{"uid":"cap_g3jYzEKs7zi7guQkioSkK","slug":"biosfera-storage-slot-reader-580cc76d","name":"Biosfera Storage Slot Reader","description":"Use when you need the raw 32-byte value of a storage slot of a contract on Base, Ethereum, Arbitrum, Optimism or Polygon via eth_getStorageAt, for example to inspect proxies, owners or packed state.","url":"https://biosfera.46-62-215-147.sslip.io/o/storage-slot?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","required":["chain","address","slot"],"properties":{"slot":{"type":"string","pattern":"^(0x[0-9a-fA-F]{1,64}|[0-9]{1,20})$"},"chain":{"enum":["base","ethereum","arbitrum","optimism","polygon"],"type":"string"},"address":{"type":"string","pattern":"^0x[0-9a-fA-F]{40}$"}},"additionalProperties":false}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":null,"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":"down","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_FHTS7ogOVGzIpd-uPbFyl","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":"Returns the raw 32-byte value stored at a specific storage slot of a smart contract on Base, Ethereum, Arbitrum, Optimism, or Polygon using eth_getStorageAt","exampleAgentPrompt":"What's the raw value stored at storage slot 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc of contract 0x1234567890abcdef1234567890abcdef12345678 on Ethereum? I need to check the EIP-1967 implementation address.","exampleUseCases":[{"title":"Inspect proxy implementation address","prompt":"Can you read storage slot 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc of the contract at 0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48 on Ethereum? I want to find out which implementation contract this proxy is pointing to."},{"title":"Check contract owner slot on Base","prompt":"Read storage slot 0 of the contract 0x2ae3f1ec7f1f5012cfc6d1b42bf2979f2b7c5f2e on Base — I need to see who is stored as the owner in the first storage slot."},{"title":"Debug packed state variables on Arbitrum","prompt":"Fetch the raw value at storage slot 5 of contract 0xfd086bc7cd5c481dcc9c85ebe478a1c0b69fcbb9 on Arbitrum so I can inspect the packed state variables stored there."}],"resultDescription":"Returns the raw 32-byte hexadecimal value stored at the specified storage slot of the given contract on the requested chain, as returned by eth_getStorageAt. Useful for reading proxy pointers, owner addresses, packed bitfields, and any other low-level on-chain state.","failureModes":["Invalid contract address format (not a 40-hex-char 0x address) returns a validation error","Invalid slot format (not a valid hex or decimal number) returns a validation error","Unsupported chain name returns an enum validation error","Contract address that does not exist on the chain returns 0x0000...0000 (empty slot, not an error)","Network RPC timeout or unavailability returns a service error","Payment not provided or insufficient returns 402 Payment Required"],"whenToPreferThis":"Use this endpoint when you need low-level, raw storage access to an EVM smart contract — especially for inspecting proxy patterns (EIP-1967, EIP-1822), reading packed state variables, or verifying ownership slots directly without relying on ABI-decoded contract calls. Prefer this over higher-level token or balance endpoints when you need arbitrary slot data not exposed by standard ERC interfaces. Covers Base, Ethereum, Arbitrum, Optimism, and Polygon.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-03T10:29:11.668Z","isFirstParty":false,"canonicalSlug":"biosfera-storage-slot-reader-580cc76d"}