SatsAPI is a Bitcoin market intelligence API using the L402 protocol — pay per call in sats, no API key, no subscription, no registration. 8 endpoints: price, mempool, on-chain, derivatives, AI signals and full market summary. Costs from 2 to 200 sats (~$0.001–$0.12). Designed for developers and autonomous AI agents. Try free: curl https://satsapi.dev/v1/demo