Every agent-payable API.

Compare an agent's advertised contract with its live x402 challenge and return deterministic proof.

Verify a UK charity against the Charity Commission for England and Wales register. Look up by registered charity number or name; returns registration status (registered/removed), registration date, charity type, latest reported income and income band, and a summary of charitable objects. Register data published under the Open Government Licence v3.0.

Composite medical-device risk card from a UDI device identifier (DI), brand, or labeler company. Returns the GUDID labeler record (brand, company, GMDN term, version/model, catalog number), MR-safety status, GUDID-cited premarket submission signal, a live openFDA recall cross-reference for the labeler, and an explainable risk level. FDA GUDID data (public domain).

Verify an SEC investment adviser by firm name or CRD number: registration status (SEC-registered / exempt reporting adviser), regulatory AUM and AUM band, Form ADV Item 11 disciplinary-disclosure flag, principal office state, and latest filing date. Public-domain SEC Form ADV data (Investment Adviser Information Reports, October 2026).

Verify a Canadian registered charity against the Canada Revenue Agency List of Charities. Look up by business number (BN, e.g. '119219814RR0001' or the 9-digit root) or by charity name (English or French). Returns legal name, BN, registered status verdict, designation (Charitable Organization / Public Foundation / Private Foundation), charity category, and mailing city/province. Data: CRA List of Charities open data (T3010), Open Government Licence - Canada.

EU public-procurement award track record for a supplier: contract-award counts, total awarded value in EUR (as published), contracting authorities, CPV codes and award dates from EU TED (Tenders Electronic Daily) contract award notices, CC BY 4.0.

Use when an agent has an email address from a form, a scrape or a CRM and must decide whether it is worth sending to. Screens the address: syntax, DNS mail exchanger, disposable domain, role account, free provider and common typos. It does not verify that the mailbox exists. A DNS failure answers 503 and is not charged.

Verify a US healthcare provider by NPI or name against the CMS NPPES registry: entity type (individual/organization), primary taxonomy specialty, practice city/state, enumeration date, and active/deactivated status. Public CMS NPPES data. City/state only — no street addresses or phone numbers.

Market salary bands + offer verdict by SOC occupation and metro area. Returns annual wage percentiles (p10/p25/median/p75/p90), mean, employment, and a below_market/competitive/above_market verdict against your offer. BLS OEWS May 2025 public-domain data.

Verify a Scottish charity against the OSCR Scottish Charity Register. Look up by Scottish charity number (SC...) or name; returns registration status verdict (registered/removed), registered date, ceased date for removed charities, constitutional form, regulatory type, and charitable purposes. Scottish register data published by OSCR under the Open Government Licence v3.0. This is the Scottish register, not the Charity Commission for England and Wales.

Verify whether a supplied public source page currently supports one atomic factual claim. Returns supported, contradicted, or insufficient-evidence plus source snippets, or explicit blocked/unreachable/unsupported states. Not a general fact checker or web search.

Verify a US healthcare facility by CMS Certification Number (CCN). Returns Medicare certification status, provider type, bed count, ownership type, accreditation, address, and phone. Source: CMS Provider of Services File (public domain).

Re-verify any exhibit402 proof-of-publication certificate for $0.02. Pass id = ERC-721 token id, Arweave tx id, or job id. The service re-downloads the permanently stored screenshot and signed manifest, recomputes every SHA-256, and checks them against the manifest and the on-chain record (immutable screenshotSha256, tokenURI, owner). Returns a machine-readable verdict with per-check detail, so an agent can confirm a certificate is genuine without trusting the issuer.

Verify an Irish charity against the Charities Regulator Register of Charities. Look up by Registered Charity Number (RCN) or name; returns registration status verdict (registered/deregistered), governing form, charitable purposes and objects, CRO number, and address. Register data published via data.gov.ie under CC BY 4.0.

Verify a UK food business's official Food Hygiene Rating (FHRS 0-5) by name, with optional postcode. Returns the rating in text, the inspection/rating date, address, business type, and local authority for each match, from UK Food Standards Agency open data (OGL v3.0). England, Wales and Northern Ireland.

