{"uid":"cap_RYKgEZAiBwzFwKexG5Dil","slug":"synapse-api-starknet-gas-estimator-2ada7dd8","name":"Synapse API — StarkNet Gas Estimator","description":"High-speed API suite for AI processing, web scraping, and smart data utilities across 57+ blockchain networks. Pay-per-call via x402.","url":"https://synapse-api-brown.vercel.app/api/starknet/gas/estimate","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"to":{"type":"string"},"data":{"type":"string"},"from":{"type":"string"},"value":{"type":"string"}}},"responseSchema":null,"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_LJwe1EhrMEoiKplwhXO4d","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":"Estimates gas fees for a transaction on the StarkNet blockchain given sender, recipient, calldata, and value","exampleAgentPrompt":"Can you estimate the gas cost for a StarkNet transaction from 0xABC...123 to 0xDEF...456 with calldata 0x1234 and a value of 0?","exampleUseCases":[{"title":"Pre-flight transaction cost check","prompt":"Before I send this StarkNet contract call, can you estimate how much gas it will use? The sender is 0xABC...123, the recipient contract is 0xDEF...456, and the calldata is 0xdeadbeef with zero ETH value."},{"title":"DeFi trade gas optimization","prompt":"I want to swap tokens on a StarkNet DEX — can you estimate the gas fee for a transaction from my wallet 0x111...AAA to the swap contract 0x222...BBB with calldata 0xcafebabe and value 0x0 so I know if it's worth it right now?"},{"title":"Smart contract deployment cost estimate","prompt":"How much gas would it cost to call this StarkNet smart contract at 0x333...CCC from address 0x444...DDD with the following calldata: 0xabcdef01 and no ETH value attached?"}],"resultDescription":"Returns an estimated gas amount (and likely fee in the StarkNet native fee token) required to execute the described transaction on the StarkNet network, allowing the caller to budget fees before broadcasting.","failureModes":["Invalid or malformed address in 'to' or 'from' fields returns an error","Malformed calldata string causes parsing failure","StarkNet node unavailability causes a timeout or 503","Transaction simulation failure if the contract call would revert","Missing required fields returns a 400 bad request"],"whenToPreferThis":"Use this endpoint when you need a quick, pay-per-call gas estimate specifically for StarkNet (a ZK-rollup L2) transactions without setting up your own StarkNet node or RPC provider. Prefer it over generic Ethereum gas estimators when the target chain is StarkNet.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T18:56:55.974Z","isFirstParty":false}