Simple x402 ping endpoint on Base that charges 100 USDC per request.
What it does
QRBase Ping 100 is a minimal x402-protocol endpoint hosted at qrbase.xyz that returns a simple success/failure response upon receiving a valid USDC payment on the Base network. Each call costs 100 USDC (represented as 100000000 in the asset's 6-decimal format). The endpoint uses the x402 payment challenge flow: an unauthenticated GET request returns HTTP 402 with payment instructions, and a subsequent request with a valid X-PAYMENT header delivers the ping response.
The response schema includes fields for success status, a message string, the on-chain payment transaction hash, and the sender address. The endpoint is tagged as "API Access" and is discoverable. The underlying site, QRBase, appears to be primarily a QR puzzle game platform; this ping endpoint seems to serve as a demonstration or test integration of the x402 payment protocol rather than providing substantive data or computation.
No dedicated documentation, OpenAPI spec, or pricing page was found for this endpoint. All technical details are derived from the x402 challenge response itself. The 100 USDC cost per call is notably high for a simple ping, suggesting this may be intended for testing payment flows rather than production use.
Capabilities
Use cases
- —Testing x402 payment flow integration with a live endpoint
- —Verifying that an agent can successfully complete an x402 USDC payment on Base
- —Demonstrating pay-per-call API access using the x402 protocol
Fit
Best for
- —Developers testing x402 payment integrations
- —Agents verifying USDC-on-Base payment capability
- —Quick smoke tests of x402 client libraries
Not for
- —Production health-check monitoring (100 USDC per call is prohibitively expensive)
- —Obtaining any substantive data or computation beyond a ping acknowledgment
Quick start
curl -X GET https://www.qrbase.xyz/api/x402/ping100
# Returns 402 with payment challenge.
# Include a valid X-PAYMENT header to complete the transaction.Example
Response
{
"sender": "0x1234...5678",
"message": "pong",
"success": true,
"x402Version": 1,
"paymentTransaction": "0xabc123...def"
}Endpoint
Quality
The endpoint is live and returns a well-formed x402 challenge with an outputSchema, but there is no documentation, no OpenAPI spec, and no dedicated docs page. The response example is inferred from the outputSchema. The site itself is a puzzle game with no API documentation.
Warnings
- —No dedicated API documentation or OpenAPI spec found
- —100 USDC per ping call is extremely high — likely a test/demo endpoint
- —Response example is inferred from outputSchema, not from an actual successful call
- —The provider site (qrbase.xyz) is primarily a puzzle game; this endpoint may not be actively maintained as a production API
Citations
- —The endpoint returns HTTP 402 with x402 version 1 challenge requiring 100 USDC on Basehttps://www.qrbase.xyz/api/x402/ping100
- —Payment is sent to address 0x07737A1fB3863202bcd3c7408b801EEd68604D39 using USDC asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://www.qrbase.xyz/api/x402/ping100
- —The output schema includes x402Version, success, message, paymentTransaction, and sender fieldshttps://www.qrbase.xyz/api/x402/ping100
- —QRBase homepage is a QR puzzle game platformhttps://www.qrbase.xyz