From de3b68740aa9d8c26286454bc760f8fd58724384 Mon Sep 17 00:00:00 2001
From: Peter Steinberger <steipete@gmail.com>
Date: Sun, 18 Jan 2026 08:02:42 +0000
Subject: [PATCH] feat(acp): add experimental ACP support

Co-authored-by: Jonathan Taylor <visionik@pobox.com>
---
 CHANGELOG.md                              |   1 +
 docs.acp.md                               | 194 ++++++++++
 docs/cli/acp.md                           | 143 +++++++
 docs/cli/index.md                         |   7 +
 docs/debugging.md                         |   1 +
 package.json                              |   5 +-
 pnpm-lock.yaml                            |  12 +
 src/acp/commands.ts                       |  40 ++
 src/acp/event-mapper.test.ts              |  34 ++
 src/acp/event-mapper.ts                   |  73 ++++
 src/acp/index.ts                          |   4 +
 src/acp/meta.ts                           |  35 ++
 src/acp/server.ts                         | 149 ++++++++
 src/acp/session-mapper.test.ts            |  57 +++
 src/acp/session-mapper.ts                 |  95 +++++
 src/acp/session.test.ts                   |  26 ++
 src/acp/session.ts                        |  93 +++++
 src/acp/translator.ts                     | 433 ++++++++++++++++++++++
 src/acp/types.ts                          |  30 ++
 src/cli/acp-cli.ts                        |  43 +++
 src/cli/program/register.subclis.ts       |   2 +
 src/gateway/server-bridge-methods-chat.ts |   3 +
 src/gateway/server-methods/chat.ts        |   3 +
 src/routing/session-key.ts                |  39 +-
 src/sessions/session-key-utils.ts         |  35 ++
 25 files changed, 1528 insertions(+), 29 deletions(-)
 create mode 100644 docs.acp.md
 create mode 100644 docs/cli/acp.md
 create mode 100644 src/acp/commands.ts
 create mode 100644 src/acp/event-mapper.test.ts
 create mode 100644 src/acp/event-mapper.ts
 create mode 100644 src/acp/index.ts
 create mode 100644 src/acp/meta.ts
 create mode 100644 src/acp/server.ts
 create mode 100644 src/acp/session-mapper.test.ts
 create mode 100644 src/acp/session-mapper.ts
 create mode 100644 src/acp/session.test.ts
 create mode 100644 src/acp/session.ts
 create mode 100644 src/acp/translator.ts
 create mode 100644 src/acp/types.ts
 create mode 100644 src/cli/acp-cli.ts
 create mode 100644 src/sessions/session-key-utils.ts

diff --git a/CHANGELOG.md b/CHANGELOG.md
index ff991ce05..949a6333b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -23,6 +23,7 @@ Docs: https://docs.clawd.bot
 - Sessions: add daily reset policy with per-type overrides and idle windows (default 4am local), preserving legacy idle-only configs. (#1146) — thanks @austinm911.
 - Docs: refresh exec/elevated/exec-approvals docs for the new flow. https://docs.clawd.bot/tools/exec-approvals
 - Docs: add node host CLI + update exec approvals/bridge protocol docs. https://docs.clawd.bot/cli/node
+- ACP: add experimental ACP support for IDE integrations (`clawdbot acp`). Thanks @visionik.
 
