
+    }
+
+    // Check allow rules
+    for (const rule of permissions.allow || []) {
+      const parsed = parseRule(rule);
+      if (matchesRule(parsed, toolName, toolInput, this.cwd)) {
+        return { decision: "allow", rule, source: "allow" };
+      }
+    }
+
+    // Check ask rules
+    for (const rule of permissions.ask || []) {
+      const parsed = parseRule(rule);
+      if (matchesRule(parsed, toolName, toolInput, this.cwd)) {
+        return { decision: "ask", rule, source: "ask" };
+      }
+    }
+
+    // No matching rule - default to ask
+    return { decision: "ask" };
+  }
+
+  /**
+   * Returns the current merged settings
+   */
+  getSettings(): ClaudeCodeSettings {
+    return this.mergedSettings;
+  }
+
+  /**
+   * Returns the current working directory
+   */
+  getCwd(): string {
+    return this.cwd;
+  }
+
+  /**
+   * Updates the working directory and reloads project-specific settings
+   */
+  async setCwd(cwd: string): Promise<void> {
+    if (this.cwd === cwd) {
+      return;
+    }
+
+    this.dispose();
+    this.cwd = cwd;
+    this.initialized = false;
+    await this.initialize();
+  }
+
+  /**
+   * Disposes of file watchers and cleans up resources
+   */
+  dispose(): void {
+    if (this.debounceTimer) {
+      clearTimeout(this.debounceTimer);
+      this.debounceTimer = null;
+    }
+
+    for (const watcher of this.watchers) {
+      watcher.close();
+    }
+    this.watchers = [];
+    this.initialized = false;
+  }
+}

src/tests/.claude/commands/say-hello.md

@@ -1,6 +1,6 @@
 ---
 description: Say hello
-argument-hint: [name]
+argument-hint: name
 ---
 
 Respond with "Hello $1" and nothing else.

src/tests/acp-agent.test.ts

@@ -166,7 +166,7 @@ describe.skipIf(!process.env.RUN_INTEGRATION_TESTS)("ACP subprocess integration"
     expect(commands).toContainEqual({
       name: "say-hello",
       description: "Say hello (project)",
-      input: { hint: "[name]" },
+      input: { hint: "name" },
     });
 
     await connection.prompt({
@@ -251,7 +251,7 @@ describe("tool conversions", () => {
       },
     };
 
-    expect(toolInfoFromToolUse(tool_use, {})).toStrictEqual({
+    expect(toolInfoFromToolUse(tool_use)).toStrictEqual({
       kind: "execute",
       title: "`rm README.md.rm`",
       content: [
@@ -276,7 +276,7 @@ describe("tool conversions", () => {
       },
     };
 
-    expect(toolInfoFromToolUse(tool_use, {})).toStrictEqual({
+    expect(toolInfoFromToolUse(tool_use)).toStrictEqual({
       kind: "search",
       title: "Find `*/**.ts`",
       content: [],
@@ -297,7 +297,7 @@ describe("tool conversions", () => {
       },
     };
 
-    expect(toolInfoFromToolUse(tool_use, {})).toStrictEqual({
+    expect(toolInfoFromToolUse(tool_use)).toStrictEqual({
       kind: "think",
       title: "Handle user's work request",
       content: [
@@ -322,7 +322,7 @@ describe("tool conversions", () => {
       },
     };
 
-    expect(toolInfoFromToolUse(tool_use, {})).toStrictEqual({
+    expect(toolInfoFromToolUse(tool_use)).toStrictEqual({
       kind: "search",
       title: "List the `/Users/test/github/claude-code-acp` directory's contents",
       content: [],
@@ -340,7 +340,7 @@ describe("tool conversions", () => {
       },
     };
 
-    expect(toolInfoFromToolUse(tool_use, {})).toStrictEqual({
+    expect(toolInfoFromToolUse(tool_use)).toStrictEqual({
       kind: "search",
       title: 'grep ".*"',
       content: [],
@@ -358,7 +358,7 @@ describe("tool conversions", () => {
       },
     };
 
-    expect(toolInfoFromToolUse(tool_use, {})).toStrictEqual({
+    expect(toolInfoFromToolUse(tool_use)).toStrictEqual({
       kind: "edit",
       title: "Write /Users/test/project/example.txt",
       content: [
@@ -384,7 +384,7 @@ describe("tool conversions", () => {
       },
     };
 
-    expect(toolInfoFromToolUse(tool_use, {})).toStrictEqual({
+    expect(toolInfoFromToolUse(tool_use)).toStrictEqual({
       kind: "edit",
       title: "Write /Users/test/project/config.json",
       content: [
@@ -409,7 +409,7 @@ describe("tool conversions", () => {
       },
     };
 
-    expect(toolInfoFromToolUse(tool_use, {})).toStrictEqual({
+    expect(toolInfoFromToolUse(tool_use)).toStrictEqual({
       kind: "read",
       title: "Read File",
       content: [],
@@ -427,7 +427,7 @@ describe("tool conversions", () => {
       },
     };
 
-    expect(toolInfoFromToolUse(tool_use, {})).toStrictEqual({
+    expect(toolInfoFromToolUse(tool_use)).toStrictEqual({
       kind: "read",
       title: "Read /Users/test/project/data.json",
       content: [],
@@ -446,7 +446,7 @@ describe("tool conversions", () => {
       },
     };
 
-    expect(toolInfoFromToolUse(tool_use, {})).toStrictEqual({
+    expect(toolInfoFromToolUse(tool_use)).toStrictEqual({
       kind: "read",
       title: "Read /Users/test/project/large.txt (1 - 100)",
       content: [],
@@ -466,7 +466,7 @@ describe("tool conversions", () => {
       },
     };
 
-    expect(toolInfoFromToolUse(tool_use, {})).toStrictEqual({
+    expect(toolInfoFromToolUse(tool_use)).toStrictEqual({
       kind: "read",
       title: "Read /Users/test/project/large.txt (51 - 150)",
       content: [],
@@ -485,7 +485,7 @@ describe("tool conversions", () => {
       },
     };
 
-    expect(toolInfoFromToolUse(tool_use, {})).toStrictEqual({
+    expect(toolInfoFromToolUse(tool_use)).toStrictEqual({
       kind: "read",
       title: "Read /Users/test/project/large.txt (from line 201)",
       content: [],
@@ -493,50 +493,6 @@ describe("tool conversions", () => {
     });
   });
 
-  it("should handle WebFetch tool calls", () => {
-    const tool_use = {
-      type: "tool_use",
-      id: "toolu_01LxEjDn8ci9SAc3qG7LbbXV",
-      name: "WebFetch",
-      input: {
-        url: "https://agentclientprotocol.com",
-        prompt:
-          "Please provide a comprehensive summary of the content on this page, including what the Agent Client Protocol is, its main features, documentation links, and any other relevant information.",
-      },
-    };
-
-    expect(toolInfoFromToolUse(tool_use, {})).toStrictEqual({
-      kind: "fetch",
-      title: "Fetch https://agentclientprotocol.com",
-      content: [
-        {
-          content: {
-            text: "Please provide a comprehensive summary of the content on this page, including what the Agent Client Protocol is, its main features, documentation links, and any other relevant information.",
-            type: "text",
-          },
-          type: "content",
-        },
-      ],
-    });
-  });
-
-  it("should handle WebSearch tool calls", () => {
-    const tool_use = {
-      type: "tool_use",
-      id: "toolu_01NYMwiZFbdoQFxYxuQDFZXQ",
-      name: "WebSearch",
-      input: {
-        query: "agentclientprotocol.com",
-      },
-    };
-
-    expect(toolInfoFromToolUse(tool_use, {})).toStrictEqual({
-      kind: "fetch",
-      title: '"agentclientprotocol.com"',
-      content: [],
-    });
-  });
-
   it("should handle KillBash entries", () => {
     const tool_use = {
       type: "tool_use",
@@ -547,7 +503,7 @@ describe("tool conversions", () => {
       },
     };
 
-    expect(toolInfoFromToolUse(tool_use, {})).toStrictEqual({
+    expect(toolInfoFromToolUse(tool_use)).toStrictEqual({
       kind: "execute",
       title: `Kill Process`,
       content: [],
@@ -564,7 +520,7 @@ describe("tool conversions", () => {
       },
     };
 
-    expect(toolInfoFromToolUse(tool_use, {})).toStrictEqual({
+    expect(toolInfoFromToolUse(tool_use)).toStrictEqual({
       kind: "execute",
       title: `Tail Logs`,
       content: [],
@@ -657,7 +613,6 @@ describe("tool conversions", () => {
         received.message.role,
         "test",
         {},
-        {},
         {} as AgentSideConnection,
         console,
       ),
@@ -891,7 +846,7 @@ describe("permission requests", () => {
 
     for (const testCase of testCases) {
       // Get the tool info that would be used in requestPermission
-      const toolInfo = toolInfoFromToolUse(testCase.toolUse, {});
+      const toolInfo = toolInfoFromToolUse(testCase.toolUse);
 
