# Proxy Contract Detector & Implementation Resolver

> Proxy Contract Detector & Implementation Resolver is a paid API for AI agents from chain.openverbs.com, paid per call via x402, $0.004/call, status unknown (last checked 2026-09-14).

Detects whether a smart contract is an upgradeable proxy and resolves its implementation address by reading EIP-1967, EIP-1822, OpenZeppelin legacy, and EIP-1167 minimal-proxy slots on-chain.

## Facts

- Endpoint: POST https://chain.openverbs.com/v1/proxy
- Price: $0.004/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/proxy-contract-detector-implementation-resolver-004bf935
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_jROGknhusKb6DJJ0iaZbL

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 proxy-contract-detector-implementation-resolver-004bf935 -d '<json body>'
```

Example prompt: Can you check if the contract at 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 on Ethereum is a proxy, and if so, what's its implementation address?

## When to prefer this

Use this endpoint when you need to programmatically determine whether a smart contract delegates its logic to another address, particularly for auditing, security screening, or resolving the true implementation behind a proxy. It covers all major proxy standards (EIP-1967, EIP-1822/UUPS, EIP-1167 minimal proxy, and OpenZeppelin legacy) in a single call, across Ethereum, Base, Arbitrum, Optimism, and Polygon. Prefer it over manual slot reads or block explorers when you need structured, machine-readable proxy metadata in an automated workflow.

## Known failure modes

- Invalid contract address format returns a validation error
- Contract is not a proxy — returns proxy type as null or 'none' with no implementation address
- Network error or RPC unavailability causes fallback attempts and may return a timeout error
- Unsupported chain name returns an error listing valid options
- Address is an EOA (not a contract) — returns no proxy info

## How this service works

Detect whether a contract is an upgradeable proxy and resolve its implementation: reads the standard EIP-1967 implementation/admin/beacon slots, EIP-1822 (UUPS), the OpenZeppelin legacy slot, and EIP-1167 minimal-proxy bytecode. Returns the proxy type, implementation, admin and beacon addresses when present. Reads live on-chain data with automatic endpoint fallback.

## Output

Returns the detected proxy type (e.g. EIP-1967, UUPS, EIP-1167, OpenZeppelin legacy, or none), the resolved implementation contract address, and where applicable the admin address and beacon address. All data is read live from on-chain storage slots with automatic RPC endpoint fallback.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "properties": {
      "chain": {
       "enum": [
        "ethereum",
        "base",
        "arbitrum",
        "optimism",
        "polygon"
       ],
       "type": "string",
       "description": "EVM chain to query. One of: ethereum, base, arbitrum, optimism, polygon. Default \"ethereum\"."
      },
      "address": {
       "type": "string",
       "pattern": "^0x[0-9a-fA-F]{40}$",
       "description": "Contract address to inspect."
      }
     },
     "additionalProperties": false
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/proxy-contract-detector-implementation-resolver-004bf935/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from chain.openverbs.com](https://www.zero.xyz/host/chain.openverbs.com/llms.txt)