 ### Fixes
 - Exec approvals: enforce allowlist when ask is off; prefer raw command for node approvals/events.
diff --git a/docs.acp.md b/docs.acp.md
new file mode 100644
index 000000000..ca664134e
--- /dev/null
+++ b/docs.acp.md
@@ -0,0 +1,194 @@
+# Clawdbot ACP Bridge
+
+This document describes how the Clawdbot ACP (Agent Client Protocol) bridge works,
+how it maps ACP sessions to Gateway sessions, and how IDEs should invoke it.
+
+## Overview
+
+`clawdbot acp` exposes an ACP agent over stdio and forwards prompts to a running
+Clawdbot Gateway over WebSocket. It keeps ACP session ids mapped to Gateway
+session keys so IDEs can reconnect to the same agent transcript or reset it on
+request.
+
+Key goals:
+
+- Minimal ACP surface area (stdio, NDJSON).
+- Stable session mapping across reconnects.
+- Works with existing Gateway session store (list/resolve/reset).
+- Safe defaults (isolated ACP session keys by default).
+
+## How can I use this
+
+Use ACP when an IDE or tooling speaks Agent Client Protocol and you want it to
+drive a Clawdbot Gateway session.
+
+Quick steps:
+
+1. Run a Gateway (local or remote).
+2. Configure the Gateway target (`gateway.remote.url` + auth) or pass flags.
+3. Point the IDE to run `clawdbot acp` over stdio.
+
+Example config:
+
+```bash
+clawdbot config set gateway.remote.url wss://gateway-host:18789
+clawdbot config set gateway.remote.token <token>
+```
+
+Example run:
+
+```bash
+clawdbot acp --url wss://gateway-host:18789 --token <token>
+```
+
+## Selecting agents
+
+ACP does not pick agents directly. It routes by the Gateway session key.
+
+Use agent-scoped session keys to target a specific agent:
+
+```bash
+clawdbot acp --session agent:main:main
+clawdbot acp --session agent:design:main
+clawdbot acp --session agent:qa:bug-123
+```
+
+Each ACP session maps to a single Gateway session key. One agent can have many
+sessions; ACP defaults to an isolated `acp:<uuid>` session unless you override
+the key or label.
+
+## Zed editor setup
+
+Add a custom ACP agent in `~/.config/zed/settings.json`:
+
+```json
+{
+  "agent_servers": {
+    "Clawdbot ACP": {
+      "type": "custom",
+      "command": "clawdbot",
+      "args": ["acp"],
+      "env": {}
+    }
+  }
+}
+```
+
+To target a specific Gateway or agent:
+
+```json
+{
+  "agent_servers": {
+    "Clawdbot ACP": {
+      "type": "custom",
+      "command": "clawdbot",
+      "args": [
+        "acp",
+        "--url", "wss://gateway-host:18789",
+        "--token", "<token>",
+        "--session", "agent:design:main"
+      ],
+      "env": {}
+    }
+  }
+}
+```
+
+In Zed, open the Agent panel and select “Clawdbot ACP” to start a thread.
+
+## Execution Model
+
+- ACP client spawns `clawdbot acp` and speaks ACP messages over stdio.
+- The bridge connects to the Gateway using existing auth config (or CLI flags).
+- ACP `prompt` translates to Gateway `chat.send`.
+- Gateway streaming events are translated back into ACP streaming events.
+- ACP `cancel` maps to Gateway `chat.abort` for the active run.
+
+## Session Mapping
+
+By default each ACP session is mapped to a dedicated Gateway session key:
+
+- `acp:<uuid>` unless overridden.
+
+You can override or reuse sessions in two ways:
+
+1) CLI defaults
+
+```bash
+clawdbot acp --session agent:main:main
+clawdbot acp --session-label "support inbox"
+clawdbot acp --reset-session
+```
+
+2) ACP metadata per session
+
+```json
+{
+  "_meta": {
+    "sessionKey": "agent:main:main",
+    "sessionLabel": "support inbox",
+    "resetSession": true,
+    "requireExisting": false
+  }
+}
+```
+
+Rules:
+
+- `sessionKey`: direct Gateway session key.
+- `sessionLabel`: resolve an existing session by label.
+- `resetSession`: mint a new transcript for the key before first use.
+- `requireExisting`: fail if the key/label does not exist.
+
+### Session Listing
+
+ACP `listSessions` maps to Gateway `sessions.list` and returns a filtered
+summary suitable for IDE session pickers. `_meta.limit` can cap the number of
+sessions returned.
+
+## Prompt Translation
+
+ACP prompt inputs are converted into a Gateway `chat.send`:
+
+- `text` and `resource` blocks become prompt text.
+- `resource_link` with image mime types become attachments.
+- The working directory can be prefixed into the prompt (default on, can be
+  disabled with `--no-prefix-cwd`).
+
+Gateway streaming events are translated into ACP `message` and `tool_call`
+updates. Terminal Gateway states map to ACP `done` with stop reasons:
+
+- `complete` -> `stop`
+- `aborted` -> `cancel`
+- `error` -> `error`
+
+## Auth + Gateway Discovery
+
+`clawdbot acp` resolves the Gateway URL and auth from CLI flags or config:
+
+- `--url` / `--token` / `--password` take precedence.
+- Otherwise use configured `gateway.remote.*` settings.
+
+## Operational Notes
+
+- ACP sessions are stored in memory for the bridge process lifetime.
+- Gateway session state is persisted by the Gateway itself.
+- `--verbose` logs ACP/Gateway bridge events to stderr (never stdout).
+- ACP runs can be canceled and the active run id is tracked per session.
+
+## Compatibility
+
+- ACP bridge uses `@agentclientprotocol/sdk` (currently 0.13.x).
+- Works with ACP clients that implement `initialize`, `newSession`,
+  `loadSession`, `prompt`, `cancel`, and `listSessions`.
+
+## Testing
+
+- Unit: `src/acp/session.test.ts` covers run id lifecycle.
+- Full gate: `pnpm lint && pnpm build && pnpm test && pnpm docs:build`.
+
+## Related Docs
+
+- CLI usage: `docs/cli/acp.md`
+- Session model: `docs/concepts/session.md`
+- Session management internals: `docs/reference/session-management-compaction.md`
diff --git a/docs/cli/acp.md b/docs/cli/acp.md
new file mode 100644
index 000000000..fae4a6390
--- /dev/null
+++ b/docs/cli/acp.md
@@ -0,0 +1,143 @@
+---
+summary: "Run the ACP bridge for IDE integrations"
+read_when:
+  - Setting up ACP-based IDE integrations
+  - Debugging ACP session routing to the Gateway
+---
+
+# acp
+
+Run the ACP (Agent Client Protocol) bridge that talks to a Clawdbot Gateway.
+
+This command speaks ACP over stdio for IDEs and forwards prompts to the Gateway
+over WebSocket. It keeps ACP sessions mapped to Gateway session keys.
+
+## Usage
+
+```bash
+clawdbot acp
+
+# Remote Gateway
+clawdbot acp --url wss://gateway-host:18789 --token <token>
+
+# Attach to an existing session key
+clawdbot acp --session agent:main:main
+
+# Attach by label (must already exist)
+clawdbot acp --session-label "support inbox"
+
+# Reset the session key before the first prompt
+clawdbot acp --session agent:main:main --reset-session
+```
+
+## How to use this
+
+Use ACP when an IDE (or other client) speaks Agent Client Protocol and you want
+it to drive a Clawdbot Gateway session.
+
+1. Ensure the Gateway is running (local or remote).
+2. Configure the Gateway target (config or flags).
+3. Point your IDE to run `clawdbot acp` over stdio.
+
+Example config (persisted):
+
+```bash
+clawdbot config set gateway.remote.url wss://gateway-host:18789
+clawdbot config set gateway.remote.token <token>
+```
+
+Example direct run (no config write):
+
+```bash
+clawdbot acp --url wss://gateway-host:18789 --token <token>
+```
+
+## Selecting agents
+
+ACP does not pick agents directly. It routes by the Gateway session key.
+
+Use agent-scoped session keys to target a specific agent:
+
+```bash
+clawdbot acp --session agent:main:main
+clawdbot acp --session agent:design:main
+clawdbot acp --session agent:qa:bug-123
+```
+
+Each ACP session maps to a single Gateway session key. One agent can have many
+sessions; ACP defaults to an isolated `acp:<uuid>` session unless you override
+the key or label.
+
+## Zed editor setup
+
+Add a custom ACP agent in `~/.config/zed/settings.json` (or use Zed’s Settings UI):
+
+```json
+{
+  "agent_servers": {
+    "Clawdbot ACP": {
+      "type": "custom",
+      "command": "clawdbot",
+      "args": ["acp"],
+      "env": {}
+    }
+  }
+}
+```
+
+To target a specific Gateway or agent:
+
+```json
+{
+  "agent_servers": {
+    "Clawdbot ACP": {
+      "type": "custom",
+      "command": "clawdbot",
+      "args": [
+        "acp",
+        "--url", "wss://gateway-host:18789",
+        "--token", "<token>",
+        "--session", "agent:design:main"
+      ],
+      "env": {}
+    }
+  }
+}
+```
+
+In Zed, open the Agent panel and select “Clawdbot ACP” to start a thread.
+
+## Session mapping
+
+By default, ACP sessions get an isolated Gateway session key with an `acp:` prefix.
+To reuse a known session, pass a session key or label:
+
+- `--session <key>`: use a specific Gateway session key.
+- `--session-label <label>`: resolve an existing session by label.
+- `--reset-session`: mint a fresh session id for that key (same key, new transcript).
+
+If your ACP client supports metadata, you can override per session:
+
+```json
+{
+  "_meta": {
+    "sessionKey": "agent:main:main",
+    "sessionLabel": "support inbox",
+    "resetSession": true
+  }
+}
+```
+
+Learn more about session keys at [/concepts/session](/concepts/session).
+
+## Options
+
+- `--url <url>`: Gateway WebSocket URL (defaults to gateway.remote.url when configured).
+- `--token <token>`: Gateway auth token.
+- `--password <password>`: Gateway auth password.
+- `--session <key>`: default session key.
+- `--session-label <label>`: default session label to resolve.
+- `--require-existing`: fail if the session key/label does not exist.
+- `--reset-session`: reset the session key before first use.
+- `--no-prefix-cwd`: do not prefix prompts with the working directory.
+- `--verbose, -v`: verbose logging to stderr.
diff --git a/docs/cli/index.md b/docs/cli/index.md
index 2af75ccdc..123841cdd 100644
--- a/docs/cli/index.md
+++ b/docs/cli/index.md
@@ -23,6 +23,7 @@ This page describes the current CLI behavior. If commands change, update this do
 - [`message`](/cli/message)
 - [`agent`](/cli/agent)
 - [`agents`](/cli/agents)
+- [`acp`](/cli/acp)
 - [`status`](/cli/status)
 - [`health`](/cli/health)
 - [`sessions`](/cli/sessions)
@@ -126,6 +127,7 @@ clawdbot [--dev] [--profile <name>] <command>
     list
     add
     delete
+  acp
   status
   health
   sessions
@@ -501,6 +503,11 @@ Options:
 - `--force`
 - `--json`
 
+### `acp`
+Run the ACP bridge that connects IDEs to the Gateway.
+
+See [`acp`](/cli/acp) for full options and examples.
+
 ### `status`
 Show linked session health and recent recipients.
 
diff --git a/docs/debugging.md b/docs/debugging.md
index 992f49421..fd754e502 100644
--- a/docs/debugging.md
+++ b/docs/debugging.md
@@ -77,6 +77,7 @@ What this does:
    - Seeds the workspace files if missing:
      `AGENTS.md`, `SOUL.md`, `TOOLS.md`, `IDENTITY.md`, `USER.md`, `HEARTBEAT.md`.
    - Default identity: **C3‑PO** (protocol droid).
+   - Skips channel providers in dev mode (`CLAWDBOT_SKIP_CHANNELS=1`).
 
 Reset flow (fresh start):
 
diff --git a/package.json b/package.json
index bd61f7823..2a0b7e7a0 100644
--- a/package.json
+++ b/package.json
@@ -81,8 +81,8 @@
     "start": "tsx src/entry.ts",
     "clawdbot": "tsx src/entry.ts",
     "gateway:watch": "tsx watch src/entry.ts gateway --force",
-    "gateway:dev": "tsx src/entry.ts --dev gateway",
-    "gateway:dev:reset": "tsx src/entry.ts --dev gateway --reset",
+    "gateway:dev": "CLAWDBOT_SKIP_CHANNELS=1 tsx src/entry.ts --dev gateway",
+    "gateway:dev:reset": "CLAWDBOT_SKIP_CHANNELS=1 tsx src/entry.ts --dev gateway --reset",
     "tui": "tsx src/entry.ts tui",
     "tui:dev": "CLAWDBOT_PROFILE=dev tsx src/entry.ts tui",
     "clawdbot:rpc": "tsx src/entry.ts agent --mode rpc --json",
@@ -140,6 +140,7 @@
   },
   "packageManager": "pnpm@10.23.0",
   "dependencies": {
+    "@agentclientprotocol/sdk": "0.13.0",
     "@buape/carbon": "0.0.0-beta-20260110172854",
     "@clack/prompts": "^0.11.0",
     "@grammyjs/runner": "^2.0.3",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index ed48ddf95..e840d87fc 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -13,6 +13,9 @@ importers:
 
   .:
     dependencies:
+      '@agentclientprotocol/sdk':
+        specifier: 0.13.0
+        version: 0.13.0(zod@4.3.5)
       '@buape/carbon':
         specifier: 0.0.0-beta-20260110172854
         version: 0.0.0-beta-20260110172854(hono@4.11.4)
@@ -357,6 +360,11 @@ importers:
 
 packages:
 
