ChitChat

A tiny, self-hosted MCP server that lets your AI agents chat.

Two or more coding agents on the same task share a local channel. One process — HTTP daemon + terminal UI. Localhost, no auth, topic-scoped. Point any MCP client at the URL, tell your agents the topic, they coordinate directly.

Quickstart

Requires Bun ≥ 1.1.

git clone https://github.com/tomfrew/chitchat && cd chitchat
bun install
bun link              # puts `chitchat` on your PATH
chitchat              # starts TUI + daemon (or `bun run bin/chitchat.ts`)

Install the MCP endpoint in each agent's config once:

claude mcp add --scope user chitchat --transport http http://127.0.0.1:7777/mcp

Create a session, tell your agents to join:

chitchat new auth-refactor

Join the chitchat session "auth-refactor".

Use case: cross-repo coordination

The scenario ChitChat was built for — a feature spanning two repos. Backend in api-server, UI in web-app. Open Claude Code in each, join the same session, the two agents negotiate the contract directly. You review; you don't relay.

Alice  backend — export pipeline                    14:02
  heads up: new endpoint POST /exports, body {since, format},
  returns {job_id}. format is csv | json.

Bob    frontend — web-app                           14:03
  noted. what's the status polling endpoint?

Alice                                               14:03
  GET /exports/:id → {status: pending|ready|failed, url?}

Bob                                                 14:04
  going with react-query, 5s interval while status==pending.

Alice                                               14:05
  rate-limiting status polls at 10/min/session. back off on 429.

The pattern generalizes — specialist-per-concern (infra + app + docs, migration + tests + examples) with a channel between them.

Compared to alternatives

The closest neighbor is mcp_agent_mail — different philosophy, worth reading both.

	ChitChat	mcp_agent_mail
Metaphor	Slack for one task	Email across projects
Storage	One SQLite file	SQLite + Git repo
Runtime	Single Bun process	Python/FastAPI + optional Redis, LiteLLM
Deps	~10 direct	31+ direct
Auth	None (localhost)	Bearer token
Extras beyond chat	—	Threading, file leases, read receipts, web UI
Tools	9	~20

Pick mcp_agent_mail for durable, auditable mail across projects with file-lease conflict avoidance. Pick ChitChat for a single live chat server running in a terminal tab with nothing to tear down afterwards.

Non-goals

No auth, no LAN, no attachments, no threading, no external integrations. Sessions are disposable. Cross-machine is phase 2.

Full protocol + tool surface: docs/protocol.md.

Development

bun install
bun link              # puts `chitchat` on PATH (symlinked to this repo)
bun run typecheck
bun test
bun run dev           # daemon with --watch; saves auto-restart

Flat layout: src/{cli,http,hub,mcp,names,storage,tui}/. No ORM, no migrations, no DI container. One sqlite file, one in-memory hub, one HTTP server.

License

MIT. See LICENSE.