pi-fast-resume

Fast session resume for pi coding agent without reading all .jsonl files.

Problem

Built-in /resume reads and parses every line of every session file to build the picker. With hundreds of sessions this is slow.

Solution

Commands that use stat() + lazy partial reads:

Command	What it does	Speed
/r1 … /r5	Instantly switch to the N-th most recent session (/r1 = latest)	<50ms (stat-only)
/rs	Paginated picker: last 20, with tier navigation	<200ms first page
/rds	Delete subagent session trees for the current project (with confirmation)	—

Install

pi install npm:pi-fast-resume

Commands

/r1 … /r5 — Instant Ranked Resume

Switch to the N-th most recent session (by mtime) in one step. No picker, no parsing.

• /r1 — most recent session
• /r2 — 2nd most recent
• … up to /r5 — 5th most recent

The current session is always excluded from the ranking, so /r1 reliably jumps to the previous session. If fewer sessions exist than the requested rank, a notice is shown and nothing is switched.

/rs — Smart Resume

Shows a paginated list of recent sessions:

• Relative time (e.g., "2h ago"), file size, session name or first message
• ▼ Load more... — next page within current filter
• ▼ Show 14d — expand to 14 days
• ▼ Show all — remove day filter entirely

Auto-escalates: if 7d is empty, jumps to 14d, then all.

Configuration

/rs set page 30    # Sessions per page (1-50, default: 20)
/rs set days 14    # Day filter for first tier (0-30, 0 = no filter, default: 7)

Config is stored in ~/.pi/agent/extensions/pi-fast-resume/config.json.

/rds — Delete Subagent Sessions

pi stores every subagent run under a subdirectory named like a top-level session (<timestamp>_<uuid>/), containing <runId>/run-N/session.jsonl. These accumulate on every subagent invocation and can bloat the sessions folder by hundreds of MB.

/rds scans the current project only, shows how many trees / runs / MB would be freed, asks for confirmation, then recursively deletes just those subagent tree subdirectories. Your real top-level *.jsonl sessions (the ones /r1…/r5 and /rs list) are never touched.

How it works

1. /r1…/r5: readdir → stat each .jsonl → sort by mtime → exclude current → switchSession(others[rank-1])
2. /rs: Same stat scan, then read only the first ~50 lines of each file on the current page to extract session name and first user message

No full file parsing. No buildSessionInfo(). No reading message content beyond the first user message.

Development

git clone https://github.com/spex66/pi-fast-resume.git
cd pi-fast-resume
npm install
npm test

License

MIT