The receipt gate that checks the claim, not just the signature
Evidence for: Three ways to fake a receipt. All three got caught.
The first receipt gate used a wrapper to record the command, exit code, output digest and assertions, then sign them. A validator checked the signature. For a push claim, it re-derived the result from the remote instead of trusting the receipt. Only the push claim had a re-check at the time. The other claim types were marked as stubs.
- Signature
- HMAC with a harness-only key
- Independent re-check at the time
- push claims only: remote compared to local via git ls-remote
- Other claim types at the time
- marked stub, honestly
- Commit date
- 2026-08-16
What it proves
A dated, hash-verifiable gate that checks a signed claim against outside evidence, which is the mechanism this account says caught the correctly-signed-but-false receipt. The three forgery runs are not in the record and stay first-hand.
Excerpt
receipt-validate.sh verifies the HMAC and, for the "pushed" claim, independently re-derives remote==local via git ls-remote rather than trusting the receipt's own assertions. only "pushed" has an implemented recheck today, the rest are marked stub honestly.
Where it lives: commit · nate-brain (the lab's operating rules) · 5f7a63bd44aa34d4ed42d7075c13ed15165c739b ·
Redaction: Commit hash, date and two sentences of the message; key paths and file names inside the repo removed.