       // Verify toolInfo has a title
       expect(toolInfo.title).toBeDefined();

src/tests/settings.test.ts

@@ -0,0 +1,617 @@
+import { describe, it, expect, beforeEach, afterEach } from "vitest";
+import { SettingsManager } from "../settings.js";
+import * as fs from "node:fs";
+import * as path from "node:path";
+import * as os from "node:os";
+
+describe("SettingsManager", () => {
+  let tempDir: string;
+  let settingsManager: SettingsManager;
+
+  beforeEach(async () => {
+    tempDir = await fs.promises.mkdtemp(path.join(os.tmpdir(), "settings-test-"));
+  });
+
+  afterEach(async () => {
+    settingsManager?.dispose();
+    await fs.promises.rm(tempDir, { recursive: true, force: true });
+  });
+
+  describe("permission checking", () => {
+    it("should return 'ask' when no settings exist", async () => {
+      settingsManager = new SettingsManager(tempDir);
+      await settingsManager.initialize();
+
+      const result = settingsManager.checkPermission("mcp__acp__Read", {
+        file_path: "/some/file.txt",
+      });
+      expect(result.decision).toBe("ask");
+    });
+
+    it("should return 'ask' for non-ACP tools (permission checks only apply to mcp__acp__* tools)", async () => {
+      const claudeDir = path.join(tempDir, ".claude");
+      await fs.promises.mkdir(claudeDir, { recursive: true });
+      await fs.promises.writeFile(
+        path.join(claudeDir, "settings.json"),
+        JSON.stringify({
+          permissions: {
+            deny: ["Read"],
+          },
+        }),
+      );
+
+      settingsManager = new SettingsManager(tempDir);
+      await settingsManager.initialize();
+
+      // Non-ACP tools should always return 'ask' regardless of rules
+      const result = settingsManager.checkPermission("Read", { file_path: "/some/file.txt" });
+      expect(result.decision).toBe("ask");
+    });
+
+    it("should allow tool use when matching allow rule exists", async () => {
+      const claudeDir = path.join(tempDir, ".claude");
+      await fs.promises.mkdir(claudeDir, { recursive: true });
+      await fs.promises.writeFile(
+        path.join(claudeDir, "settings.json"),
+        JSON.stringify({
+          permissions: {
+            allow: ["Read"],
+          },
+        }),
+      );
+
+      settingsManager = new SettingsManager(tempDir);
+      await settingsManager.initialize();
+
+      const result = settingsManager.checkPermission("mcp__acp__Read", {
+        file_path: "/some/file.txt",
+      });
+      expect(result.decision).toBe("allow");
+      expect(result.rule).toBe("Read");
+    });
+
+    it("should deny tool use when matching deny rule exists", async () => {
+      const claudeDir = path.join(tempDir, ".claude");
+      await fs.promises.mkdir(claudeDir, { recursive: true });
+      await fs.promises.writeFile(
+        path.join(claudeDir, "settings.json"),
+        JSON.stringify({
+          permissions: {
+            deny: ["Read(./.env)"],
+          },
+        }),
+      );
+
+      settingsManager = new SettingsManager(tempDir);
+      await settingsManager.initialize();
+
+      const result = settingsManager.checkPermission("mcp__acp__Read", {
+        file_path: path.join(tempDir, ".env"),
+      });
+      expect(result.decision).toBe("deny");
+      expect(result.rule).toBe("Read(./.env)");
+    });
+
+    it("should prioritize deny rules over allow rules", async () => {
+      const claudeDir = path.join(tempDir, ".claude");
+      await fs.promises.mkdir(claudeDir, { recursive: true });
+      await fs.promises.writeFile(
+        path.join(claudeDir, "settings.json"),
+        JSON.stringify({
+          permissions: {
+            allow: ["Read"],
+            deny: ["Read(./.env)"],
+          },
+        }),
+      );
+
+      settingsManager = new SettingsManager(tempDir);
+      await settingsManager.initialize();
+
+      // .env should be denied
+      const envResult = settingsManager.checkPermission("mcp__acp__Read", {
+        file_path: path.join(tempDir, ".env"),
+      });
+      expect(envResult.decision).toBe("deny");
+
+      // other files should be allowed
+      const otherResult = settingsManager.checkPermission("mcp__acp__Read", {
+        file_path: path.join(tempDir, "other.txt"),
+      });
+      expect(otherResult.decision).toBe("allow");
+    });
+
+    it("should handle ACP-prefixed tool names", async () => {
+      const claudeDir = path.join(tempDir, ".claude");
+      await fs.promises.mkdir(claudeDir, { recursive: true });
+      await fs.promises.writeFile(
+        path.join(claudeDir, "settings.json"),
+        JSON.stringify({
+          permissions: {
+            allow: ["Read"],
+          },
+        }),
+      );
+
+      settingsManager = new SettingsManager(tempDir);
+      await settingsManager.initialize();
+
+      const result = settingsManager.checkPermission("mcp__acp__Read", {
+        file_path: "/some/file.txt",
+      });
+      expect(result.decision).toBe("allow");
+    });
+  });
+
+  describe("Bash permission rules", () => {
+    it("should match exact Bash commands without :* wildcard", async () => {
+      const claudeDir = path.join(tempDir, ".claude");
+      await fs.promises.mkdir(claudeDir, { recursive: true });
+      await fs.promises.writeFile(
+        path.join(claudeDir, "settings.json"),
+        JSON.stringify({
+          permissions: {
+            // Per docs: Bash(npm run build) matches the EXACT command "npm run build"
+            allow: ["Bash(npm run lint)"],
+          },
+        }),
+      );
+
+      settingsManager = new SettingsManager(tempDir);
+      await settingsManager.initialize();
+
+      // Exact match should be allowed
+      const exactResult = settingsManager.checkPermission("mcp__acp__Bash", {
+        command: "npm run lint",
+      });
+      expect(exactResult.decision).toBe("allow");
+
+      // Command with extra arguments should NOT match (exact match only)
+      const withArgsResult = settingsManager.checkPermission("mcp__acp__Bash", {
+        command: "npm run lint --fix",
+      });
+      expect(withArgsResult.decision).toBe("ask");
+
+      // Similar command should NOT match (exact match only)
+      const similarResult = settingsManager.checkPermission("mcp__acp__Bash", {
+        command: "npm run linting",
+      });
+      expect(similarResult.decision).toBe("ask");
+
+      // Different command should not match
+      const differentResult = settingsManager.checkPermission("mcp__acp__Bash", {
+        command: "npm run test",
+      });
+      expect(differentResult.decision).toBe("ask");
+    });
+
+    it("should match Bash commands with :* wildcard suffix (prefix matching)", async () => {
+      const claudeDir = path.join(tempDir, ".claude");
+      await fs.promises.mkdir(claudeDir, { recursive: true });
+      await fs.promises.writeFile(
+        path.join(claudeDir, "settings.json"),
+        JSON.stringify({
+          permissions: {
+            // The :* suffix is a convention to make prefix matching explicit
+            allow: ["Bash(npm run:*)"],
+          },
+        }),
+      );
+
+      settingsManager = new SettingsManager(tempDir);
+      await settingsManager.initialize();
+
+      // Any command starting with "npm run" should match (prefix matching with :*)
+      const lintResult = settingsManager.checkPermission("mcp__acp__Bash", {
+        command: "npm run lint",
+      });
+      expect(lintResult.decision).toBe("allow");
+
+      const testResult = settingsManager.checkPermission("mcp__acp__Bash", {
+        command: "npm run test",
+      });
+      expect(testResult.decision).toBe("allow");
+
+      // Commands with additional args also match
+      const withArgsResult = settingsManager.checkPermission("mcp__acp__Bash", {
+        command: "npm run test --watch",
+      });
+      expect(withArgsResult.decision).toBe("allow");
+
+      // Non-matching command
+      const installResult = settingsManager.checkPermission("mcp__acp__Bash", {
+        command: "npm install",
+      });
+      expect(installResult.decision).toBe("ask");
+    });
+
+    it("should not allow shell operators to bypass prefix matching", async () => {
+      const claudeDir = path.join(tempDir, ".claude");
+      await fs.promises.mkdir(claudeDir, { recursive: true });
+      await fs.promises.writeFile(
+        path.join(claudeDir, "settings.json"),
+        JSON.stringify({
+          permissions: {
+            allow: ["Bash(safe-cmd:*)"],
+          },
+        }),
+      );
+
+      settingsManager = new SettingsManager(tempDir);
+      await settingsManager.initialize();
+
+      // Normal prefix match should work
+      const normalResult = settingsManager.checkPermission("mcp__acp__Bash", {
+        command: "safe-cmd --flag",
+      });
+      expect(normalResult.decision).toBe("allow");
+
+      // Shell operators should NOT be allowed (per docs: Claude Code is aware of shell operators)
+      const andResult = settingsManager.checkPermission("mcp__acp__Bash", {
+        command: "safe-cmd && malicious-cmd",
+      });
+      expect(andResult.decision).toBe("ask");
+
+      const orResult = settingsManager.checkPermission("mcp__acp__Bash", {
+        command: "safe-cmd || malicious-cmd",
+      });
+      expect(orResult.decision).toBe("ask");
+
+      const semicolonResult = settingsManager.checkPermission("mcp__acp__Bash", {
+        command: "safe-cmd; malicious-cmd",
+      });
+      expect(semicolonResult.decision).toBe("ask");
+
+      const pipeResult = settingsManager.checkPermission("mcp__acp__Bash", {
+        command: "safe-cmd | malicious-cmd",
+      });
+      expect(pipeResult.decision).toBe("ask");
+
+      const subshellResult = settingsManager.checkPermission("mcp__acp__Bash", {
+        command: "safe-cmd $(malicious-cmd)",
+      });
+      expect(subshellResult.decision).toBe("ask");
+
+      const backtickResult = settingsManager.checkPermission("mcp__acp__Bash", {
+        command: "safe-cmd `malicious-cmd`",
+      });
+      expect(backtickResult.decision).toBe("ask");
+
+      const newlineResult = settingsManager.checkPermission("mcp__acp__Bash", {
+        command: "safe-cmd\nmalicious-cmd",
+      });
+      expect(newlineResult.decision).toBe("ask");
+    });
+
+    it("should deny dangerous Bash commands", async () => {
+      const claudeDir = path.join(tempDir, ".claude");
+      await fs.promises.mkdir(claudeDir, { recursive: true });
+      await fs.promises.writeFile(
+        path.join(claudeDir, "settings.json"),
+        JSON.stringify({
+          permissions: {
+            deny: ["Bash(curl:*)", "Bash(wget:*)"],
+          },
+        }),
+      );
+
+      settingsManager = new SettingsManager(tempDir);
+      await settingsManager.initialize();
+