EU VAT number validation via official VIES (all 27 EU states + XI): valid/invalid, name, address, consultation (proof) number

Check whether an email address is well-formed and its domain can receive mail, before you send. Five DNS checks on an email address, no message sent: syntax, MX presence and hosts, SPF record, DMARC policy, disposable domain, role address. Returns deliverable as NO, RISKY or LIKELY. It does not open an SMTP session and says so: mailbox existence is explicitly not c…

Verify whether a business is a registered money services business (MSB) with FinCEN. Returns registration status, MSB activities (money transmitter, check casher, etc.), DBA names, and address. Public-domain FinCEN data.

Verify a New Zealand charity against the Charities Services Charities Register. Look up by charity registration number (CC…) or name; returns registration status verdict (registered/deregistered), registration date, deregistration date and reason where applicable, main sector and activity, and the charity's stated charitable purpose. Register open data licensed CC BY 3.0 NZ.

Verify an email address. Uses one verifier credit on all attempted verifications.

Verify an FAA aircraft tail (N-number) registration: status, expiration, make/model, serial, registration fraud & expiry flags. Public-domain FAA Releasable Aircraft Database. Registrant identity is never returned (49 U.S.C. §44114) — only registrant type.

Verify an x402 payment settled: tx hash -> status, amount, from/to, block

Verify any Base transaction by hash. Returns validity, from, to, block, gas used.

Verify any US college by name or IPEDS UNITID. Returns tuition (in-state/out-of-state), selectivity (applicants, admit rate, yield), enrollment, and 150% graduation rate. Public-domain NCES IPEDS data.

Zero-Retention Multimodal Invoice/XML/UBL Attestor across 12 Global Registries & 30 ECB Currencies (Notional-Tiered x402 Pricing)

Boolean verdict with reasons: is this address a real factory-issued B20 on Base? Checks the 0xB200 address prefix, ERC-20 readability, and whether the B20 feature set is activated on the registry. ?address=0x…

Verify whether a cited source supports an exact factual claim

Checks whether a signature was made by a claimed EVM address: EIP-191 personal_sign messages, EIP-712 typed data or a raw 32-byte digest, verified by ecrecover for wallets or ERC-1271 isValidSignature for smart-contract wallets (Safe, Coinbase Smart Wallet) on Ethereum, Base, Arbitrum, Optimism or Polygon. Returns validity, method, recovered signer and digest. Free sample: https://onchain-health.mick8511.workers.dev/sample

UK VAT number format + check-digit test: Checks a UK VAT number's format and HMRC check digits (mod 97 / 9755). Catches fake or mistyped VAT numbers instantly without an HMRC call. Use /v1/business/check to confirm live registration.

Verify up to 25 email addresses per call: syntax, domain MX/A record, disposable-domain, and role-account checks. Does not perform SMTP/mailbox verification.

Verify a JSON Web Token's signature and claims against a shared secret (HS*) or a PEM public key (RS/ES/PS). Returns { valid, payload } on success or { valid: false, reason } for a bad signature, expired/not-yet-active token, or a failed issuer/audience/subject check. Pass `algorithms` to pin the accepted signing algorithms and prevent algorithm-confusion attacks.

Verify custodian holds claimed assets

Verify output another AI agent hands back, by code alone, for $0.005: no model call, answers in about a second. Recomputes the deliverable's written sums, totals, percentages, dates, weekdays, time spans, unit conversions, and list counts; checks lengths the task asks for; flags placeholders and prompt injection; measures words, items, and JSON shape. Signed receipt, tier lite. For every requirement judged, use accept ($0.03).

Verify if a person meets a minimum age requirement based on their date of birth. Returns exact age, whether the threshold is met, and days until the threshold (if not met). Accounts for leap years.

Verify a Base/BSC transaction receipt for a payout or claim: status, block, sender, gas, decoded ERC-20 Transfer logs and a sha256 evidence digest. 0.01 USDC via x402 on Base. POST only. Free sample: /samples

Verify up to 20 Base transactions in one call

Recovers the address that signed a personal_sign (EIP-191) message and tells you whether it matches the address you expected. This is how you prove a wallet is controlled by whoever is talking to you.

Approval check for one wallet and one ERC-20 token on Base: how much each spender (up to 10 app or router addresses) is allowed to move, flagging unlimited approvals and approvals covering the full balance, plus approvals made through Uniswap Permit2 with their expiry. Defaults to checking Permit2 itself. Useful before signing, for wallet hygiene, and for spotting approvals to revoke. Read-only. Not charged for invalid addresses or non-tokens.

