prep v0.10.0 (#140)

- **Migrate from permission MCP server to canUseTool callback**
- **Use SDK suggestions for permission updates**

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## 0.10.0
+
+- Update to @anthropic-ai/claude-agent-sdk@v0.1.30
+- Use `canUseTool` callback instead of launching an HTTP MCP server for permission checks.
+
 ## 0.9.0
 
 - Support slash commands coming from MCP servers (Prompts)

docs/RELEASES.md

@@ -0,0 +1,24 @@
+## How to publish a new release
+
+1. Create a new branch prep-vX.X.X
+
+```sh
+git checkout -b prep-vX.X.X
+```
+
+2. Bump the version in package.json
+
+```sh
+npm version vX.X.X
+```
+
+3. Add a new entry in CHANGELOG.md
+4. Create a PR for `prev-vX.X.X` & merge it
+5. Create tag and push it
+
+```sh
+git tag vX.X.X
+git push origin vX.X.X
+```
+
+6. Paste CHANGELOG into release notes and publish the version on GitHub

package.json

@@ -3,7 +3,7 @@
   "publishConfig": {
     "access": "public"
   },
-  "version": "0.9.0",
+  "version": "0.10.0",
   "description": "An ACP-compatible coding agent powered by the Claude Code SDK (TypeScript)",
   "main": "dist/lib.js",
   "bin": {
@@ -52,29 +52,25 @@
   "license": "Apache-2.0",
   "dependencies": {
     "@agentclientprotocol/sdk": "0.5.1",
-    "@anthropic-ai/claude-agent-sdk": "0.1.27",
-    "@anthropic-ai/claude-code": "2.0.27",
-    "@modelcontextprotocol/sdk": "1.20.2",
+    "@anthropic-ai/claude-agent-sdk": "0.1.30",
+    "@anthropic-ai/claude-code": "2.0.32",
+    "@modelcontextprotocol/sdk": "1.21.0",
     "diff": "8.0.2",
-    "express": "5.1.0",
-    "minimist": "1.2.8",
     "uuid": "13.0.0"
   },
   "devDependencies": {
-    "@anthropic-ai/sdk": "0.67.0",
-    "@types/express": "5.0.4",
-    "@types/minimist": "1.2.5",
-    "@types/node": "24.9.1",
+    "@anthropic-ai/sdk": "0.68.0",
+    "@types/node": "24.10.0",
     "@types/uuid": "10.0.0",
-    "@typescript-eslint/eslint-plugin": "8.46.2",
-    "@typescript-eslint/parser": "8.46.2",
-    "@vitest/ui": "4.0.3",
-    "eslint": "9.38.0",
+    "@typescript-eslint/eslint-plugin": "8.46.3",
+    "@typescript-eslint/parser": "8.46.3",
+    "@vitest/ui": "4.0.6",
+    "eslint": "9.39.1",
     "eslint-config-prettier": "10.1.8",
-    "globals": "16.4.0",
+    "globals": "16.5.0",
     "prettier": "3.6.2",
     "ts-node": "10.9.2",
     "typescript": "5.9.3",
-    "vitest": "4.0.3"
+    "vitest": "4.0.6"
   }
 }

src/acp-agent.ts

@@ -26,6 +26,7 @@ import {
   WriteTextFileResponse,
 } from "@agentclientprotocol/sdk";
 import {
+  CanUseTool,
   McpServerConfig,
   Options,
   PermissionMode,
@@ -40,13 +41,7 @@ import * as os from "node:os";
 import { v7 as uuidv7 } from "uuid";
 import { nodeToWebReadable, nodeToWebWritable, Pushable, unreachable } from "./utils.js";
 import { SessionNotification } from "@agentclientprotocol/sdk";
-import {
-  createMcpServer,
-  createPermissionMcpServer,
-  PERMISSION_TOOL_NAME,
-  toolNames,
-} from "./mcp-server.js";
-import { AddressInfo } from "node:net";
+import { createMcpServer, EDIT_TOOL_NAMES, toolNames } from "./mcp-server.js";
 import {
   toolInfoFromToolUse,
   planEntries,
@@ -177,17 +172,6 @@ export class ClaudeAcpAgent implements Agent {
       instance: server,
     };
 
