@maxdai/pi-session-modify

A Pi extension that edits the current session's history in place: rewrite one message, or drop one whole turn.

Two commands:

| Command | What it does | |---|---| | /psm-edit | Pick one message on the current branch (user / assistant / toolResult), edit its text in Pi's own editor, then reload | | /psm-remove | Pick one turn (a user message and everything it caused) and delete it, then reload |

Both work by rewriting the affected lines of the session JSONL and reloading that same file, so the transcript redraws from disk and the model sees the new content on the next request.

Install

pi install npm:@maxdai/pi-session-modify

Or add it to ~/.pi/agent/settings.json:

{
  "packages": ["npm:@maxdai/pi-session-modify"]
}

Usage

/psm-edit      → list of messages → pick one → edit → Enter
/psm-remove    → list of turns    → pick one → confirm

• The list is windowed (↑↓ / jk / PgUp PgDn / g G), oldest at the top, cursor starts on the newest entry
• /psm-edit opens Pi's editor: Enter submit, Shift+Enter newline, Ctrl+G hand off to $EDITOR
• Edits replace the text blocks only; thinking, toolCall and image blocks are kept as they are
• Text-only assistant turns (toolCall without text) are not offered for editing
• /psm-remove keeps bookkeeping entries (usage, model_change, labels, context_edit, …) and reparents them, so only the conversation goes away

What it touches on disk

Next to the session file, in the same directory:

| File | Purpose | |---|---| | <session>.psm-log | append-only undo log: the original line for every edit, the removed lines for every delete, and every parentId change | | <session>.psm-tmp | transient temp file, renamed over the session on success |

Nothing else. Files ending in .psm-log / .psm-tmp are ignored by Pi's session list.

Safety

• The session file is version-checked before writing and re-read afterwards: entry count, id set and every parentId must still resolve, or the command reports a failure
• The log line is written before the session file, so a crash between the two leaves a record, not a silent change
• /psm-remove refuses to run when the turn contains a compaction.firstKeptEntryId (deleting it would silently drop the context that follows) or when another branch hangs off the removed range
• Writes are synchronous end to end, so a background writer in the same Pi process cannot interleave between reading and renaming
• The whole-file backup is deliberately not taken: it would discard entries appended after the edit. The .psm-log restores any single change exactly

Requirements

• Pi ≥ 1.4.0
• Session format version 3
• Reloading happens through ctx.switchSession(). The TUI redraws itself; pi-web needs ≥ 1.2.10 to refresh the browser on an extension-driven session change (older versions: reload the page manually)
• One Pi process per session file (Pi does not lock session files)

Limits

Not supported on purpose:

• inserting a new message into the middle of a history
• editing custom_message entries
• editing across branches (only the current branch is listed)
• remembering the previous selection (one command, one change, done)

License

MIT