feat(cli): port ACP to V2 (#37907)

packages/cli/src/commands/commands.ts

@@ -34,6 +34,7 @@ export const Commands = Spec.make(typeof OPENCODE_CLI_NAME === "string" ? OPENCO
     ),
   },
   commands: [
+    Spec.make("acp", { description: "Start an Agent Client Protocol server" }),
     Spec.make("api", {
       description: "Make a request to the running server",
       params: {

packages/cli/src/commands/handlers/acp.ts

@@ -0,0 +1,36 @@
+import { AgentSideConnection, ndJsonStream } from "@agentclientprotocol/sdk"
+import { OpenCode } from "@opencode-ai/client/promise"
+import { Service } from "@opencode-ai/client/effect/service"
+import { Effect } from "effect"
+import { ACP } from "../../acp/agent"
+import { Commands } from "../commands"
+import { Runtime } from "../../framework/runtime"
+import { Standalone } from "../../services/standalone"
+
+export default Runtime.handler(
+  Commands.commands.acp,
+  Effect.fn("cli.acp")(function* () {
+    process.env.OPENCODE_CLIENT = "acp"
+    const endpoint = yield* Standalone.start()
+    const client = OpenCode.make({ baseUrl: endpoint.url, headers: Service.headers(endpoint) })
+    const input = new WritableStream<Uint8Array>({
+      write: (chunk) =>
+        new Promise<void>((resolve, reject) => {
+          process.stdout.write(chunk, (error) => (error ? reject(error) : resolve()))
+        }),
+    })
+    const output = new ReadableStream<Uint8Array>({
+      start(controller) {
+        process.stdin.on("data", (chunk: Buffer) => controller.enqueue(new Uint8Array(chunk)))
+        process.stdin.on("end", () => controller.close())
+        process.stdin.on("error", (error) => controller.error(error))
+      },
+    })
+    const stream = ndJsonStream(input, output)
+    const connection = new AgentSideConnection((connection) => ACP.create(client, connection), stream)
+    process.stdin.resume()
+    yield* Effect.promise(() => connection.closed)
+    // EOF owns this stdio process; exiting also closes the private server's lease pipe.
+    yield* Effect.sync(() => process.exit(0))
+  }),
+)