-    // Ideally replace with `canUseTool`
-    const permissionServer = await createPermissionMcpServer(this, sessionId);
-    const address = permissionServer.address() as AddressInfo;
-    mcpServers["acpPermission"] = {
-      type: "http",
-      url: "http://127.0.0.1:" + address.port + "/mcp",
-      headers: {
-        "x-acp-proxy-session-id": sessionId,
-      },
-    };
-
     let systemPrompt: Options["systemPrompt"] = { type: "preset", preset: "claude_code" };
     if (params._meta?.systemPrompt) {
       const customPrompt = params._meta.systemPrompt;
@@ -214,7 +198,7 @@ export class ClaudeAcpAgent implements Agent {
       // But it doesn't work in root mode, so we only activate it if it will work.
       allowDangerouslySkipPermissions: !IS_ROOT,
       permissionMode,
-      permissionPromptToolName: PERMISSION_TOOL_NAME,
+      canUseTool: this.canUseTool(sessionId),
       stderr: (err) => console.error(err),
       // note: although not documented by the types, passing an absolute path
       // here works to find zed's managed node version.
@@ -431,6 +415,10 @@ export class ClaudeAcpAgent implements Agent {
           }
           break;
         }
+        case "tool_progress":
+          break;
+        case "auth_status":
+          break;
         default:
           unreachable(message);
       }
@@ -491,6 +479,126 @@ export class ClaudeAcpAgent implements Agent {
     this.fileContentCache[params.path] = params.content;
     return response;
   }
+
+  canUseTool(sessionId: string): CanUseTool {
+    return async (toolName, toolInput, { suggestions, toolUseID }) => {
+      const session = this.sessions[sessionId];
+      if (!session) {
+        return {
+          behavior: "deny",
+          message: "Session not found",
+          interrupt: true,
+        };
+      }
+
+      if (toolName === "ExitPlanMode") {
+        const response = await this.client.requestPermission({
+          options: [
+            {
+              kind: "allow_always",
+              name: "Yes, and auto-accept edits",
+              optionId: "acceptEdits",
+            },
+            { kind: "allow_once", name: "Yes, and manually approve edits", optionId: "default" },
+            { kind: "reject_once", name: "No, keep planning", optionId: "plan" },
+          ],
+          sessionId,
+          toolCall: {
+            toolCallId: toolUseID,
+            rawInput: toolInput,
+          },
+        });
+
+        if (
+          response.outcome?.outcome === "selected" &&
+          (response.outcome.optionId === "default" || response.outcome.optionId === "acceptEdits")
+        ) {
+          session.permissionMode = response.outcome.optionId;
+          await this.client.sessionUpdate({
+            sessionId,
+            update: {
+              sessionUpdate: "current_mode_update",
+              currentModeId: response.outcome.optionId,
+            },
+          });
+
+          return {
+            behavior: "allow",
+            updatedInput: toolInput,
+            updatedPermissions: suggestions ?? [
+              { type: "setMode", mode: response.outcome.optionId, destination: "session" },
+            ],
+          };
+        } else {
+          return {
+            behavior: "deny",
+            message: "User rejected request to exit plan mode.",
+            interrupt: true,
+          };
+        }
+      }
+
+      if (
+        session.permissionMode === "bypassPermissions" ||
+        (session.permissionMode === "acceptEdits" && EDIT_TOOL_NAMES.includes(toolName))
+      ) {
+        return {
+          behavior: "allow",
+          updatedInput: toolInput,
+          updatedPermissions: suggestions ?? [
+            { type: "addRules", rules: [{ toolName }], behavior: "allow", destination: "session" },
+          ],
+        };
+      }
+
+      const response = await this.client.requestPermission({
+        options: [
+          {
+            kind: "allow_always",
+            name: "Always Allow",
+            optionId: "allow_always",
+          },
+          { kind: "allow_once", name: "Allow", optionId: "allow" },
+          { kind: "reject_once", name: "Reject", optionId: "reject" },
+        ],
+        sessionId,
+        toolCall: {
+          toolCallId: toolUseID,
+          rawInput: toolInput,
+        },
+      });
+      if (
+        response.outcome?.outcome === "selected" &&
+        (response.outcome.optionId === "allow" || response.outcome.optionId === "allow_always")
+      ) {
+        // If Claude Code has suggestions, it will update their settings already
+        if (response.outcome.optionId === "allow_always") {
+          return {
+            behavior: "allow",
+            updatedInput: toolInput,
+            updatedPermissions: suggestions ?? [
+              {
+                type: "addRules",
+                rules: [{ toolName }],
+                behavior: "allow",
+                destination: "session",
+              },
+            ],
+          };
+        }
+        return {
+          behavior: "allow",
+          updatedInput: toolInput,
+        };
+      } else {
+        return {
+          behavior: "deny",
+          message: "User refused permission to run tool",
+          interrupt: true,
+        };
+      }
+    };
+  }
 }
 
