chainverdict.xyz x402 offerings

Latest Base block: number, timestamp and hash. The cheapest call on the service — useful as a liveness and connectivity check.

Native ETH and ERC-20 token balances for a Base address in one call, read live from chain at a stated block height.

Validate an EU VAT number's structure and per-country check digits. Format only — no VIES lookup, so it does not confirm the registration is active or belongs to the named trader.

Base gas price oracle: current gas cost on Base, base fee and priority fee in gwei, at a stated block height. For agents deciding whether to transact now or wait.

Validate an IBAN structurally: country length rules, character set and the ISO 7064 mod-97 check. Deterministic. A structurally valid IBAN is not proof the account exists, is open, or belongs to the party you are paying.

Validate up to 500 identifiers in a single call — IBAN, VAT, BIC, LEI and ISIN mixed freely. One payment instead of 500, for reconciliation and onboarding runs. Same structural scope as the individual validators.

Verify a Base transaction actually did what a counterparty says it did: confirmation depth, success or revert, value, token, sender and recipient. Use it to confirm an inbound payment before releasing goods or data.

Wallet risk profile for a Base address before you pay it or accept payment from it: EOA or contract, first and last seen, transaction and counterparty counts, contract-verification status, and any flags raised. Behavioural signals only — they describe activity, not intent.

Token safety check for an ERC-20 on Base: is this token a scam, a honeypot, or safe to hold? Examines ownership and mint authority, proxy upgradeability, liquidity and holder concentration, transfer-restriction patterns. Returns hold/caution/avoid with a score and the signals behind it. Heuristic static analysis, not a security audit — a proxy contract can change its implementation after this check.

Live TLS probe of a hostname: certificate validity and expiry, issuer, chain completeness, protocol and cipher. Confirms an endpoint you are about to send data to is actually serving a valid certificate right now.

Resolve a token symbol or contract address to the canonical Base contract, so an agent swapping or accepting 'USDC' gets the real one. Catches lookalike and impostor contracts sharing a symbol.

Total and circulating supply for an ERC-20 on Base, read live from chain with decimals applied and the block height returned.

Convert an HTML document to clean Markdown for LLM ingestion: strips scripts, styles and navigation chrome, preserves headings, lists, tables and links. Deterministic for identical input.

Structured diff of two text blocks: per-line additions, deletions and changes, plus an identical flag. Use it to detect whether a contract, policy or spec changed between two fetches.

Validate a Legal Entity Identifier against ISO 17442: 20 characters, allowed character set and mod-97 check digits. Structural only — no GLEIF registry lookup, so it does not confirm the LEI is issued or active.

Validate a BIC/SWIFT code against ISO 9362: 8 or 11 characters, bank and country segments, location and branch codes. Structural only; does not confirm the institution is reachable.

Validate an ISIN against ISO 6166: country prefix, 9-character NSIN and Luhn check digit. Structural only; does not confirm the instrument exists or is tradeable.

Analyse a domain for brand impersonation: homoglyph substitution, character insertion and omission, TLD swaps and known-brand proximity. Returns a suspicion verdict with the specific patterns matched. Heuristic — a match is a reason to check, not proof of intent.

Email-authentication posture for a domain: SPF record and policy, DMARC policy and alignment, DKIM selector presence. Use it to judge whether mail claiming to be from a counterparty can be trusted. Live DNS.

Recent transfer activity for an ERC-20 on Base: transfer count and volume over the sampled window, for judging whether a token is actually in use. Live chain read.

Native ETH and ERC-20 token balances for a Base address in one call, read live from chain at a stated block height.

Validate an IBAN structurally: country length rules, character set and the ISO 7064 mod-97 check. Deterministic. A structurally valid IBAN is not proof the account exists, is open, or belongs to the party you are paying.