+      const curlResult = settingsManager.checkPermission("mcp__acp__Bash", {
+        command: "curl https://example.com",
+      });
+      expect(curlResult.decision).toBe("deny");
+
+      const wgetResult = settingsManager.checkPermission("mcp__acp__Bash", {
+        command: "wget https://example.com",
+      });
+      expect(wgetResult.decision).toBe("deny");
+
+      const lsResult = settingsManager.checkPermission("mcp__acp__Bash", { command: "ls -la" });
+      expect(lsResult.decision).toBe("ask");
+    });
+  });
+
+  describe("file path glob matching", () => {
+    it("should match exact file paths", async () => {
+      const claudeDir = path.join(tempDir, ".claude");
+      await fs.promises.mkdir(claudeDir, { recursive: true });
+      await fs.promises.writeFile(
+        path.join(claudeDir, "settings.json"),
+        JSON.stringify({
+          permissions: {
+            deny: ["Read(./.env)"],
+          },
+        }),
+      );
+
+      settingsManager = new SettingsManager(tempDir);
+      await settingsManager.initialize();
+
+      const envResult = settingsManager.checkPermission("mcp__acp__Read", {
+        file_path: path.join(tempDir, ".env"),
+      });
+      expect(envResult.decision).toBe("deny");
+
+      const otherResult = settingsManager.checkPermission("mcp__acp__Read", {
+        file_path: path.join(tempDir, ".envrc"),
+      });
+      expect(otherResult.decision).toBe("ask");
+    });
+
+    it("should match glob patterns with single wildcard", async () => {
+      const claudeDir = path.join(tempDir, ".claude");
+      await fs.promises.mkdir(claudeDir, { recursive: true });
+      await fs.promises.writeFile(
+        path.join(claudeDir, "settings.json"),
+        JSON.stringify({
+          permissions: {
+            deny: ["Read(./.env.*)"],
+          },
+        }),
+      );
+
+      settingsManager = new SettingsManager(tempDir);
+      await settingsManager.initialize();
+
+      const envLocalResult = settingsManager.checkPermission("mcp__acp__Read", {
+        file_path: path.join(tempDir, ".env.local"),
+      });
+      expect(envLocalResult.decision).toBe("deny");
+
+      const envProdResult = settingsManager.checkPermission("mcp__acp__Read", {
+        file_path: path.join(tempDir, ".env.production"),
+      });
+      expect(envProdResult.decision).toBe("deny");
+
+      // Plain .env should not match .env.*
+      const plainEnvResult = settingsManager.checkPermission("mcp__acp__Read", {
+        file_path: path.join(tempDir, ".env"),
+      });
+      expect(plainEnvResult.decision).toBe("ask");
+    });
+
+    it("should match glob patterns with double wildcard (recursive)", async () => {
+      const claudeDir = path.join(tempDir, ".claude");
+      await fs.promises.mkdir(claudeDir, { recursive: true });
+      await fs.promises.writeFile(
+        path.join(claudeDir, "settings.json"),
+        JSON.stringify({
+          permissions: {
+            deny: ["Read(./secrets/**)"],
+          },
+        }),
+      );
+
+      settingsManager = new SettingsManager(tempDir);
+      await settingsManager.initialize();
+
+      const secretResult = settingsManager.checkPermission("mcp__acp__Read", {
+        file_path: path.join(tempDir, "secrets", "api-key.txt"),
+      });
+      expect(secretResult.decision).toBe("deny");
+
+      const nestedSecretResult = settingsManager.checkPermission("mcp__acp__Read", {
+        file_path: path.join(tempDir, "secrets", "deep", "nested", "key.txt"),
+      });
+      expect(nestedSecretResult.decision).toBe("deny");
+
+      const otherResult = settingsManager.checkPermission("mcp__acp__Read", {
+        file_path: path.join(tempDir, "public", "file.txt"),
+      });
+      expect(otherResult.decision).toBe("ask");
+    });
+
+    it("should handle home directory expansion", async () => {
+      const claudeDir = path.join(tempDir, ".claude");
+      await fs.promises.mkdir(claudeDir, { recursive: true });
+      await fs.promises.writeFile(
+        path.join(claudeDir, "settings.json"),
+        JSON.stringify({
+          permissions: {
+            allow: ["Read(~/.zshrc)"],
+          },
+        }),
+      );
+
+      settingsManager = new SettingsManager(tempDir);
+      await settingsManager.initialize();
+
+      const zshrcResult = settingsManager.checkPermission("mcp__acp__Read", {
+        file_path: path.join(os.homedir(), ".zshrc"),
+      });
+      expect(zshrcResult.decision).toBe("allow");
+    });
+  });
+
+  describe("settings merging", () => {
+    it("should merge project and local settings", async () => {
+      const claudeDir = path.join(tempDir, ".claude");
+      await fs.promises.mkdir(claudeDir, { recursive: true });
+
+      // Project settings
+      await fs.promises.writeFile(
+        path.join(claudeDir, "settings.json"),
+        JSON.stringify({
+          permissions: {
+            allow: ["Read"],
+          },
+        }),
+      );
+
+      // Local settings
+      await fs.promises.writeFile(
+        path.join(claudeDir, "settings.local.json"),
+        JSON.stringify({
+          permissions: {
+            deny: ["Read(./.env)"],
+          },
+        }),
+      );
+
+      settingsManager = new SettingsManager(tempDir);
+      await settingsManager.initialize();
+
+      // Read should be allowed in general
+      const readResult = settingsManager.checkPermission("mcp__acp__Read", {
+        file_path: path.join(tempDir, "file.txt"),
+      });
+      expect(readResult.decision).toBe("allow");
+
+      // But .env should be denied (local settings take precedence)
+      const envResult = settingsManager.checkPermission("mcp__acp__Read", {
+        file_path: path.join(tempDir, ".env"),
+      });
+      expect(envResult.decision).toBe("deny");
+    });
+  });
+
+  describe("ask rules", () => {
+    it("should return 'ask' for matching ask rules", async () => {
+      const claudeDir = path.join(tempDir, ".claude");
+      await fs.promises.mkdir(claudeDir, { recursive: true });
+      await fs.promises.writeFile(
+        path.join(claudeDir, "settings.json"),
+        JSON.stringify({
+          permissions: {
+            ask: ["Bash(git push:*)"],
+          },
+        }),
+      );
+
+      settingsManager = new SettingsManager(tempDir);
+      await settingsManager.initialize();
+
+      const result = settingsManager.checkPermission("mcp__acp__Bash", {
+        command: "git push origin main",
+      });
+      expect(result.decision).toBe("ask");
+      expect(result.rule).toBe("Bash(git push:*)");
+    });
+  });
+
+  describe("Edit and Write tools", () => {
+    it("should handle Edit tool permissions", async () => {
+      const claudeDir = path.join(tempDir, ".claude");
+      await fs.promises.mkdir(claudeDir, { recursive: true });
+      await fs.promises.writeFile(
+        path.join(claudeDir, "settings.json"),
+        JSON.stringify({
+          permissions: {
+            deny: ["Edit(./package-lock.json)"],
+          },
+        }),
+      );
+
+      settingsManager = new SettingsManager(tempDir);
+      await settingsManager.initialize();
+
+      const lockFileResult = settingsManager.checkPermission("mcp__acp__Edit", {
+        file_path: path.join(tempDir, "package-lock.json"),
+      });
+      expect(lockFileResult.decision).toBe("deny");
+
+      const otherResult = settingsManager.checkPermission("mcp__acp__Edit", {
+        file_path: path.join(tempDir, "package.json"),
+      });
+      expect(otherResult.decision).toBe("ask");
+    });
+
+    it("should handle mcp__acp__Edit and mcp__acp__Write tool names", async () => {
+      const claudeDir = path.join(tempDir, ".claude");
+      await fs.promises.mkdir(claudeDir, { recursive: true });
+      await fs.promises.writeFile(
+        path.join(claudeDir, "settings.json"),
+        JSON.stringify({
+          permissions: {
+            allow: ["Edit", "Write"],
+          },
+        }),
+      );
+
+      settingsManager = new SettingsManager(tempDir);
+      await settingsManager.initialize();
+
+      const editResult = settingsManager.checkPermission("mcp__acp__Edit", {
+        file_path: "/some/file.ts",
+      });
+      expect(editResult.decision).toBe("allow");
+
+      const writeResult = settingsManager.checkPermission("mcp__acp__Write", {
+        file_path: "/some/file.ts",
+      });
+      expect(writeResult.decision).toBe("allow");
+    });
+  });
+
+  describe("getSettings", () => {
+    it("should return merged settings", async () => {
+      const claudeDir = path.join(tempDir, ".claude");
+      await fs.promises.mkdir(claudeDir, { recursive: true });
+      await fs.promises.writeFile(
+        path.join(claudeDir, "settings.json"),
+        JSON.stringify({
+          permissions: {
+            allow: ["Read", "Bash(npm:*)"],
+            deny: ["Read(./.env)"],
+          },
+          env: {
+            FOO: "bar",
+          },
+        }),
+      );
+
+      settingsManager = new SettingsManager(tempDir);
+      await settingsManager.initialize();
+
+      const settings = settingsManager.getSettings();
+      expect(settings.permissions?.allow).toContain("Read");
+      expect(settings.permissions?.allow).toContain("Bash(npm:*)");
+      expect(settings.permissions?.deny).toContain("Read(./.env)");
+      expect(settings.env?.FOO).toBe("bar");
+    });
+  });
+
+  describe("setCwd", () => {
+    it("should reload settings when cwd changes", async () => {
+      const claudeDir1 = path.join(tempDir, ".claude");
+      await fs.promises.mkdir(claudeDir1, { recursive: true });
+      await fs.promises.writeFile(
+        path.join(claudeDir1, "settings.json"),
+        JSON.stringify({
+          permissions: {
+            allow: ["Read"],
+          },
+        }),
+      );
+
+      settingsManager = new SettingsManager(tempDir);
+      await settingsManager.initialize();
+
+      let result = settingsManager.checkPermission("mcp__acp__Read", { file_path: "/file.txt" });
+      expect(result.decision).toBe("allow");
+
+      // Create a new temp directory with different settings
+      const tempDir2 = await fs.promises.mkdtemp(path.join(os.tmpdir(), "settings-test-2-"));
+      const claudeDir2 = path.join(tempDir2, ".claude");
+      await fs.promises.mkdir(claudeDir2, { recursive: true });
+      await fs.promises.writeFile(
+        path.join(claudeDir2, "settings.json"),
+        JSON.stringify({
+          permissions: {
+            deny: ["Read"],
+          },
+        }),
+      );
+
+      await settingsManager.setCwd(tempDir2);
+
+      result = settingsManager.checkPermission("mcp__acp__Read", { file_path: "/file.txt" });
+      expect(result.decision).toBe("deny");
+
+      // Cleanup second temp dir
+      await fs.promises.rm(tempDir2, { recursive: true, force: true });
+    });
+  });
+});

