Auto Agent Claude Code plugin

The local half of Auto Agent's Send to Claude. On a web app running on your machine (localhost, 127.0.0.1, *.localhost), the Auto Agent browser extension lets you pick an element, say what is wrong (or rewrite its text in place, or comment on the page) and press Send to Claude. This plugin receives that feedback and hands it to the Claude Code session working on the app's repository, which fixes it and reports back to the extension.

Chrome: Auto Agent extension ──WebSocket, 127.0.0.1──▶ auto-agent plugin ──MCP──▶ Claude Code
   pick · comment · send                                   queue                fixes the code
   ◀──────────────── Queued → Claude is fixing → Done, with a summary ──────────────────────

Pages on deployed demos are unaffected: there the extension still sends feedback to Auto Agent.

Watch the guide

https://github.com/user-attachments/assets/a61e9003-7a13-4883-a139-f99ebdc2c938

A 76-second walkthrough, no sound: install the plugin, start Claude with the channel, pin feedback on an app running on localhost, send it, and review Claude's fix. To download it: docs/media/auto-agent-claude-code-guide.mp4.

Related MCP server: mcp-comfyui

Install

Requires Node.js 20 or newer, Claude Code, and the Auto Agent extension in Chrome.

In Claude Code, in your project:

/plugin marketplace add saigontechnology/auto-agent-mcp
/plugin install auto-agent@auto-agent

Or from a terminal:

claude plugin marketplace add saigontechnology/auto-agent-mcp
claude plugin install auto-agent@auto-agent

saigontechnology/auto-agent-mcp is short for https://github.com/saigontechnology/auto-agent-mcp.git; either works. The marketplace is named auto-agent and holds one plugin, also named auto-agent.

Restart Claude Code. The plugin starts one server per session. There is nothing to pair: the extension finds the session by itself. If it ever does not, see Connect manually.

To get a newer version later:

/plugin marketplace update auto-agent

Let Claude start fixing as soon as feedback arrives (optional)

Channels are a Claude Code research preview. To have feedback pushed straight into the session, start Claude with:

claude --dangerously-load-development-channels plugin:auto-agent@auto-agent

Claude Code shows a warning first; choose I am using this for local development. A shell alias helps: alias claudefix='claude --dangerously-load-development-channels plugin:auto-agent@auto-agent'.

Without the flag everything still works: run /auto-agent:fix when the extension shows Queued. /auto-agent:connect prints the code for Connect manually. A hook also reminds Claude of waiting feedback when you send a prompt.

Use it

1. Start Claude Code in your app's repository (with the channel flag above if you want fixes to start on their own), run the app, and open it on localhost.

2. Click the Auto Agent icon to open the panel. No sign-in is needed on a local page. The panel shows To Claude · <repository>. If no session is found yet, it lists the install steps; start Claude Code and press Retry. With several sessions running, pick one (remembered per site; Change picks another).

3. Choose Select and click an element, say what should change, and press Save. Text rewrites a piece of text in place, and Add page comment covers the whole page. Each draft is numbered on the page.

4. Press Send N drafts to Claude. The batch shows Queued, then Claude is fixing, then Done, Partly done or Couldn't fix, with Claude's summary and each item's outcome.

Feedback sent while Claude Code is closed shows Not yet received and goes out when it starts. A queued batch can be cancelled, and a batch Claude Code refused can go back to drafts.

Connect manually

The extension looks for sessions on ports 47320–47329 every few seconds. When it does not find yours (the session list is empty, the wrong session is shown, or it stays on Waiting for Claude Code):

1. Press the refresh icon (↻) next to Change, or at the top of the session list, to look on every port again, including ports that refused an earlier handshake.

2. Still not there? In Claude Code, run:

   /auto-agent:connect

   Claude calls auto_agent_get_session and prints this session's connect code, <port>:<sessionId>, for example 47321:690c66af-7bf3-4388-9a9a-9fca822f294b. You can also ask Claude for auto_agent_get_session directly.

3. In the panel, choose Connect manually (on the "No Claude Code session" card, or Change → Connect manually), paste the code and press Connect. The extension connects straight to that port, checks that the session id matches, and sends this site's feedback to that session from then on.

4. The panel shows To Claude · <repository> for the session the code named. Change and the refresh icon stay next to it.

The code changes every time the Claude Code session restarts; run /auto-agent:connect again for the new one.

If /auto-agent:connect reports that the session has no extension link, all ten ports are taken (or the server could not start): close a Claude Code session you no longer use and restart this one.

What Claude gets

A batch can be claimed by one session only, so two Claude windows on the same repository never fix the same feedback twice.

