{"description":"Prepaid credits: pay once with x402 (USDC or EURC) and get an API key. Each call with header X-API-Key costs the same as its x402 price and is taken from the balance; failed calls (HTTP 4xx/5xx) are refunded. For MCP clients and tools that cannot sign a payment per call.","packs":{"$20":{"credit":"$22","price":"20.0","path":"/api/v1/credits/buy/20"},"$5":{"credit":"$5","price":"5.0","path":"/api/v1/credits/buy/5"},"$50":{"credit":"$60","price":"50.0","path":"/api/v1/credits/buy/50"}},"buy":"POST /api/v1/credits/buy/5 (or /20, /50) with an x402 payment; the answer contains apiKey, shown once","topUp":"the same call with your key in X-API-Key adds the pack to that key","card":{"buy":"POST /api/v1/credits/checkout/5 (or /20, /50), free: returns a url to a Stripe payment page; a person pays by card there","key":"shown once on the success page, or to the first GET /api/v1/credits/checkout/session/{sessionId} after payment","topUp":"the same call with your credit key in X-API-Key adds the pack to that key"},"use":{"http":"send X-API-Key: mi_... on any paid route","mcp":"add \"headers\": {\"X-API-Key\": \"mi_...\"} next to \"url\" in your MCP client config"},"signInWithWallet":{"how":"sign extensions[\"sign-in-with-x\"].info (CAIP-122: SIWE for EVM incl. EIP-1271 smart wallets, Sign-In-With-Solana) and send it base64-encoded in the SIGN-IN-WITH-X header; x402 clients with the SIWX extension do this by themselves","rules":"a proof is valid 5 minutes and once; if the wallet's credit does not cover the call, the 402 says so in signIn","what":"No key needed: the wallet that paid for the pack signs the sign-in-with-x challenge of any 402 and the call is taken from its credit","spec":"https://docs.x402.org/extensions/sign-in-with-x"},"balance":"GET /api/v1/credits/balance with X-API-Key (free)","rules":["Credits do not expire","Per-call prices are the x402 prices of each route (see /openapi.json)","Calls answered with HTTP 400 or above are refunded"]}