{"uid":"cap_gmcBjNlVBBQF17KghUAB2","slug":"base-address-nonce-lookup-4b1a499f","name":"Base Address Nonce Lookup","description":"Transaction count (nonce) for a Base address, latest and pending. Use when an agent needs the next nonce for a Base address before signing a transaction.","url":"https://x402-data-api.sigrunner.workers.dev/chain/nonce?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","properties":{"address":{"type":"string","description":"0x-prefixed 20-byte Base address"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","required":["address","nonce_latest","nonce_pending","chain"],"properties":{"chain":{"type":"string"},"address":{"type":"string"},"nonce_latest":{"type":"integer"},"nonce_pending":{"type":"integer"}}}}}}},"responseSchema":{"type":"json","example":{"chain":"base","address":"0x4200000000000000000000000000000000000006","nonce_latest":1,"nonce_pending":1}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.002","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","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":"$0.002/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_B7H8upsIZqgtUJik5ifpy","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.002","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns the latest and pending transaction count (nonce) for a given Base mainnet address, useful for determining the next nonce before signing a transaction.","exampleAgentPrompt":"What's the current nonce for Base address 0x4200000000000000000000000000000000000006 — I need both the latest confirmed and pending values before I sign my next transaction.","exampleUseCases":[{"title":"Pre-signing nonce check for raw transaction","prompt":"Before I sign and broadcast this Base transaction, fetch the latest and pending nonce for 0xAbCd1234... so I can set the right nonce field and avoid a replacement error."},{"title":"Wallet sequencing for automated agent","prompt":"My agent is about to send several Base transactions in sequence from 0x9F3a... — can you grab the current confirmed and pending nonce so it can number each transaction correctly?"},{"title":"Stuck transaction diagnosis","prompt":"I think I have a stuck pending transaction on Base from address 0x7Ee2... — check the latest confirmed nonce versus the pending nonce to see if there's a gap."}],"resultDescription":"A JSON object containing the Base chain identifier, the queried address, the latest confirmed nonce (number of mined transactions), and the pending nonce (including transactions in the mempool), e.g. {\"chain\":\"base\",\"address\":\"0x...\",\"nonce_latest\":1,\"nonce_pending\":1}.","failureModes":["Missing or malformed address parameter returns an error","Non-0x-prefixed or invalid address length causes a validation failure","Address not found on Base mainnet may return nonce of 0","Network or RPC issues may cause temporary unavailability","Payment failure (x402) blocks access if USDC funds are insufficient"],"whenToPreferThis":"Choose this endpoint when an AI agent or transaction-signing workflow needs to determine the correct nonce for a Base mainnet address before constructing or submitting a transaction. It is especially useful for avoiding nonce collisions or identifying stuck transactions by comparing latest vs. pending values. Prefer this over general-purpose Ethereum RPC calls when operating within the x402 micropayment ecosystem on Base.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-20T12:36:09.480Z","isFirstParty":false,"canonicalSlug":"base-address-nonce-lookup-4b1a499f"}