{"uid":"cap_JFn85Vs8XYj1bXtC9yvKf","slug":"ens-name-resolution-forward-reverse-on-ethereum-base-optimism-818cf8d8","name":"ENS Name Resolution (Forward & Reverse) on Ethereum/Base/Optimism","description":"Pay-per-call on-chain API for AI agents and developers: wallet audits, token safety audits (honeypot detection), live gas prices, token prices, transaction receipts, balances, ENS resolution, block data, ERC-20 allowances, transaction simulation, swap quotes and multicall batches — all computed on-chain via public RPCs (no external market API). Pay per request in USDC on Base via the x402 exact scheme (EIP-3009 transferWithAuthorization). No API key, no signup, no subscription.","url":"https://x402-audit.tatschluizguilherme.workers.dev/ens","method":"GET","headers":{},"bodySchema":null,"responseSchema":{"type":"json","example":{"name":"vitalik.eth","type":"forward","found":true,"address":"0xd8da6bf26964af9d7eed9e03e53415d37aa96045","network":"mainnet","resolver":"0x231b0ee14048e9dccd1d247744d114a4eb5e8e63","blockNumber":25684589,"requestedAt":"2026-08-05T00:40:00.000Z"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.1","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":"$0.1/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.1","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.1","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_q9UB8Ca5BcvAmG19EVIeY","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.1","costPer":"request","priority":0,"asset":null,"unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Resolves ENS names to Ethereum addresses (forward) or Ethereum addresses to ENS names (reverse) across Mainnet, Base, and Optimism via on-chain registry lookup","exampleAgentPrompt":"Before I send payment, can you resolve vitalik.eth to its Ethereum address on Mainnet so I can confirm who I'm paying?","exampleUseCases":[{"title":"Identity check before crypto payment","prompt":"I'm about to send 500 USDC to 'alice.eth' on Ethereum Mainnet — can you resolve that ENS name to its actual wallet address so I can double-check before I send?"},{"title":"Reverse lookup of unknown wallet address","prompt":"I got a transfer from 0x983110309620D911731Ac0932219af06091b6744 on Base — does that address have an ENS name associated with it?"},{"title":"Verify ENS name matches expected address","prompt":"Can you confirm that 'treasury.myprotocol.eth' still resolves to 0xAbCd1234... on Optimism? I want to make sure it hasn't been changed before we proceed."}],"resultDescription":"Returns the resolved Ethereum address (for forward lookups) or ENS name string (for reverse lookups), along with the chain on which the resolution was performed and any relevant registry metadata such as resolution status.","failureModes":["ENS name not registered or expired — returns null or empty address","Address has no reverse ENS record set — returns null name","Unsupported chain specified — returns error indicating valid chains are Mainnet, Base, or Optimism","Malformed ENS name or invalid Ethereum address input — returns validation error","On-chain RPC node unavailability causing resolution timeout","Name resolves to zero address (0x000...000) indicating unset or burned record"],"whenToPreferThis":"Choose this endpoint when you need to perform ENS name resolution on Ethereum Mainnet, Base, or Optimism — particularly as a pre-payment identity verification step. It covers both forward and reverse resolution in a single API, supporting multiple EVM chains simultaneously, which is ideal for multi-chain wallet applications or payment agents that need to confirm counterparty identity before executing a transaction.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T00:44:59.777Z","isFirstParty":false}