+  '@agentclientprotocol/sdk@0.13.0':
+    resolution: {integrity: sha512-Z6/Fp4cXLbYdMXr5AK752JM5qG2VKb6ShM0Ql6FimBSckMmLyK54OA20UhPYoH4C37FSFwUTARuwQOwQUToYrw==}
+    peerDependencies:
+      zod: ^3.25.0 || ^4.0.0
+
   '@anthropic-ai/sdk@0.71.2':
     resolution: {integrity: sha512-TGNDEUuEstk/DKu0/TflXAEt+p+p/WhTlFzEnoosvbaDU2LTjm42igSdlL0VijrKpWejtOKxX0b8A7uc+XiSAQ==}
     hasBin: true
@@ -4581,6 +4589,10 @@ packages:
 
 snapshots:
 
+  '@agentclientprotocol/sdk@0.13.0(zod@4.3.5)':
+    dependencies:
+      zod: 4.3.5
+
   '@anthropic-ai/sdk@0.71.2(zod@4.3.5)':
     dependencies:
       json-schema-to-ts: 3.1.1
diff --git a/src/acp/commands.ts b/src/acp/commands.ts
new file mode 100644
index 000000000..6bd8e85a8
--- /dev/null
+++ b/src/acp/commands.ts
@@ -0,0 +1,40 @@
+import type { AvailableCommand } from "@agentclientprotocol/sdk";
+
+export function getAvailableCommands(): AvailableCommand[] {
+  return [
+    { name: "help", description: "Show help and common commands." },
+    { name: "commands", description: "List available commands." },
+    { name: "status", description: "Show current status." },
+    {
+      name: "context",
+      description: "Explain context usage (list|detail|json).",
+      input: { hint: "list | detail | json" },
+    },
+    { name: "whoami", description: "Show sender id (alias: /id)." },
+    { name: "id", description: "Alias for /whoami." },
+    { name: "subagents", description: "List or manage sub-agents." },
+    { name: "config", description: "Read or write config (owner-only)." },
+    { name: "debug", description: "Set runtime-only overrides (owner-only)." },
+    { name: "usage", description: "Toggle usage footer (off|tokens|full)." },
+    { name: "stop", description: "Stop the current run." },
+    { name: "restart", description: "Restart the gateway (if enabled)." },
+    { name: "dock-telegram", description: "Route replies to Telegram." },
+    { name: "dock-discord", description: "Route replies to Discord." },
+    { name: "dock-slack", description: "Route replies to Slack." },
+    { name: "activation", description: "Set group activation (mention|always)." },
+    { name: "send", description: "Set send mode (on|off|inherit)." },
+    { name: "reset", description: "Reset the session (/new)." },
+    { name: "new", description: "Reset the session (/reset)." },
+    {
+      name: "think",
+      description: "Set thinking level (off|minimal|low|medium|high|xhigh).",
+    },
+    { name: "verbose", description: "Set verbose mode (on|full|off)." },
+    { name: "reasoning", description: "Toggle reasoning output (on|off|stream)." },
+    { name: "elevated", description: "Toggle elevated mode (on|off)." },
+    { name: "model", description: "Select a model (list|status|<name>)." },
+    { name: "queue", description: "Adjust queue mode and options." },
+    { name: "bash", description: "Run a host command (if enabled)." },
+    { name: "compact", description: "Compact the session history." },
+  ];
+}
diff --git a/src/acp/event-mapper.test.ts b/src/acp/event-mapper.test.ts
new file mode 100644
index 000000000..c1e787d8e
--- /dev/null
+++ b/src/acp/event-mapper.test.ts
@@ -0,0 +1,34 @@
+import { describe, expect, it } from "vitest";
+
+import { extractAttachmentsFromPrompt, extractTextFromPrompt } from "./event-mapper.js";
+
+describe("acp event mapper", () => {
+  it("extracts text and resource blocks into prompt text", () => {
+    const text = extractTextFromPrompt([
+      { type: "text", text: "Hello" },
+      { type: "resource", resource: { text: "File contents" } },
+      { type: "resource_link", uri: "https://example.com", title: "Spec" },
+      { type: "image", data: "abc", mimeType: "image/png" },
+    ]);
+
+    expect(text).toBe(
+      "Hello\nFile contents\n[Resource link (Spec)] https://example.com",
+    );
+  });
+
+  it("extracts image blocks into gateway attachments", () => {
+    const attachments = extractAttachmentsFromPrompt([
+      { type: "image", data: "abc", mimeType: "image/png" },
+      { type: "image", data: "", mimeType: "image/png" },
+      { type: "text", text: "ignored" },
+    ]);
+
+    expect(attachments).toEqual([
+      {
+        type: "image",
+        mimeType: "image/png",
+        content: "abc",
+      },
+    ]);
+  });
+});
diff --git a/src/acp/event-mapper.ts b/src/acp/event-mapper.ts
new file mode 100644
index 000000000..6e3e22f17
--- /dev/null
+++ b/src/acp/event-mapper.ts
@@ -0,0 +1,73 @@
+import type { ContentBlock, ImageContent, ToolKind } from "@agentclientprotocol/sdk";
+
+export type GatewayAttachment = {
+  type: string;
+  mimeType: string;
+  content: string;
+};
+
+export function extractTextFromPrompt(prompt: ContentBlock[]): string {
+  const parts: string[] = [];
+  for (const block of prompt) {
+    if (block.type === "text") {
+      parts.push(block.text);
+      continue;
+    }
+    if (block.type === "resource") {
+      const resource = block.resource as { text?: string } | undefined;
+      if (resource?.text) parts.push(resource.text);
+      continue;
+    }
+    if (block.type === "resource_link") {
+      const title = block.title ? ` (${block.title})` : "";
+      const uri = block.uri ?? "";
+      const line = uri ? `[Resource link${title}] ${uri}` : `[Resource link${title}]`;
+      parts.push(line);
+    }
+  }
+  return parts.join("\n");
+}
+
+export function extractAttachmentsFromPrompt(prompt: ContentBlock[]): GatewayAttachment[] {
+  const attachments: GatewayAttachment[] = [];
+  for (const block of prompt) {
+    if (block.type !== "image") continue;
+    const image = block as ImageContent;
+    if (!image.data || !image.mimeType) continue;
+    attachments.push({
+      type: "image",
+      mimeType: image.mimeType,
+      content: image.data,
+    });
+  }
+  return attachments;
+}
+
+export function formatToolTitle(
+  name: string | undefined,
+  args: Record<string, unknown> | undefined,
+): string {
+  const base = name ?? "tool";
+  if (!args || Object.keys(args).length === 0) return base;
+  const parts = Object.entries(args).map(([key, value]) => {
+    const raw = typeof value === "string" ? value : JSON.stringify(value);
+    const safe = raw.length > 100 ? `${raw.slice(0, 100)}...` : raw;
+    return `${key}: ${safe}`;
+  });
+  return `${base}: ${parts.join(", ")}`;
+}
+
+export function inferToolKind(name?: string): ToolKind | undefined {
+  if (!name) return "other";
+  const normalized = name.toLowerCase();
+  if (normalized.includes("read")) return "read";
+  if (normalized.includes("write") || normalized.includes("edit")) return "edit";
+  if (normalized.includes("delete") || normalized.includes("remove")) return "delete";
+  if (normalized.includes("move") || normalized.includes("rename")) return "move";
+  if (normalized.includes("search") || normalized.includes("find")) return "search";
+  if (normalized.includes("exec") || normalized.includes("run") || normalized.includes("bash")) {
+    return "execute";
+  }
+  if (normalized.includes("fetch") || normalized.includes("http")) return "fetch";
+  return "other";
+}
diff --git a/src/acp/index.ts b/src/acp/index.ts
new file mode 100644
index 000000000..6af9efffb
--- /dev/null
+++ b/src/acp/index.ts
@@ -0,0 +1,4 @@
+export { serveAcpGateway } from "./server.js";
+export { createInMemorySessionStore } from "./session.js";
+export type { AcpSessionStore } from "./session.js";
+export type { AcpServerOptions } from "./types.js";
diff --git a/src/acp/meta.ts b/src/acp/meta.ts
new file mode 100644
index 000000000..277b7491a
--- /dev/null
+++ b/src/acp/meta.ts
@@ -0,0 +1,35 @@
+export function readString(
+  meta: Record<string, unknown> | null | undefined,
+  keys: string[],
+): string | undefined {
+  if (!meta) return undefined;
+  for (const key of keys) {
+    const value = meta[key];
+    if (typeof value === "string" && value.trim()) return value.trim();
+  }
+  return undefined;
+}
+
+export function readBool(
+  meta: Record<string, unknown> | null | undefined,
+  keys: string[],
+): boolean | undefined {
+  if (!meta) return undefined;
+  for (const key of keys) {
+    const value = meta[key];
+    if (typeof value === "boolean") return value;
+  }
+  return undefined;
+}
+
+export function readNumber(
+  meta: Record<string, unknown> | null | undefined,
+  keys: string[],
+): number | undefined {
+  if (!meta) return undefined;
+  for (const key of keys) {
+    const value = meta[key];
+    if (typeof value === "number" && Number.isFinite(value)) return value;
+  }
+  return undefined;
+}
diff --git a/src/acp/server.ts b/src/acp/server.ts
new file mode 100644
index 000000000..4ca1c4681
--- /dev/null
+++ b/src/acp/server.ts
@@ -0,0 +1,149 @@
+#!/usr/bin/env node
+import { Readable, Writable } from "node:stream";
+import { fileURLToPath } from "node:url";
+
+import { AgentSideConnection, ndJsonStream } from "@agentclientprotocol/sdk";
+
+import { loadConfig } from "../config/config.js";
+import { resolveGatewayAuth } from "../gateway/auth.js";
+import { buildGatewayConnectionDetails } from "../gateway/call.js";
+import { GatewayClient } from "../gateway/client.js";
+import { isMainModule } from "../infra/is-main.js";
+import {
+  GATEWAY_CLIENT_MODES,
+  GATEWAY_CLIENT_NAMES,
+} from "../utils/message-channel.js";
+import { AcpGatewayAgent } from "./translator.js";
+import type { AcpServerOptions } from "./types.js";
+
+export function serveAcpGateway(opts: AcpServerOptions = {}): void {
+  const cfg = loadConfig();
+  const connection = buildGatewayConnectionDetails({
+    config: cfg,
+    url: opts.gatewayUrl,
+  });
+
+  const isRemoteMode = cfg.gateway?.mode === "remote";
+  const remote = isRemoteMode ? cfg.gateway?.remote : undefined;
+  const auth = resolveGatewayAuth({ authConfig: cfg.gateway?.auth, env: process.env });
+
+  const token =
+    opts.gatewayToken ??
+    (isRemoteMode ? remote?.token?.trim() : undefined) ??
+    process.env.CLAWDBOT_GATEWAY_TOKEN ??
+    auth.token;
+  const password =
+    opts.gatewayPassword ??
+    (isRemoteMode ? remote?.password?.trim() : undefined) ??
+    process.env.CLAWDBOT_GATEWAY_PASSWORD ??
+    auth.password;
+
+  let agent: AcpGatewayAgent | null = null;
+  const gateway = new GatewayClient({
+    url: connection.url,
+    token: token || undefined,
+    password: password || undefined,
+    clientName: GATEWAY_CLIENT_NAMES.CLI,
+    clientDisplayName: "ACP",
+    clientVersion: "acp",
+    mode: GATEWAY_CLIENT_MODES.CLI,
+    onEvent: (evt) => {
+      void agent?.handleGatewayEvent(evt);
+    },
+    onHelloOk: () => {
+      agent?.handleGatewayReconnect();
+    },
+    onClose: (code, reason) => {
+      agent?.handleGatewayDisconnect(`${code}: ${reason}`);
+    },
+  });
+
+  const input = Writable.toWeb(process.stdout);
+  const output = Readable.toWeb(process.stdin) as ReadableStream<Uint8Array>;
+  const stream = ndJsonStream(input, output);
+
+  new AgentSideConnection((conn) => {
+    agent = new AcpGatewayAgent(conn, gateway, opts);
+    agent.start();
+    return agent;
+  }, stream);
+
+  gateway.start();
+}
+
+function parseArgs(args: string[]): AcpServerOptions {
+  const opts: AcpServerOptions = {};
+  for (let i = 0; i < args.length; i += 1) {
+    const arg = args[i];
+    if (arg === "--url" || arg === "--gateway-url") {
+      opts.gatewayUrl = args[i + 1];
+      i += 1;
+      continue;
+    }
+    if (arg === "--token" || arg === "--gateway-token") {
+      opts.gatewayToken = args[i + 1];
+      i += 1;
+      continue;
+    }
+    if (arg === "--password" || arg === "--gateway-password") {
+      opts.gatewayPassword = args[i + 1];
+      i += 1;
+      continue;
+    }
+    if (arg === "--session") {
+      opts.defaultSessionKey = args[i + 1];
+      i += 1;
+      continue;
+    }
+    if (arg === "--session-label") {
+      opts.defaultSessionLabel = args[i + 1];
+      i += 1;
+      continue;
+    }
+    if (arg === "--require-existing") {
+      opts.requireExistingSession = true;
+      continue;
+    }
+    if (arg === "--reset-session") {
+      opts.resetSession = true;
+      continue;
+    }
+    if (arg === "--no-prefix-cwd") {
+      opts.prefixCwd = false;
+      continue;
+    }
+    if (arg === "--verbose" || arg === "-v") {
+      opts.verbose = true;
+      continue;
+    }
+    if (arg === "--help" || arg === "-h") {
+      printHelp();
+      process.exit(0);
+    }
+  }
+  return opts;
+}
+
+function printHelp(): void {
+  console.log(`Usage: clawdbot acp [options]
+
+Gateway-backed ACP server for IDE integration.
+
+Options:
+  --url <url>             Gateway WebSocket URL
+  --token <token>         Gateway auth token
+  --password <password>   Gateway auth password
+  --session <key>         Default session key (e.g. "agent:main:main")
+  --session-label <label> Default session label to resolve
+  --require-existing      Fail if the session key/label does not exist
+  --reset-session         Reset the session key before first use
+  --no-prefix-cwd         Do not prefix prompts with the working directory
+  --verbose, -v           Verbose logging to stderr
+  --help, -h              Show this help message
+`);
+}
+
+if (isMainModule({ currentFile: fileURLToPath(import.meta.url) })) {
+  const opts = parseArgs(process.argv.slice(2));
+  serveAcpGateway(opts);
+}
diff --git a/src/acp/session-mapper.test.ts b/src/acp/session-mapper.test.ts
new file mode 100644
index 000000000..d92315db9
--- /dev/null
+++ b/src/acp/session-mapper.test.ts
