Research on garrytan/gstack surfaced 5 patterns worth importing into
our cron / agent setup. These are skills, not platform code — they
guide how the cron and our own subagents work, not what the platform
does at runtime.
## New skills
1. **cross-vendor-review** — adversarial second-model review for
noteworthy PRs (auth, billing, data deletion, migrations). Catches
the 15-30% of bugs single-model review misses. Inspired by
gstack's /codex.
2. **careful-mode** — REFUSE/WARN/ALLOW lists for destructive
commands. Refuses force-push to main, blocks merging draft PRs,
prevents rm -rf outside scratch dirs. Inspired by gstack's
/careful + /freeze.
3. **cron-learnings** — per-project JSONL of operational learnings
appended at the end of every tick, replayed at the start of the
next. Stops the cron from re-litigating decided issues.
Inspired by gstack's /learn.
4. **cron-retro** — weekly retrospective auto-posted as a GitHub
issue. Sunday 23:07 local. Tracks PR count, time-to-merge, gate
failure trends, code-review severity over time. Inspired by
gstack's /retro.
5. **llm-judge** — cheap LLM-as-judge eval to catch "agent shipped
the wrong thing" — the failure mode unit tests miss. Plug into
issue-pickup pipeline so worker-agent draft PRs get scored before
being marked ready. Inspired by gstack's tier-3 test infra.
## Cron updates (session-only, c5074cd5 + 060d136c)
- Hourly triage cron now opens with careful-mode activation +
cron-learnings replay (Step 0)
- code-review skill on every PR being considered for merge
(Step 2 supplement A — already present, formalized)
- cross-vendor-review on noteworthy PRs (Step 2 supplement B — new)
- llm-judge on issue-pickup draft PRs before marking ready (Step 4)
- Status report now includes cross-vendor pass/fail and llm-judge
scores (Step 5)
- End-of-tick cron-learnings append (Step 5)
- New weekly cron at Sun 23:07 invokes the cron-retro skill
## What we did NOT take from gstack
- Their browser fork — not our product
- The 23 named roles — we have agent role templates already
- Bun toolchain — adds yet another runtime to our stack
- /design-shotgun and design-tool variants — we're not a design tool
- /document-release — our update-docs skill already covers this
See PR description for full research notes.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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