Trust & methodology

How Deprecast detects API changes

Every primary alert shows a trust receipt: source, method, and freshness. This page explains what those fields mean — and what we deliberately do not do.

What we watch

  • OpenAPI diff — where a vendor publishes a machine-readable OpenAPI (or equivalent) spec, we snapshot and diff successive versions for removed paths, methods, required fields, and other breaking schema moves.
  • Changelog — where vendors publish RSS/Atom or HTML changelogs, we fetch public feeds and classify entries for deprecation, sunset, and breaking language.
  • Manual/curated — rare curated notices when a public feed is not yet wired; always labeled as such on the receipt.

What we do not do

  • No customer API keys — we never ask for or store your production vendor credentials.
  • No traffic sniffing, APM agents, or gateway mirrors of your runtime calls.
  • We do not claim to see private / authenticated-only vendor docs behind your account.

Critical-only surfaces

Public radar, digests, and the default dashboard event stream filter to actionable API risk: deprecations, sunsets, removals, and breaking changes. Pure additive “new feature” notes are dropped so the feed stays operator-grade.

Severity chips (urgent vs digest) reflect how loud we think the signal should be — urgency is not a confidence score.

Reading a trust receipt

Source
Link to the vendor changelog, spec, or docs page when we have one. If missing, we say “Source unavailable” instead of hiding the field.
Method
How the change was detected: OpenAPI diff, Changelog, or Manual/curated.
Freshness
Prefer the vendor’s published release time when known; otherwise “First seen” when Deprecast first recorded the event. We do not invent clock precision the source did not provide.

Cadence, false positives, silence

  • Fetch cadence is best-effort continuous monitoring — not a contractual SLA on Free or Indie.
  • Silence can mean “nothing broke” or “source paused / fetch error.” Per-vendor scan health detail is a P1 follow-up; today, empty radar states say so honestly.
  • Dashboard thumbs up/down (with optional reason chips) let you mark signal quality per event without removing a vendor from the watchlist.
  • Labeled sample / demo events are for empty-stream onboarding only — never mixed in as live detections without a badge.