{"slug":"preflight402-com-v1-btc-tx-context-058bc1","title":"Call before signing a Bitcoin transaction when you need chain context for its in","host":"preflight402.com","method":"POST","resource":"https://preflight402.com/v1/btc/tx-context","category":"market","description":"Call before signing a Bitcoin transaction when you need chain context for its inputs: whether each prevout exists, whether it is already spent, its value in sats and its confirmations. Resolves up to 10 inputs against a public explorer at about one request per second, so a full batch can take over 2","price_listed":0.1,"price_asked":0.1,"state":"answering","state_label":"Answering","checks_7d":1,"answered_7d":1,"latency_ms_median":39,"reported_calls_30d":1,"reported_payers_30d":1,"networks":["eip155:8453"],"badge":"unverified","paid_checks_7d":0,"paid_ok_7d":0,"example_input":{"body":{"inputs":[{"txid":"4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b","vout":0}]},"bodyType":"json","method":"POST","type":"http"},"output_schema":{"$schema":"https://json-schema.org/draft/2020-12/schema","properties":{"input":{"additionalProperties":false,"properties":{"body":{"additionalProperties":false,"properties":{"inputs":{"items":{"additionalProperties":false,"properties":{"txid":{"pattern":"^[0-9a-f]{64}$","type":"string"},"vout":{"maximum":100000,"minimum":0,"type":"integer"}},"required":["txid","vout"],"type":"object"},"maxItems":10,"minItems":1,"type":"array"},"network":{"default":"mainnet","enum":["mainnet","testnet"],"type":"string"}},"required":["inputs"],"type":"object"},"bodyType":{"enum":["json","form-data","text"],"type":"string"},"method":{"enum":["POST"],"type":"string"},"type":{"const":"http","type":"string"}},"required":["type","method","bodyType","body"],"type":"object"},"output":{"properties":{"example":{"type":"object"},"type":{"type":"string"}},"required":["type"],"type":"object"}},"required":["input"],"type":"object"},"history":[{"day":"2026-09-28","reachable":true,"status":402,"valid_402":true,"asked_usdc":0.1,"price_match":true,"latency_ms":39,"error":null}],"description_full":"Call before signing a Bitcoin transaction when you need chain context for its inputs: whether each prevout exists, whether it is already spent, its value in sats and its confirmations. Resolves up to 10 inputs against a public explorer at about one request per second, so a full batch can take over 20 seconds; figures reflect chain state at checked_at. Describes on-chain facts with source links; never advises whether to sign.","last_updated":"2026-09-28T08:47:40.391Z","schemes":["exact"]}