@@ -0,0 +1,57 @@
+import { describe, expect, it, vi } from "vitest";
+
+import type { GatewayClient } from "../gateway/client.js";
+import { parseSessionMeta, resolveSessionKey } from "./session-mapper.js";
+
+function createGateway(resolveLabelKey = "agent:main:label"): {
+  gateway: GatewayClient;
+  request: ReturnType<typeof vi.fn>;
+} {
+  const request = vi.fn(async (method: string, params: Record<string, unknown>) => {
+    if (method === "sessions.resolve" && "label" in params) {
+      return { ok: true, key: resolveLabelKey };
+    }
+    if (method === "sessions.resolve" && "key" in params) {
+      return { ok: true, key: params.key as string };
+    }
+    return { ok: true };
+  });
+
+  return {
+    gateway: { request } as unknown as GatewayClient,
+    request,
+  };
+}
+
+describe("acp session mapper", () => {
+  it("prefers explicit sessionLabel over sessionKey", async () => {
+    const { gateway, request } = createGateway();
+    const meta = parseSessionMeta({ sessionLabel: "support", sessionKey: "agent:main:main" });
+
+    const key = await resolveSessionKey({
+      meta,
+      fallbackKey: "acp:fallback",
+      gateway,
+      opts: {},
+    });
+
+    expect(key).toBe("agent:main:label");
+    expect(request).toHaveBeenCalledTimes(1);
+    expect(request).toHaveBeenCalledWith("sessions.resolve", { label: "support" });
+  });
+
+  it("lets meta sessionKey override default label", async () => {
+    const { gateway, request } = createGateway();
+    const meta = parseSessionMeta({ sessionKey: "agent:main:override" });
+
+    const key = await resolveSessionKey({
+      meta,
+      fallbackKey: "acp:fallback",
+      gateway,
+      opts: { defaultSessionLabel: "default-label" },
+    });
+
+    expect(key).toBe("agent:main:override");
+    expect(request).not.toHaveBeenCalled();
+  });
+});
diff --git a/src/acp/session-mapper.ts b/src/acp/session-mapper.ts
new file mode 100644
index 000000000..1a575a413
--- /dev/null
+++ b/src/acp/session-mapper.ts
@@ -0,0 +1,95 @@
+import type { GatewayClient } from "../gateway/client.js";
+
+import type { AcpServerOptions } from "./types.js";
+import { readBool, readString } from "./meta.js";
+
+export type AcpSessionMeta = {
+  sessionKey?: string;
+  sessionLabel?: string;
+  resetSession?: boolean;
+  requireExisting?: boolean;
+  prefixCwd?: boolean;
+};
+
+export function parseSessionMeta(meta: unknown): AcpSessionMeta {
+  if (!meta || typeof meta !== "object") return {};
+  const record = meta as Record<string, unknown>;
+  return {
+    sessionKey: readString(record, ["sessionKey", "session", "key"]),
+    sessionLabel: readString(record, ["sessionLabel", "label"]),
+    resetSession: readBool(record, ["resetSession", "reset"]),
+    requireExisting: readBool(record, ["requireExistingSession", "requireExisting"]),
+    prefixCwd: readBool(record, ["prefixCwd"]),
+  };
+}
+
+export async function resolveSessionKey(params: {
+  meta: AcpSessionMeta;
+  fallbackKey: string;
+  gateway: GatewayClient;
+  opts: AcpServerOptions;
+}): Promise<string> {
+  const requestedLabel = params.meta.sessionLabel ?? params.opts.defaultSessionLabel;
+  const requestedKey = params.meta.sessionKey ?? params.opts.defaultSessionKey;
+  const requireExisting =
+    params.meta.requireExisting ?? params.opts.requireExistingSession ?? false;
+
+  if (params.meta.sessionLabel) {
+    const resolved = await params.gateway.request<{ ok: true; key: string }>(
+      "sessions.resolve",
+      { label: params.meta.sessionLabel },
+    );
+    if (!resolved?.key) {
+      throw new Error(`Unable to resolve session label: ${params.meta.sessionLabel}`);
+    }
+    return resolved.key;
+  }
+
+  if (params.meta.sessionKey) {
+    if (!requireExisting) return params.meta.sessionKey;
+    const resolved = await params.gateway.request<{ ok: true; key: string }>(
+      "sessions.resolve",
+      { key: params.meta.sessionKey },
+    );
+    if (!resolved?.key) {
+      throw new Error(`Session key not found: ${params.meta.sessionKey}`);
+    }
+    return resolved.key;
+  }
+
+  if (requestedLabel) {
+    const resolved = await params.gateway.request<{ ok: true; key: string }>(
+      "sessions.resolve",
+      { label: requestedLabel },
+    );
+    if (!resolved?.key) {
+      throw new Error(`Unable to resolve session label: ${requestedLabel}`);
+    }
+    return resolved.key;
+  }
+
+  if (requestedKey) {
+    if (!requireExisting) return requestedKey;
+    const resolved = await params.gateway.request<{ ok: true; key: string }>(
+      "sessions.resolve",
+      { key: requestedKey },
+    );
+    if (!resolved?.key) {
+      throw new Error(`Session key not found: ${requestedKey}`);
+    }
+    return resolved.key;
+  }
+
+  return params.fallbackKey;
+}
+
+export async function resetSessionIfNeeded(params: {
+  meta: AcpSessionMeta;
+  sessionKey: string;
+  gateway: GatewayClient;
+  opts: AcpServerOptions;
+}): Promise<void> {
+  const resetSession = params.meta.resetSession ?? params.opts.resetSession ?? false;
+  if (!resetSession) return;
+  await params.gateway.request("sessions.reset", { key: params.sessionKey });
+}
diff --git a/src/acp/session.test.ts b/src/acp/session.test.ts
new file mode 100644
index 000000000..619df3b5e
--- /dev/null
+++ b/src/acp/session.test.ts
@@ -0,0 +1,26 @@
+import { describe, expect, it, afterEach } from "vitest";
+
+import { createInMemorySessionStore } from "./session.js";
+
+describe("acp session manager", () => {
+  const store = createInMemorySessionStore();
+
+  afterEach(() => {
+    store.clearAllSessionsForTest();
+  });
+
+  it("tracks active runs and clears on cancel", () => {
+    const session = store.createSession({
+      sessionKey: "acp:test",
+      cwd: "/tmp",
+    });
+    const controller = new AbortController();
+    store.setActiveRun(session.sessionId, "run-1", controller);
+
+    expect(store.getSessionByRunId("run-1")?.sessionId).toBe(session.sessionId);
+
+    const cancelled = store.cancelActiveRun(session.sessionId);
+    expect(cancelled).toBe(true);
+    expect(store.getSessionByRunId("run-1")).toBeUndefined();
+  });
+});
diff --git a/src/acp/session.ts b/src/acp/session.ts
new file mode 100644
index 000000000..83ed88f4b
--- /dev/null
+++ b/src/acp/session.ts
@@ -0,0 +1,93 @@
+import { randomUUID } from "node:crypto";
+
+import type { AcpSession } from "./types.js";
+
+export type AcpSessionStore = {
+  createSession: (params: {
+    sessionKey: string;
+    cwd: string;
+    sessionId?: string;
+  }) => AcpSession;
+  getSession: (sessionId: string) => AcpSession | undefined;
+  getSessionByRunId: (runId: string) => AcpSession | undefined;
+  setActiveRun: (sessionId: string, runId: string, abortController: AbortController) => void;
+  clearActiveRun: (sessionId: string) => void;
+  cancelActiveRun: (sessionId: string) => boolean;
+  clearAllSessionsForTest: () => void;
+};
+
+export function createInMemorySessionStore(): AcpSessionStore {
+  const sessions = new Map<string, AcpSession>();
+  const runIdToSessionId = new Map<string, string>();
+
+  const createSession: AcpSessionStore["createSession"] = (params) => {
+    const sessionId = params.sessionId ?? randomUUID();
+    const session: AcpSession = {
+      sessionId,
+      sessionKey: params.sessionKey,
+      cwd: params.cwd,
+      createdAt: Date.now(),
+      abortController: null,
+      activeRunId: null,
+    };
+    sessions.set(sessionId, session);
+    return session;
+  };
+
+  const getSession: AcpSessionStore["getSession"] = (sessionId) => sessions.get(sessionId);
+
+  const getSessionByRunId: AcpSessionStore["getSessionByRunId"] = (runId) => {
+    const sessionId = runIdToSessionId.get(runId);
+    return sessionId ? sessions.get(sessionId) : undefined;
+  };
+
+  const setActiveRun: AcpSessionStore["setActiveRun"] = (
+    sessionId,
+    runId,
+    abortController,
+  ) => {
+    const session = sessions.get(sessionId);
+    if (!session) return;
+    session.activeRunId = runId;
+    session.abortController = abortController;
+    runIdToSessionId.set(runId, sessionId);
+  };
+
+  const clearActiveRun: AcpSessionStore["clearActiveRun"] = (sessionId) => {
+    const session = sessions.get(sessionId);
+    if (!session) return;
+    if (session.activeRunId) runIdToSessionId.delete(session.activeRunId);
+    session.activeRunId = null;
+    session.abortController = null;
+  };
+
+  const cancelActiveRun: AcpSessionStore["cancelActiveRun"] = (sessionId) => {
+    const session = sessions.get(sessionId);
+    if (!session?.abortController) return false;
+    session.abortController.abort();
+    if (session.activeRunId) runIdToSessionId.delete(session.activeRunId);
+    session.abortController = null;
+    session.activeRunId = null;
+    return true;
+  };
+
+  const clearAllSessionsForTest: AcpSessionStore["clearAllSessionsForTest"] = () => {
+    for (const session of sessions.values()) {
+      session.abortController?.abort();
+    }
+    sessions.clear();
+    runIdToSessionId.clear();
+  };
+
+  return {
+    createSession,
+    getSession,
+    getSessionByRunId,
+    setActiveRun,
+    clearActiveRun,
+    cancelActiveRun,
+    clearAllSessionsForTest,
+  };
+}
+
+export const defaultAcpSessionStore = createInMemorySessionStore();
diff --git a/src/acp/translator.ts b/src/acp/translator.ts
new file mode 100644
index 000000000..a3430c8fc
--- /dev/null
+++ b/src/acp/translator.ts
@@ -0,0 +1,433 @@
+import { randomUUID } from "node:crypto";
+
+import type {
+  Agent,
+  AgentSideConnection,
+  AuthenticateRequest,
+  AuthenticateResponse,
+  CancelNotification,
+  InitializeRequest,
+  InitializeResponse,
+  ListSessionsRequest,
+  ListSessionsResponse,
+  LoadSessionRequest,
+  LoadSessionResponse,
+  NewSessionRequest,
+  NewSessionResponse,
+  PromptRequest,
+  PromptResponse,
+  SetSessionModeRequest,
+  SetSessionModeResponse,
+  StopReason,
+} from "@agentclientprotocol/sdk";
+import { PROTOCOL_VERSION } from "@agentclientprotocol/sdk";
+
+import type { GatewayClient } from "../gateway/client.js";
+import type { EventFrame } from "../gateway/protocol/index.js";
+import type { SessionsListResult } from "../gateway/session-utils.js";
+import { getAvailableCommands } from "./commands.js";
+import { readBool, readNumber, readString } from "./meta.js";
+import {
+  extractAttachmentsFromPrompt,
+  extractTextFromPrompt,
+  formatToolTitle,
+  inferToolKind,
+} from "./event-mapper.js";
+import { parseSessionMeta, resetSessionIfNeeded, resolveSessionKey } from "./session-mapper.js";
+import { ACP_AGENT_INFO, type AcpServerOptions } from "./types.js";
+import { defaultAcpSessionStore, type AcpSessionStore } from "./session.js";
+
+type PendingPrompt = {
+  sessionId: string;
+  sessionKey: string;
+  idempotencyKey: string;
+  resolve: (response: PromptResponse) => void;
+  reject: (err: Error) => void;
+  sentTextLength?: number;
+  sentText?: string;
+  toolCalls?: Set<string>;
+};
+
+type AcpGatewayAgentOptions = AcpServerOptions & {
+  sessionStore?: AcpSessionStore;
+};
+
+export class AcpGatewayAgent implements Agent {
+  private connection: AgentSideConnection;
+  private gateway: GatewayClient;
+  private opts: AcpGatewayAgentOptions;
+  private log: (msg: string) => void;
+  private sessionStore: AcpSessionStore;
+  private pendingPrompts = new Map<string, PendingPrompt>();
+
+  constructor(
+    connection: AgentSideConnection,
+    gateway: GatewayClient,
+    opts: AcpGatewayAgentOptions = {},
+  ) {
+    this.connection = connection;
+    this.gateway = gateway;
+    this.opts = opts;
+    this.log = opts.verbose
+      ? (msg: string) => process.stderr.write(`[acp] ${msg}\n`)
+      : () => {};
+    this.sessionStore = opts.sessionStore ?? defaultAcpSessionStore;
+  }
+
+  start(): void {
+    this.log("ready");
+  }
+
+  handleGatewayReconnect(): void {
+    this.log("gateway reconnected");
+  }
+
+  handleGatewayDisconnect(reason: string): void {
+    this.log(`gateway disconnected: ${reason}`);
+    for (const pending of this.pendingPrompts.values()) {
+      pending.reject(new Error(`Gateway disconnected: ${reason}`));
+      this.sessionStore.clearActiveRun(pending.sessionId);
+    }
+    this.pendingPrompts.clear();
+  }
+
+  async handleGatewayEvent(evt: EventFrame): Promise<void> {
+    if (evt.event === "chat") {
+      await this.handleChatEvent(evt);
+      return;
+    }
+    if (evt.event === "agent") {
+      await this.handleAgentEvent(evt);
+    }
+  }
+
+  async initialize(_params: InitializeRequest): Promise<InitializeResponse> {
+    return {
+      protocolVersion: PROTOCOL_VERSION,
+      agentCapabilities: {
+        loadSession: true,
+        promptCapabilities: {
+          image: true,
+          audio: false,
+          embeddedContext: true,
+        },
+        mcpCapabilities: {
+          http: false,
+          sse: false,
+        },
+        sessionCapabilities: {
+          list: {},
+        },
+      },
+      agentInfo: ACP_AGENT_INFO,
+      authMethods: [],
+    };
+  }
+
+  async newSession(params: NewSessionRequest): Promise<NewSessionResponse> {
+    if (params.mcpServers.length > 0) {
+      this.log(`ignoring ${params.mcpServers.length} MCP servers`);
+    }
+
+    const sessionId = randomUUID();
+    const meta = parseSessionMeta(params._meta);
+    const sessionKey = await resolveSessionKey({
+      meta,
+      fallbackKey: `acp:${sessionId}`,
+      gateway: this.gateway,
