Pre-launch: AxiomCode is not yet open — we are not yet accepting submissions or payments, and certificates are not yet being issued. These pages describe the service as it will operate when it opens.
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How it works

Three steps. Every one of them checkable.

1. Submit the artifact

Paste Lean 4 code into the web verifier, POST it to the REST API, or call the verify tool on our MCP server. What you submit is hashed (SHA-256) the moment it arrives — that hash becomes part of the certificate, so the verdict can never drift away from the code it describes.

2. The engine checks the proof — for real

The verification engine runs the actual Lean toolchain (lake build) against your artifact in an isolated project. It is deliberately adversarial toward sloppy proofs:

  • Vacuous builds rejected. A target that compiles nothing is not a proof of anything.
  • sorry and admit rejected. Placeholders are not proofs.
  • Broken proofs rejected. If the toolchain reports an error, the verdict is FAILED, with the log attached.
  • Unfinished work reported honestly. Something that doesn’t compile yet gets INCOMPLETE — never a pass.

A pass means one thing: the toolchain compiled your artifact and the proof checked. The full transcript ships with the verdict.

3. The certificate seals the evidence

On PASSED, the certification authority issues a signed certificate. The certificate credentials the code — our assessment that the artifact was built to its specification, as mechanically checked — and we hold no responsibility beyond this assessment. It contains:

FieldMeaning
artifact_sha256Hash of exactly the code that was checked
verdictPASSED, with the toolchain transcript reference
toolchainLean / lake versions that ran the check
issuerAxiomCode CA
serialUnique serial number
validity90-day window (notBefore / notAfter)
signatureCA signature over all of the above

Check any certificate, no account needed: paste it into the certificate checker. You’ll get VALID, REVOKED, or EXPIRED — with the reason. Revocation is published, not hidden: if a toolchain bug ever invalidates a verdict, the serial goes on the public revocation list.

Interfaces