Add session/close support (#409)

~Waiting for
https://github.com/agentclientprotocol/agent-client-protocol/pull/723.~

---------

Co-authored-by: Ben Brandt <benjamin.j.brandt@gmail.com>

package-lock.json

@@ -9,7 +9,7 @@
       "version": "0.21.0",
       "license": "Apache-2.0",
       "dependencies": {
-        "@agentclientprotocol/sdk": "0.15.0",
+        "@agentclientprotocol/sdk": "0.16.1",
         "@anthropic-ai/claude-agent-sdk": "0.2.71",
         "zod": "^3.25.0 || ^4.0.0"
       },
@@ -33,9 +33,9 @@
       }
     },
     "node_modules/@agentclientprotocol/sdk": {
-      "version": "0.15.0",
-      "resolved": "https://registry.npmjs.org/@agentclientprotocol/sdk/-/sdk-0.15.0.tgz",
-      "integrity": "sha512-TH4utu23Ix8ec34srBHmDD4p3HI0cYleS1jN9lghRczPfhFlMBNrQgZWeBBe12DWy27L11eIrtciY2MXFSEiDg==",
+      "version": "0.16.1",
+      "resolved": "https://registry.npmjs.org/@agentclientprotocol/sdk/-/sdk-0.16.1.tgz",
+      "integrity": "sha512-1ad+Sc/0sCtZGHthxxvgEUo5Wsbw16I+aF+YwdiLnPwkZG8KAGUEAPK6LM6Pf69lCyJPt1Aomk1d+8oE3C4ZEw==",
       "license": "Apache-2.0",
       "peerDependencies": {
         "zod": "^3.25.0 || ^4.0.0"

package.json

@@ -60,7 +60,7 @@
   "author": "Zed Industries",
   "license": "Apache-2.0",
   "dependencies": {
-    "@agentclientprotocol/sdk": "0.15.0",
+    "@agentclientprotocol/sdk": "0.16.1",
     "@anthropic-ai/claude-agent-sdk": "0.2.71",
     "zod": "^3.25.0 || ^4.0.0"
   },

src/acp-agent.ts

@@ -34,6 +34,8 @@ import {
   SetSessionModelResponse,
   SetSessionModeRequest,
   SetSessionModeResponse,
+  CloseSessionRequest,
+  CloseSessionResponse,
   TerminalHandle,
   TerminalOutputResponse,
   WriteTextFileRequest,
@@ -117,6 +119,7 @@ type Session = {
   promptRunning: boolean;
   pendingMessages: Map<string, { resolve: (cancelled: boolean) => void; order: number }>;
   nextPendingOrder: number;
+  abortController: AbortController;
 };
 
 type BackgroundTerminal =
@@ -338,6 +341,7 @@ export class ClaudeAcpAgent implements Agent {
           fork: {},
           list: {},
           resume: {},
+          close: {},
         },
       },
       agentInfo: {
@@ -844,6 +848,19 @@ export class ClaudeAcpAgent implements Agent {
     await session.query.interrupt();
   }
 
+  async unstable_sessionClose(params: CloseSessionRequest): Promise<CloseSessionResponse> {
+    const session = this.sessions[params.sessionId];
+    if (!session) {
+      throw new Error("Session not found");
+    }
+    await this.cancel({ sessionId: params.sessionId });
+
+    session.abortController.abort();
+    delete this.sessions[params.sessionId];
+
+    return {};
+  }
+
   async unstable_setSessionModel(
     params: SetSessionModelRequest,
   ): Promise<SetSessionModelResponse | void> {
@@ -871,6 +888,9 @@ export class ClaudeAcpAgent implements Agent {
     if (!session) {
       throw new Error("Session not found");
     }
+    if (typeof params.value !== "string") {
+      throw new Error(`Invalid value for config option ${params.configId}: ${params.value}`);
+    }
 
     const option = session.configOptions.find((o) => o.id === params.configId);
     if (!option) {
@@ -900,7 +920,9 @@ export class ClaudeAcpAgent implements Agent {
     }
 
     session.configOptions = session.configOptions.map((o) =>
-      o.id === params.configId ? { ...o, currentValue: params.value } : o,
+      o.id === params.configId && typeof o.currentValue === "string"
+        ? { ...o, currentValue: params.value }
+        : o,
     );
 
     return { configOptions: session.configOptions };
@@ -1125,7 +1147,7 @@ export class ClaudeAcpAgent implements Agent {
     if (!session) return;
 
     session.configOptions = session.configOptions.map((o) =>
-      o.id === configId ? { ...o, currentValue: value } : o,
+      o.id === configId && typeof o.currentValue === "string" ? { ...o, currentValue: value } : o,
     );
 
     await this.client.sessionUpdate({
@@ -1220,6 +1242,8 @@ export class ClaudeAcpAgent implements Agent {
       userProvidedOptions?.tools ??
       (params._meta?.disableBuiltInTools === true ? [] : { type: "preset", preset: "claude_code" });
 
