# Base Contract ABI Lookup

> Base Contract ABI Lookup is a paid API for AI agents from ari001.tailb4ac3a.ts.net, paid per call via x402, $0.002/call, status down (last checked 2026-10-31).

Returns the ABI (Application Binary Interface) of a smart contract deployed on the Base blockchain, given its address.

## Facts

- Endpoint: GET https://ari001.tailb4ac3a.ts.net/v1/ventures/x402_chain_reads_v1/base_contract_abi?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: down
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/base-contract-abi-lookup-11b96d8c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_BNqIUKQ00lsTSzfE14eLm

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 base-contract-abi-lookup-11b96d8c
```

Example prompt: Can you fetch the ABI for the Base smart contract at address 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 so I can see what functions it exposes?

## When to prefer this

Use this endpoint when you need the ABI for a contract specifically deployed on the Base L2 network. Prefer this over Ethereum mainnet ABI lookups when working with Base-native contracts, DeFi protocols on Base, or Base token contracts. It is especially useful when you need to programmatically interact with a contract (encoding calldata, decoding events) and need to discover its interface first.

## Known failure modes

- Invalid or malformed address (not matching 0x + 40 hex pattern) returns a validation error
- Contract address not found or not verified on Base returns an empty or error response
- Unverified contracts may not have an ABI available
- Network connectivity issues to Base RPC may cause timeouts
- Rate limiting or payment failures may block the request

## How this service works

ARYSPHERE sells AI-written verdicts on Base token contracts (a grade, a one-liner, a roast and the contract's facts) and Base/Ethereum chain reads, paid per call in USDC on Base over x402 v2. No account and no API key.

## Output

Returns the contract's ABI as a JSON array containing all function signatures, input/output parameter types, state mutability, and event definitions for the smart contract deployed at the given Base network address.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "address": {
       "type": "string",
       "pattern": "^0x[0-9a-fA-F]{40}$",
       "description": "contract, 0x + 40 hex"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "chain": "base",
  "method": "abi",
  "result": {
   "abi": [
    {
     "type": "constructor",
     "inputs": [
      {
       "name": "implementationContract",
       "type": "address",
       "internalType": "address"
      }
     ],
     "stateMutability": "nonpayable"
    },
    {
     "name": "AdminChanged",
     "type": "event",
     "inputs": [
      {
       "name": "previousAdmin",
       "type": "address",
       "indexed": false,
       "internalType": "address"
      },
      {
       "name": "newAdmin",
       "type": "address",
       "indexed": false,
       "internalType": "address"
      }
     ],
     "anonymous": false
    },
    ""
   ],
   "match": "exact_match",
   "proxy": {
    "isProxy": true,
    "proxyType": "ZeppelinOSProxy",
    "implementations": [
     {
      "name": "FiatTokenV2_2",
      "address": "0x2Ce6311ddAE708829bc0784C967b7d77D19FD779"
     }
    ]
   },
   "address": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
   "isProxy": true,
   "verified": true,
   "implementation": "0x2Ce6311ddAE708829bc0784C967b7d77D19FD779"
  },
  "service": "x402_chain_reads_v1.base_contract_abi"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/base-contract-abi-lookup-11b96d8c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from ari001.tailb4ac3a.ts.net](https://www.zero.xyz/host/ari001.tailb4ac3a.ts.net/llms.txt)