 async function getAvailableModels(query: Query): Promise<SessionModelState> {

src/lib.ts

@@ -13,12 +13,7 @@ export {
   Pushable,
   unreachable,
 } from "./utils.js";
-export {
-  createMcpServer,
-  createPermissionMcpServer,
-  PERMISSION_TOOL_NAME,
-  toolNames,
-} from "./mcp-server.js";
+export { createMcpServer, toolNames } from "./mcp-server.js";
 export { toolInfoFromToolUse, planEntries, toolUpdateFromToolResult } from "./tools.js";
 
 // Export types

src/mcp-server.ts

@@ -1,15 +1,10 @@
-import express from "express";
-
 import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
 import { z } from "zod";
-import { Server } from "node:http";
 import { ClaudeAcpAgent } from "./acp-agent.js";
 import { ClientCapabilities, TerminalOutputResponse } from "@agentclientprotocol/sdk";
 import * as diff from "diff";
 
 import { sleep, unreachable, extractLinesWithByteLimit } from "./utils.js";
-import { PermissionResult } from "@anthropic-ai/claude-agent-sdk";
 
 export const SYSTEM_REMINDER = `
 
@@ -38,7 +33,7 @@ export const toolNames = {
   bashOutput: SERVER_PREFIX + unqualifiedToolNames.bashOutput,
 };
 
-const editToolNames = [toolNames.edit, toolNames.write];
+export const EDIT_TOOL_NAMES = [toolNames.edit, toolNames.write];
 
 export function createMcpServer(
   agent: ClaudeAcpAgent,
@@ -578,189 +573,6 @@ In sessions with ${toolNames.killShell} always use it instead of KillShell.`,
   return server;
 }
 
