SMOKE

Payment smoke

Confirms the x402 gate and PAYMENT-RESPONSE. Not a product tool. Do not call for production work. Not listed on Bazaar.

SMOKE $0.001 USDC GET /v1/tools/ping

When to use

Confirms the x402 gate and PAYMENT-RESPONSE. Not a product tool. Do not call for production work. Not listed on Bazaar.

Try

Opens the live endpoint. Unpaid browser requests show the paywall; agents should send Accept: application/json.

/v1/tools/ping

Full URL: https://api.fetchx402.com/v1/tools/ping

Request

GET /v1/tools/ping · x402 V2 · USDC on Base · $0.001 USDC

x402 V2 curl

Expect HTTP 402 and a PAYMENT-REQUIRED header until you retry with PAYMENT-SIGNATURE.

curl -i -H "Accept: application/json" "https://api.fetchx402.com/v1/tools/ping"

Cursor mcp.json

Intended config for @fetchx402/mcp. This is not npm @x402/fetch (a payment fetch wrapper).

{
  "mcpServers": {
    "fetchx402": {
      "args": [
        "-y",
        "@fetchx402/mcp"
      ],
      "command": "npx",
      "env": {
        "X402_PRIVATE_KEY": "0xYOUR_SPENDING_KEY"
      }
    }
  }
}

Query parameters

Name	Type	Required	Description
`probe`	string	optional	Ignored. Payment smoke test takes no input.

Success fields

Field	Type	Description
`ok`	boolean	Always true after a successful settle
`service`	string	Product name

Example

Frozen fixture. Not a live lookup.

{
  "ok": true,
  "service": "fetchx402"
}

Payment

Unpaid requests return HTTP 402 with a base64 PAYMENT-REQUIRED header. Retry the same URL with PAYMENT-SIGNATURE. Settlement completes before the tool runs. Full handshake and shared payment errors: Payments.

Errors

HTTP	Code	When
402	`payment_required`	Missing or invalid PAYMENT-SIGNATURE; decode the PAYMENT-REQUIRED header
409	`payment_in_progress`	The same authorization nonce is already being settled; retry shortly
429	`rate_limited`	Too many requests from this client
503	`settlement_uncertain`	Settlement is unconfirmed; retry with the same PAYMENT-SIGNATURE
503	`facilitator_unavailable`	Payment facilitator unavailable
503	`facilitator_misconfigured`	Payment facilitator is not configured
503	`facilitator_unauthorized`	Payment facilitator rejected credentials
503	`ledger_unavailable`	Payment ledger unavailable
503	`payment_unavailable`	Payment processing unavailable

Guarantees

Settlement finishes before the tool executes. Uncertain settlement fails closed (HTTP 503).
Execution is timeout-bounded and concurrency-capped.
Not listed on Bazaar. Do not call this for production work.