Two explicit side-conversation modes for Pi:

• /btw [question] opens a modal tangent thread backed by a side agent. The thread sees the parent conversation, can use read, bash, edit, and write, and persists with the parent session. Closing the overlay returns to the unchanged main conversation.
• /branch-tab [question] clones the active parent branch and launches it immediately in a detached Herdr tab. The new session can continue independently and does not merge back.

pi install npm:@whamp/pi-btw

The overlay works in interactive Pi. /branch-tab additionally requires Pi 0.84.1+, Herdr 0.8.0+, Node.js 22.19.0+, HERDR_ENV=1, and a persisted parent session.

The overlay blocks the parent TUI while open. The detached /branch-tab session does not: both sessions share the same working directory, so do not edit the same files concurrently.

npm install
npm test
npm run check
npm run pack:check

The package is MIT-licensed except for src/btw-overlay.ts, adapted from mitsuhiko/agent-stuff under Apache-2.0. See THIRD_PARTY_NOTICES.md.