# x402node Contract ABI Fetcher

> x402node Contract ABI Fetcher is a paid API for AI agents from api.x402node.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-16).

Returns the verified ABI (function and event signatures) for a smart contract on a specified EVM chain, enabling correct contract call encoding.

## Facts

- Endpoint: GET https://api.x402node.dev/chain/contract-abi
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402node-contract-abi-fetcher-5f201ecb
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_TxzzZMGLksFwTAZmtqtXo

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 x402node-contract-abi-fetcher-5f201ecb
```

Example prompt: Can you fetch the verified ABI for the contract at 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D on Ethereum mainnet so I can encode a call to its swap function?

## When to prefer this

Use this endpoint when an agent needs to programmatically interact with a smart contract and must have accurate function or event signatures. Prefer this over relying on LLM-generated ABIs (which hallucinate) or manual lookups. Especially useful when the target chain is one of several supported EVM networks and the contract address is known.

## Known failure modes

- Contract address not verified or ABI not available — returns error with no ABI data
- Unsupported chain identifier — returns error indicating the chain is not supported
- Invalid contract address format — returns validation error
- Contract exists but has no verified source code — ABI cannot be returned
- Network or upstream provider timeout — returns 5xx error

## How this service works

Fetch the verified ABI of a smart contract with function and event signatures across multiple EVM chains - required for agents to correctly encode contract calls, which LLMs cannot retrieve live. contract abi, get abi, contract interface, function signatures, abi fetch, contract methods Accepts payment on Base or Solana — either network works.

## Output

Returns the verified ABI of the smart contract including all function signatures (name, inputs, outputs, state mutability) and event signatures, allowing the agent to correctly encode contract calls or decode transaction data on the specified EVM chain.

## 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"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "address"
     ],
     "properties": {
      "chain": {
       "type": "string",
       "description": "ethereum, base (default), arbitrum, optimism, polygon, bsc"
      },
      "address": {
       "type": "string",
       "description": "Contract address (required)"
      }
     }
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402node-contract-abi-fetcher-5f201ecb/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.x402node.dev](https://www.zero.xyz/host/api.x402node.dev/llms.txt)