+      opts: this.opts,
+    });
+    await resetSessionIfNeeded({
+      meta,
+      sessionKey,
+      gateway: this.gateway,
+      opts: this.opts,
+    });
+
+    const session = this.sessionStore.createSession({
+      sessionId,
+      sessionKey,
+      cwd: params.cwd,
+    });
+    this.log(`newSession: ${session.sessionId} -> ${session.sessionKey}`);
+    await this.sendAvailableCommands(session.sessionId);
+    return { sessionId: session.sessionId };
+  }
+
+  async loadSession(params: LoadSessionRequest): Promise<LoadSessionResponse> {
+    if (params.mcpServers.length > 0) {
+      this.log(`ignoring ${params.mcpServers.length} MCP servers`);
+    }
+
+    const meta = parseSessionMeta(params._meta);
+    const sessionKey = await resolveSessionKey({
+      meta,
+      fallbackKey: params.sessionId,
+      gateway: this.gateway,
+      opts: this.opts,
+    });
+    await resetSessionIfNeeded({
+      meta,
+      sessionKey,
+      gateway: this.gateway,
+      opts: this.opts,
+    });
+
+    const session = this.sessionStore.createSession({
+      sessionId: params.sessionId,
+      sessionKey,
+      cwd: params.cwd,
+    });
+    this.log(`loadSession: ${session.sessionId} -> ${session.sessionKey}`);
+    await this.sendAvailableCommands(session.sessionId);
+    return {};
+  }
+
+  async unstable_listSessions(params: ListSessionsRequest): Promise<ListSessionsResponse> {
+    const limit = readNumber(params._meta, ["limit"]) ?? 100;
+    const result = await this.gateway.request<SessionsListResult>("sessions.list", { limit });
+    const cwd = params.cwd ?? process.cwd();
+    return {
+      sessions: result.sessions.map((session) => ({
+        sessionId: session.key,
+        cwd,
+        title: session.displayName ?? session.label ?? session.key,
+        updatedAt: session.updatedAt ? new Date(session.updatedAt).toISOString() : undefined,
+        _meta: {
+          sessionKey: session.key,
+          kind: session.kind,
+          channel: session.channel,
+        },
+      })),
+      nextCursor: null,
+    };
+  }
+
+  async authenticate(_params: AuthenticateRequest): Promise<AuthenticateResponse> {
+    return {};
+  }
+
+  async setSessionMode(
+    params: SetSessionModeRequest,
+  ): Promise<SetSessionModeResponse | void> {
+    const session = this.sessionStore.getSession(params.sessionId);
+    if (!session) {
+      throw new Error(`Session ${params.sessionId} not found`);
+    }
+    if (!params.modeId) return {};
+    try {
+      await this.gateway.request("sessions.patch", {
+        key: session.sessionKey,
+        thinkingLevel: params.modeId,
+      });
+      this.log(`setSessionMode: ${session.sessionId} -> ${params.modeId}`);
+    } catch (err) {
+      this.log(`setSessionMode error: ${String(err)}`);
+    }
+    return {};
+  }
+
+  async prompt(params: PromptRequest): Promise<PromptResponse> {
+    const session = this.sessionStore.getSession(params.sessionId);
+    if (!session) {
+      throw new Error(`Session ${params.sessionId} not found`);
+    }
+
+    if (session.abortController) {
+      this.sessionStore.cancelActiveRun(params.sessionId);
+    }
+
+    const abortController = new AbortController();
+    const runId = randomUUID();
+    this.sessionStore.setActiveRun(params.sessionId, runId, abortController);
+
+    const meta = parseSessionMeta(params._meta);
+    const userText = extractTextFromPrompt(params.prompt);
+    const attachments = extractAttachmentsFromPrompt(params.prompt);
+    const prefixCwd = meta.prefixCwd ?? this.opts.prefixCwd ?? true;
+    const message = prefixCwd ? `[Working directory: ${session.cwd}]\n\n${userText}` : userText;
+
+    return new Promise<PromptResponse>((resolve, reject) => {
+      this.pendingPrompts.set(params.sessionId, {
+        sessionId: params.sessionId,
+        sessionKey: session.sessionKey,
+        idempotencyKey: runId,
+        resolve,
+        reject,
+      });
+
+      this.gateway
+        .request(
+          "chat.send",
+          {
+            sessionKey: session.sessionKey,
+            message,
+            attachments: attachments.length > 0 ? attachments : undefined,
+            idempotencyKey: runId,
+            thinking: readString(params._meta, ["thinking", "thinkingLevel"]),
+            deliver: readBool(params._meta, ["deliver"]),
+            timeoutMs: readNumber(params._meta, ["timeoutMs"]),
+          },
+          { expectFinal: true },
+        )
+        .catch((err) => {
+          this.pendingPrompts.delete(params.sessionId);
+          this.sessionStore.clearActiveRun(params.sessionId);
+          reject(err instanceof Error ? err : new Error(String(err)));
+        });
+    });
+  }
+
+  async cancel(params: CancelNotification): Promise<void> {
+    const session = this.sessionStore.getSession(params.sessionId);
+    if (!session) return;
+
+    this.sessionStore.cancelActiveRun(params.sessionId);
+    try {
+      await this.gateway.request("chat.abort", { sessionKey: session.sessionKey });
+    } catch (err) {
+      this.log(`cancel error: ${String(err)}`);
+    }
+
+    const pending = this.pendingPrompts.get(params.sessionId);
+    if (pending) {
+      this.pendingPrompts.delete(params.sessionId);
+      pending.resolve({ stopReason: "cancelled" });
+    }
+  }
+
+  private async handleAgentEvent(evt: EventFrame): Promise<void> {
+    const payload = evt.payload as Record<string, unknown> | undefined;
+    if (!payload) return;
+    const stream = payload.stream as string | undefined;
+    const data = payload.data as Record<string, unknown> | undefined;
+    const sessionKey = payload.sessionKey as string | undefined;
+    if (!stream || !data || !sessionKey) return;
+
+    if (stream !== "tool") return;
+    const phase = data.phase as string | undefined;
+    const name = data.name as string | undefined;
+    const toolCallId = data.toolCallId as string | undefined;
+    if (!toolCallId) return;
+
+    const pending = this.findPendingBySessionKey(sessionKey);
+    if (!pending) return;
+
+    if (phase === "start") {
+      if (!pending.toolCalls) pending.toolCalls = new Set();
+      if (pending.toolCalls.has(toolCallId)) return;
+      pending.toolCalls.add(toolCallId);
+      const args = data.args as Record<string, unknown> | undefined;
+      await this.connection.sessionUpdate({
+        sessionId: pending.sessionId,
+        update: {
+          sessionUpdate: "tool_call",
+          toolCallId,
+          title: formatToolTitle(name, args),
+          status: "in_progress",
+          rawInput: args,
+          kind: inferToolKind(name),
+        },
+      });
+      return;
+    }
+
+    if (phase === "result") {
+      const isError = Boolean(data.isError);
+      await this.connection.sessionUpdate({
+        sessionId: pending.sessionId,
+        update: {
+          sessionUpdate: "tool_call_update",
+          toolCallId,
+          status: isError ? "failed" : "completed",
+          rawOutput: data.result,
+        },
+      });
+    }
+  }
+
+  private async handleChatEvent(evt: EventFrame): Promise<void> {
+    const payload = evt.payload as Record<string, unknown> | undefined;
+    if (!payload) return;
+
+    const sessionKey = payload.sessionKey as string | undefined;
+    const state = payload.state as string | undefined;
+    const runId = payload.runId as string | undefined;
+    const messageData = payload.message as Record<string, unknown> | undefined;
+    if (!sessionKey || !state) return;
+
+    const pending = this.findPendingBySessionKey(sessionKey);
+    if (!pending) return;
+    if (runId && pending.idempotencyKey !== runId) return;
+
+    if (state === "delta" && messageData) {
+      await this.handleDeltaEvent(pending.sessionId, messageData);
+      return;
+    }
+
+    if (state === "final") {
+      this.finishPrompt(pending.sessionId, pending, "end_turn");
+      return;
+    }
+    if (state === "aborted") {
+      this.finishPrompt(pending.sessionId, pending, "cancelled");
+      return;
+    }
+    if (state === "error") {
+      this.finishPrompt(pending.sessionId, pending, "refusal");
+    }
+  }
+
+  private async handleDeltaEvent(
+    sessionId: string,
+    messageData: Record<string, unknown>,
+  ): Promise<void> {
+    const content = messageData.content as Array<{ type: string; text?: string }> | undefined;
+    const fullText = content?.find((c) => c.type === "text")?.text ?? "";
+    const pending = this.pendingPrompts.get(sessionId);
+    if (!pending) return;
+
+    const sentSoFar = pending.sentTextLength ?? 0;
+    if (fullText.length <= sentSoFar) return;
+
+    const newText = fullText.slice(sentSoFar);
+    pending.sentTextLength = fullText.length;
+    pending.sentText = fullText;
+
+    await this.connection.sessionUpdate({
+      sessionId,
+      update: {
+        sessionUpdate: "agent_message_chunk",
+        content: { type: "text", text: newText },
+      },
+    });
+  }
+
+  private finishPrompt(
+    sessionId: string,
+    pending: PendingPrompt,
+    stopReason: StopReason,
+  ): void {
+    this.pendingPrompts.delete(sessionId);
+    this.sessionStore.clearActiveRun(sessionId);
+    pending.resolve({ stopReason });
+  }
+
+  private findPendingBySessionKey(sessionKey: string): PendingPrompt | undefined {
+    for (const pending of this.pendingPrompts.values()) {
+      if (pending.sessionKey === sessionKey) return pending;
+    }
+    return undefined;
+  }
+
+  private async sendAvailableCommands(sessionId: string): Promise<void> {
+    await this.connection.sessionUpdate({
+      sessionId,
+      update: {
+        sessionUpdate: "available_commands_update",
+        availableCommands: getAvailableCommands(),
+      },
+    });
+  }
+
+}
diff --git a/src/acp/types.ts b/src/acp/types.ts
new file mode 100644
index 000000000..8773bf706
--- /dev/null
+++ b/src/acp/types.ts
@@ -0,0 +1,30 @@
+import type { SessionId } from "@agentclientprotocol/sdk";
+
+import { VERSION } from "../version.js";
+
+export type AcpSession = {
+  sessionId: SessionId;
+  sessionKey: string;
+  cwd: string;
+  createdAt: number;
+  abortController: AbortController | null;
+  activeRunId: string | null;
+};
+
+export type AcpServerOptions = {
+  gatewayUrl?: string;
+  gatewayToken?: string;
+  gatewayPassword?: string;
+  defaultSessionKey?: string;
+  defaultSessionLabel?: string;
+  requireExistingSession?: boolean;
+  resetSession?: boolean;
+  prefixCwd?: boolean;
+  verbose?: boolean;
+};
+
+export const ACP_AGENT_INFO = {
+  name: "clawdbot-acp",
+  title: "Clawdbot ACP Gateway",
+  version: VERSION,
+};
diff --git a/src/cli/acp-cli.ts b/src/cli/acp-cli.ts
new file mode 100644
index 000000000..c6628b7aa
--- /dev/null
+++ b/src/cli/acp-cli.ts
@@ -0,0 +1,43 @@
+import type { Command } from "commander";
+
+import { serveAcpGateway } from "../acp/server.js";
+import { defaultRuntime } from "../runtime.js";
+import { formatDocsLink } from "../terminal/links.js";
+import { theme } from "../terminal/theme.js";
+
+export function registerAcpCli(program: Command) {
+  program
+    .command("acp")
+    .description("Run an ACP bridge backed by the Gateway")
+    .option("--url <url>", "Gateway WebSocket URL (defaults to gateway.remote.url when configured)")
+    .option("--token <token>", "Gateway token (if required)")
+    .option("--password <password>", "Gateway password (if required)")
+    .option("--session <key>", "Default session key (e.g. agent:main:main)")
+    .option("--session-label <label>", "Default session label to resolve")
+    .option("--require-existing", "Fail if the session key/label does not exist", false)
+    .option("--reset-session", "Reset the session key before first use", false)
+    .option("--no-prefix-cwd", "Do not prefix prompts with the working directory", false)
+    .option("--verbose, -v", "Verbose logging to stderr", false)
+    .addHelpText(
+      "after",
+      () => `\n${theme.muted("Docs:")} ${formatDocsLink("/cli/acp", "docs.clawd.bot/cli/acp")}\n`,
+    )
+    .action((opts) => {
+      try {
+        serveAcpGateway({
+          gatewayUrl: opts.url as string | undefined,
+          gatewayToken: opts.token as string | undefined,
+          gatewayPassword: opts.password as string | undefined,
+          defaultSessionKey: opts.session as string | undefined,
+          defaultSessionLabel: opts.sessionLabel as string | undefined,
+          requireExistingSession: Boolean(opts.requireExisting),
+          resetSession: Boolean(opts.resetSession),
+          prefixCwd: !opts.noPrefixCwd,
+          verbose: Boolean(opts.verbose),
+        });
+      } catch (err) {
+        defaultRuntime.error(String(err));
+        defaultRuntime.exit(1);
+      }
+    });
+}
diff --git a/src/cli/program/register.subclis.ts b/src/cli/program/register.subclis.ts
index 5790a75a7..16d9c29bf 100644
--- a/src/cli/program/register.subclis.ts
+++ b/src/cli/program/register.subclis.ts
@@ -1,6 +1,7 @@
 import type { Command } from "commander";
 import { loadConfig } from "../../config/config.js";
 import { registerPluginCliCommands } from "../../plugins/cli.js";
+import { registerAcpCli } from "../acp-cli.js";
 import { registerChannelsCli } from "../channels-cli.js";
 import { registerCronCli } from "../cron-cli.js";
 import { registerDaemonCli } from "../daemon-cli.js";
@@ -23,6 +24,7 @@ import { registerTuiCli } from "../tui-cli.js";
 import { registerUpdateCli } from "../update-cli.js";
 
