Validate an x402 endpoint

The validate endpoint lets sellers and agents check that an x402 endpoint’s Bazaar-discovery configuration is correct before going live. CDP probes the seller’s URL live, runs a set of preflight checks, and reports whether the CDP Facilitator would index the resource for Bazaar discovery.

This endpoint is read-only: it performs no payment and does not index the resource. Use it as a pre-flight check while wiring up your route, and again any time you change your payment requirements or Bazaar extension.

POST https://api.cdp.coinbase.com/platform/v2/x402/validate

No API key is required — this route is unauthenticated, like the discovery endpoints. For the full OpenAPI schema and status codes, see Validate x402 endpoint in the x402 Facilitator API Reference.

Request

Field	Type	Required	Description
`resource`	string	Yes	HTTPS URL of the x402 endpoint to validate. Must use the `https://` scheme.
`method`	string	No	HTTP method used to probe the endpoint. Only `GET` and `POST` are supported (default `GET`); other verbs are rejected because x402 resources are expected to respond to these methods.

curl -X POST https://api.cdp.coinbase.com/platform/v2/x402/validate \
  -H "Content-Type: application/json" \
  -d '{
    "resource": "https://api.example.com/weather/forecast",
    "method": "GET"
  }'

Response

The response gives you the observed facts about your endpoint, the individual preflight check results, the facilitator’s simulated accept/reject decision, and — if your endpoint is already indexed — its current Bazaar index status.

Example `200` JSON (validate)

{
  "valid": true,
  "statusCode": 402,
  "x402Version": 2,
  "preflight": [
    {
      "check": "reachable",
      "passed": true,
      "detail": "Endpoint responded to the probe request.",
      "severity": "required"
    },
    {
      "check": "returns_402",
      "passed": true,
      "detail": "Endpoint responded with HTTP 402 Payment Required.",
      "expected": "402",
      "actual": "402",
      "severity": "required"
    },
    {
      "check": "has_bazaar_extension",
      "passed": true,
      "detail": "Endpoint advertises an extensions.bazaar block.",
      "severity": "required"
    },
    {
      "check": "parse",
      "passed": true,
      "detail": "Payment requirements parsed successfully.",
      "severity": "required"
    }
  ],
  "paymentRequirements": {
    "scheme": "exact",
    "network": "eip155:8453",
    "amount": "1000",
    "asset": "0x...",
    "payTo": "0x...",
    "maxTimeoutSeconds": 60
  },
  "bazaarExtension": {
    "info": { "input": { "type": "http", "method": "GET" } },
    "schema": {}
  },
  "simulation": {
    "outcome": "accepted"
  },
  "index": {
    "active": true,
    "lastCrawledAt": "2026-06-01T12:00:00Z",
    "quality": {
      "l30DaysTotalCalls": 42,
      "l30DaysUniquePayers": 15,
      "lastCalledAt": "2026-06-01T12:00:00Z"
    }
  }
}

Top-level fields

Field	Type	Description
`valid`	`boolean`	`true` if all required preflight checks passed and the facilitator would index the resource.
`statusCode`	`integer \| null`	HTTP status code the endpoint returned, or `null` if it was not reachable.
`x402Version`	`integer \| null`	x402 protocol version advertised by the endpoint, or `null` if it could not be determined. A bare integer (not the version enum) so malformed values are surfaced as-is.
`preflight`	`array`	All preflight check results in run order.
`paymentRequirements`	`object \| null`	Raw decoded 402 payment requirements, or `null` if the endpoint was unreachable or the payload was unparseable. Lets you inspect exactly what your endpoint advertises.
`bazaarExtension`	`object \| null`	The `extensions.bazaar` block from the endpoint’s discovery metadata, or `null` if absent or unreachable.
`simulation`	`object`	The simulated facilitator decision.
`index`	`object \| null`	Bazaar index status if the endpoint is already indexed, otherwise `null`.

Preflight checks

Each entry in preflight reports one check. Well-known check names are reachable, returns_402, has_bazaar_extension, and parse — additional checks may be added in future versions, so handle unknown values gracefully.

Field	Type	Description
`check`	`string`	Name of the check.
`passed`	`boolean`	Whether the check passed.
`detail`	`string`	Human-readable explanation of the result.
`expected`	`string`	The value the check expected, when applicable.
`actual`	`string`	The value the check observed, when applicable.
`severity`	`string`	`required` — a hard indexing requirement that affects `valid` when it fails; or `advisory` — a quality recommendation (for example, a missing output schema) that improves discoverability but does not make the endpoint invalid.

Simulation

Field	Type	Description
`outcome`	`string`	`accepted` if the facilitator would index the resource, or `rejected` if it would not.
`rejectionReason`	`string`	Reason the resource would be rejected. Present only when `outcome` is `rejected`.

Index status

Present only when the endpoint is already indexed in the Bazaar.

Field	Type	Description
`active`	`boolean`	Whether the indexed resource is active and served in discovery results.
`lastCrawledAt`	`string \| null`	When the endpoint was last crawled, or `null` if indexed but not yet crawled.
`quality`	`object`	Quality metrics (for example `l30DaysTotalCalls`, `l30DaysUniquePayers`, `lastCalledAt`), present only when the endpoint has call history. See Quality ranking.

How to use it

Before going live — after wiring up your x402 middleware and Bazaar extension, call validate to confirm your endpoint returns 402, advertises a parseable extensions.bazaar block, and would be accepted.
Inspect what you advertise — read paymentRequirements and bazaarExtension to verify the payment terms and discovery metadata your endpoint is actually serving match what you intended.
Fix advisory findings to rank higher — advisory checks (like a missing output schema) do not block indexing but do affect quality ranking. Address them to improve discoverability.

A passing validate result confirms your endpoint is ready to be discovered, not that it is already in search. Indexing still requires at least one successful settlement through the CDP Facilitator — see When does my endpoint appear?.

GET STARTED

WALLETS

PAYMENTS

STABLECOINS

TRADING

ONCHAIN TOOLS

CUSTOMERS

WEBHOOKS

CONSUMER APIS

BUSINESS APIS

INSTITUTIONAL APIS

Request

Response

Top-level fields

Preflight checks

Simulation

Index status

How to use it

​Request

​Response

​Top-level fields

​Preflight checks

​Simulation

​Index status

​How to use it

Request

Response

Top-level fields

Preflight checks

Simulation

Index status

How to use it