NumProof MCP server

NumProof

<!-- mcp-name: io.github.projecttron/numproof -->

The deterministic numeric truth layer for AI agents and spreadsheets.

Your agent writes "gross margin improved from 42.1% to 44.8%" or "the workbook is internally consistent" — NumProof tells you, deterministically, whether that number is VERIFY, REFUTE, or ABSTAIN, with a counterexample, cell/formula provenance, and a signed, machine-checkable audit bundle. It's exact arithmetic and symbolic math — not an LLM judging another LLM.

• ✅ Verify a single math/finance claim, or batch thousands in CI
• ✅ Audit xlsx/csv rows: footing, cross-footing, balance-sheet ties, margins, formula cells — with provenance
• ✅ Diff two report versions; evaluate covenant rule packs (DSCR, Debt/EBITDA, current ratio, …)
• ✅ Signed evidence bundle (JSON + HTML/PDF/ZIP) anyone can re-verify offline
• ✅ API · CLI · MCP server · optional x402 pay-per-call

This repo is the open-source client (SDK + MCP). The verification engine runs as a hosted

service — pip install numproof, point it at the API, done. (Same shape as stripe-python:

the SDK is open, the engine is the service.)

Live demo (no key): https://numproof.com · Docs: https://numproof.com/docs

30-second start

pip install numproof

from numproof import NumProof

np = NumProof.from_env()              # NUMPROOF_API_KEY (get a free key: see below)

print(np.verify("120 + 90 + 340 + 15 == 565"))
# {'verdict': 'VERIFY', 'certificate': 'EXACT_ARITHMETIC', ...}

print(np.verify("a 50% loss needs a 100% gain to break even"))   # VERIFY: (1-0.5)*(1+1.0)==1
print(np.verify("two 10% raises equal a 21% total increase"))    # VERIFY
print(np.verify("operating margin is 18% when EBIT is 180 and revenue is 1000"))  # VERIFY

No install? It's just HTTP:

curl -s https://numproof.com/demo -H 'Content-Type: application/json' \
  -d '{"claim":"gross margin is 60% when gross profit is 600 and revenue is 1000"}'

Free API key:

curl -s https://numproof.com/signup -X POST -H 'Content-Type: application/json' -d '{}'

Audit a spreadsheet (with provenance)

rows = [["Revenue", 1000], ["COGS", 400], ["Gross Profit", 600], ["Gross Margin", "60%"]]
print(np.audit_rows(rows)["verdict"])          # PASS  (600/1000 == 60%, footing, ties, ...)

# covenant rule packs: DSCR, Debt/EBITDA, current ratio, custom thresholds
print(np.covenant_rows(
    [["EBITDA", 500], ["Debt Service", 300], ["Debt", 1200]],
    rule_pack="credit_covenants_basic",
)["verdict"])

Every audit/diff/covenant result can be returned as a signed bundle + human-readable HTML/PDF report (format="zip"). Recipients verify it without trusting you or NumProof:

curl -s https://numproof.com/audit/verify -H 'Content-Type: application/json' -d @bundle.json
# {"valid": true, "verdict": "PASS", "signer": "0x...", ...}

Use it from an AI agent (MCP)

NumProof ships an MCP server so Claude / OpenAI-style agents can call it as a tool — gate every numeric claim before it reaches a user, report, or auditor.

python -m numproof.mcp

{ "mcpServers": { "numproof": { "command": "python", "args": ["-m", "numproof.mcp"] } } }

Or point any MCP client at the hosted descriptor: https://numproof.com/mcp.json.

See examples/ for runnable scripts (verify, audit, covenants, agent-gate, MCP).

Drop-in guardrails for agent frameworks

Verify the numbers your agent emits before it acts, in the framework you already use (numproof/integrations/ — each lazily imports its framework, so the numproof client stays stdlib-only):

Shortened. The full README is on GitHub.