OOMPF

Provenance and revisions

Provenance is what lets you trust and reproduce a shared profile. OOMPF keeps just enough to re-fetch and re-verify the source — and nothing that would leak its contents.

What OOMPF records

  • Canonical source URL — the normalized public Gist URL, unique across the index. It is the source of truth; OOMPF stores no YAML bytes.
  • Source revision — the GitHub revision (git SHA) of the exact snapshot OOMPF indexed. On the profile page it links to the corresponding Gist revision when available.
  • Content fingerprint — the SHA-256 of the exact YAML bytes OOMPF indexed. It is copyable and explained as a verification value, and it is re-checked at install time.
  • Profile id — a stable opaque id derived from the canonical source URL. It is represented by the page URL, https://oompf.run/p/<id>, and is not printed as a second redundant identifier.

Freshness

A pinned revision is reproducible but says nothing about whether the source moved on. Every six hours OOMPF re-fetches each indexed source’s current head and records four facts, all visible on the profile page and in the profile metadata API:

  • Last checked — when the source was last re-fetched. Absent until the first sweep reaches that profile.
  • Changed since indexed — when the source was first observed to differ from the indexed fingerprint. While this is set, the page’s facts describe the earlier revision, and re-registering the source brings the record up to date.
  • Consecutive check failures — a single failure is reported as a failed check and retried; repeated failures flag the source as unreachable, which is what a deleted or newly private Gist looks like. GitHub answers 404 for both, so the flag stays reversible rather than deleting anything.
  • Last check outcome — not_found (GitHub answered 404) or unreachable (reached, but no longer a single usable profile YAML). Only the code is stored, never a raw error message.

A check that could not be performed is not a verdict. GitHub’s unauthenticated API allows 60 requests an hour per IP and OOMPF calls it from shared Cloudflare addresses, so rate-limited and 5xx responses are expected; those rows are left untouched — same last-checked time, same failure count — and come back first on the next sweep. Only a definite answer about the source is ever recorded.

The sweep records signals only. It never rewrites indexed facts, so a source changing under you can never silently change what the index says it contained.

Why it matters

  • Reproducibility. For an OOMPF URL or id, oompf add fetches the exact indexed Gist revision rather than the Gist’s latest state.
  • Verification. Before writing locally, oompf add re-validates that pinned snapshot and rejects it unless its SHA-256 matches the indexed fingerprint.
  • Idempotence. Re-registering an unchanged source resolves to the same id and leaves the record untouched.

Direct Gist URLs and ids remain supported for inspection only. They have no OOMPF index record to verify against, so oompf add rejects them rather than installing unpinned bytes.

The full values are available in the expanded provenance section of each profile page and in the profile metadata API.