{"x402Version":1,"error":"payment required","accepts":[{"scheme":"exact","network":"base","chainId":8453,"asset":"0x833589fcd6edb6e08f4c7c32d4f71b54bda02913","assetSymbol":"USDC","maxAmountRequired":"50000","amountUsdc":0.05,"payTo":"0x298830dcC5844867Ba011bceEa3DB2E37104EeD0","resource":"https://smeltworks.com/momentumsignals/v1/momentum","description":"0.05 USDC on Base buys 25 calls.","mimeType":"application/json"}],"howToPay":["1. Send at least 0.05 USDC (Base, chainId 8453) to 0x298830dcC5844867Ba011bceEa3DB2E37104EeD0.","2. Retry this request with header 'X-PAYMENT-TX: <your tx hash>'.","3. That hash is your API key for 25 calls. Reuse it until spent.","Payment is verified on-chain by this server. No signup, no key, no account."],"service":{"name":"Momentum Signals API","description":"Volatility-adjusted cross-sectional momentum rankings for the top-50 crypto assets and 40 US equities/sector ETFs. Pay per bundle in USDC on Base; the tx hash is the API key — no signup, no account.","category":"data","endpoints":["/v1/crypto/preview","/v1/crypto","/v1/crypto/{symbol}","/v1/preview","/v1/momentum","/v1/signal/{symbol}"]}}