# Multichain RPC Contract Proxy

> Multichain RPC Contract Proxy 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 whether a smart contract is a proxy and resolves its implementation address across EVM chains including Base, Polygon, Arbitrum, Optimism, and Ethereum.

## Facts

- Endpoint: GET https://multichain-rpc.clankerceo.workers.dev/contract-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-contract-proxy-cbb50e48
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_rN1me-76qIxiFlNUNTE_U

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-contract-proxy-cbb50e48
```

Example prompt: Can you check if the contract at 0x1234...abcd on Base is a proxy, and if so, what's the implementation address behind it?

## When to prefer this

Choose this endpoint when you need a cheap, pay-per-call lookup to determine if a specific smart contract on a major EVM chain is a proxy and to resolve its implementation address. It is ideal for agents performing smart contract analysis, security audits, or protocol monitoring without needing to run their own RPC infrastructure. Prefer it over full-node queries or general-purpose EVM explorers when cost efficiency and multi-chain support are priorities.

## Known failure modes

- Invalid or non-checksummed contract address returns an error or empty result
- Unsupported chain name returns an error — only Base, Polygon, Arbitrum, Optimism, and Ethereum are supported
- Non-proxy contracts return is_proxy: false with no implementation address
- Network timeouts on the underlying RPC may cause delayed or failed responses
- Missing required query parameters (chain or address) result in a 400-style error

## How this service works

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

## Output

A JSON object containing the queried chain name, the contract address, whether the contract is a proxy (is_proxy boolean), the detected proxy pattern (e.g. eip1967.implementation), and the resolved implementation contract address if a proxy is detected.

## 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-contract-proxy-cbb50e48/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)