{"uid":"cap_xjfk24phY9ka1BXRfMz0A","slug":"xerxes-base-balance-lookup-e8127c70","name":"Xerxes Base Balance Lookup","description":"Base native or ERC-20 balance at the current head. GET /v1/base/balance/{addr} for ETH wei; add ?token=0x… for balanceOf at that token. Proof-stamped. No USD quote. Dead RPC is unread, not zero.","url":"https://ari001.tailb4ac3a.ts.net/v1/base/balance/:addr","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","HEAD","DELETE"],"type":"string"},"pathParams":{"type":"object","required":["addr"],"properties":{"addr":{"type":"string","description":"20-byte 0x address on Base"}}},"queryParams":{"type":"object","properties":{}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.005","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":"$0.005/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_QKLHa_rHL4moQzo8LzOY8","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.005","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns the native ETH (in wei) or ERC-20 token balance for a given Base network address at the current chain head, with proof stamping.","exampleAgentPrompt":"What's the current ETH balance in wei for Base address 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045? Also check its USDC balance using token contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913.","exampleUseCases":[{"title":"DeFi portfolio balance check","prompt":"Check the current ETH balance on Base for wallet 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 and also look up how many USDC tokens it holds — token contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913."},{"title":"Pre-transaction funding verification","prompt":"Before I send a transaction, can you confirm that 0xAb5801a7D398351b8bE11C439e05C5B3259aeC9B actually has ETH on Base right now? Give me the exact wei amount."},{"title":"Agent wallet treasury monitoring","prompt":"I want to know the current on-chain ETH balance of my agent's Base wallet at 0x1234567890abcdef1234567890abcdef12345678 — I need the raw wei figure, proof-stamped at the current head."}],"resultDescription":"Returns the balance at the current chain head: native ETH expressed in wei for the given Base address, or the ERC-20 balanceOf amount when a token contract address is supplied. The response includes a cryptographic proof stamp. If the underlying RPC node is unreachable, the endpoint returns an unread/error state rather than reporting a zero balance, distinguishing connectivity failures from genuinely empty wallets.","failureModes":["Dead or unreachable RPC node returns an unread/error state rather than zero — agent must distinguish this from a true zero balance","Invalid or malformed 0x address returns an error response","Token contract address not a valid ERC-20 returns an error or zero","No USD conversion provided — agent must separately fetch price data if fiat value is needed","Payment failure via x402 protocol blocks the request","Rate limiting or node congestion may delay response"],"whenToPreferThis":"Choose this endpoint when you need a proof-stamped, current-head native ETH or ERC-20 balance for a specific Base network address, especially when auditability matters (the proof stamp distinguishes it from raw RPC calls). Prefer it over generic RPC calls when operating in an agentic context where accountability and payment-gated access provide trust guarantees. Not suitable when you need historical balances at a specific block, a USD quote, or balances on chains other than Base.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T06:30:26.823Z","isFirstParty":false}