NumProof · Independent verification

Independent verification for the numbers your AI says.

NumProof checks numeric and financial claims deterministically — VERIFY / REFUTE with cell-level provenance — and returns a signed receipt anyone can re-check offline. An agent can recompute a number itself; it can't issue an attestation a second party trusts. Not an LLM judge.

Try it — no key needed Read the docs →
RECEIPT · finance-audit-v1SIGNED ∎
VERIFY
(R−C)/R == 1 − C/R
certificateEXACT_ARITHMETIC
signer0x9bbD…268c
bundle4ece0882…c421cd
algorithmETH-EIP191-SECP256K1
∎ re-checkable offline · zero trust
∎VERIFY / REFUTE
exact rational arithmetic, not a model judge
∎signed receipt
re-check offline, zero trust
∎cell provenance
spreadsheet & covenant audits
Try it — no key needed

Run the verifier in real time

Each result below is computed live by the public NumProof MCP endpoint — VERIFY / REFUTE with provenance, returned as a signed bundle.

01

Agent claim gate

No API key required for this demo.
verify_claim
Ready.
02

Spreadsheet audit demo

Revenue
Gross Profit
Gross Margin (=B2/B1)
Formula Sum (=SUM(B1:B2))
Runs through public MCP audit_rows, so the result is free and signed when signing is configured.
audit_rows
Ready.
03

Report diff demo

Before
Revenue draft
Gross Profit
After
Revenue final
Gross Profit
New Metric
Runs through public MCP diff_rows and returns a signed changed/added/removed bundle.
diff_rows
Ready.
Reference

API surface

EndpointUse
/verifyone claim, x402 or API key
/verify/batchCI and agent batches
/verify/auditsigned paid audit bundle
/verify/diffsigned report version diff
/verify/covenantssigned covenant rule-pack checks
/sample/finance-covenantspublic signed finance sample
/rule-packseditable covenant starter templates
/audit/verifypublic signature verification
Agents

MCP tools

ToolUse
verify_claimclaim verdict and counterexample
audit_rowssigned spreadsheet audit
diff_rowssigned report version diff
covenant_rulesbounded rule-pack checks

Hosted MCP descriptor points clients to /mcp.

Explore

Everything in NumProof

→Read the API docsendpoints, billing, examples →Compare planspricing & credits →Finance workflowaudits, diffs, covenants →Run paid samplesthe workbench →Verify a signed bundleoffline checker →Inspect rule packscovenant templates →Request a finance pilottalk to the team →Get an API keystart building →Top up creditsUSDC on Base