Don’t trust our AI — verify our proof.

The certification authority for software correctness. Submit your specification. Our engine compiles it, checks the proof mechanically, and issues a signed certificate — binding your code hash, the verification result, and our identity — that anyone can re-check without trusting us.

Verify something free How it works

10 free trial verifications · no certificate until you pay · certificates valid 90 days, revocable, publicly checkable

The problem

AI writes code. Nobody can prove it’s right.

Code review is opinion. Tests are samples. Audits are expensive snapshots. When software has to be right — money movement, access control, safety logic, smart contracts — “looks good to me” is not evidence. AxiomCode sells verification-as-evidence: a mechanical proof, checked by a real toolchain, sealed into a certificate you can hand to a regulator, a customer, or a counterparty.

Submit

Send a Lean 4 specification through the web UI, the REST API, or the MCP server — the way your agent already talks to tools.

We check it mechanically

The engine compiles your spec with the real Lean toolchain and checks the proof. Vacuous builds, sorry, admit, and broken proofs are rejected — loudly.

You get a certificate

A signed certificate binding your artifact hash, the verdict, the toolchain, the issuer, and a validity window. Anyone can re-verify it without trusting us.

The guarantee

Our honesty is structural, not promised.

A certificate authority lives or dies on one thing: never saying “verified” when it isn’t. So we built the incentives into the system:

Mis-issuance is the existential risk

Every certificate carries a serial number, issuer identity, and validity window. If our toolchain is ever wrong, we revoke — publicly, through a published revocation list. Like TLS, but for correctness.

Expiry drives re-verification

Certificates last 90 days. Software changes; proofs should be re-run. Renewal is the business model, the same way TLS renewal is.

You don’t have to trust us

The certificate binds the artifact hash and the proof transcript. Re-run the check yourself with the published toolchain. “Don’t trust our AI — verify our proof” isn’t a slogan; it’s the architecture.

Who it’s for

Whoever has to prove it’s correct.

The buyer isn’t whoever writes the code. It’s whoever must demonstrate correctness to a third party:

Regulated software teams — hand a certificate to the auditor instead of a test report.
Fintech & smart contracts — money logic with a machine-checked proof attached.
AI agent builders — agents that ship code can now ship the proof too. Call us from your agent over MCP.
Procurement & contracts — “certified correct” as a deliverable, checkable by the buyer.

See pricing

Honest scope

What we certify today — and what we don’t.

Today the engine verifies Lean 4 specifications: it compiles the artifact you submit and checks the proof the toolchain actually ran. The certificate says exactly what was checked — the artifact hash, the toolchain version, the verdict — and nothing more. We do not claim your whole system is correct, your spec matches your intent, or your deployment matches the artifact. Read the Certificate Policy for the precise meaning of every field.

Verification is evidence, not opinion. The evidence is bounded, and we publish the bounds.