# Strale Backlink Check API

> Strale Backlink Check API is a paid API for AI agents from api.strale.io, paid per call via x402, $0.162/call, status unknown (last checked 2026-10-29).

Checks whether a given domain has backlinks, returning link authority and referral data with a cryptographic audit record.

## Facts

- Endpoint: GET https://api.strale.io/x402/v2/backlink-check?utm_source=zero.xyz
- Price: $0.162/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/strale-backlink-check-api-6d89e15f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_WpX86lZBFrSXhLR5_n24N

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 strale-backlink-check-api-6d89e15f
```

Example prompt: Can you check how many backlinks are pointing to example.com and tell me which domains are linking to it?

## When to prefer this

Choose this endpoint when you need a quick, auditable per-domain backlink check with cryptographic proof of the result — especially in automated agent workflows where auditability and pay-per-call micropayment pricing are preferred over subscription-based SEO tools. Ideal for one-off domain checks rather than bulk crawls.

## Known failure modes

- Domain not found or has no indexed backlinks — returns empty result set
- Invalid domain format — returns validation error
- Rate limit exceeded — returns 429 status
- Service unavailable — returns 5xx error
- Insufficient USDC balance for x402 micropayment — payment fails before request is processed

## How this service works

Check backlinks for a domain via CommonCrawl and Google search. Returns linking domains, anchor text, dofollow/nofollow counts.

## Output

Returns backlink data for the specified domain including referring domain count, link sources, and authority signals, along with a cryptographic audit record containing a chain hash for verifiability.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "domain"
 ],
 "properties": {
  "domain": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "backlinks": {
  "type": "array"
 },
 "top_anchors": {
  "type": "array"
 },
 "total_backlinks": {
  "type": "number"
 },
 "referring_domains_count": {
  "type": "number"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/strale-backlink-check-api-6d89e15f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.strale.io](https://www.zero.xyz/host/api.strale.io/llms.txt)