src/tests/tools.test.ts

@@ -0,0 +1,318 @@
+import { describe, it, expect } from "vitest";
+import { AgentSideConnection } from "@agentclientprotocol/sdk";
+import { ToolResultBlockParam } from "@anthropic-ai/sdk/resources";
+import {
+  BetaMCPToolResultBlock,
+  BetaTextBlock,
+  BetaWebSearchResultBlock,
+  BetaWebSearchToolResultBlock,
+  BetaBashCodeExecutionToolResultBlock,
+  BetaBashCodeExecutionResultBlock,
+} from "@anthropic-ai/sdk/resources/beta.mjs";
+import { toAcpNotifications, ToolUseCache, Logger } from "../acp-agent.js";
+
+describe("rawOutput in tool call updates", () => {
+  const mockClient = {} as AgentSideConnection;
+  const mockLogger: Logger = { log: () => {}, error: () => {} };
+
+  it("should include rawOutput with string content for tool_result", () => {
+    const toolUseCache: ToolUseCache = {
+      toolu_123: {
+        type: "tool_use",
+        id: "toolu_123",
+        name: "Bash",
+        input: { command: "echo hello" },
+      },
+    };
+
+    const toolResult: ToolResultBlockParam = {
+      type: "tool_result",
+      tool_use_id: "toolu_123",
+      content: "hello\n",
+      is_error: false,
+    };
+
+    const notifications = toAcpNotifications(
+      [toolResult],
+      "assistant",
+      "test-session",
+      toolUseCache,
+      mockClient,
+      mockLogger,
+    );
+
+    expect(notifications).toHaveLength(1);
+    expect(notifications[0].update).toMatchObject({
+      sessionUpdate: "tool_call_update",
+      toolCallId: "toolu_123",
+      status: "completed",
+      rawOutput: "hello\n",
+    });
+  });
+
+  it("should include rawOutput with array content for tool_result", () => {
+    const toolUseCache: ToolUseCache = {
+      toolu_456: {
+        type: "tool_use",
+        id: "toolu_456",
+        name: "Read",
+        input: { file_path: "/test/file.txt" },
+      },
+    };
+
+    // ToolResultBlockParam content can be string or array of TextBlockParam
+    const toolResult: ToolResultBlockParam = {
+      type: "tool_result",
+      tool_use_id: "toolu_456",
+      content: [{ type: "text", text: "Line 1\nLine 2\nLine 3" }],
+      is_error: false,
+    };
+
+    const notifications = toAcpNotifications(
+      [toolResult],
+      "assistant",
+      "test-session",
+      toolUseCache,
+      mockClient,
+      mockLogger,
+    );
+
+    expect(notifications).toHaveLength(1);
+    expect(notifications[0].update).toMatchObject({
+      sessionUpdate: "tool_call_update",
+      toolCallId: "toolu_456",
+      status: "completed",
+      rawOutput: [{ type: "text", text: "Line 1\nLine 2\nLine 3" }],
+    });
+  });
+
+  it("should include rawOutput for mcp_tool_result with string content", () => {
+    const toolUseCache: ToolUseCache = {
+      toolu_789: {
+        type: "tool_use",
+        id: "toolu_789",
+        name: "mcp__server__tool",
+        input: { query: "test" },
+      },
+    };
+
+    // BetaMCPToolResultBlock content can be string or Array<BetaTextBlock>
+    const toolResult: BetaMCPToolResultBlock = {
+      type: "mcp_tool_result",
+      tool_use_id: "toolu_789",
+      content: '{"result": "success", "data": [1, 2, 3]}',
+      is_error: false,
+    };
+
+    const notifications = toAcpNotifications(
+      [toolResult],
+      "assistant",
+      "test-session",
+      toolUseCache,
+      mockClient,
+      mockLogger,
+    );
+
+    expect(notifications).toHaveLength(1);
+    expect(notifications[0].update).toMatchObject({
+      sessionUpdate: "tool_call_update",
+      toolCallId: "toolu_789",
+      status: "completed",
+      rawOutput: '{"result": "success", "data": [1, 2, 3]}',
+    });
+  });
+
+  it("should include rawOutput for mcp_tool_result with array content", () => {
+    const toolUseCache: ToolUseCache = {
+      toolu_abc: {
+        type: "tool_use",
+        id: "toolu_abc",
+        name: "mcp__server__search",
+        input: { term: "test" },
+      },
+    };
+
+    // BetaTextBlock requires citations field
+    const arrayContent: BetaTextBlock[] = [
+      { type: "text", text: "Result 1", citations: null },
+      { type: "text", text: "Result 2", citations: null },
+    ];
+
+    const toolResult: BetaMCPToolResultBlock = {
+      type: "mcp_tool_result",
+      tool_use_id: "toolu_abc",
+      content: arrayContent,
+      is_error: false,
+    };
+
+    const notifications = toAcpNotifications(
+      [toolResult],
+      "assistant",
+      "test-session",
+      toolUseCache,
+      mockClient,
+      mockLogger,
+    );
+
+    expect(notifications).toHaveLength(1);
+    expect(notifications[0].update).toMatchObject({
+      sessionUpdate: "tool_call_update",
+      toolCallId: "toolu_abc",
+      status: "completed",
+      rawOutput: arrayContent,
+    });
+  });
+
+  it("should include rawOutput for web_search_tool_result", () => {
+    const toolUseCache: ToolUseCache = {
+      toolu_web: {
+        type: "tool_use",
+        id: "toolu_web",
+        name: "WebSearch",
+        input: { query: "test search" },
+      },
+    };
+
+    // BetaWebSearchResultBlock from SDK
+    const searchResults: BetaWebSearchResultBlock[] = [
+      {
+        type: "web_search_result",
+        url: "https://example.com",
+        title: "Example",
+        encrypted_content: "encrypted content here",
+        page_age: "2 days ago",
+      },
+    ];
+
+    const toolResult: BetaWebSearchToolResultBlock = {
+      type: "web_search_tool_result",
+      tool_use_id: "toolu_web",
+      content: searchResults,
+    };
+
+    const notifications = toAcpNotifications(
+      [toolResult],
+      "assistant",
+      "test-session",
+      toolUseCache,
+      mockClient,
+      mockLogger,
+    );
+
+    expect(notifications).toHaveLength(1);
+    expect(notifications[0].update).toMatchObject({
+      sessionUpdate: "tool_call_update",
+      toolCallId: "toolu_web",
+      status: "completed",
+      rawOutput: searchResults,
+    });
+  });
+
+  it("should include rawOutput for bash_code_execution_tool_result", () => {
+    const toolUseCache: ToolUseCache = {
+      toolu_bash: {
+        type: "tool_use",
+        id: "toolu_bash",
+        name: "Bash",
+        input: { command: "ls -la" },
+      },
+    };
+
+    // BetaBashCodeExecutionResultBlock from SDK
+    const bashResult: BetaBashCodeExecutionResultBlock = {
+      type: "bash_code_execution_result",
+      stdout: "file1.txt\nfile2.txt",
+      stderr: "",
+      return_code: 0,
+      content: [],
+    };
+
+    const toolResult: BetaBashCodeExecutionToolResultBlock = {
+      type: "bash_code_execution_tool_result",
+      tool_use_id: "toolu_bash",
+      content: bashResult,
+    };
+
+    const notifications = toAcpNotifications(
+      [toolResult],
+      "assistant",
+      "test-session",
+      toolUseCache,
+      mockClient,
+      mockLogger,
+    );
+
+    expect(notifications).toHaveLength(1);
+    expect(notifications[0].update).toMatchObject({
+      sessionUpdate: "tool_call_update",
+      toolCallId: "toolu_bash",
+      status: "completed",
+      rawOutput: bashResult,
+    });
+  });
+
+  it("should set status to failed when is_error is true", () => {
+    const toolUseCache: ToolUseCache = {
+      toolu_err: {
+        type: "tool_use",
+        id: "toolu_err",
+        name: "Bash",
+        input: { command: "invalid_command" },
+      },
+    };
+
+    const toolResult: ToolResultBlockParam = {
+      type: "tool_result",
+      tool_use_id: "toolu_err",
+      content: "command not found: invalid_command",
+      is_error: true,
+    };
+
+    const notifications = toAcpNotifications(
+      [toolResult],
+      "assistant",
+      "test-session",
+      toolUseCache,
+      mockClient,
+      mockLogger,
+    );
+
+    expect(notifications).toHaveLength(1);
+    expect(notifications[0].update).toMatchObject({
+      sessionUpdate: "tool_call_update",
+      toolCallId: "toolu_err",
+      status: "failed",
+      rawOutput: "command not found: invalid_command",
+    });
+  });
+
+  it("should not emit tool_call_update for TodoWrite (emits plan instead)", () => {
+    const toolUseCache: ToolUseCache = {
+      toolu_todo: {
+        type: "tool_use",
+        id: "toolu_todo",
+        name: "TodoWrite",
+        input: { todos: [{ content: "Test task", status: "pending" }] },
+      },
+    };
+
+    const toolResult: ToolResultBlockParam = {
+      type: "tool_result",
+      tool_use_id: "toolu_todo",
+      content: "Todos updated successfully",
+      is_error: false,
+    };
+
+    const notifications = toAcpNotifications(
+      [toolResult],
+      "assistant",
+      "test-session",
+      toolUseCache,
+      mockClient,
+      mockLogger,
+    );
+
+    // TodoWrite should not emit tool_call_update - it emits plan updates instead
+    expect(notifications).toHaveLength(0);
+  });
+});

