{"uid":"cap_ygh1cmwjIG9fVXMvrc95q","slug":"salt19-base-contract-state-lookup-ba0cc7d7","name":"SALT19 Base Contract State Lookup","description":"SALT19 is an independent applied AI systems lab behind EvoMind governed cognition, the MCP-native Agent Utility Grid, the ARCS research community, AeroClear UAS flight intelligence, and practical software for real-world work.","url":"https://api.salt19.com/v1/base-contract-state","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"address":{"type":"string","pattern":"^0x[0-9a-fA-F]{40}$"}}},"responseSchema":{"type":"json","example":{"token":{"symbol":"USDC","decimals":6},"code_bytes":1234,"is_contract":true,"block_number":12345678}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","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":"$0.01/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_iZeNzNA0Zp7nvVMfG3Rip","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Retrieves the base on-chain state of an Ethereum address, including whether it is a contract, its bytecode size, and current block context.","exampleAgentPrompt":"Can you check whether 0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984 is a smart contract on-chain and tell me its bytecode size and what block we're at?","exampleUseCases":[{"title":"Verify contract vs EOA before transfer","prompt":"Before I send funds, can you check if 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 is actually a smart contract or just a regular wallet, and give me its bytecode size?"},{"title":"Smart contract deployment confirmation","prompt":"I just deployed a contract — can you confirm that 0xdAC17F958D2ee523a2206206994597C13D831ec7 now shows up as a contract on-chain with bytecode, and what block number confirmed it?"},{"title":"Due diligence on unknown address","prompt":"I found this address 0x6B175474E89094C44Da98b954EedeAC495271d0F in a transaction — can you pull its base contract state and tell me if it's a contract, how big its bytecode is, and the current block?"}],"resultDescription":"Returns a JSON object containing: whether the address is a smart contract (is_contract boolean), the size of its deployed bytecode in bytes (code_bytes), the current block number (block_number), and token context including symbol (USDC) and decimals (6).","failureModes":["Invalid address format (not a valid 0x hex address) — request rejected before on-chain query","Address not found or network unavailable — may return is_contract false or error","Payment failure via x402 protocol — call not processed if USDC payment of $0.01 not confirmed","Rate limiting or quota exceeded — HTTP 429 or similar","Node RPC failure — upstream blockchain node unavailable causing 5xx response"],"whenToPreferThis":"Use this endpoint when you need a fast, cheap ($0.01 USDC) on-chain lookup of an Ethereum address's base state — specifically whether it is a contract, its bytecode footprint, and the current block. Prefer this over full blockchain explorers when you only need contract/EOA classification and bytecode size without full ABI decoding, event logs, or transaction history. Ideal for agent workflows that gate logic on whether an address is a contract before taking further action.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T12:37:06.772Z","isFirstParty":false}