Recall

Query the session activity index for event history, file change logs, decisions, and errors. The session index is written continuously by the PostToolUse hook and persists across compaction events.

Skill type: Rigid -- follow exactly, no shortcuts.

Execution model: Direct execution by the orchestrator. No subagent dispatch. No Agent/Task tool needed.

Announce at start: Output [recall] Querying session activity index... before any processing.

Session Index Discovery

The session index lives at:

~/.claude/projects/<project-hash>/memory/session-index/<session-id>/
  events.jsonl      # append-only event log
  summary.md        # rolling narrative summary

Discover the index path:

1. Compute project hash: echo -n "<absolute project dir>" | sha256sum | cut -c1-16
2. Glob for ~/.claude/projects/<hash>/memory/session-index/*/events.jsonl
3. Pick the most recently modified events.jsonl — its parent directory is the active session index
4. If no session index exists, return:

   No session index found. Enable session indexing by adding the PostToolUse hook — see hooks/README.md.

Tool constraint: Use Read and Glob tools for session-index access. Do not use Bash to access ~/.claude/ paths (safety hooks block this).

Query Modes

No Arguments: /recall

Return the full contents of summary.md. If summary.md does not exist but events.jsonl does, read the last 20 entries from events.jsonl and format them as a table.

Keyword Search: /recall what files did I edit

1. Read events.jsonl using the Read tool
2. Search all entries for lines containing any of the query keywords (case-insensitive match on the summary and detail fields)
3. Return up to 20 most recent matching entries, formatted as a table

Type Filter: /recall errors, /recall decisions, /recall edits

Map common words to event types:

Query Word	Event Type(s)
errors	error
decisions	decision
edits, files	file_edit, file_create
commits	git_commit
tests	test_run
phases	phase_change

Filter events.jsonl to matching types. Return up to 20 most recent entries.

Time Range: /recall last 30 minutes, /recall last hour

Parse the time expression:

• "last N minutes" -> filter events with ts within the last N minutes
• "last N hours" / "last hour" -> filter events within the last N hours
• "today" -> filter events from today (UTC)

Return up to 20 most recent matching entries.

Output Format

For summary mode (no arguments), return the raw summary.md content.

For filtered/search results, format as:

## Recall: [query description]
**Showing:** [N] events from [time range or filter description]

| Time | Type | Summary |
|------|------|---------|
| 14:30 | file_edit | Modified src/auth/middleware.ts: added rate limiting |
| 14:32 | file_create | Created docs/plans/auth-rate-limit.md |
| ... | ... | ... |

Cap output at 20 entries. If more entries match, note the total: *(showing 20 of 47 matching events)*.

Event Schema Reference

Each line in events.jsonl follows this schema (see skills/shared/session-index-convention.md for full details):

{
  "ts": "2026-04-07T14:30:00Z",
  "seq": 1,
  "type": "file_edit | file_create | git_commit | git_checkout | test_run | error | decision | phase_change | skill_start | skill_end",
  "summary": "One-line human-readable summary, max 120 chars",
  "detail": { "type-specific payload" }
}

Integration with Pipeline Skills

Pipeline skills can invoke /recall internally after compaction to supplement CSB-based recovery:

1. Existing recovery: Read CSB / pipeline-status.md / handoff manifest
2. Supplementary: Read summary.md from the session index for narrative context
3. Targeted: Query specific events via /recall for focused context (e.g., /recall errors to recover error history)

This is additive -- it does not replace existing recovery mechanisms.

Red Flags

• Using Bash to access ~/.claude/ paths (use Read/Glob tools instead)
• Treating session index as authoritative over CSB state (session index is supplementary narrative, CSB is authoritative state)
• Returning more than 20 events in a single recall (wastes context budget)
• Failing silently when the session index is missing (must return a helpful message pointing to hook setup)