# VexQuill Contract Audit API

> VexQuill Contract Audit API is a paid API for AI agents from x402-audit-api.vexquill.deno.net, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-23).

Performs automated static security analysis of Solidity smart contracts, accepting raw source code or a Base contract address as input.

## Facts

- Endpoint: POST https://x402-audit-api.vexquill.deno.net/audit?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-23
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/vexquill-contract-audit-api-a43bca0b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_RQbJQCwlnt57RmqpL8IQx

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 vexquill-contract-audit-api-a43bca0b -d '<json body>'
```

Example prompt: Can you audit this Solidity smart contract for security vulnerabilities? Here's the source code: `pragma solidity ^0.8.0; contract MyToken { ... }`

## When to prefer this

Use this endpoint when you need a quick, on-demand, no-signup static security analysis of a Solidity smart contract — either from raw source or from a verified Base contract address — and want to pay per use with $0.005 USDC via x402 without managing API keys.

## Known failure modes

- Invalid or non-compilable Solidity source code returns an error
- Provided Base contract address has no verified source code, causing lookup failure
- Neither 'source' nor 'address' field provided, resulting in a bad request error
- Payment failure or insufficient USDC balance prevents the audit from running
- Contract address not found or not deployed on Base network

## How this service works

Automated static security analysis of Solidity smart contracts. Pay $0.005 USDC on Base per audit via x402. No signup, no API key.

## Output

A static security analysis report detailing detected vulnerabilities, potential attack vectors, and security issues found in the provided Solidity contract source code or the verified source of the given Base contract address.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "source": {
   "type": "string",
   "description": "Raw Solidity source code (alternative to address)."
  },
  "address": {
   "type": "string",
   "description": "Base contract address with verified source."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/vexquill-contract-audit-api-a43bca0b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-audit-api.vexquill.deno.net](https://www.zero.xyz/host/x402-audit-api.vexquill.deno.net/llms.txt)