 export function registerSubCliCommands(program: Command) {
+  registerAcpCli(program);
   registerDaemonCli(program);
   registerGatewayCli(program);
   registerLogsCli(program);
diff --git a/src/gateway/server-bridge-methods-chat.ts b/src/gateway/server-bridge-methods-chat.ts
index d4834a57b..5bd8ab31d 100644
--- a/src/gateway/server-bridge-methods-chat.ts
+++ b/src/gateway/server-bridge-methods-chat.ts
@@ -6,6 +6,7 @@ import { resolveAgentTimeoutMs } from "../agents/timeout.js";
 import { agentCommand } from "../commands/agent.js";
 import { mergeSessionEntry, updateSessionStore } from "../config/sessions.js";
 import { registerAgentRunContext } from "../infra/agent-events.js";
+import { isAcpSessionKey } from "../routing/session-key.js";
 import { defaultRuntime } from "../runtime.js";
 import {
   abortChatRunById,
@@ -385,6 +386,7 @@ export const handleChatBridgeMethods: BridgeMethodHandler = async (ctx, nodeId,
           runId: clientRunId,
           status: "started" as const,
         };
+        const lane = isAcpSessionKey(p.sessionKey) ? p.sessionKey : undefined;
         void agentCommand(
           {
             message: parsedMessage,
@@ -397,6 +399,7 @@ export const handleChatBridgeMethods: BridgeMethodHandler = async (ctx, nodeId,
             timeout: Math.ceil(timeoutMs / 1000).toString(),
             messageChannel: `node(${nodeId})`,
             abortSignal: abortController.signal,
+            lane,
           },
           defaultRuntime,
           ctx.deps,
diff --git a/src/gateway/server-methods/chat.ts b/src/gateway/server-methods/chat.ts
index 96730af07..4ac678b1f 100644
--- a/src/gateway/server-methods/chat.ts
+++ b/src/gateway/server-methods/chat.ts
@@ -7,6 +7,7 @@ import { resolveAgentTimeoutMs } from "../../agents/timeout.js";
 import { agentCommand } from "../../commands/agent.js";
 import { mergeSessionEntry, updateSessionStore } from "../../config/sessions.js";
 import { registerAgentRunContext } from "../../infra/agent-events.js";
+import { isAcpSessionKey } from "../../routing/session-key.js";
 import { defaultRuntime } from "../../runtime.js";
 import { resolveSendPolicy } from "../../sessions/send-policy.js";
 import { INTERNAL_MESSAGE_CHANNEL } from "../../utils/message-channel.js";
@@ -299,6 +300,7 @@ export const chatHandlers: GatewayRequestHandlers = {
       };
       respond(true, ackPayload, undefined, { runId: clientRunId });
 