Security model

• The server listens on 127.0.0.1 only, on the first free port of 47320–47329, path /auto-agent.

• A connection must come from the Auto Agent extension (Origin: chrome-extension://halobcdjpokedneejfmdjecjgdkejjdk) to a loopback Host; web pages, other extensions and DNS-rebinding hosts are refused at the handshake. There is no pairing token.

• Everything captured from a web page is passed to Claude as fenced, untrusted data with an instruction never to follow it.

• The server has no tool that runs commands or writes files in your repository; code changes go through Claude's normal permissions.

Files

~/.auto-agent/                0700
  queue/<repo-key>/<batch>/   batch.json, state.json

Finished batches are deleted after 7 days. Set AUTO_AGENT_HOME to use another directory.

Protocol

The extension and server speak protocol 1 over WebSocket. Types, schemas and the batch markdown renderer are in @auto-agent/protocol (packages/protocol), which the extension links to.

Development

git clone https://github.com/saigontechnology/auto-agent-mcp.git auto-agent-claude-plugin
cd auto-agent-claude-plugin
pnpm install
pnpm test          # unit tests
pnpm test:e2e      # builds, then drives plugin/dist/server.mjs end to end
pnpm build         # rebuild plugin/dist (commit the result; a test checks it is fresh)
pnpm compile       # type-check
pnpm bump-version-patch   # or -minor / -major: bump the version everywhere and rebuild plugin/dist (do this in every release PR)
pnpm --filter @auto-agent/protocol build   # build the protocol package the extension links to

The extension repository links @auto-agent/protocol from ../auto-agent-claude-plugin/packages/protocol, so check the two repositories out next to each other.

AUTO_AGENT_EXTENSION_IDS=<id>[,<id>] allows extra extension ids, for unpacked builds made without the Auto Agent key.

Design: docs/specs/2026-10-02-claude-plugin-design.md.

Origin

Forked from PickFix (github.com/ledutu-studio/pickfix-mcp at 1c01a8c), MIT. See LICENSE.

Tiếng Việt

Plugin này nhận feedback từ extension Auto Agent khi bạn review app chạy ở localhost, rồi chuyển cho Claude Code đang mở trong repo của app để sửa. Xem video hướng dẫn (tiếng Anh, 1 phút 16 giây): docs/media/auto-agent-claude-code-guide.mp4.

1. Cài trong Claude Code (cần Node.js 20 trở lên): /plugin marketplace add saigontechnology/auto-agent-mcp rồi /plugin install auto-agent@auto-agent, sau đó khởi động lại Claude Code. Không cần ghép cặp. Cập nhật bản mới: /plugin marketplace update auto-agent.

2. Muốn Claude tự sửa ngay khi nhận feedback: mở Claude bằng claude --dangerously-load-development-channels plugin:auto-agent@auto-agent.

3. Không dùng cờ đó thì gõ /auto-agent:fix khi panel hiện Queued.

4. Mở app ở localhost, mở panel Auto Agent (không cần đăng nhập), chọn Select rồi click vào phần tử cần sửa, ghi nội dung và Save, cuối cùng bấm Send N drafts to Claude. Panel hiện Queued → Claude is fixing → Done kèm tóm tắt của Claude.

Kết nối thủ công

Extension tự dò các port 47320–47329 vài giây một lần. Nếu panel không thấy phiên Claude Code của bạn:

1. Bấm icon refresh (↻) cạnh Change hoặc ở đầu danh sách phiên để dò lại tất cả port.

2. Vẫn không thấy thì gõ /auto-agent:connect trong Claude Code. Claude gọi auto_agent_get_session và in ra mã kết nối dạng <port>:<sessionId>, ví dụ 47321:690c66af-7bf3-4388-9a9a-9fca822f294b.

3. Trong panel, chọn Connect manually (hoặc Change → Connect manually), dán mã rồi bấm Connect. Extension nối thẳng vào port đó, kiểm tra session id có khớp không, rồi từ đó gửi feedback của trang này tới phiên ấy. Panel chuyển sang To Claude · <tên repo>. Ảnh minh hoạ từng bước có ở mục Connect manually.

Mã đổi mỗi khi phiên Claude Code khởi động lại, lúc đó chạy lại /auto-agent:connect. Nếu panel báo The extension did not respond, extension vẫn đang chạy bản cũ: vào chrome://extensions và bấm reload ở Auto Agent (/reload-plugins chỉ nạp lại plugin, không nạp lại extension). Các lỗi khác và cách xử lý: xem bảng ở mục Connect manually.