{"uid":"cap_-NL8oh3MsKln9_8NK9oDc","slug":"base-eth-balance-nonce-lookup-2d08394d","name":"Base ETH Balance & Nonce Lookup","description":"Live native ETH balance + nonce for a wallet on Base: wallet=0x..","url":"https://kr-x402-mvp.kgy5612.workers.dev/crypto/eth-balance?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","required":["wallet"],"properties":{"wallet":{"type":"string","pattern":"^0x[0-9a-fA-F]{40}$","examples":["0xe4be4d0bd82d8e68203deff81f79ede0529f2617"],"description":"Wallet"}},"additionalProperties":false}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"type":"json","example":{"block":53204016,"chain":"base","nonce":0,"wallet":"0xe4be4d0bd82d8e68203deff81f79ede0529f2617","balance_eth":0,"balance_wei":"0"}},"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":"$0.002/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_E9iywiz2tRfyOamSfM8KD","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.002","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns the live native ETH balance (in ETH and Wei) plus transaction nonce for a given wallet address on the Base blockchain.","exampleAgentPrompt":"What's the current ETH balance and nonce for wallet 0xe4be4d0bd82d8e68203deff81f79ede0529f2617 on Base?","exampleUseCases":[{"title":"Pre-payment counterparty ETH check","prompt":"Before I send payment to 0xAbC123...dEf456, check their ETH balance on Base to make sure they have enough to cover gas for the transaction."},{"title":"Agent self-balance monitoring","prompt":"Check the current native ETH balance and nonce for my agent wallet 0xe4be4d0bd82d8e68203deff81f79ede0529f2617 on Base so I know if I need to top it up."},{"title":"Nonce verification before transaction submission","prompt":"What's the current nonce for wallet 0x1234567890abcdef1234567890abcdef12345678 on Base? I need to make sure I'm not reusing a transaction sequence number."}],"resultDescription":"A JSON object containing the wallet address, native ETH balance as a decimal float and as a Wei string, the current transaction nonce (number of transactions sent), the block number at time of query, and the chain identifier ('base').","failureModes":["Invalid wallet address format (not matching ^0x[0-9a-fA-F]{40}$) returns an error","Missing wallet query parameter returns a validation error","Network or RPC unavailability may return a 5xx error","Payment failure (insufficient USDC for x402 fee) blocks the request"],"whenToPreferThis":"Choose this endpoint when you need real-time native ETH balance and nonce data for a Base wallet in a single lightweight call — especially for onchain AI agents doing pre-payment checks, self-monitoring, or counterparty verification on Base L2 specifically. Prefer this over general blockchain explorers when you need machine-readable JSON at $0.002/call via x402 micropayment, and when you specifically need the nonce alongside balance in one response.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-31T18:42:26.503Z","isFirstParty":false,"canonicalSlug":"base-eth-balance-nonce-lookup-2d08394d"}