+      const lane = isAcpSessionKey(p.sessionKey) ? p.sessionKey : undefined;
       void agentCommand(
         {
           message: parsedMessage,
@@ -311,6 +313,7 @@ export const chatHandlers: GatewayRequestHandlers = {
           timeout: Math.ceil(timeoutMs / 1000).toString(),
           messageChannel: INTERNAL_MESSAGE_CHANNEL,
           abortSignal: abortController.signal,
+          lane,
         },
         defaultRuntime,
         context.deps,
diff --git a/src/routing/session-key.ts b/src/routing/session-key.ts
index 98c63c3e6..687d63fdc 100644
--- a/src/routing/session-key.ts
+++ b/src/routing/session-key.ts
@@ -1,3 +1,15 @@
+import {
+  parseAgentSessionKey,
+  type ParsedAgentSessionKey,
+} from "../sessions/session-key-utils.js";
+
+export {
+  isAcpSessionKey,
+  isSubagentSessionKey,
+  parseAgentSessionKey,
+  type ParsedAgentSessionKey,
+} from "../sessions/session-key-utils.js";
+
 export const DEFAULT_AGENT_ID = "main";
 export const DEFAULT_MAIN_KEY = "main";
 export const DEFAULT_ACCOUNT_ID = "default";
@@ -11,11 +23,6 @@ export function normalizeMainKey(value: string | undefined | null): string {
   return trimmed ? trimmed : DEFAULT_MAIN_KEY;
 }
 
