x402-protocol-integration

Validates a 402 challenge — fetched from a URL without paying, or supplied directly — against PaymentRequiredV1Schema and PaymentRequiredV2Schema of the installed @x402/core reference implementation. Reports the detected version and how it was detected, every error with field, expected, found and spec_ref naming package, version, schema and field path, whether the network is valid CAIP-2, whether the asset is a known and canonical token address or a bridged variant, whether the declared inputSch

X402 Challenge Version Check: X402 Challenge Version Check compares challenge protocol version with supported versions from bounded caller-supplied values without an external provider. Call X402 Challenge Version Check before paying for or accepting an x402 or agent delivery assembled from caller-supplied challenge and result metadata. Returns contract-specific checks, normalized evidence, mismatch reasons, and an explicit acceptance or rejection status for X402 Challenge Version Check as versi…

X402 Scheme Select: X402 Scheme Select selects the first buyer-supported payment scheme from challenge options from bounded caller-supplied values without an external provider. Call X402 Scheme Select before paying for or accepting an x402 or agent delivery assembled from caller-supplied challenge and result metadata. Returns contract-specific checks, normalized evidence, mismatch reasons, and an explicit acceptance or rejection status for X402 Scheme Select as versioned deterministic JSON. Pri…

X402 Network Match: X402 Network Match compares a challenge network identifier with buyer-supported networks from bounded caller-supplied values without an external provider. Call X402 Network Match before paying for or accepting an x402 or agent delivery assembled from caller-supplied challenge and result metadata. Returns contract-specific checks, normalized evidence, mismatch reasons, and an explicit acceptance or rejection status for X402 Network Match as versioned deterministic JSON. Price…

X402 Payment Replay Key: X402 Payment Replay Key derives a stable non-secret replay-detection key from payment metadata from bounded caller-supplied values without an external provider. Call X402 Payment Replay Key before paying for or accepting an x402 or agent delivery assembled from caller-supplied challenge and result metadata. Returns contract-specific checks, normalized evidence, mismatch reasons, and an explicit acceptance or rejection status for X402 Payment Replay Key as versioned dete…

X402 Pay To Match: X402 Pay To Match compares challenge pay-to address with an expected merchant address from bounded caller-supplied values without an external provider. Call X402 Pay To Match before paying for or accepting an x402 or agent delivery assembled from caller-supplied challenge and result metadata. Returns contract-specific checks, normalized evidence, mismatch reasons, and an explicit acceptance or rejection status for X402 Pay To Match as versioned deterministic JSON. Price: $0.0…

X402 Timeout Check: X402 Timeout Check checks challenge expiration and minimum buyer processing time from bounded caller-supplied values without an external provider. Call X402 Timeout Check before paying for or accepting an x402 or agent delivery assembled from caller-supplied challenge and result metadata. Returns contract-specific checks, normalized evidence, mismatch reasons, and an explicit acceptance or rejection status for X402 Timeout Check as versioned deterministic JSON. Price: $0.001…

X402 Accepts Rank: X402 Accepts Rank ranks challenge accepts entries against buyer network and asset preferences from bounded caller-supplied values without an external provider. Call X402 Accepts Rank before paying for or accepting an x402 or agent delivery assembled from caller-supplied challenge and result metadata. Returns contract-specific checks, normalized evidence, mismatch reasons, and an explicit acceptance or rejection status for X402 Accepts Rank as versioned deterministic JSON. Pri…

X402 Payment Deadline Check: X402 Payment Deadline Check checks payment authorization deadline against caller time budgets from bounded caller-supplied values without an external provider. Call X402 Payment Deadline Check before paying for or accepting an x402 or agent delivery assembled from caller-supplied challenge and result metadata. Returns contract-specific checks, normalized evidence, mismatch reasons, and an explicit acceptance or rejection status for X402 Payment Deadline Check as ver…

X402 Payment Nonce Check: X402 Payment Nonce Check checks a payment nonce for presence, length, and caller-known reuse from bounded caller-supplied values without an external provider. Call X402 Payment Nonce Check before paying for or accepting an x402 or agent delivery assembled from caller-supplied challenge and result metadata. Returns contract-specific checks, normalized evidence, mismatch reasons, and an explicit acceptance or rejection status for X402 Payment Nonce Check as versioned det…