Risk check for an ERC-20 token on Base before buying, accepting, or holding it: reads the contract and its proxy implementation for owner powers (minting, pausing, blacklisting wallets, changing buy/sell taxes, trade limits, trading switches, burning others' tokens, upgrades), checks whether ownership was renounced and how much supply the owner holds. Returns a verdict, 0-100 risk score, and plain-language flags. Read-only. Not charged for invalid addresses or non-tokens.

Pre-signing check for Base. Send a transaction (to, data, value, from) or a typed-data signature request and get what it does in plain words plus red flags: unlimited or wallet-targeted approvals, NFT approve-all, off-chain permits, sends to a token's own contract or the dead address, OFAC or scam-listed counterparties, risky tokens, and calls that would fail (simulated from your wallet). Verdict ok, caution, danger or block. Not charged for invalid input.

Domain report: registration date, expiry, registrar, status, and name servers from the official registry (RDAP), plus DNS records (A, AAAA, MX, NS, CAA) and email security (SPF, DMARC policy), with flags for new, expiring, or misconfigured domains. Useful for vetting a company, vendor, or link before trusting it. Not charged for invalid or reserved domain names.

Check dependencies for known vulnerabilities before installing or shipping: up to 20 packages (npm, PyPI, Go, Maven, crates.io, RubyGems, NuGet, Packagist and more, by name and version or purl) against the OSV.dev database. Returns each advisory with CVE IDs, severity and CVSS score, fixed versions, the smallest safe upgrade, and links. Not charged for invalid input or if OSV.dev can't be reached.

Turns messy LLM output into valid JSON: strips Markdown code fences and surrounding prose, fixes trailing commas, single quotes, unquoted keys, comments, Python True/None, cut-off brackets, and stringified JSON. Optionally validates the result against a JSON Schema (draft 4 to 2020-12) and lists each error with its location. Returns the parsed data, the JSON text, and what was changed. Not charged if no JSON can be recovered or the input is invalid.

Prompt-injection screen for text or a web page an agent is about to read: finds instruction overrides (many languages and obfuscated spellings), fake system or role markers, jailbreak personas, data-exfiltration links, requests for keys or seed phrases, tool, shell, or payment hijacks, and hidden content (invisible Unicode smuggling, zero-width and bidi characters, HTML comments, hidden elements, base64). Returns a verdict, 0-100 risk score, findings, and cleaned text. Not charged on bad input.

Base mainnet balance lookup for one address: ETH and USDC balances (human-readable and raw units), transaction count, and whether the address is a wallet or a contract, at the latest block. Useful for checking that a wallet is funded before a payment, confirming a payout landed, or screening a counterparty. Read-only. Not charged for an invalid address or when Base can't be reached.

Resolves Basenames (name.base.eth, on Base) and ENS names (name.eth, on Ethereum) to wallet addresses, including a Base-specific address and profile records (avatar, description, url, X, GitHub). Or give an 0x address to get its primary name, verified by resolving the name back to the same address. A bare name like jesse means jesse.base.eth. Useful before sending funds to a name or labeling counterparties. Read-only. Not charged for invalid or unregistered names.

Batch website safety check: the full /safe report for several URLs in one call, priced per site and cheaper than single checks. Each result has a verdict (safe, caution, unsafe), a 0-100 score, and evidence-backed flags for TLS, redirects, security headers, mixed content, insecure forms, and domain age, plus a summary count. Useful for screening every link in a search result, email, or document at once. Not charged if no site can be checked.

Look up one NFT on Base by contract and token ID: ERC-721 or ERC-1155, current owner (wallet or contract), collection name and symbol, and its metadata: name, description, image link, animation, traits. Reads ipfs://, ar://, https and inline on-chain metadata. Pass owner to confirm a wallet holds it (and its ERC-1155 balance). Read-only. Not charged for invalid input, tokens that don't exist, or when Base can't be reached.

Current time from a reliable server clock: UTC ISO timestamp, Unix seconds and milliseconds, and optionally the local date, time, weekday, and UTC offset in any IANA time zone (daylight saving handled). Useful because language models don't know the current date or time. Not charged for an unknown time zone.

Website safety check plus a Google Web Risk lookup for malware, phishing, and unwanted software. Includes the full /safe report: verdict (safe, caution, unsafe), 0-100 score, TLS, redirects, security headers, mixed content, insecure forms, and domain age. A blocklist hit makes the verdict unsafe. Useful for screening links before a payment, login, or download. Not charged if the blocklist cannot be reached.