{"uid":"cap_USD2nJXZSkieDvO_Veq6R","slug":"mach-gallery-base-eth-call-779f53f7","name":"Mach Gallery Base ETH Call","description":"Fast, low-cost Base data for autonomous agents. No API keys, no subscriptions; pay per call with USDC over x402.","url":"https://api.mach.gallery/api/base/eth-call?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"to":{"type":"string","pattern":"^0x[0-9a-fA-F]{40}$","description":"Smart-contract address on Base mainnet."},"data":{"type":"string","pattern":"^0x[0-9a-fA-F]*$","maxLength":32770,"description":"0x-prefixed ABI calldata for a read-only eth_call."},"block":{"anyOf":[{"type":"string"},{"type":"integer","minimum":0}],"description":"Base block selector: block number or tag such as latest, safe, finalized, pending or earliest."}}},"responseSchema":{"type":"json","example":{"result":"0x","network":"eip155:8453"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.005","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":"$0.005/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_X_EVvRT8bAZCa1ZjuDs2M","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":"Executes a read-only eth_call on the Base (EVM chain ID 8453) network at a given contract address, returning the raw hex result.","exampleAgentPrompt":"Call the Base smart contract at 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 with calldata 0x70a08231000000000000000000000000abcdef1234567890abcdef1234567890abcdef12 at the latest block and give me the raw result.","exampleUseCases":[{"title":"Read ERC-20 token balance on Base","prompt":"Check the USDC balance of address 0xAbCdEf1234567890AbCdEf1234567890AbCdEf12 on Base by calling the balanceOf function on the USDC contract at 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 — give me the raw hex return value."},{"title":"Query DeFi protocol state on Base","prompt":"Call the Uniswap V3 pool contract at 0x1234567890abcdef1234567890abcdef12345678 on Base with the slot0 calldata 0x3850c7bd at the latest block so I can read the current price and tick."},{"title":"Verify on-chain ownership at historic block","prompt":"At block 19500000 on Base, call the NFT contract at 0xdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef with ownerOf calldata for token ID 42 and return the raw hex result so I can confirm who owned it then."}],"resultDescription":"A JSON object containing 'result' (the raw ABI-encoded hex return value from the contract call) and 'network' (always 'eip155:8453' for Base). If the call reverts or the address has no code, appropriate error data is returned.","failureModes":["Invalid EVM address format (must be 0x + 40 hex chars) returns a 400 validation error","Malformed or oversized calldata (>32770 hex chars) rejected with 400","Contract reverts: result may contain revert reason encoded in hex","Non-existent contract address returns 0x (empty result, no code at address)","Payment failure via x402 (insufficient USDC balance) results in 402 response before execution","Unknown or invalid block number/tag returns an error from the underlying node"],"whenToPreferThis":"Choose this endpoint when you need pay-per-call, keyless access to Base (EVM chain 8453) contract read operations without managing API key subscriptions or running your own node. It is ideal for autonomous agents that make infrequent or unpredictable call volumes and want to pay exactly $0.005 USDC per query via x402. Prefer it over self-hosted RPC nodes or subscription-based providers when cost predictability and zero-setup are priorities for Base-specific smart contract queries.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-02T04:37:24.940Z","isFirstParty":false,"canonicalSlug":"mach-gallery-base-eth-call-779f53f7"}