Agent Plugin

The buildd agent plugin makes your own interactive coding session (Claude Code, Codex or Cursor) visible in buildd from the moment it opens. It bundles the MCP server, a short session skill, and lifecycle hooks.

The MCP server still does all the work: claiming, progress, notes, PRs and completion go through the buildd tool exactly as before. The hooks only tell buildd that the session exists.

What you get

• Presence without a slot. An open session shows under Activity → Interactive sessions as Working, Online, Offline or Ended, with its client and repo. Presence never counts against your agent capacity. A scripted run nobody is attending (claude -p, an SDK script, a Cursor background agent) isn't listed unless it claims a task.
• Claims tie to the session. When your session calls claim_task, buildd links the session to the worker that claim created. The task then shows the client it runs in (for example "Claude Code · local") where a runner name would appear.
• Closing the session releases the task. Exiting a session releases its worker once. An unfinished task goes back to the queue. Nothing is marked completed, and a task you already finished stays finished. /clear keeps the claim, because the session itself is still running.
• Steering reaches you. A message sent with send_agent_message waits in the task's queue. On Claude Code and Codex, the next prompt you submit reminds the agent to pick it up with update_progress.

This pairs naturally with local missions: claim each task from your session, and closing the session gives back anything you didn't finish.

Install

With the buildd CLI (recommended)

Installs the hooks and skill for every client it detects. No credential is written into any hook file; the hooks read the key buildd login stored.

buildd login
buildd install --global          # or `buildd install` inside one repo
buildd install --status --global # see what is installed
buildd install --uninstall --global

Uninstall removes only buildd's own hook handlers. Your other hooks and settings are left as they were.

As a Claude Code plugin

export BUILDD_API_KEY=bld_your_api_key
claude plugin marketplace add buildd-ai/buildd
claude plugin install buildd@buildd

Client notes

• Codex asks you to trust each new hook before it runs. Review them with /hooks after installing; buildd does not pre-trust them. Add the MCP server with the codex mcp add command the installer prints.
• Cursor resolves project hook commands from the project root. The CLI writes absolute paths, so prefer it to copying hook files by hand. Add the MCP server under Settings → MCP.

What the hooks send

Four events, and nothing else: start, touch (at most once a minute), bind (after your own claim_task succeeds) and end. Each carries the client name, a session id, the client version where the client reports one, and the repo as owner/name. Credentials and host are stripped from the remote URL before it leaves your machine.

The hooks never send prompts, responses, reasoning, transcripts, tool output or secrets, and buildd rejects any event carrying an extra field. The session id is stored only as a hash.

The hooks always fail open. If buildd is down, slow, or you aren't logged in, the hook exits quietly within a few seconds and your session carries on.

Client support

If a session crashes without sending end, it reads Offline after about ten minutes, and its task is released by the normal idle timeout for interactive sessions.

Configuration

Without the hooks, everything still works over MCP alone. buildd just doesn't see your session until it claims a task.