x402-protocol demo chat endpoint accepting USDC micropayments on Base
What it does
This is a demonstration chat API endpoint hosted on the x402 protocol documentation/discovery site (x402repo.vercel.app). It accepts HTTP POST requests and is gated behind an x402 payment challenge, requiring USDC payment on the Base network. The endpoint charges up to 0.002 USDC per request (2000 base units with 6 decimals), settling to the wallet address 0xAbF01df9428EaD5418473A7c91244826A3Af23b3 via the "exact" payment scheme.
The hosting site serves as the primary documentation hub for the x402 open payment protocol, containing quickstart guides, code examples, API references, and specifications for TypeScript, Go, Python, and Java SDKs. The /api/chat endpoint itself appears to be a reference implementation demonstrating how x402-protected APIs work in practice. No dedicated documentation for this specific endpoint's request/response schema was found in the crawl — the site focuses on the protocol itself rather than documenting this particular chat resource.
The x402 challenge is live and well-formed (v1 protocol, exact scheme, Base network, USDC asset at 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913). The endpoint accepts POST with application/json content type and is marked as discoverable. However, without documentation on the expected request body format or response structure, callers will need to experiment or inspect the source code to determine the correct payload shape.
Capabilities
Use cases
- —Testing x402 client implementations against a live payment-gated endpoint
- —Demonstrating how x402 micropayments work for chat/LLM APIs
- —Building agents that can autonomously pay for chat completions via x402
Fit
Best for
- —Developers learning the x402 protocol who need a live test endpoint
- —Agent builders experimenting with autonomous crypto-paid API calls
- —x402 client library integration testing
Not for
- —Production chat/LLM workloads requiring documented SLAs and schemas
- —Users without a Base network USDC wallet
- —Applications needing free or high-volume chat completions
Quick start
import { withPayment } from '@x402/fetch';
const response = await withPayment(
fetch('https://x402repo.vercel.app/api/chat', {
method: 'POST',
headers: { 'Content-Type': 'application/json' },
body: JSON.stringify({ message: 'Hello' })
}),
{ wallet: yourWallet }
);Example
Request
{
"message": "Hello, how are you?"
}Endpoint
Quality
The x402 challenge is live and well-formed, confirming the endpoint exists and accepts payments. However, there is no documentation for the chat endpoint's request/response schema, no OpenAPI spec, and no description field in the challenge. The request body format and response structure are entirely inferred. The site is primarily an x402 protocol documentation hub, not a documented API service.
Warnings
- —No documentation found for the /api/chat endpoint's request or response schema
- —The example_request_json is speculative — the actual expected payload is unknown
- —No description provided in the x402 challenge's description field
- —This appears to be a demo/reference endpoint, not a production service
- —Price is extremely low (0.002 USDC) suggesting this is a test/demo resource
Citations
- —The endpoint returns a valid x402 v1 challenge with exact scheme on Base network using USDChttps://x402repo.vercel.app/api/chat
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://x402repo.vercel.app/api/chat
- —maxAmountRequired is 2000 base units (0.002 USDC with 6 decimals)https://x402repo.vercel.app/api/chat
- —The site hosts x402 protocol documentation including quickstarts, code examples, API references, and specs for TypeScript, Go, Python, and Javahttps://x402repo.vercel.app