x402 Crypto Research API

Endpoints (10 live)

• GET /api/signal/:asset — Compact trend signal (bullish/neutral/bearish + score). Assets: btc,eth,sol,xrp,doge,ada,avax,link,dot,ltc,bch,uni,aave,xlm,hbar,shib,sui,near,atom,fil. Free delayed sample: /api/sample/signal (0.003 USDC on Base)
• GET /api/firm/risk-snapshot — Use before interacting with an unfamiliar Base (chain 8453) address: returns a public-data red-flag snapshot (contract vs EOA, EIP-7702 delegation, source verification, upgradeable proxy, age, activity, ETH/USDC balance, risk level). Pass ?address=0x... Errors: 400 invalid address. Informational only. (0.03 USDC on Base)
• GET /api/x402/preflight — One-call Base (8453) preflight: risk snapshot + live ERC-20 approvals + OFAC SDN screen + optional x402 invoice check (?invoice= JSON or base64). Returns risk, approvals, invoice, sanctions and summary {verdict proceed|review|stop, flags}. Free sample: /api/preflight/sample. 400 bad input; 503 not charged. Informational, not a guarantee. (0.05 USDC on Base)
• GET /api/x402/approval-enumerate — List live ERC-20 approvals for a Base (8453) address: token, spender, current allowance, unlimited flag. status ok (complete, approvals found) / none (complete, zero active) / unknown (data incomplete; reason given; never reported as none). Pass ?address=0x... Errors: 400 invalid address; 503 indexer/RPC unavailable (not charged). Read-only; never signs. (0.03 USDC on Base)
• GET /api/x402/settlement-status — Check an x402 settlement on Base (chain 8453): tx exists/succeeded, USDC Transfer and AuthorizationUsed events (from, to, amount), confirmations. Pass ?tx=0x... Errors: 400 invalid tx hash. Read-only. (0.02 USDC on Base)
• GET /api/x402/invoice-decode — Use before paying any x402 invoice: decodes a base64 PAYMENT-REQUIRED header (query ?header= or JSON body {header}) and checks scheme exact, Base mainnet, Base USDC asset, payTo (EOA/contract/EIP-7702), human amount, timeout; returns verdict ok/warn/fail with reasons. Errors: 400 invalid header. Read-only; never signs or pays. (0.02 USDC on Base)
• GET /api/signal/btc — Compact trend signal (bullish/neutral/bearish + score). Assets: btc,eth,sol,xrp,doge,ada,avax,link,dot,ltc,bch,uni,aave,xlm,hbar,shib,sui,near,atom,fil. Free delayed sample: /api/sample/signal (0.003 USDC on Base)
• GET /api/brief/btc — Technical + sentiment research brief (price, 24h/7d change, RSI14, SMA20/50, trend, Fear & Greed). Assets: btc,eth,sol,xrp,doge,ada,avax,link,dot,ltc,bch,uni,aave,xlm,hbar,shib,sui,near,atom,fil (0.03 USDC on Base)
• GET /api/signal-batch — Live trend signals for up to 10 assets in one call, flat price regardless of count. Pass ?assets=btc,eth,... from: btc,eth,sol,xrp,doge,ada,avax,link,dot,ltc,bch,uni,aave,xlm,hbar,shib,sui,near,atom,fil. Errors (before payment): 400 missing/unsupported/too many assets. (0.02 USDC on Base)
• POST /api/x402/invoice-decode — Use before paying any x402 invoice: decodes a base64 PAYMENT-REQUIRED header (query ?header= or JSON body {header}) and checks scheme exact, Base mainnet, Base USDC asset, payTo (EOA/contract/EIP-7702), human amount, timeout; returns verdict ok/warn/fail with reasons. Errors: 400 invalid header. Read-only; never signs or pays. (0.02 USDC on Base)