src/tests/typescript-declarations.test.ts

@@ -0,0 +1,558 @@
+import { describe, it, expect, beforeAll, afterAll, beforeEach, afterEach } from "vitest";
+import * as fs from "node:fs";
+import * as path from "node:path";
+import * as os from "node:os";
+import { spawnSync } from "child_process";
+
+describe.skipIf(!process.env.RUN_INTEGRATION_TESTS)(
+  "TypeScript declaration files integration",
+  () => {
+    let tempDir: string;
+    let tarballPath: string;
+    const projectRoot = path.resolve(__dirname, "../..");
+
+    // Base configuration templates
+    const basePackageJson = {
+      name: "ts-declaration-test",
+      version: "1.0.0",
+      type: "module",
+      dependencies: {},
+      devDependencies: {
+        typescript: "5.9.3",
+        "@types/node": "25.0.3",
+      },
+    };
+
+    const baseTsConfig = {
+      compilerOptions: {
+        target: "ES2020",
+        module: "NodeNext",
+        moduleResolution: "NodeNext",
+        lib: ["ES2020"],
+        strict: true,
+        esModuleInterop: true,
+        skipLibCheck: true, // Skip checking dependency internals, focus on our types
+        noEmit: true,
+        declaration: false,
+      },
+      include: ["*.ts"],
+    };
+
+    // Build and pack the package once for all tests
+    beforeAll(async () => {
+      // Step 1: Clean dist folder to ensure fresh build
+      const distPath = path.join(projectRoot, "dist");
+      await fs.promises.rm(distPath, { recursive: true, force: true });
+      console.log("Cleaned dist folder");
+
+      console.log("Building package...");
+
+      // Step 2: Build the package
+      const buildResult = spawnSync("npm", ["run", "build"], {
+        cwd: projectRoot,
+        stdio: "pipe",
+        encoding: "utf-8",
+      });
+
+      if (buildResult.status !== 0) {
+        throw new Error(`Build failed: ${buildResult.stderr || buildResult.stdout}`);
+      }
+
+      console.log("Packing package...");
+
+      // Step 3: Pack to create tarball
+      const packResult = spawnSync("npm", ["pack", "--pack-destination", os.tmpdir()], {
+        cwd: projectRoot,
+        stdio: "pipe",
+        encoding: "utf-8",
+      });
+
+      if (packResult.status !== 0) {
+        throw new Error(`Pack failed: ${packResult.stderr || packResult.stdout}`);
+      }
+
+      // Get the tarball filename from stdout (npm pack outputs the filename)
+      const tarballName = packResult.stdout.trim().split("\n").pop();
+      if (!tarballName) {
+        throw new Error("Failed to get tarball name from npm pack output");
+      }
+      tarballPath = path.join(os.tmpdir(), tarballName);
+
+      console.log(`Tarball created at: ${tarballPath}`);
+    }, 60000); // 60 second timeout for build
+
+    // Clean up the tarball after all tests
+    afterAll(async () => {
+      if (tarballPath && fs.existsSync(tarballPath)) {
+        await fs.promises.unlink(tarballPath);
+        console.log("Cleaned up tarball");
+      }
+    });
+
+    // Create fresh temp directory for each test
+    beforeEach(async () => {
+      tempDir = await fs.promises.mkdtemp(path.join(os.tmpdir(), "ts-declaration-test-"));
+    });
+
+    // Clean up temp directory after each test
+    afterEach(async () => {
+      if (tempDir) {
+        await fs.promises.rm(tempDir, { recursive: true, force: true });
+      }
+    });
+
+    // Helper function to set up a test TypeScript project
+    async function setupTestProject(
+      packageJson: object = basePackageJson,
+      tsconfig: object = baseTsConfig,
+    ): Promise<void> {
+      // Write package.json
+      await fs.promises.writeFile(
+        path.join(tempDir, "package.json"),
+        JSON.stringify(packageJson, null, 2),
+      );
+
+      // Write tsconfig.json
+      await fs.promises.writeFile(
+        path.join(tempDir, "tsconfig.json"),
+        JSON.stringify(tsconfig, null, 2),
+      );
+
+      // Install all dependencies (TypeScript, @types/node, and the tarball)
+      console.log(`Installing dependencies in ${tempDir}...`);
+      const installResult = spawnSync("npm", ["install", tarballPath], {
+        cwd: tempDir,
+        stdio: "pipe",
+        encoding: "utf-8",
+        timeout: 60000, // 60 second timeout
+      });
+
+      if (installResult.status !== 0) {
+        throw new Error(`npm install failed: ${installResult.stderr || installResult.stdout}`);
+      }
+    }
+
+    // Helper function to run TypeScript type checking
+    function runTypeCheck(srcDir: string = tempDir): {
+      success: boolean;
+      output: string;
+    } {
+      const result = spawnSync("npx", ["tsc", "--noEmit"], {
+        cwd: srcDir,
+        stdio: "pipe",
+        encoding: "utf-8",
+        timeout: 30000, // 30 second timeout
+      });
+
+      return {
+        success: result.status === 0,
+        output: result.stdout + result.stderr,
+      };
+    }
+
+    // Helper function to write a test TypeScript file
+    async function writeTestFile(filename: string, content: string): Promise<void> {
+      await fs.promises.writeFile(path.join(tempDir, filename), content);
+    }
+
+    // Test 1: Main exports import verification
+    it("should successfully type-check main exports", async () => {
+      await setupTestProject();
+
+      await writeTestFile(
+        "test-main-exports.ts",
+        `
+import {
+  ClaudeAcpAgent,
+  runAcp,
+  toAcpNotifications,
+  streamEventToAcpNotifications,
+  SettingsManager,
+  createMcpServer,
+  loadManagedSettings,
+  applyEnvironmentSettings,
+  nodeToWebReadable,
+  nodeToWebWritable,
+  Pushable,
+  unreachable,
+  toolInfoFromToolUse,
+  planEntries,
+  toolUpdateFromToolResult,
+  createPreToolUseHook,
+  toolNames,
+} from "@zed-industries/claude-code-acp";
+
+// Type-only imports
+import type {
+  ToolUpdateMeta,
+  NewSessionMeta,
+  ClaudeCodeSettings,
+  PermissionSettings,
+  PermissionDecision,
+  PermissionCheckResult,
+  SettingsManagerOptions,
+  ClaudePlanEntry,
+} from "@zed-industries/claude-code-acp";
+
+// Verify exports exist and have expected types
+const _runAcp: typeof runAcp = runAcp;
+const _createMcpServer: typeof createMcpServer = createMcpServer;
+const _toolNames: typeof toolNames = toolNames;
+`,
+      );
+
+      const result = runTypeCheck();
+      if (!result.success) {
+        console.error("TypeScript errors:", result.output);
+      }
+      expect(result.success).toBe(true);
+    }, 120000);
+
+    // Test 2: Deep imports verification (backwards compatibility)
+    it("should successfully type-check deep imports", async () => {
+      await setupTestProject();
+
+      await writeTestFile(
+        "test-deep-imports.ts",
+        `
+// Deep import from dist/tools.js
+import {
+  acpToolNames,
+  EDIT_TOOL_NAMES,
+  ACP_TOOL_NAME_PREFIX,
+  toolInfoFromToolUse,
+  planEntries,
+} from "@zed-industries/claude-code-acp/dist/tools.js";
+
+// Deep import from dist/settings.js
+import {
+  SettingsManager,
+  getManagedSettingsPath,
+} from "@zed-industries/claude-code-acp/dist/settings.js";
+
+// Deep import from dist/utils.js
+import {
+  Pushable,
+  nodeToWebReadable,
+  nodeToWebWritable,
+  loadManagedSettings,
+} from "@zed-industries/claude-code-acp/dist/utils.js";
+
+// Verify types work
+const prefix: string = ACP_TOOL_NAME_PREFIX;
+const editTools: readonly string[] = EDIT_TOOL_NAMES;
+`,
+      );
+
+      const result = runTypeCheck();
+      if (!result.success) {
+        console.error("TypeScript errors:", result.output);
+      }
+      expect(result.success).toBe(true);
+    }, 120000);
+
+    // Test 3: SettingsManager type shape verification
+    it("should verify SettingsManager has correct type shape", async () => {
+      await setupTestProject();
+
+      await writeTestFile(
+        "test-settings-manager.ts",
+        `
+import {
+  SettingsManager,
+  ClaudeCodeSettings,
+  PermissionCheckResult,
+  SettingsManagerOptions
+} from "@zed-industries/claude-code-acp";
+
+// Test constructor signature
+const options: SettingsManagerOptions = {
+  onChange: () => {},
+  logger: { log: console.log, error: console.error },
+};
+declare const cwd: string;
