Use Eckari from whatever agent stack you already have.
Three access surfaces, one capability contract. No account is required for x402 access.
MCP
Connect once and the agent sees the whole catalogue — companies, entities, domains, FX, weather, location and parcels — as tools named by capability id.
- Endpoint
- https://api.eckari.com/mcp
- Registry name
- com.eckari/capabilities
- Tool name
- company_uk_status
x402 over HTTP
Call the endpoint, read the payment requirements from the 402, authorize, retry. The second response is the canonical answer.
- 1 call the capability endpoint
- 2 receive 402 with price and requirements (PAYMENT-REQUIRED header)
- 3 authorize payment
- 4 retry with the PAYMENT-SIGNATURE header
- 5 receive the canonical response (PAYMENT-RESPONSE header carries settlement)
curl -i "https://api.eckari.com/v1/companies/uk/00445790/status" → HTTP 402 PAYMENT-REQUIRED: <base64 x402 v2 challenge> price 0.003 USD curl -i "https://api.eckari.com/v1/companies/uk/00445790/status" \ -H "PAYMENT-SIGNATURE: <base64 x402 v2 PaymentPayload>" → HTTP 200 PAYMENT-RESPONSE: <base64 settlement> canonical answer
Account and API-key access is part of the architecture and will open separately.
Machine-readable discovery
Every capability, price and schema is published for agents to read directly. The documentation on this site is generated from the same registry.
Deterministic errors
Invalid input is rejected before any payment or upstream call. A capability that cannot be fulfilled to contract fails with a stable code rather than a partial answer.
INVALID_INPUT rejected before paymentAUTHENTICATION_REQUIREDINVALID_API_KEYPROJECT_DISABLEDCAPABILITY_NOT_ALLOWEDBUDGET_EXCEEDEDBILLING_REQUIREDPAYMENT_REQUIRED payment required or not authorisedPAYMENT_FAILEDCAPABILITY_UNAVAILABLEUPSTREAM_RATE_LIMITEDUPSTREAM_UNAVAILABLE the source could not answerNOT_FOUND the record does not exist upstreamAMBIGUOUS_IDENTIFIERUNSUPPORTED_REGIONLICENCE_RESTRICTEDINTERNAL_ERROR