# Vextorium EVM Token Approval Revoke

> Vextorium EVM Token Approval Revoke is a paid API for AI agents from api.vextorium.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-19).

Generates calldata to revoke (zero-out) an ERC-20 token approval for a specified spender on EVM chains

## Facts

- Endpoint: POST https://api.vextorium.com/v1/revoke-approval?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-19
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/vextorium-evm-token-approval-revoke-8b5adb28
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_r1PfuHBrUh55-0qcrzzg6

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability vextorium-evm-token-approval-revoke-8b5adb28 -d '<json body>'
```

Example prompt: Generate the transaction calldata to revoke the USDC token approval I previously granted to the Uniswap v3 router at 0x2626664c2603336E57B271c5C0b26F421741e481 — the token contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913.

## When to prefer this

Use this endpoint when you need to programmatically generate ERC-20 approval revocation calldata for an EVM wallet without connecting directly to a node. It is ideal for AI agents that need to produce ready-to-sign transaction data for revoking allowances across any ERC-20 token and spender pair, especially as part of a DeFi security workflow or post-incident response where speed matters. Pay-per-call via USDC/x402 makes it suitable for agent pipelines without subscription overhead.

## Known failure modes

- Invalid or malformed token address returns an error
- Invalid or malformed spender address returns an error
- Unsupported token contract may return null or error data
- Network connectivity issues may cause request timeout
- Missing required fields (token or spender) will fail schema validation

## How this service works

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.

## Output

Returns a JSON object containing: the token contract address (for), raw hex-encoded calldata (data) for an approve(address,uint256) call with amount set to zero, the ETH value to send (value, typically '0'), the function signature (function), decoded arguments array, and a human-readable note instructing the user to sign and send the transaction from the wallet that originally granted the allowance.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "token": {
   "type": "string"
  },
  "spender": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "for": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
  "data": "0x095ea7b30000000000000000000000002626664c2603336e57b271c5c0b26f421741e4810000000000000000000000000000000000000000000000000000000000000000",
  "note": "Sign and send this transaction from the wallet that granted the allowance.",
  "value": "0",
  "function": "approve(address,uint256)",
  "arguments": [
   "0x2626664c2603336E57B271c5C0b26F421741e481",
   "0"
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/vextorium-evm-token-approval-revoke-8b5adb28/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.vextorium.com](https://www.zero.xyz/host/api.vextorium.com/llms.txt)