+const manager = new SettingsManager(cwd, options);
+
+// Test method signatures
+async function testMethods() {
+  // initialize returns Promise<void>
+  await manager.initialize();
+
+  // checkPermission returns PermissionCheckResult
+  const result: PermissionCheckResult = manager.checkPermission(
+    "mcp__acp__Read",
+    { file_path: "/some/path" }
+  );
+
+  // Verify decision type
+  const decision: "allow" | "deny" | "ask" = result.decision;
+  const rule: string | undefined = result.rule;
+  const source: "allow" | "deny" | "ask" | undefined = result.source;
+
+  // getSettings returns ClaudeCodeSettings
+  const settings: ClaudeCodeSettings = manager.getSettings();
+
+  // getCwd returns string
+  const currentCwd: string = manager.getCwd();
+
+  // setCwd returns Promise<void>
+  await manager.setCwd("/new/path");
+
+  // dispose returns void
+  manager.dispose();
+}
+`,
+      );
+
+      const result = runTypeCheck();
+      if (!result.success) {
+        console.error("TypeScript errors:", result.output);
+      }
+      expect(result.success).toBe(true);
+    }, 120000);
+
+    // Test 4: ClaudeAcpAgent instantiation and type verification
+    it("should verify ClaudeAcpAgent has correct type shape", async () => {
+      await setupTestProject();
+
+      await writeTestFile(
+        "test-claude-acp-agent.ts",
+        `
+import { ClaudeAcpAgent } from "@zed-industries/claude-code-acp";
+import type { AgentSideConnection } from "@agentclientprotocol/sdk";
+
+// ClaudeAcpAgent should be a class that can be instantiated
+declare const mockConnection: AgentSideConnection;
+declare const mockLogger: { log: (...args: any[]) => void; error: (...args: any[]) => void };
+
+// Test constructor - accepts AgentSideConnection and optional logger
+const agent = new ClaudeAcpAgent(mockConnection, mockLogger);
+
+// Verify it has sessions property
+const sessions: Record<string, any> = agent.sessions;
+
+// Verify it has client property
+const client: AgentSideConnection = agent.client;
+
+// Verify it has logger property
+const logger = agent.logger;
+`,
+      );
+
+      const result = runTypeCheck();
+      if (!result.success) {
+        console.error("TypeScript errors:", result.output);
+      }
+      expect(result.success).toBe(true);
+    }, 120000);
+
+    // Test 5: Type-only exports work correctly
+    it("should verify type-only exports are usable", async () => {
+      await setupTestProject();
+
+      await writeTestFile(
+        "test-type-exports.ts",
+        `
+import type {
+  ClaudeCodeSettings,
+  PermissionSettings,
+  PermissionDecision,
+  PermissionCheckResult,
+  SettingsManagerOptions,
+  ClaudePlanEntry,
+  ToolUpdateMeta,
+  NewSessionMeta,
+} from "@zed-industries/claude-code-acp";
+
+// Test ClaudeCodeSettings shape
+const settings: ClaudeCodeSettings = {
+  permissions: {
+    allow: ["Read"],
+    deny: ["Read(./.env)"],
+    ask: ["Bash"],
+    additionalDirectories: ["/extra"],
+    defaultMode: "default",
+  },
+  env: {
+    API_KEY: "secret",
+  },
+};
+
+// Test PermissionSettings shape
+const perms: PermissionSettings = {
+  allow: ["Read"],
+  deny: ["Write"],
+};
+
+// Test PermissionDecision
+const decisions: PermissionDecision[] = ["allow", "deny", "ask"];
+
+// Test ClaudePlanEntry shape
+const planEntry: ClaudePlanEntry = {
+  content: "Do something",
+  status: "pending",
+  activeForm: "Doing something",
+};
+
+// Test valid status values
+const validStatuses: ClaudePlanEntry["status"][] = [
+  "pending",
+  "in_progress",
+  "completed",
+];
+
+// Test ToolUpdateMeta shape
+const toolMeta: ToolUpdateMeta = {
+  claudeCode: {
+    toolName: "Read",
+    toolResponse: { success: true },
+  },
+};
+
+// Test NewSessionMeta shape
+const sessionMeta: NewSessionMeta = {
+  claudeCode: {
+    options: {},
+  },
+};
+`,
+      );
+
+      const result = runTypeCheck();
+      if (!result.success) {
+        console.error("TypeScript errors:", result.output);
+      }
+      expect(result.success).toBe(true);
+    }, 120000);
+
+    // Test 6: Function signatures verification
+    it("should verify function signatures are correct", async () => {
+      await setupTestProject();
+
+      await writeTestFile(
+        "test-function-signatures.ts",
+        `
+import {
+  runAcp,
+  createMcpServer,
+  toolInfoFromToolUse,
+  planEntries,
+  createPreToolUseHook,
+  loadManagedSettings,
+  applyEnvironmentSettings,
+  SettingsManager,
+} from "@zed-industries/claude-code-acp";
+
+import type { ClaudeCodeSettings } from "@zed-industries/claude-code-acp";
+
+// runAcp should be a function with no parameters that returns void
+const runAcpType: () => void = runAcp;
+
+// toolInfoFromToolUse should accept any and return object with title and kind
+const info = toolInfoFromToolUse({ name: "Read", input: {} });
+const title: string = info.title;
+const kind: string = info.kind;
+
+// planEntries should accept todos array and return array
+const entries = planEntries({
+  todos: [
+    { content: "test", status: "pending", activeForm: "testing" }
+  ]
+});
+// entries should be an array
+const entriesArray: any[] = entries;
+
+// createPreToolUseHook should accept SettingsManager and optional logger
+declare const settingsManager: SettingsManager;
+const hook = createPreToolUseHook(settingsManager, console);
+
+// loadManagedSettings should return ClaudeCodeSettings | null
+const managedSettings: ClaudeCodeSettings | null = loadManagedSettings();
+
+// applyEnvironmentSettings should accept ClaudeCodeSettings and return void
+const applyResult: void = applyEnvironmentSettings({ permissions: {} });
+`,
+      );
+
+      const result = runTypeCheck();
+      if (!result.success) {
+        console.error("TypeScript errors:", result.output);
+      }
+      expect(result.success).toBe(true);
+    }, 120000);
+
+    // Test 7: Pushable generic class verification
+    it("should verify Pushable class works correctly", async () => {
+      await setupTestProject();
+
+      await writeTestFile(
+        "test-pushable.ts",
+        `
+import { Pushable } from "@zed-industries/claude-code-acp";
+
+// Pushable should be a generic class
+const pushable = new Pushable<string>();
+
+// Should have push method
+pushable.push("test");
+
+// Should have end method
+pushable.end();
+
+// Should implement AsyncIterable
+async function consume() {
+  for await (const item of pushable) {
+    const str: string = item;
+  }
+}
+
+// Generic type parameter should work
+const numPushable = new Pushable<number>();
+numPushable.push(42);
+
+interface MyType { id: number; name: string; }
+const customPushable = new Pushable<MyType>();
+customPushable.push({ id: 1, name: "test" });
+`,
+      );
+
+      const result = runTypeCheck();
+      if (!result.success) {
+        console.error("TypeScript errors:", result.output);
+      }
+      expect(result.success).toBe(true);
+    }, 120000);
+
+    // Test 8: Verify incorrect types fail
+    it("should fail type-check with incorrect types", async () => {
+      await setupTestProject();
+
+      await writeTestFile(
+        "test-invalid-types.ts",
+        `
+import { SettingsManager, ClaudeCodeSettings } from "@zed-industries/claude-code-acp";
+
+// This should fail - SettingsManager constructor requires string cwd
+// @ts-expect-error - Testing that wrong argument type fails
+const badManager = new SettingsManager(123);
+
+// This should fail - ClaudeCodeSettings permissions must be an object
+const badSettings: ClaudeCodeSettings = {
+  // @ts-expect-error - Testing that wrong type fails
+  permissions: "not-an-object",
+};
+`,
+      );
+
+      // This test should PASS because we expect tsc to catch these errors
+      // with @ts-expect-error directives
+      const result = runTypeCheck();
+      if (!result.success) {
+        // If it fails, it means @ts-expect-error didn't catch the error
+        // which could mean the types are too permissive
+        console.error("TypeScript errors (expected @ts-expect-error to catch):", result.output);
+      }
+      expect(result.success).toBe(true);
+    }, 120000);
+  },
+);

