pi-session-surgery

A destructive Pi extension that rebuilds a session without persisted tool history.

This is not context pruning. It rewrites the session JSONL file into a smaller replacement session, then switches Pi to that session.

Safety model

• /session-surgery shows the preview and always asks for confirmation.
• The original JSONL is copied to ~/.pi/agent/session-backups/<session-id>/ first.
• The replacement is validated before Pi switches to it.
• The backup is never overwritten by restore.
• The old visible session file is removed only after the switch succeeds.

The replacement keeps user messages, assistant text and thinking, model and thinking-level changes, session info, compaction records, and its surgery metadata. It removes tool calls, tool results, bash execution records, and other extension entries.

Each slim session stores a non-context link to the backup of its immediate parent. This lets restore find the right manifest without a path.

Commands

/session-surgery
/session-surgery restore
/session-surgery restore ~/.pi/agent/session-backups/<session-id>/<backup>/manifest.json

restore without a path restores the immediate parent backup linked to the current session. Both forms show the backup details and ask for confirmation.

The package uses Pi's switchSession() lifecycle. It does not patch Pi's core or call reload as a substitute for session switching. Release steps are documented in RELEASING.md.

Development

npm install
npm run check