Complete API specification for the HTTPayer Relay service endpoints.

Base URL: https://api.httpayer.com/relay

Version: 1.0

Overview

The HTTPayer Relay service implements a privacy-first payment relay for x402-gated APIs.

Supports both EVM (Base) and Solana networks.

Payment Flow (Mode A – Privacy-First)

  1. Client sends request to relay without payment header
  2. Relay queries target API → receives 402 Payment Required
  3. Relay responds with 402 containing HTTPayer payment instructions
  4. Client pays HTTPayer on preferred chain
  5. Client retries request with X-PAYMENT
  6. Relay validates payment, pays target API on behalf of client
  7. Relay forwards request to target and returns response

Configuration

Parameter Default Description
RELAY_FEE_PERCENTAGE 10% HTTPayer relay fee percentage
MAX_DAILY_RELAY_PER_WALLET $100 USD Daily spending limit per wallet
MAX_DAILY_RELAY_TOTAL $1,000 USD System-wide relay volume limit
ASYNC_THRESHOLD_MS 120,000ms When to switch to async mode
MAX_ASYNC_POLLING_MS 60,000ms Max blockchain polling time