# ERC-20 Approval Enumerator for Base (Chain 8453)

> ERC-20 Approval Enumerator for Base (Chain 8453) is a paid API for AI agents from x402-research-iota.vercel.app, paid per call via x402, $0.03/call, status unknown (last checked 2026-10-29).

Lists all live ERC-20 token approvals for a given Base network address, returning token, spender, current allowance, and whether the approval is unlimited.

## Facts

- Endpoint: GET https://x402-research-iota.vercel.app/api/x402/approval-enumerate?utm_source=zero.xyz
- Price: $0.03/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/erc-20-approval-enumerator-for-base-chain-8453-195c9e86
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Zauv2wMB-AnHjlmrumKoN

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 erc-20-approval-enumerator-for-base-chain-8453-195c9e86
```

Example prompt: Can you list all the active ERC-20 token approvals for my Base wallet 0xAbC1234567890123456789012345678901234567 — I want to know which contracts are approved to spend my tokens and whether any have unlimited allowances?

## When to prefer this

Choose this endpoint when you need a live, read-only enumeration of all active ERC-20 approvals for a specific Base (chain 8453) wallet address, especially when assessing approval risk before DeFi interactions, auditing wallets for unlimited allowances, or checking for suspicious spenders after a potential compromise. Prefer this over generic blockchain explorers when you need structured, machine-readable approval data with explicit unlimited-flag and risk-count fields, and are willing to pay $0.03 USDC per call via x402.

## Known failure modes

- 400 Bad Request — address parameter is missing or not a valid 0x-prefixed 40-hex-char Ethereum address
- 503 Service Unavailable — underlying indexer or RPC node is unreachable; call is not charged
- status: 'unknown' — data is incomplete; reason field explains why full coverage could not be confirmed

## How this service works

List live ERC-20 approvals for a Base (8453) address: token, spender, current allowance, unlimited flag. status ok (complete, approvals found) / none (complete, zero active) / unknown (data incomplete; reason given; never reported as none). Pass ?address=0x... Errors: 400 invalid address; 503 indexer/RPC unavailable (not charged). Read-only; never signs.

## Output

Returns a JSON object with: status ('ok' if approvals found, 'none' if zero active approvals, 'unknown' if data is incomplete), the queried address, chainId (8453), a boolean 'complete' flag, an array of approval objects each containing token address, spender address, current allowance, and an unlimited flag, a highRiskCount, coverage metadata, and an optional reason/reasons field explaining any data gaps.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "address"
     ],
     "properties": {
      "address": {
       "type": "string",
       "pattern": "^0x[0-9a-fA-F]{40}$"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "counts": {
       "type": "object"
      },
      "reason": {
       "type": [
        "string",
        "null"
       ]
      },
      "signed": {
       "type": "boolean"
      },
      "status": {
       "enum": [
        "ok",
        "none",
        "unknown"
       ],
       "type": "string"
      },
      "address": {
       "type": "string"
      },
      "chainId": {
       "type": "number"
      },
      "reasons": {
       "type": "array",
       "items": {
        "type": "string"
       }
      },
      "complete": {
       "type": "boolean"
      },
      "coverage": {
       "type": "object"
      },
      "approvals": {
       "type": "array",
       "items": {
        "type": "object"
       }
      },
      "limitations": {
       "type": "array",
       "items": {
        "type": "string"
       }
      },
      "coverageNote": {
       "type": "string"
      },
      "highRiskCount": {
       "type": "number"
      }
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/erc-20-approval-enumerator-for-base-chain-8453-195c9e86/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-research-iota.vercel.app](https://www.zero.xyz/host/x402-research-iota.vercel.app/llms.txt)