src/tools.ts

@@ -1,6 +1,29 @@
 import { PlanEntry, ToolCallContent, ToolCallLocation, ToolKind } from "@agentclientprotocol/sdk";
-import { replaceAndCalculateLocation, SYSTEM_REMINDER, toolNames } from "./mcp-server.js";
+import { SYSTEM_REMINDER } from "./mcp-server.js";
+import * as diff from "diff";
 import { ToolResultBlockParam, WebSearchToolResultBlockParam } from "@anthropic-ai/sdk/resources";
+
+const acpUnqualifiedToolNames = {
+  read: "Read",
+  edit: "Edit",
+  write: "Write",
+  bash: "Bash",
+  killShell: "KillShell",
+  bashOutput: "BashOutput",
+};
+
+export const ACP_TOOL_NAME_PREFIX = "mcp__acp__";
+export const acpToolNames = {
+  read: ACP_TOOL_NAME_PREFIX + acpUnqualifiedToolNames.read,
+  edit: ACP_TOOL_NAME_PREFIX + acpUnqualifiedToolNames.edit,
+  write: ACP_TOOL_NAME_PREFIX + acpUnqualifiedToolNames.write,
+  bash: ACP_TOOL_NAME_PREFIX + acpUnqualifiedToolNames.bash,
+  killShell: ACP_TOOL_NAME_PREFIX + acpUnqualifiedToolNames.killShell,
+  bashOutput: ACP_TOOL_NAME_PREFIX + acpUnqualifiedToolNames.bashOutput,
+};
+
+export const EDIT_TOOL_NAMES = [acpToolNames.edit, acpToolNames.write];
+
 import {
   BetaBashCodeExecutionToolResultBlockParam,
   BetaCodeExecutionToolResultBlockParam,
@@ -12,6 +35,7 @@ import {
 } from "@anthropic-ai/sdk/resources/beta.mjs";
 import { HookCallback } from "@anthropic-ai/claude-agent-sdk";
 import { Logger } from "./acp-agent.js";
+import { SettingsManager } from "./settings.js";
 
 interface ToolInfo {
   title: string;
@@ -26,11 +50,7 @@ interface ToolUpdate {
   locations?: ToolCallLocation[];
 }
 
-export function toolInfoFromToolUse(
-  toolUse: any,
-  cachedFileContent: { [key: string]: string },
-  logger: Logger = console,
-): ToolInfo {
+export function toolInfoFromToolUse(toolUse: any): ToolInfo {
   const name = toolUse.name;
   const input = toolUse.input;
 
@@ -75,7 +95,7 @@ export function toolInfoFromToolUse(
       };
 
     case "Bash":
-    case toolNames.bash:
+    case acpToolNames.bash:
       return {
         title: input?.command ? "`" + input.command.replaceAll("`", "\\`") + "`" : "Terminal",
         kind: "execute",
@@ -91,7 +111,7 @@ export function toolInfoFromToolUse(
       };
 
     case "BashOutput":
-    case toolNames.bashOutput:
+    case acpToolNames.bashOutput:
       return {
         title: "Tail Logs",
         kind: "execute",
@@ -99,14 +119,14 @@ export function toolInfoFromToolUse(
       };
 
     case "KillShell":
-    case toolNames.killShell:
+    case acpToolNames.killShell:
       return {
         title: "Kill Process",
         kind: "execute",
         content: [],
       };
 
-    case toolNames.read: {
+    case acpToolNames.read: {
       let limit = "";
       if (input.limit) {
         limit =
@@ -152,30 +172,10 @@ export function toolInfoFromToolUse(
         locations: [],
       };
 
