Show HN: Give your coding agents the ability to message each other

5 months ago

MCP Agent Mail is a coordination layer for coding agents, providing email-like features such as identities, inbox/outbox, and searchable message history.
It includes advisory file reservation 'leases' to prevent agents from overwriting each other's work and supports GitHub-Flavored Markdown messages with images.
The system is designed for FastMCP clients and CLI tools (e.g., Claude Code, Codex, Gemini CLI) to coordinate across one or more codebases.
Installation is straightforward with a provided script that sets up a Python 3.14 virtual environment and starts an HTTP server on port 8765.
Key features include registering agent identities, sending/receiving messages, managing file reservations, and searching message history.
The system integrates with Git for human-auditable artifacts and SQLite for indexing and queries.
A web UI is available for human operators to review agent activity, browse messages, and perform searches.
Human Overseer feature allows human operators to send high-priority messages to agents, which are clearly marked and prioritized.
The system supports cross-project coordination with AI-powered project discovery and explicit contact approvals.
Configuration is managed via environment variables, with options for JWT authentication, rate limiting, and logging.
The project is under active development, with detailed design captured in project_idea_and_guide.md.

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