-export type ParsedAgentSessionKey = {
-  agentId: string;
-  rest: string;
-};
-
 export function toAgentRequestSessionKey(storeKey: string | undefined | null): string | undefined {
   const raw = (storeKey ?? "").trim();
   if (!raw) return undefined;
@@ -70,28 +77,6 @@ export function normalizeAccountId(value: string | undefined | null): string {
   );
 }
 
-export function parseAgentSessionKey(
-  sessionKey: string | undefined | null,
-): ParsedAgentSessionKey | null {
-  const raw = (sessionKey ?? "").trim();
-  if (!raw) return null;
-  const parts = raw.split(":").filter(Boolean);
-  if (parts.length < 3) return null;
-  if (parts[0] !== "agent") return null;
-  const agentId = parts[1]?.trim();
-  const rest = parts.slice(2).join(":");
-  if (!agentId || !rest) return null;
-  return { agentId, rest };
-}
-
-export function isSubagentSessionKey(sessionKey: string | undefined | null): boolean {
-  const raw = (sessionKey ?? "").trim();
-  if (!raw) return false;
-  if (raw.toLowerCase().startsWith("subagent:")) return true;
-  const parsed = parseAgentSessionKey(raw);
-  return Boolean((parsed?.rest ?? "").toLowerCase().startsWith("subagent:"));
-}
-
 export function buildAgentMainSessionKey(params: {
   agentId: string;
   mainKey?: string | undefined;
diff --git a/src/sessions/session-key-utils.ts b/src/sessions/session-key-utils.ts
new file mode 100644
index 000000000..2bc90591d
--- /dev/null
+++ b/src/sessions/session-key-utils.ts
@@ -0,0 +1,35 @@
+export type ParsedAgentSessionKey = {
+  agentId: string;
+  rest: string;
+};
+
+export function parseAgentSessionKey(
+  sessionKey: string | undefined | null,
+): ParsedAgentSessionKey | null {
+  const raw = (sessionKey ?? "").trim();
+  if (!raw) return null;
+  const parts = raw.split(":").filter(Boolean);
+  if (parts.length < 3) return null;
+  if (parts[0] !== "agent") return null;
+  const agentId = parts[1]?.trim();
+  const rest = parts.slice(2).join(":");
+  if (!agentId || !rest) return null;
+  return { agentId, rest };
+}
+
+export function isSubagentSessionKey(sessionKey: string | undefined | null): boolean {
+  const raw = (sessionKey ?? "").trim();
+  if (!raw) return false;
+  if (raw.toLowerCase().startsWith("subagent:")) return true;
+  const parsed = parseAgentSessionKey(raw);
+  return Boolean((parsed?.rest ?? "").toLowerCase().startsWith("subagent:"));
+}
+
+export function isAcpSessionKey(sessionKey: string | undefined | null): boolean {
+  const raw = (sessionKey ?? "").trim();
+  if (!raw) return false;
+  const normalized = raw.toLowerCase();
+  if (normalized.startsWith("acp:")) return true;
+  const parsed = parseAgentSessionKey(raw);
+  return Boolean((parsed?.rest ?? "").toLowerCase().startsWith("acp:"));
+}