-    case toolNames.edit:
+    case acpToolNames.edit:
     case "Edit": {
       const path = input?.file_path ?? input?.file_path;
-      let oldText = input.old_string ?? null;
-      let newText = input.new_string ?? "";
-      let affectedLines: number[] = [];
 
-      if (path && oldText) {
-        try {
-          const oldContent = cachedFileContent[path] || "";
-          const newContent = replaceAndCalculateLocation(oldContent, [
-            {
-              oldText,
-              newText,
-              replaceAll: false,
-            },
-          ]);
-          oldText = oldContent;
-          newText = newContent.newContent;
-          affectedLines = newContent.lineNumbers;
-        } catch (e) {
-          logger.error(e);
-        }
-      }
       return {
         title: path ? `Edit \`${path}\`` : "Edit",
         kind: "edit",
@@ -185,20 +185,16 @@ export function toolInfoFromToolUse(
                 {
                   type: "diff",
                   path,
-                  oldText,
-                  newText,
+                  oldText: input.old_string ?? null,
+                  newText: input.new_string ?? "",
                 },
               ]
             : [],
-        locations: path
-          ? affectedLines.length > 0
-            ? affectedLines.map((line) => ({ line, path }))
-            : [{ path }]
-          : [],
+        locations: path ? [{ path }] : undefined,
       };
     }
 
-    case toolNames.write: {
+    case acpToolNames.write: {
       let content: ToolCallContent[] = [];
       if (input && input.file_path) {
         content = [
@@ -309,7 +305,9 @@ export function toolInfoFromToolUse(
         label += " -P";
       }
 
-      label += ` "${input.pattern}"`;
+      if (input.pattern) {
+        label += ` "${input.pattern}"`;
+      }
 
       if (input.path) {
         label += ` ${input.path}`;
@@ -418,9 +416,19 @@ export function toolUpdateFromToolResult(
     | BetaToolSearchToolResultBlockParam,
   toolUse: any | undefined,
 ): ToolUpdate {
+  if (
+    "is_error" in toolResult &&
+    toolResult.is_error &&
+    toolResult.content &&
+    toolResult.content.length > 0
+  ) {
+    // Only return errors
+    return toAcpContentUpdate(toolResult.content, true);
+  }
+
   switch (toolUse?.name) {
     case "Read":
-    case toolNames.read:
+    case acpToolNames.read:
       if (Array.isArray(toolResult.content) && toolResult.content.length > 0) {
         return {
           content: toolResult.content.map((content: any) => ({
@@ -449,21 +457,60 @@ export function toolUpdateFromToolResult(
       }
       return {};
 
-    case toolNames.bash:
+    case acpToolNames.edit: {
+      const content: ToolCallContent[] = [];
+      const locations: ToolCallLocation[] = [];
+
+      if (
+        Array.isArray(toolResult.content) &&
+        toolResult.content.length > 0 &&
+        "text" in toolResult.content[0] &&
+        typeof toolResult.content[0].text === "string"
+      ) {
+        const patches = diff.parsePatch(toolResult.content[0].text);
+        console.error(JSON.stringify(patches));
+        for (const { oldFileName, newFileName, hunks } of patches) {
+          for (const { lines, newStart } of hunks) {
+            const oldText = [];
+            const newText = [];
+            for (const line of lines) {
+              if (line.startsWith("-")) {
+                oldText.push(line.slice(1));
+              } else if (line.startsWith("+")) {
+                newText.push(line.slice(1));
+              } else {
+                oldText.push(line.slice(1));
+                newText.push(line.slice(1));
+              }
+            }
+            if (oldText.length > 0 || newText.length > 0) {
+              locations.push({ path: newFileName || oldFileName, line: newStart });
+              content.push({
+                type: "diff",
+                path: newFileName || oldFileName,
+                oldText: oldText.join("\n") || null,
+                newText: newText.join("\n"),
+              });
+            }
+          }
+        }
+      }
+
+      const result: ToolUpdate = {};
+      if (content.length > 0) {
+        result.content = content;
+      }
+      if (locations.length > 0) {
+        result.locations = locations;
+      }
+      return result;
+    }
+
+    case acpToolNames.bash:
     case "edit":
     case "Edit":
-    case toolNames.edit:
-    case toolNames.write:
+    case acpToolNames.write:
     case "Write": {
-      if (
-        "is_error" in toolResult &&
-        toolResult.is_error &&
-        toolResult.content &&
-        toolResult.content.length > 0
-      ) {
-        // Only return errors
-        return toAcpContentUpdate(toolResult.content, true);
-      }
       return {};
     }
 
@@ -596,3 +643,54 @@ export const createPostToolUseHook =
     }
     return { continue: true };
   };
+
+/**
+ * Creates a PreToolUse hook that checks permissions using the SettingsManager.
+ * This runs before the SDK's built-in permission rules, allowing us to enforce
+ * our own permission settings for ACP-prefixed tools.
+ */
+export const createPreToolUseHook =
+  (settingsManager: SettingsManager, logger: Logger = console): HookCallback =>
+  async (input: any, _toolUseID: string | undefined) => {
+    if (input.hook_event_name !== "PreToolUse") {
+      return { continue: true };
+    }
+
+    const toolName = input.tool_name;
+    const toolInput = input.tool_input;
+
+    const permissionCheck = settingsManager.checkPermission(toolName, toolInput);
+
+    if (permissionCheck.decision !== "ask") {
+      logger.log(
+        `[PreToolUseHook] Tool: ${toolName}, Decision: ${permissionCheck.decision}, Rule: ${permissionCheck.rule}`,
+      );
+    }
+
+    switch (permissionCheck.decision) {
+      case "allow":
+        return {
+          continue: true,
+          hookSpecificOutput: {
+            hookEventName: "PreToolUse" as const,
+            permissionDecision: "allow" as const,
+            permissionDecisionReason: `Allowed by settings rule: ${permissionCheck.rule}`,
+          },
+        };
+
+      case "deny":
+        return {
+          continue: true,
+          hookSpecificOutput: {
+            hookEventName: "PreToolUse" as const,
+            permissionDecision: "deny" as const,
+            permissionDecisionReason: `Denied by settings rule: ${permissionCheck.rule}`,
+          },
+        };
+
+      case "ask":
+      default:
+        // Let the normal permission flow continue
+        return { continue: true };
+    }
+  };

src/utils.ts

@@ -3,8 +3,8 @@
 import { Readable, Writable } from "node:stream";
 import { WritableStream, ReadableStream } from "node:stream/web";
 import { readFileSync } from "node:fs";
-import { platform } from "node:os";
 import { Logger } from "./acp-agent.js";
+import { ClaudeCodeSettings, getManagedSettingsPath } from "./settings.js";
 
 // Useful for bridging push-based and async-iterator-based code.
 export class Pushable<T> implements AsyncIterable<T> {
@@ -90,39 +90,15 @@ export function sleep(time: number): Promise<void> {
   return new Promise((resolve) => setTimeout(resolve, time));
 }
 
-interface ManagedSettings {
-  permissions?: {
-    allow?: string[];
-    deny?: string[];
-  };
-  env?: Record<string, string>;
-}
-
-// Following the rules in https://docs.anthropic.com/en/docs/claude-code/settings#settings-files
-// This can be removed once the SDK supports it natively.
-function getManagedSettingsPath(): string {
-  const os = platform();
-  switch (os) {
-    case "darwin":
-      return "/Library/Application Support/ClaudeCode/managed-settings.json";
-    case "linux": // including WSL
-      return "/etc/claude-code/managed-settings.json";
-    case "win32":
-      return "C:\\ProgramData\\ClaudeCode\\managed-settings.json";
-    default:
-      return "/etc/claude-code/managed-settings.json";
-  }
-}
-
-export function loadManagedSettings(): ManagedSettings | null {
+export function loadManagedSettings(): ClaudeCodeSettings | null {
   try {
-    return JSON.parse(readFileSync(getManagedSettingsPath(), "utf8")) as ManagedSettings;
+    return JSON.parse(readFileSync(getManagedSettingsPath(), "utf8")) as ClaudeCodeSettings;
   } catch {
     return null;
   }
 }
 
-export function applyEnvironmentSettings(settings: ManagedSettings): void {
+export function applyEnvironmentSettings(settings: ClaudeCodeSettings): void {
   if (settings.env) {
     for (const [key, value] of Object.entries(settings.env)) {
       process.env[key] = value;

tsconfig.json

@@ -9,7 +9,9 @@
     "forceConsistentCasingInFileNames": true,
     "skipLibCheck": true,
     "outDir": "dist",
-    "rootDir": "src"
+    "rootDir": "src",
+    "declaration": true,
+    "declarationMap": true
   },
   "include": ["src/**/*.ts"],
   "exclude": ["node_modules", "dist"]