-const UNQUALIFIED_PERMISSION_TOOL_NAME = "permission";
-const PERMISSION_SERVER_PREFIX = "mcp__acpPermission__";
-export const PERMISSION_TOOL_NAME = PERMISSION_SERVER_PREFIX + UNQUALIFIED_PERMISSION_TOOL_NAME;
-
-/**
- * Separate permission tool. Needs to be an HTTP server for now, because Claude Code doesn't
- * support permission tools via SDK servers.
- * Ideally it moves to the `canUseTool` callback in the future.
- */
-export function createPermissionMcpServer(
-  agent: ClaudeAcpAgent,
-  sessionId: string,
-): Promise<Server> {
-  const server = new McpServer(
-    { name: "acpPermission", version: "1.0.0" },
-    { capabilities: { tools: {} } },
-  );
-
-  const alwaysAllowedTools: { [key: string]: boolean } = {};
-  server.registerTool(
-    UNQUALIFIED_PERMISSION_TOOL_NAME,
-    {
-      title: "Permission Tool",
-      description: "Used to request tool permissions",
-      inputSchema: {
-        tool_name: z.string(),
-        input: z.any(),
-        tool_use_id: z.string().optional(),
-      },
-    },
-    async (input) => {
-      const result = await canUseTool(input);
-
-      return {
-        content: [{ type: "text", text: JSON.stringify(result) }],
-      };
-    },
-  );
-
-  async function canUseTool(input: {
-    tool_use_id?: string;
-    tool_name: string;
-    input?: any;
-  }): Promise<PermissionResult> {
-    const session = agent.sessions[sessionId];
-    if (!session) {
-      return {
-        behavior: "deny",
-        message: "Session not found",
-      };
-    }
-
-    if (input.tool_name === "ExitPlanMode") {
-      const response = await agent.client.requestPermission({
-        options: [
-          {
-            kind: "allow_always",
-            name: "Yes, and auto-accept edits",
-            optionId: "acceptEdits",
-          },
-          { kind: "allow_once", name: "Yes, and manually approve edits", optionId: "default" },
-          { kind: "reject_once", name: "No, keep planning", optionId: "plan" },
-        ],
-        sessionId,
-        toolCall: {
-          toolCallId: input.tool_use_id!,
-          rawInput: input.input,
-        },
-      });
-
-      if (
-        response.outcome?.outcome === "selected" &&
-        (response.outcome.optionId === "default" || response.outcome.optionId === "acceptEdits")
-      ) {
-        session.permissionMode = response.outcome.optionId;
-        await agent.client.sessionUpdate({
-          sessionId,
-          update: {
-            sessionUpdate: "current_mode_update",
-            currentModeId: response.outcome.optionId,
-          },
-        });
-
-        return {
-          behavior: "allow",
-          updatedInput: input.input,
-          updatedPermissions: [
-            { type: "setMode", mode: response.outcome.optionId, destination: "session" },
-          ],
-        };
-      } else {
-        return {
-          behavior: "deny",
-          message: "User rejected request to exit plan mode.",
-        };
-      }
-    }
-
-    if (
-      session.permissionMode === "bypassPermissions" ||
-      (session.permissionMode === "acceptEdits" && editToolNames.includes(input.tool_name)) ||
-      alwaysAllowedTools[input.tool_name]
-    ) {
-      return {
-        behavior: "allow",
-        updatedInput: input.input,
-      };
-    }
-
-    const response = await agent.client.requestPermission({
-      options: [
-        {
-          kind: "allow_always",
-          name: "Always Allow",
-          optionId: "allow_always",
-        },
-        { kind: "allow_once", name: "Allow", optionId: "allow" },
-        { kind: "reject_once", name: "Reject", optionId: "reject" },
-      ],
-      sessionId,
-      toolCall: {
-        toolCallId: input.tool_use_id!,
-        rawInput: input.input,
-      },
-    });
-    if (
-      response.outcome?.outcome === "selected" &&
-      (response.outcome.optionId === "allow" || response.outcome.optionId === "allow_always")
-    ) {
-      if (response.outcome.optionId === "allow_always") {
-        alwaysAllowedTools[input.tool_name] = true;
-      }
-      return {
-        behavior: "allow",
-        updatedInput: input.input,
-      };
-    } else {
-      return {
-        behavior: "deny",
-        message: "User refused permission to run tool",
-      };
-    }
-  }
-
-  const app = express();
-  app.use(express.json());
-
-  app.post("/mcp", async (req, res) => {
-    try {
-      const transport: StreamableHTTPServerTransport = new StreamableHTTPServerTransport({
-        sessionIdGenerator: undefined,
-      });
-      res.on("close", () => {
-        transport.close();
-        server.close();
-      });
-      await server.connect(transport);
-      await transport.handleRequest(req, res, req.body);
-    } catch (error) {
-      if (!res.headersSent) {
-        res.status(500).json({
-          jsonrpc: "2.0",
-          error: {
-            code: -32603,
-            message: `Internal server error: ${error}`,
-          },
-          id: null,
-        });
-      }
-    }
-  });
-
-  return new Promise((resolve, reject) => {
-    const listener = app.listen(0, "127.0.0.1", (error) => {
-      if (error) {
-        reject(error);
-        return;
-      }
-      resolve(listener);
-    });
-  });
-}
-
 function stripCommonPrefix(a: string, b: string): string {
   let i = 0;
   while (i < a.length && i < b.length && a[i] === b[i]) {