Postbag is a local MCP server that lets Claude Code and Codex ask each other for code reviews
Both sessions join a named "bag" in the same repo, and a review request or reply lands in the other agent as a new turn through its own input, with no daemon, polling, or hooks and one shared local log. The MIT server needs Python 3.10+ and a Codex CLI with codex queue, installs with pipx install 'postbag[mcp]', and is tested on macOS.
