# Contract Inspector

> Contract Inspector is a paid API for AI agents from bess-x402.onrender.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-29).

Inspects an EVM address to determine if it's a wallet or contract, its bytecode size, token standard (ERC-20/721/1155), name, symbol, decimals, supply, owner, and proxy implementation.

## Facts

- Endpoint: GET https://bess-x402.onrender.com/v1/evm/contract?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/contract-inspector-4c565aae
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_o135M3sKhfz5iOF2xGhGA

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 contract-inspector-4c565aae
```

Example prompt: Before I interact with this address, can you inspect 0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984 on Ethereum and tell me if it's a wallet or contract, what token standard it uses, its name, symbol, decimals, and total supply?

## When to prefer this

Use this endpoint when you need a comprehensive one-shot inspection of an unknown EVM address before interacting with it — it combines address type detection, token standard identification, and proxy resolution in a single call. Prefer it over chain-specific block explorers when you need programmatic access, or over raw RPC calls when you want pre-parsed token metadata without writing ABI decoding logic. Best suited for pre-interaction due-diligence flows.

## Known failure modes

- Invalid or malformed 0x address returns an error
- Unsupported chain name returns a validation error
- Non-existent or zero-bytecode address may return minimal info with no token details
- Contracts that don't implement standard interfaces may return null for name/symbol/supply
- Network timeouts or RPC failures may cause 5xx errors
- Unverified or non-standard proxy patterns may not have implementation detected

## How this service works

What is at an EVM address: wallet (with EIP-7702 delegate) or contract, bytecode size, token standard (ERC-20/721/1155), name, symbol, decimals, supply, owner() and proxy implementation. Use before interacting with an unknown address.

## Output

Returns a structured JSON object containing: address type (EOA wallet or contract), whether it has an EIP-7702 delegate, bytecode size in bytes, detected token standard (ERC-20, ERC-721, ERC-1155, or none), token name, symbol, decimals, total supply, owner() address if available, and proxy implementation address if the contract is a proxy.

## 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",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "address"
     ],
     "properties": {
      "chain": {
       "type": "string",
       "description": "ethereum, base, arbitrum, optimism or polygon"
      },
      "address": {
       "type": "string",
       "description": "0x address"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/contract-inspector-4c565aae/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from bess-x402.onrender.com](https://www.zero.xyz/host/bess-x402.onrender.com/llms.txt)