+    const abortController = userProvidedOptions?.abortController || new AbortController();
+
     const options: Options = {
       systemPrompt,
       settingSources: ["user", "project", "local"],
@@ -1280,6 +1304,7 @@ export class ClaudeAcpAgent implements Agent {
         ],
       },
       ...creationOpts,
+      abortController,
     };
 
     if (creationOpts?.resume === undefined || creationOpts?.forkSession) {
@@ -1288,7 +1313,6 @@ export class ClaudeAcpAgent implements Agent {
     }
 
     // Handle abort controller from meta options
-    const abortController = userProvidedOptions?.abortController;
     if (abortController?.signal.aborted) {
       throw new Error("Cancelled");
     }
@@ -1376,6 +1400,7 @@ export class ClaudeAcpAgent implements Agent {
       promptRunning: false,
       pendingMessages: new Map(),
       nextPendingOrder: 0,
+      abortController,
     };
 
     return {

src/tests/acp-agent.test.ts

@@ -1,4 +1,4 @@
-import { describe, it, expect, beforeAll, afterAll } from "vitest";
+import { describe, it, expect, beforeAll, afterAll, vi } from "vitest";
 import { spawn, spawnSync } from "child_process";
 import {
   Agent,
@@ -1328,6 +1328,7 @@ describe("stop reason propagation", () => {
       promptRunning: false,
       pendingMessages: new Map(),
       nextPendingOrder: 0,
+      abortController: new AbortController(),
     };
   }
 
@@ -1416,3 +1417,80 @@ describe("stop reason propagation", () => {
     ).rejects.toThrow("Internal error");
   });
 });
+
+describe("session/close", () => {
+  function createMockAgent() {
+    const mockClient = {
+      sessionUpdate: async () => {},
+    } as unknown as AgentSideConnection;
+    return new ClaudeAcpAgent(mockClient, { log: () => {}, error: () => {} });
+  }
+
+  function injectSession(agent: ClaudeAcpAgent, sessionId: string) {
+    function* empty() {}
+    const gen = Object.assign(empty(), { interrupt: vi.fn() });
+    agent.sessions[sessionId] = {
+      query: gen as any,
+      input: new Pushable(),
+      cancelled: false,
+      cwd: "/test",
+      permissionMode: "default",
+      settingsManager: {} as any,
+      accumulatedUsage: {
+        inputTokens: 0,
+        outputTokens: 0,
+        cachedReadTokens: 0,
+        cachedWriteTokens: 0,
+      },
+      configOptions: [],
+      promptRunning: false,
+      pendingMessages: new Map(),
+      nextPendingOrder: 0,
+      abortController: new AbortController(),
+    };
+    return agent.sessions[sessionId]!;
+  }
+
+  it("should close an existing session and remove it", async () => {
+    const agent = createMockAgent();
+    const session = injectSession(agent, "session-1");
+
+    expect(agent.sessions["session-1"]).toBeDefined();
+
+    const result = await agent.unstable_sessionClose({ sessionId: "session-1" });
+
+    expect(result).toEqual({});
+    expect(agent.sessions["session-1"]).toBeUndefined();
+    expect(session.query.interrupt).toHaveBeenCalled();
+  });
+
+  it("should abort the session's abort controller", async () => {
+    const agent = createMockAgent();
+    const session = injectSession(agent, "session-2");
+
+    expect(session.abortController.signal.aborted).toBe(false);
+
+    await agent.unstable_sessionClose({ sessionId: "session-2" });
+
+    expect(session.abortController.signal.aborted).toBe(true);
+  });
+
+  it("should throw when closing a non-existent session", async () => {
+    const agent = createMockAgent();
+
+    await expect(agent.unstable_sessionClose({ sessionId: "non-existent" })).rejects.toThrow(
+      "Session not found",
+    );
+  });
+
+  it("should not affect other sessions when closing one", async () => {
+    const agent = createMockAgent();
+    injectSession(agent, "session-a");
+    injectSession(agent, "session-b");
+
+    await agent.unstable_sessionClose({ sessionId: "session-a" });
+
+    expect(agent.sessions["session-a"]).toBeUndefined();
+    expect(agent.sessions["session-b"]).toBeDefined();
+  });
+});