Route any LLM through Prova. Every completion arrives with a certificate of logical soundness backed by 2,400+ Lean 4 theorems, or a precise diagnosis of where reasoning fails.
Not a heuristic. Not a classifier. A mathematical proof.
Verifies logical structure only, not factual accuracy or ethical appropriateness. What does a certificate mean?
New · Live gateway
Point your existing OpenAI client at the Prova gateway. The response you already ship now arrives with a formal Prova verdict attached — VALID, INVALID, or flagged inline. No SDK change. No pipeline rewrite.
// Before
const openai = new OpenAI({
baseURL: "https://api.openai.com/v1",
apiKey: process.env.OPENAI_API_KEY,
})// After — every response is verified by Prova
const openai = new OpenAI({
baseURL: "https://api.prova.cobound.dev/v1",
apiKey: process.env.OPENAI_API_KEY,
defaultHeaders: { "X-Prova-Policy": "flag" },
})Try a live call
Policies: observe (default, attach verdict), flag (append warning for INVALID), strict (block INVALID with 422).
EU AI Act · August 2026
The EU AI Act requires demonstrable proof that high-risk AI systems reason correctly. Prova generates tamper-evident certificates backed by mathematically verified theorems, accepted by compliance teams and auditors.
Example certificates
All three STEMI criteria independently satisfied: symptoms, ECG changes, elevated troponin. Diagnosis confirmed; emergent catheterization lab activation is indicated.
High-risk score leads to extended sentence. Extended sentence drives re-arrest. Re-arrest data recalculates the rate used to assign the original score. The conclusion validates the premise.
Revenue grew 10.5% while operating costs grew only 6.9%. Operating margin expanded from 23.7% to 26.2%, confirming positive operating leverage in FY2023.
Legitimate interest confirmed. Scope within precedent. Adequate consideration received. All three Delaware enforceability requirements independently satisfied.
The AAA rating justifies low default correlation assumptions. Those assumptions produce AAA ratings. Market demand at AAA spreads is treated as independent validation of both.
The case is valid because it appears in databases. It appears in databases because the AI tool confirms it. The AI tool confirms it because the case is valid. The loop closes on a case that does not exist.
How it works
Claude identifies the logical structure: premises, claims, dependencies, conclusions. Your reasoning chain becomes a directed graph.
The cobound-validator checks graph topology. If H1(K;Z) = 0, the argument has no circular dependencies. This is mathematics, not a statistical guess.
A permanent, tamper-evident certificate is issued with a SHA-256 integrity hash. Valid certificates confirm structural soundness. Invalid ones pinpoint exactly where reasoning fails.