$ cat ~/map/pi-duo.md

pi-duo

Two persistent, resumable peer agents — Austin implements up front, Tony verifies behind — sharing each other's live session context.

extensions✓ Sep 19

Run pi install git:github.com/atfa/pi-duo, then /reload; pi -e git:github.com/atfa/pi-duo loads the extension for one session without writing the install config. Requires pi 0.85.1 or newer.

## TL;DR

A pi extension that runs two persistent, resumable pi sessions on one project: Austin implements in the foreground while Tony investigates, tests, and reviews in the background, exchanging messages through each other's real session context under a shared goal, todo, and decision surface.

## Key points

• $Peers with real context: duo_send delivers a message into the peer's persistent session instead of a markdown file, and both sides keep independent, resumable histories — /duo stop preserves history and /duo resume brings both sessions back.
• $A shared surface inside the project: goals, todos, decisions, a message audit trail, and workspace ownership persist under .pi-duo/, which the README recommends gitignoring.
• $Single-writer by default: in austin-only mode Austin is the only writer of project files while Tony sticks to read-only analysis and testing; the transferable mode lets the two hand workspace ownership over explicitly.
• $Loop protection: a total message budget, consecutive peer-only limits, suppression of similar messages, and deferred slots for key messages keep the two agents from talking in circles.
• $Concurrency safety: revision counters, atomic renames, cross-process locks, and stale-lock recovery guard the shared state; pi-duo is not an OS-level sandbox, and the README suggests git repositories or throwaway branches while it is in beta.
• $Optional model split: both roles can share one model or run different providers and models, provided the current pi configuration can reach both; pi-duo ships no API keys of its own.

## FAQ

## References

• README ↗

Last updated: Sep 19, 2026