# skills.onesource.io Ethereum Proxy Pattern Detector

> skills.onesource.io Ethereum Proxy Pattern Detector is a paid API for AI agents from skills.onesource.io, paid per call via x402, $0.005000/call, status unknown (last checked 2026-10-12).

Detects whether an Ethereum address is a proxy contract and identifies its pattern (EIP-1967, UUPS, Transparent/slot0) along with the implementation address

## Facts

- Endpoint: GET https://skills.onesource.io/api/chain/proxy/0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48?utm_source=zero.xyz
- Price: $0.005000/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/skills-onesource-io-95ea7e2b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_XQLRM5HvBr_xjuIVP3R6s

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 skills-onesource-io-95ea7e2b
```

Example prompt: Is 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 a proxy contract on Ethereum mainnet, and if so what proxy pattern does it use and what's the implementation address behind it?

## When to prefer this

Use this endpoint when you need to determine if a smart contract is upgradeable and identify its proxy architecture pattern via low-level storage slot inspection (eth_getStorageAt). Prefer this over generic contract info endpoints when the specific proxy type and implementation address are needed for security auditing, contract interaction routing, or DeFi due diligence.

## Known failure modes

- Invalid address format (not a valid 0x hex address) — returns validation error
- Address is an EOA (externally owned account), not a contract — is_contract: false, is_proxy: false
- Unsupported network specified — enum validation error
- RPC timeout or node unavailability — upstream error
- Non-proxy contract — returns is_proxy: false with no implementation address

## How this service works

Detect proxy patterns (EIP-1967, UUPS, Transparent) via eth_getStorageAt

## Output

Returns an object with: the queried address, a boolean is_proxy indicating if it's a proxy, the proxy_type (e.g. 'slot0', 'EIP-1967', 'UUPS', 'Transparent', or 'none'), a boolean is_contract confirming the address is a contract, and the implementation address if applicable. Also includes metadata with endpoint and request_id.

## Example request

```json
{
 "input": {
  "type": "http",
  "method": "GET"
 }
}
```

## 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": {
     "type": "string",
     "const": "GET"
    }
   },
   "additionalProperties": false
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "data",
  "meta"
 ],
 "properties": {
  "data": {
   "type": "object",
   "required": [
    "address",
    "is_proxy",
    "proxy_type",
    "implementation",
    "is_contract"
   ],
   "properties": {
    "address": {
     "type": "string"
    },
    "is_proxy": {
     "type": "boolean"
    },
    "proxy_type": {
     "type": "string"
    },
    "is_contract": {
     "type": "boolean"
    },
    "implementation": {
     "type": "string"
    }
   }
  },
  "meta": {
   "type": "object",
   "required": [
    "endpoint",
    "request_id"
   ],
   "properties": {
    "endpoint": {
     "type": "string"
    },
    "request_id": {
     "type": "string"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/skills-onesource-io-95ea7e2b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from skills.onesource.io](https://www.zero.xyz/host/skills.onesource.io/llms.txt)