{"uid":"cap_ytRMzJgVRx_Wr7IHBSS5R","slug":"base-mainnet-contract-code-check-4cbb02d1","name":"Base Mainnet Contract Code Check","description":"Contract-code check for a Base mainnet address (is_contract + code size + EIP-7702 delegated-EOA detection).","url":"https://x402-data-api.sigrunner.workers.dev/chain/code","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"}}}}},"responseSchema":{"type":"json","example":{"chain":"base","address":"0x4200000000000000000000000000000000000006","is_contract":true,"code_size_bytes":6234,"delegate_address":null,"is_eip7702_delegate":false}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","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":"$0.001/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_RSaBeB9fUC-xaEgSvQ3O4","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Checks a Base mainnet address to determine if it is a contract, returns bytecode size, and detects EIP-7702 delegated EOA status.","exampleAgentPrompt":"Can you check if 0x1234567890abcdef1234567890abcdef12345678 is a smart contract or a regular wallet on Base mainnet, and tell me if it's EIP-7702 delegated?","exampleUseCases":null,"resultDescription":"Returns a JSON object indicating whether the address is a contract (is_contract boolean), the bytecode size in bytes, and whether the address is an EIP-7702 delegated EOA, all scoped to Base mainnet.","failureModes":["Invalid or missing address parameter returns an error","Non-0x-prefixed address may fail validation","Undeployed or zero-code addresses return is_contract: false with code size 0","Network or RPC errors may cause transient failures","Payment not completed returns 402 status"],"whenToPreferThis":"Use this endpoint when you need to quickly classify a Base mainnet address as a smart contract vs EOA, retrieve its deployed bytecode size, or specifically detect EIP-7702 delegated account status — particularly useful for DeFi onboarding flows, wallet profiling, or security screening pipelines where contract vs wallet distinction matters.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T00:45:29.300Z","isFirstParty":false}