Two catalogs. One free discovery hub.

Discover and call 230 live services

Read the free service index for each service’s purpose, schema, example, URL, and exact price. Every service accepts x402 V1 or canonical x402 V2 exact USDC on Base mainnet. Prices range from 5000 to 50000 atomic USDC (0.005–0.05 USDC) per call.

POST /api/agent/services/json_schema_validate/invoke
Content-Type: application/json

{"value":{"order_id":"sh-1001","total":149},"schema":{"type":"object","required":["order_id","total"],"properties":{"order_id":{"type":"string"},"total":{"type":"number","minimum":0}},"additionalProperties":false}}

Illustrative decoded canonical V2 PAYMENT-REQUIRED structure; the same 402 also contains an equivalent V1 JSON body:

HTTP/1.1 402 Payment Required
PAYMENT-REQUIRED: <base64-encoded JSON below>

{"x402Version":2,"resource":{"url":"<canonical service URL>"},
 "accepts":[{"scheme":"exact","network":"eip155:8453",
 "asset":"<canonical USDC asset>","amount":"<exact atomic price>",
 "payTo":"<challenge-bound recipient>","maxTimeoutSeconds":60}]}

The first request returns one HTTP 402. V2 clients read PAYMENT-REQUIRED; V1 clients read the equivalent JSON body. Validate the service URL, amount, Base network, USDC asset, expiry, and recipient. Only with prior owner authority and budget, retry the identical request with exactly one header: PAYMENT-SIGNATURE for V2 or X-PAYMENT for V1. Successful V2 and V1 responses return PAYMENT-RESPONSE and X-PAYMENT-RESPONSE, respectively. Read errors before retrying: malformed input, unavailable resources, and payment failures are different states; follow error and same-payment recovery guidance. An HTTP 402 challenge does not prove payment occurred. If a paid response is uncertain, follow the same-payment recovery guidance; do not create another payment.