Core insight: the most expensive failures arrive quietly and multiply; intentional, small canaries surface those cascades early so reversions stay cheap. The Canary File is a tiny habit you create in under ten minutes for any initiative: pick 3 high‑signal sentinels (one technical, one behavioral, one reputation/ops), define a cheap proving action that exercises the edge case, and attach an immediate rollback + comms snippet. In this episode I give the exact one‑line Canary token, three deployment patterns (internal smoke canary, partner-facing canary, public-safe canary), and two constrained AI patterns to 1) auto-synthesize candidate sentinels from logs and memos and 2) simulate canary outcomes with provenance lines. You get a 7‑day pilot: attach a Canary File to one launch, run the cheap repro each day, and commit to the rollback if any sentinel trips. CTA: subscribe. Stay agentic.