verify
12 tools that catch the failure JSON-Schema can't: AI output that's the right type but the wrong number — or simply hallucinated. JSON-Schema validation, real check-digit format checks (IBAN, Luhn, ISBN, EAN, ISIN, VIN, SWIFT/BIC, VAT...), arithmetic consistency (line items sum to total), date ordering, a business-rule DSL, and source grounding. Deterministic, no network, audit receipt per call.
How to pay
Subscribe
$9/month
Predictable monthly cost with included usage. Best for steady, high-volume traffic.
- Unlimited tools within plan limits
- One API key, billed once a month
- Cancel any time
verify — a deterministic guard for AI output
LLMs now reliably produce structured output. They do not reliably produce correct output. A model can emit JSON that passes its schema, has a type-valid IBAN and a plausible total — and still be wrong: the line items don't add up, the IBAN fails its check digit, or an "extracted" figure never appeared in the source.
verify catches exactly that. It runs no model, makes no network calls, and returns a verifiable receipt on every call.
12 tools
- validate_schema — JSON Schema (Draft 2020-12); every violation with a JSON Pointer.
- validate_formats / validate_format — real check digits: IBAN (mod-97), credit card (Luhn), ISBN, EAN/UPC, ISIN, ABA routing, SWIFT/BIC, VAT, VIN, plus email, uuid, currency & country codes.
- check_arithmetic — relations like subtotal + tax == total over field expressions, exact Decimal.
- check_totals / check_line_items — line items sum to the stated total; qty * unit_price == line_total.
- check_dates — ordering and bounds (start <= end, not in the future).
- check_rules — declarative DSL: required / required_if / in_set / range / regex / mutually_exclusive / depends_on.
- check_grounding — anti-hallucination: each value must actually appear in the source text.
- check_unique / cross_reference — duplicate detection and referential integrity.
- verify_contract — run any combination in one call → pass/fail + integrity score.
Great for
Invoice & document extraction, KYC / finance, agent guardrails — anywhere a type-valid but wrong value would cost you. Deterministic, no PII, audit receipt on every call.