{"uid":"cap_fsjK3BlcodS3AFCZj_51V","slug":"onesource-ethereum-storage-slot-reader-45fc26b3","name":"OneSource Ethereum Storage Slot Reader","description":"Read a raw storage slot from any Ethereum contract via eth_getStorageAt","url":"https://api.onesource.io/api/chain/storage","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","HEAD","DELETE"],"type":"string"},"queryParams":{"type":"object","required":["contract","slot"],"properties":{"slot":{"type":"string","pattern":"^0x[a-fA-F0-9]+$"},"block":{"oneOf":[{"type":"integer","minimum":0},{"enum":["latest","pending","earliest","safe","finalized"],"type":"string"},{"type":"string","pattern":"^0[xX][a-fA-F0-9]+$"}]},"network":{"enum":["ethereum","sepolia","robinhood"],"type":"string","default":"ethereum"},"contract":{"type":"string","pattern":"^0x[a-fA-F0-9]{40}$"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","required":["data","meta"],"properties":{"data":{"type":"object","properties":{"value":{"type":"string"}},"description":"Endpoint-specific response payload"},"meta":{"type":"object","required":["endpoint","request_id"],"properties":{"endpoint":{"type":"string"},"cost_usdc":{"type":"string"},"request_id":{"type":"string"},"payment_chain":{"type":"string"},"payment_token":{"type":"string"}}},"error":{"type":["object","null"],"properties":{"code":{"type":"integer"},"message":{"type":"string"}}}}}}}}},"responseSchema":{"type":"json","example":{"data":{"value":"0x0000000000000000000000000000000000000000000000000000000000000001"},"meta":{"endpoint":"/api/chain/storage","cost_usdc":"0.001","request_id":"00000000abcdef01","payment_chain":"base","payment_token":"USDC"}}},"example":{"request":{"slot":"0x1","block":"latest","network":"ethereum","contract":"0x1f9840a85d5af5bf1d1762f925bdaddc4201f984"},"response":{"data":{"value":"0x0000000000000000000000001a9c8182c09f50c8318d769245bea52c32be35bc"},"meta":{"endpoint":"/api/chain/storage","request_id":"0a801bc64c8fd772"}}},"exampleRequest":{"slot":"0x1","block":"latest","network":"ethereum","contract":"0x1f9840a85d5af5bf1d1762f925bdaddc4201f984"},"tags":["x402"],"displayCostAmount":"0.005","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"settled","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__uw5ahbeFZKo06UjWqD9E","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":"Reads a raw storage slot value from an Ethereum smart contract at a specified block on mainnet or Sepolia testnet","exampleAgentPrompt":"What's the value stored in storage slot 0x0 of the USDT contract (0xdac17f958d2ee523a2206206994597c13d831ec7) on Ethereum mainnet at the latest block?","exampleUseCases":null,"resultDescription":"Returns a JSON object containing the queried contract address, the storage slot index, the block reference, and the 32-byte hex-encoded value stored at that slot (e.g. '0x0000000000000000000000000000000000000000000000000000000000000001')","failureModes":["Invalid contract address format returns 4xx validation error","Invalid slot hex string returns 4xx validation error","Contract does not exist at that block returns zero value","Invalid block number or tag returns error","Network not 'ethereum' or 'sepolia' returns validation error","Payment failure via x402/MPP returns 402 Payment Required"],"whenToPreferThis":"Use this endpoint when you need low-level EVM storage slot access — for inspecting raw contract state, reading packed storage variables, or verifying on-chain data that isn't exposed through a contract's public ABI. 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