Artifact attestation: a signed statement about an artifact: what it is and how it was made.

01Definition

A signed claim attached to a specific artifact.

An attestation is a statement about an artifact, such as a build output or a file, bound to that artifact by its cryptographic digest and signed by the system that made the statement. It says what the artifact is and how it came to be: which source, which workflow, which inputs.

GitHub offers artifact attestations for workflows, signed through Sigstore, so anyone can later verify that an artifact was produced by a particular workflow run.

• Bound to a digest
• Signed by the system that made it
• Verifiable later

02Why it matters

It turns “trust me” into something you can check.

Without an attestation, the claim that a file came from a clean build is just a claim. With one, a reader can check the signature, the identity behind it and the digest of the file in front of them. Supply-chain frameworks such as SLSA are built on attestations of this kind.

The same mechanism can carry a verdict about a code change: which commits were checked and what was found.

• Checkable provenance
• Foundation of SLSA
• Can carry a verdict

03In Verify

Planned for public repositories.

Verify's signed receipts are designed to use GitHub artifact attestations, an in-toto statement in a Sigstore bundle, for public repositories. That part is written and tested in code but is not live end to end yet. Private repositories get an unsigned receipt until TraceAxiom's own signer exists.

Verify is not installable yet.