{"uid":"cap_oEd60Jow8cdpMkHIDaevC","slug":"x402-transaction-watch-439e7315","name":"x402 Transaction Watch","description":"Transaction confirmation watch primitive for autonomous agents. Check whether an EVM transaction is pending, confirmed or reverted and return confirmations plus next-check state. Supply previous_state_hash on later polls to detect status changes without keeping server-side state.","url":"https://x402-gateway-production-1f21.up.railway.app/agent/transaction-watch?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method","bodyType","body"],"properties":{"body":{"type":"object","required":["tx_hash"],"properties":{"network":{"enum":["base","ethereum"],"type":"string","default":"base"},"tx_hash":{"type":"string","pattern":"^0x[a-fA-F0-9]{64}$"},"previous_state_hash":{"type":"string","pattern":"^[a-fA-F0-9]{64}$"}},"additionalProperties":false},"type":{"type":"string","const":"http"},"method":{"enum":["POST"],"type":"string"},"bodyType":{"enum":["json","form-data","text"],"type":"string"}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"type":"json","example":{"status":"ready"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.003","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"registry","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.003/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_xZKkE_OHTl7kuflMhRhAB","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.003","costPer":"request","priority":0,"asset":null,"unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Monitors a blockchain transaction by hash and detects state changes, returning a deterministic status snapshot for Base or Ethereum networks.","exampleAgentPrompt":"Watch transaction 0xabc123...def456 on Base and let me know if its state has changed since the last time we checked — the previous state hash was 9f3c...a1b2.","exampleUseCases":[{"title":"Confirm DeFi swap completion","prompt":"Keep an eye on transaction 0x4f2a...c891 on Base — I just submitted a swap and want to know the moment it moves from pending to confirmed."},{"title":"Detect on-chain payment settlement","prompt":"Check if this Ethereum transaction 0x7e1d...f302 has settled yet and compare it against the state hash 3a9c...7f44 we recorded earlier so I know if anything changed."},{"title":"Agentic payment pipeline verification","prompt":"After sending USDC on Base, verify that transaction 0xb88c...0d71 is ready and report whether its current state differs from hash a12e...9c03 I logged previously."}],"resultDescription":"Returns a JSON object with a 'status' field (e.g. 'ready') indicating the current state of the monitored transaction, enabling the caller to detect whether the on-chain state has changed relative to a previously recorded hash.","failureModes":["Invalid tx_hash format (must be 0x-prefixed 64 hex chars) returns validation error","Invalid previous_state_hash format returns schema error","Unsupported network value (not 'base' or 'ethereum') rejected by enum constraint","Transaction not yet indexed or not found on the specified network","Payment failure or insufficient USDC balance blocks the x402-gated request","Network timeout if the RPC node is slow to respond"],"whenToPreferThis":"Choose this endpoint when you need deterministic, hash-based change detection for a specific transaction on Base or Ethereum — particularly in agentic pipelines where you need to poll or compare state over time without duplicating logic. Prefer it over generic block explorers when you need a machine-payable, structured API response rather than a human-facing UI, and when you already have a previous state hash to compare against.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-10T12:36:11.194Z","isFirstParty":false,"canonicalSlug":"x402-transaction-watch-439e7315"}