{"uid":"cap_eSE7LJnkxbn1Zk6c5-OIj","slug":"onesource-ethereum-transaction-nonce-lookup-3b274c2d","name":"OneSource Ethereum Transaction Nonce Lookup","description":"Next transaction nonce for any Ethereum wallet via eth_getTransactionCount - how many txs it has sent","url":"https://api.onesource.io/api/chain/nonce/:address","method":"GET","headers":{},"bodySchema":null,"responseSchema":null,"example":{"request":{"block":"latest","address":"0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045","network":"ethereum"},"response":{"data":{"nonce":"0x1708"},"meta":{"endpoint":"/api/chain/nonce/0xd8da6bf26964af9d7eed9e03e53415d37aa96045","request_id":"57e2fc6b1466bbb6"}}},"exampleRequest":{"block":"latest","address":"0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045","network":"ethereum"},"tags":["x402"],"displayCostAmount":"0.003","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"settled","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_oxvDpeqA-r9jDA9_wDU6J","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.003","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns the next transaction nonce (transaction count) for any Ethereum wallet address via eth_getTransactionCount","exampleAgentPrompt":"What's the next nonce for Ethereum wallet 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 on mainnet — I need to know how many transactions it has sent so I can sign my next transaction correctly.","exampleUseCases":null,"resultDescription":"Returns the transaction nonce (count of transactions sent) for the specified Ethereum address, representing the next nonce to use when constructing a new transaction. Can be queried at a specific block number, block tag (latest, pending, earliest, safe, finalized), or hex block reference.","failureModes":["Invalid Ethereum address format (not 0x + 40 hex chars) — returns validation error","Unknown network value other than 'ethereum' or 'sepolia' — returns error","Invalid block parameter format — returns validation error","Node RPC timeout or upstream Ethereum node unavailability — returns 5xx error","Payment failure (x402) — returns 402 Payment Required"],"whenToPreferThis":"Use this endpoint when you need to determine the correct nonce for constructing and signing a new Ethereum transaction, or when you need to audit how many transactions a wallet has sent. Useful for transaction sequencing, replay protection, and wallet activity checks. Supports both mainnet and Sepolia testnet, and allows querying at specific historical blocks for forensic or analytical purposes.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T06:44:11.707Z","isFirstParty":false}