AlgoVoi Pay (Payable Core) API
Tenant-free, pay-per-call verification rail (OpenAPI 3.1.0 "AlgoVoi Payable Core" 1.0.0, 17 operations). No account and no API key: each paid operation (verify an x402/AP2 receipt JWS, verify an RFC 9421 HTTP message signature, screen a URL; a compliance receipt is "coming soon") answers a strict x402 v2 402 challenge with one accept per lane across twelve mainnet chains, and the resubmitted call with X-PAYMENT returns the result plus an offline-verifiable Ed25519 payable receipt binding request hash, response hash and settled payment. GET on any paid URL is a free 402 probe; GET/POST /pay/v1/negotiate is a free chain-agnostic lane negotiation; /v1/receipt/verify is a free unsigned tier (120/min). The same host serves the A2A JSON-RPC door (/a2a), MPP and AP2 twins, a did:web document, the receipt JWKS and an x402 descriptor.