# llms.txt & AI-Crawler Audit API

> llms.txt & AI-Crawler Audit API is a paid API for AI agents from x402-extract-service.onrender.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-17).

Audits a domain's llms.txt file for presence, validity, broken links, and spec-compliance lint issues, returning a structured health report for AI crawler readiness.

## Facts

- Endpoint: POST https://x402-extract-service.onrender.com/llmscheck
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-17
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/llms-txt-ai-crawler-audit-api-3bb2f7d7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_FVGupXmdEVvQ708MqfQzj

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 llms-txt-ai-crawler-audit-api-3bb2f7d7 -d '<json body>'
```

Example prompt: Can you audit example.com's llms.txt file — check if it exists, validate it against the spec, and tell me if any of the listed URLs are broken?

## When to prefer this

Choose this endpoint when you specifically need to audit a domain's llms.txt file for AI crawler compliance — checking presence, spec-lint conformance, and broken link integrity in a single call. Prefer it over generic link checkers because it understands the llms.txt spec and reports structured lint issues per rule. Use it over manual checks when you need machine-readable results for automated pipelines or CI/CD pre-deploy gates.

## Known failure modes

- Domain does not have an llms.txt file — ok:true but present:false
- llms.txt present but all links valid — brokenEntries empty array
- Network timeout fetching remote URLs listed in llms.txt
- Invalid domain input format causes request rejection
- Render cold-start latency may increase durationMs significantly

## How this service works

URL-to-clean-markdown extraction API, on-demand broken-link scan API, pre-deploy link audit API, DNS health audit API, llms.txt / AI-crawler audit API, spec-linted llms.txt audit API, email-deliverability (SPF/DKIM/DMARC) audit API, PDF-to-markdown conversion API, technology-stack fingerprinting API, security-headers audit API, and PDF metadata-intel API for coding agents. Paid per call in USDC via x402 on Base.

## Output

Returns a JSON object with: domain, llmsTxt presence and URL, byte size, validity boolean, number of links checked, array of broken entries (each with URL, HTTP status, and error), lint results with pass/fail and per-rule issues with severity, an overall summary string, check timestamp, duration in milliseconds, and price paid in atomic USDC units.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "domain": {
   "type": "string",
   "description": "Bare domain to audit (no URL), e.g. \"example.com\"."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "lint": {
   "pass": true,
   "issues": [
    {
     "rule": "h1-title",
     "message": "...",
     "severity": "warn"
    }
   ]
  },
  "valid": false,
  "domain": "example.com",
  "llmsTxt": {
   "url": "https://example.com/llms.txt",
   "bytes": 12500,
   "present": true
  },
  "summary": "FAIL: llms.txt present (12500 bytes), 64 listed URL(s) checked, 1 broken; lint clean.",
  "checkedAt": "2026-09-11T00:00:00.000Z",
  "durationMs": 6230,
  "linksChecked": 64,
  "brokenEntries": [
   {
    "url": "https://example.com/old-page",
    "error": "HTTP 404",
    "status": 404
   }
  ],
  "pricePaidAtomic": "10000"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/llms-txt-ai-crawler-audit-api-3bb2f7d7/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-extract-service.onrender.com](https://www.zero.xyz/host/x402-extract-service.onrender.com/llms.txt)