summary: "Overview and quickstart for @tryinget/pi-telemetry." read_when:

• "Starting work in this package workspace."
• "Changing telemetry collection, shards, aggregation, review snapshots, or the dashboard." system4d: container: "Monorepo package for Pi runtime telemetry." compass: "Make runtime behavior observable as bounded metadata, for the operator and the agent, without creating a new authority surface." engine: "Pi events -> metadata-only records -> day shards -> bounded aggregates -> dashboard/tool/review snapshot." fog: "The trap is telemetry drifting into payload capture, secret storage, evidence authority, or automatic KES promotion."

@tryinget/pi-telemetry

Mirror-only runtime telemetry for Pi: compaction lifecycle, tool calls, Prompt Vault queries, skill loads, self-driving follow-up outcomes, and subagent dispatches.

pi events -> pi.telemetry.v1 records -> ~/.pi/agent/telemetry/<day>.jsonl shards
          -> /telemetry HTML dashboard (operator)
          -> telemetry tool aggregates (agent)
          -> /telemetry review digest-bound observation snapshot (explicit handoff)

Surfaces

• Collector (src/collector.ts) — subscribes to tool_call/tool_result/ tool_execution_end, turn_start, session_before_compact, session_compact. Metadata-only: tool names, ok/fail, duration, bounded error first-line signatures, skill names, typed delivery outcomes. Never payloads, message text, or secrets.
• Store (src/store.ts) — append-only NDJSON day shards with 2 MB rotation, 30-day retention pruning, and windowed reads. PI_TELEMETRY_DIR overrides the directory; PI_TELEMETRY_DISABLED=1 disables collection.
• Aggregates (src/aggregate.ts) — bounded summaries: per-day/per-kind counts, top failing tools, compaction pressure (including unresolved begins = failed/aborted passes and stalled-after-compaction counts), vault/skill usage, follow-up outcomes, subagent throughput per profile.
• /telemetry [days] — regenerates a self-contained HTML dashboard (inline data, no external assets, no server) at <telemetry-dir>/dashboard.html.
• /telemetry review [days] — writes a bounded pi.telemetry-review-snapshot.v1 JSON artifact under <telemetry-dir>/reviews/. The snapshot binds the exact window, producer version, live/backfill coverage, controlled metrics, bounded breakdowns, source-event-set digest, explicit nonclaims, and a canonical snapshot digest. It excludes session IDs, working directories, raw errors, payloads, queries, and message text. Its reader rejects duplicate JSON members and final-component symlinks; files are owner-only, single-link regular files and are checked for mutation during reads.
• /telemetry backfill [days] — derives telemetry from persisted session JSONL into <day>.backfill.jsonl shards (idempotent per session file, skips sessions already covered by live collection). Backfilled events carry source: "backfill" so measured-live vs derived-from-history stays distinguishable in aggregates and the dashboard provenance line. Derivation coverage is honest: compaction, turns, tool calls (no durations), skill loads. Live-only kinds (follow-up, vault, subagent, compaction_failure, compaction_begin) are never backfilled because session JSONL does not hold them completely.
• telemetry tool — model-callable bounded aggregates: telemetry({ window_days: 7, group_by: "day" | "kind" | "tool" }).
• Review API (@tryinget/pi-telemetry/review-snapshot) — builds, validates, safely loads, and writes the published snapshot contract. The JSON Schema is schemas/telemetry-review-snapshot-v1.schema.json.

Review and KES handoff

A review snapshot is an observation artifact, not an evidence receipt or learning. An owning workflow may explicitly:

1. validate the snapshot and digest;
2. persist a bounded reference in Agent Kernel;
3. route it to the applicable owner-local KES adapter;
4. crystallize at most a candidate learning;
5. submit that candidate to a separate content-review lifecycle.

No step authorizes the next automatically. A crossed metric threshold is a review trigger, not causality proof, verified evidence, KES acceptance, or content promotion. See docs/telemetry-review-snapshots.md.

Boundaries

• Telemetry is a mirror-only projection. It is not AK/KES evidence, not decision authority, and not a durable owner surface.
• Review snapshots preserve source coverage and metric-domain sample size. Most samples are event counts; message-omission rate uses compacted-message count and may exceed the number of telemetry events.
• Missing or zero events may reflect disabled collection, retention, malformed/unavailable shards, incomplete backfill, or no observed activity.
• The source-event-set digest excludes session IDs, working directories, and raw error signatures. Aggregate failures remain visible without making private origin or error prose observable through digest changes.
• Compaction failures are emitted at the source: pi-session-compaction records stage-tagged compaction_failure events (preset / preset_directive / default_preset / stock_fallback / final) through @tryinget/pi-telemetry/emit at every fallback and failure site. Unresolved-begin counts remain the fallback signal for hosts or versions without that emitter.
• Stall detection correlates compaction ends with subsequent turn_start events in the same session (10-minute threshold) and only covers sessions observed live by this collector.

Development

npm run check     # lint + typecheck when configured + tests + release contract
node --test tests/*.test.mjs