x402 is the open HTTP-native stablecoin micropayment protocol that lets AI agents pay each other per request. Built by Coinbase, contributed to the Linux Foundation in April 2026, backed by Cloudflare, Stripe, AWS, Google, Visa, Mastercard, and others.
An agent wanting to use a service makes a normal HTTP request. If payment is required, the server returns HTTP 402 with payment terms. The agent's wallet signs and submits a USDC payment via a facilitator (Coinbase CDP is dominant). Settlement is sub-2-second on Base or Solana. The agent retries with a payment header and gets the response. The whole exchange is one round-trip layer above HTTP, no API keys involved.
| Grade | Service | Category | Uptime | Source |
|---|---|---|---|---|
| A+ | dTelecom STT | AI | 100.0% | x402 list |
| A+ | Spraay Gateway | AI | 100.0% | x402 list |
| B | AgentMail | AI | 100.0% | x402 list |
| A+ | Robtex | Data | 100.0% | x402 list |
| A+ | AskClaude | AI | 100.0% | x402 list |
| A+ | Neynar | Data | 100.0% | x402 list |
| B | Interzoid | Data | 100.0% | x402 list |
| A+ | Zerion | Data | 100.0% | x402 list |
| A | StableEmail | AI | 100.0% | x402 list |
| A+ | Mycelia Signal | Data | 100.0% | x402 list |
| B | Browserbase | Compute | 100.0% | x402 list |
| B | Pinata | Content | 100.0% | x402 list |
| A | Venice AI | AI | 100.0% | x402 list |
| A+ | Otto AI | AI | 100.0% | x402 list |
| A+ | SocioLogic RNG | Data | 100.0% | x402 list |
| A+ | QuickNode | Compute | 100.0% | x402 list |
| A+ | Nansen | Data | 100.0% | x402 list |
| A | CoinMarketCap | Data | 100.0% | x402 list |
| A | Messari | Data | 100.0% | x402 list |
| A+ | Snack Money | Finance | 100.0% | x402 list |
| A | GPU-Bridge | Compute | 100.0% | x402 list |
| A+ | Gloria AI | Data | 100.0% | x402 list |
| A+ | CoinGecko | Data | 99.6% | x402 list |
| D | x402mail | AI | — | x402 list |
| C | Anthropic | Inference | — | agentic market |
Start with the Coinbase x402 docs, deploy on Cloudflare Workers, and list yourself on Agentic.market. Your service will appear on this page within 15 minutes once it's discoverable.