Session Observatory — Live Event Logging
Most session retrospectives are written from memory at the end. Memory is lossy. This skill captures the habit of logging events as they happen, so the retrospective has real data to work with.
When to Activate
- At session start — log
start <mission-name>as one of the first
Bash tool calls, so the started_commit is recorded.
- When friction hits — hook fired repeatedly, tool failed, command took
longer than expected, user corrected you.
- When something works unusually well — a technique that you'd recommend
to future sessions.
- Before and after irreversible actions — commits, pushes, destructive ops.
- On progress markers — every ~10% through a long job.
- At session close — log
end, then rungenerate.mjsto produce the
SESSION-RETRO.md.
Commands
# Start
node tools/session-retro/observe.mjs start "<mission-name>"
# Log an event
node tools/session-retro/observe.mjs event <kind> "<label>" '<json-payload>'
# Check in on the log
node tools/session-retro/observe.mjs status
# End (archives current.jsonl to a dated file)
node tools/session-retro/observe.mjs endEvent Kinds (standard)
| Kind | When | Example label | |------|------|---------------| | friction | Something took more effort than it should have | "read-before-edit hook fired N times" | | win | Something worked notably well | "idempotent pipeline saved 3 re-runs" | | correction | User or hook corrected direction | "user reminded: no Co-Authored-By" | | tool-use | Notable tool invocation | "installed better-sqlite3 as optional dep" | | decision | Judgment call deserving review | "committed 1,881 generated files" | | gap | Missing skill/agent/chipset | "no batch-rewriter for N-script cascade" | | checkpoint | Progress marker for long-running work | "Pass 2 chapters: 300/602" |
Free-form kinds are allowed but less useful for aggregation. Prefer the standard list.
Payload Conventions
Payloads are free-form JSON. Common fields:
count— numeric count of the occurrencefile/files— paths involvedduration_min— wall-clock timecost/tokens— resource spendimpact—"workflow"|"output"|"blocked"|"none"opportunity— what skill/agent would have helped
Retroactive Logging
If you didn't log live, you can backfill at session close by reviewing what happened and calling observe event for each remembered moment. Better than nothing. The timestamp will be session-end rather than event-time, but the kinds and labels are still useful.
Integration with Retrospective Generator
Events from current.jsonl are consumed by tools/session-retro/generate.mjs and rendered in the SESSION-RETRO.md under Observations, grouped by kind. The human-authored sections (What Worked, What Could Be Better) then reference specific events as evidence.
Example — This Skill's First Use
The release-history feature session logged 33 events retroactively:
- 6 friction (read-before-edit fires, 11-script cascade, no checkpoint for
LLM run, ghost-seeding cascade, over-eager regex, hidden drift)
- 4 wins (background Monitor, idempotent pipeline, recursive self-improvement,
fresh-repo demo)
- 3 corrections (no Co-Authored-By, dev not main, link chapter files)
- 4 decisions (publish full tree, SQLite default, allowlist gates, Commits column)
- 4 gaps (batch-rewriter, portable-schema, decision-framework, session-token)
- 3 tool-uses (better-sqlite3, claude -p, git tags)
- 9 checkpoints (pass-by-pass progress)
Those 33 events became the concrete evidence for the retro's "What Worked" / "What Could Be Better" / "Recommendations" sections.
Anti-patterns
- Logging every command. Too noisy. Log inflection points.
- Vague labels. "Problem happened" is useless. "Retro extractor missed
H3 headings — 57 files hid as a result" is useful.
- Skipping at session close. The log isn't useful if
endnever runs
and the JSONL never archives. Generate the retro before context dies.
Related
tools/session-retro/observe.mjs— the logger itselftools/session-retro/generate.mjs— the retrospective generatordecision-framework-invoker— often co-fires withdecisionevents