{"uid":"cap_XkhFk0oaRtpPBbfhibqBg","slug":"vextorium-erc-20-approval-revocation-transaction-builder-6a83390f","name":"Vextorium ERC-20 Approval Revocation Transaction Builder","description":"Build the transaction that revokes a contract's permission over an ERC-20 token (approve(spender, 0)): target and calldata ready to sign in your wallet. Nothing is sent.","url":"https://api.vextorium.com/revocar-aprobacion-pago?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"token":{"type":"string"},"gastador":{"type":"string"}}},"responseSchema":{"type":"json","example":{"nota":"Firma y envía esta transacción desde la wallet que dio el permiso.","para":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","datos":"0x095ea7b30000000000000000000000002626664c2603336e57b271c5c0b26f421741e4810000000000000000000000000000000000000000000000000000000000000000","valor":"0","funcion":"approve(address,uint256)","argumentos":["0x2626664c2603336E57B271c5C0b26F421741e481","0"]}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.003","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":"$0.003/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_OMWIqiWtXa-q-0UpcSpHw","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.003","costPer":"request","priority":0,"asset":"EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Builds the unsigned transaction calldata to revoke a spender's ERC-20 token approval (approve(spender, 0)) — ready to sign and broadcast, nothing is sent on-chain.","exampleAgentPrompt":"Build me the transaction to revoke the spending approval that 0x2626664c2603336E57B271c5C0b26F421741e481 has over my USDC token at 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 — I want the calldata ready to sign in my wallet.","exampleUseCases":[{"title":"Revoke DEX router token allowance","prompt":"I want to remove Uniswap's permission to spend my USDC — give me the transaction data to set the approval for 0x2626664c2603336E57B271c5C0b26F421741e481 to zero on the USDC contract at 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913."},{"title":"Security audit post-hack revocation","prompt":"A protocol I used was just exploited. Build me the calldata to revoke their contract at 0xAbCd1234...5678 from spending my DAI at 0x6B175474E89094C44Da98b954EedeAC495271d0F so I can sign and broadcast it immediately."},{"title":"Batch allowance cleanup workflow","prompt":"I'm cleaning up old token approvals — can you generate the unsigned approve(spender,0) transaction for the old bridge contract 0xAaaa...1111 on my WETH token at 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2?"}],"resultDescription":"A JSON object containing: the target token contract address (`para`), the full hex-encoded calldata (`datos`) for approve(address,uint256) with amount=0, the ETH value to send (always '0'), the function signature string, the decoded arguments array, and a human-readable note reminding the user to sign and send the transaction from the wallet that originally granted the permission.","failureModes":["Invalid or malformed token address returns an error","Invalid or malformed spender (gastador) address returns an error","Non-ERC-20 contract address may produce calldata that reverts on-chain","Network errors or upstream timeout return a 5xx response","Missing required fields (token or gastador) return a 400-level validation error"],"whenToPreferThis":"Choose this endpoint when you need to programmatically construct a revoke-approval transaction without connecting a wallet to a UI. Ideal for agents automating wallet security workflows, post-exploit remediation bots, or any flow that needs raw calldata for approve(spender, 0) on ERC-20 tokens deployed on EVM chains like Base or Ethereum. Prefer this over manual ABI encoding when you want a simple, paid REST call that returns ready-to-sign target + calldata.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-16T18:48:08.255Z","isFirstParty":false,"canonicalSlug":"vextorium-erc-20-approval-revocation-transaction-builder-6a83390f"}