AI API without signup
Send an unauthenticated request, pay the quoted rail, then complete the same AI call.
No API key
Request
POST /api/v1/chat/completions
content-type: application/json
x-x402: true
{
"model": "gpt-4.1-nano",
"messages": [
{
"role": "user",
"content": "Reply with one sentence about why HTTP 402 is useful for AI agents."
}
],
"stream": false
}Payment quote
Rails shown here come from the live 402 response.
Request a quote to see payment options.