X402 Asset Match: X402 Asset Match compares a challenge asset identifier with buyer-supported assets from bounded caller-supplied values without an external provider. Call X402 Asset Match before paying for or accepting an x402 or agent delivery assembled from caller-supplied challenge and result metadata. Returns contract-specific checks, normalized evidence, mismatch reasons, and an explicit acceptance or rejection status for X402 Asset Match as versioned deterministic JSON. Price: $0.001 USD…

X402 Resource Match: X402 Resource Match compares challenge resource URL with the intended paid resource from bounded caller-supplied values without an external provider. Call X402 Resource Match before paying for or accepting an x402 or agent delivery assembled from caller-supplied challenge and result metadata. Returns contract-specific checks, normalized evidence, mismatch reasons, and an explicit acceptance or rejection status for X402 Resource Match as versioned deterministic JSON. Price:…

X402 Challenge Shape Check: X402 Challenge Shape Check checks required top-level fields in a caller-supplied payment challenge from bounded caller-supplied values without an external provider. Call X402 Challenge Shape Check before paying for or accepting an x402 or agent delivery assembled from caller-supplied challenge and result metadata. Returns contract-specific checks, normalized evidence, mismatch reasons, and an explicit acceptance or rejection status for X402 Challenge Shape Check as v…

X402 Amount Budget Check: X402 Amount Budget Check checks challenge raw amount against an exact buyer call budget from bounded caller-supplied values without an external provider. Call X402 Amount Budget Check before paying for or accepting an x402 or agent delivery assembled from caller-supplied challenge and result metadata. Returns contract-specific checks, normalized evidence, mismatch reasons, and an explicit acceptance or rejection status for X402 Amount Budget Check as versioned determin…

X402 Payment Header Shape: X402 Payment Header Shape checks a caller-supplied payment header for bounded base64 or JSON shape from bounded caller-supplied values without an external provider. Call X402 Payment Header Shape before paying for or accepting an x402 or agent delivery assembled from caller-supplied challenge and result metadata. Returns contract-specific checks, normalized evidence, mismatch reasons, and an explicit acceptance or rejection status for X402 Payment Header Shape as vers…

Cryptographic verification of the offer-receipt extension of x402. Accepts a signed offer in eip712, jws or eip191 form — either bundled as {format, payload, signature} or as payload plus a separate signature — and an optional signed receipt. Recovers the signer, compares it with the payTo of the offer, compares receipt and offer field by field and names every divergence with the value on each side, checks whether the offer has expired and whether the receipt timestamps are plausible against sta

A stateless rule check for agents that pay for x402 endpoints. You supply the proposed payment, your policy and the amounts already spent this hour and this day; this endpoint keeps no ledger of its own and returns your counters unchanged. Every configured rule — max_per_call, max_per_hour, max_per_day, allowed_chains, allowed_assets, allowed_recipients, blocked_recipients, require_schema — is reported individually as erfuellt, verletzt, nicht_pruefbar or nicht_gesetzt, together with the limit a

Reads the public x402 Bazaar catalogue and finds offers comparable to yours, either from a resource_url whose 402 challenge is fetched without paying, or from a category and description you supply. Every comparable offer is listed with its price, its provider host, a similarity score and the terms both sides share, so comparability is justified rather than asserted; the formula, its weights and the inclusion threshold are stated in the answer. Prices are aggregated as median, p25 and p75 over co

Live quality verdict for any x402 endpoint: availability, latency percentiles, 402-offer conformance, price-drift and payTo-stability flags. Deterministic and re-verifiable.

Card BIN Lookup x402 — BIN lookup - resolve issuer, scheme, type and country for a card BIN

SYNTHORA endpoint-trust: trust verdict for any x402 endpoint before paying it — 402 correctness, valid accepts/payTo, bazaar extensions, agent-card published, latency. Observed behavior, not declarations. The pre-payment check for buying agents. $0.005 USDC x402 Base.

Daily state of the x402 agent economy: observed USDC inflow, seller ranking, category demand, growth, and coverage. Reports its real observation window; concentration adjustment applied only when scan coverage supports it.

Leaderboard of x402 sellers by observed USDC inflow, with distinct payers, an HHI concentration measure and wash-risk flags. Sellers below the observation floor are returned unrated, not accused. The payer-graph discount applies only where wallet scan coverage supports it. HHI measures concentration, not common control.

x402 services first listed since a given date, with first archive observation and conservative early-traction evidence from observed inflow. Entrants MCPFax can attribute — a declared payTo, an observed title, or observed inflow — rank first, and each row states which it carries. A window identifying nobody is refused 422 and charges nothing. Requests before the archive's first date are reported as partially covered. Use this for deal flow on who just entered the market.