Minimal x402 test endpoint that returns "Hello World" for $0.001 USDC on Base.
What it does
hello-world-x402.vercel.app is a basic x402 V2 demonstration service hosted on Vercel. It exposes several GET endpoints (/hello, /world, /test1, /test2, /test3) that each return a simple text response upon receiving a valid x402 payment of $0.001 USDC on Base Mainnet (chain ID 8453). The service also provides a discovery endpoint at /.well-known/x402.
The /hello endpoint is the canonical entry point. When called without payment, it returns an HTTP 402 challenge per the x402 protocol. After the caller settles $0.001 USDC to the recipient address 0x2a47E248ee3B5f3e680b5F6B5832E5EF1206b7e3, the endpoint responds with its payload. This makes it useful for testing x402 client libraries, agent payment flows, and integration scaffolding.
There is no OpenAPI schema, no detailed documentation, and no additional functionality beyond the hello-world response. The service is intentionally minimal — a reference implementation for developers building or validating x402-compatible tooling.
Capabilities
Use cases
- —Testing x402 client library implementations against a live endpoint
- —Validating agent payment flows with a low-cost real transaction
- —Demonstrating the x402 protocol handshake (402 challenge → payment → response)
- —Integration testing for wallets or agents that need to handle HTTP 402 challenges
Fit
Best for
- —Developers building x402-compatible clients or agents
- —Quick smoke tests of USDC payment pipelines on Base Mainnet
- —Learning how the x402 protocol works with a real, live endpoint
Not for
- —Production data retrieval or any real-world utility beyond testing
- —High-throughput or latency-sensitive workloads
Quick start
curl -i https://hello-world-x402.vercel.app/hello
# Returns HTTP 402 with x402 payment challenge.
# After settling $0.001 USDC on Base to 0x2a47E248ee3B5f3e680b5F6B5832E5EF1206b7e3,
# re-send the request with the x402 payment proof header to receive the response.Endpoint
Quality
The endpoint is live (402 challenge captured) and the root page provides clear pricing and network info, but there is no OpenAPI schema, no documentation, no response examples, and the x402 challenge body was empty in the probe. This is a minimal test service with sparse metadata.
Warnings
- —No OpenAPI or schema available — response format is unknown beyond 'Hello World' text
- —The x402 challenge object captured in the probe was empty ({}), so exact payment parameters could not be verified from the wire challenge alone
- —No docs, README, or usage guide is served by the endpoint
- —This is a test/demo service; it provides no real-world utility beyond protocol validation
Citations
- —Service describes itself as 'A basic x402 V2 test endpoint returning Hello World' with $0.001 USDC price on Base Mainnethttps://hello-world-x402.vercel.app
- —Recipient address is 0x2a47E248ee3B5f3e680b5F6B5832E5EF1206b7e3, USDC contract 0x833589fcd6edb6e08f4c7c32d4f71b54bda02913, chain ID 8453https://hello-world-x402.vercel.app
- —Five payment-gated endpoints (/hello, /world, /test1, /test2, /test3) plus a discovery endpoint at /.well-known/x402https://hello-world-x402.vercel.app