# Multichain RPC – Proxy Pattern Detector

> Multichain RPC – Proxy Pattern Detector is a paid API for AI agents from multichain-rpc.clankerceo.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-14).

Detects upgradeable proxy patterns (EIP-1967, UUPS, Transparent, Beacon) for a given contract address and returns the current implementation address.

## Facts

- Endpoint: GET https://multichain-rpc.clankerceo.workers.dev/proxy
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/multichain-rpc-proxy-pattern-detector-0c9d919e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_3XVROZgX_lbkQLVJ67b7X

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 multichain-rpc-proxy-pattern-detector-0c9d919e
```

Example prompt: Can you check if the contract 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 on Ethereum is a proxy and tell me what implementation address it points to?

## When to prefer this

Use this endpoint when you need to determine whether an unknown smart contract on a supported EVM chain (Base, Polygon, Arbitrum, Optimism, Ethereum) is an upgradeable proxy before trusting or calling it. It is particularly valuable for security audits, DeFi agent workflows, and any scenario where you must know the actual code being executed behind a contract address. Prefer this over manual slot reads or generic RPC calls because it automatically detects multiple proxy standards (EIP-1967, UUPS, Transparent, Beacon) in a single call.

## Known failure modes

- Contract address not found or invalid — returns is_proxy false or error
- Unsupported chain identifier — returns error indicating invalid chain
- Contract is not a proxy — returns is_proxy: false with no implementation address
- RPC timeout or network congestion — may return a timeout or 5xx error
- Malformed address input — returns validation error

## How this service works

Cheap, factual EVM chain lookups priced per call in USDC. Base, Polygon, Arbitrum, Optimism and Ethereum.

## Output

Returns a JSON object with the chain, the queried contract address, the detected proxy pattern name (e.g. 'eip1967.implementation', 'uups', 'transparent', 'beacon'), a boolean is_proxy flag, and the resolved implementation contract address if a proxy was found.

## 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",
    "queryParams"
   ],
   "properties": {
    "type": {
     "enum": [
      "http"
     ],
     "type": "string"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "chain": {
       "type": "string"
      },
      "address": {
       "type": "string"
      }
     }
    }
   }
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "enum": [
      "json"
     ],
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "chain": "base",
  "address": "0x…",
  "pattern": "eip1967.implementation",
  "is_proxy": true,
  "implementation": "0x…"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/multichain-rpc-proxy-pattern-detector-0c9d919e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from multichain-rpc.clankerceo.workers.dev](https://www.zero.xyz/host/multichain-rpc.clankerceo.workers.dev/llms.txt)