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. Latest finding: four of every five dollars flowing into listed x402 wallets settled outside the protocol.
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 |
|---|---|---|---|---|
| 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 |
| A | 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 | 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+ | CoinGecko | 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 |
| B | Dokimo Verify API | Verification | 100.0% | x402 list |
| A+ | Blixtworks img-categorize | AI | 100.0% | x402 list |
| A+ | Jobero job search | AI | 100.0% | x402 list |
| B | Resonant Glyph Research Synthesis | Data | 100.0% | x402 list |
| B | Comrades of War — Spanish Gaming Community Archive API | Data | 100.0% | x402 list |
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.