# BuiltWith Recommendations via Locus x402

> BuiltWith Recommendations via Locus x402 is a paid API for AI agents from builtwith.x402.paywithlocus.com, paid per call via x402, $0.035/call, status unknown (last checked 2026-09-15).

Returns technology-based domain recommendations — similar sites and related domains — for a given website using BuiltWith's 100M+ site database.

## Facts

- Endpoint: POST https://builtwith.x402.paywithlocus.com/builtwith/recommendations
- Price: $0.035/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/builtwith-recommendations-via-locus-x402-8cd7a22e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Si4iUkBgE1rO17wKaMK4g

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 builtwith-recommendations-via-locus-x402-8cd7a22e -d '<json body>'
```

Example prompt: Can you find websites that are similar to or related to shopify.com based on their technology profile?

## When to prefer this

Choose this endpoint when you need to discover websites that are similar or related to a given domain based on shared technology profiles, especially for competitive intelligence, lead generation, or market research. It is backed by BuiltWith's massive 100M+ site index, making it more comprehensive than manual research. Prefer this over general web search when you specifically want technology-signal-based domain similarity rather than keyword or content similarity.

## Known failure modes

- Invalid or unresolvable domain returns empty or error data
- Domain not indexed in BuiltWith database returns no recommendations
- Malformed LOOKUP field causes request failure
- Payment failure or insufficient USDC balance blocks the call
- Rate limiting or gateway timeout from the x402 proxy

## How this service works

Technology profiling for websites — detect tech stacks, find sites using specific technologies, discover domain relationships, trends, and competitive intelligence across 100M+ websites.

## Output

A JSON object containing recommended/related domains for the given website, likely including domain names and signals derived from shared or similar technology stacks, along with payment confirmation metadata (settled USDC, authorized amount) and a request ID for status tracking.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "LOOKUP": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "data": {},
  "payment": {
   "scheme": "exact",
   "settledUsdc": "0.001000",
   "authorizedMaxUsdc": "0.001000"
  },
  "request": {
   "id": "00000000-0000-4000-8000-000000000000",
   "statusUrl": "/requests/00000000-0000-4000-8000-000000000000"
  },
  "success": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/builtwith-recommendations-via-locus-x402-8cd7a22e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from builtwith.x402.paywithlocus.com](https://www.zero.xyz/host/builtwith.x402.paywithlocus.com/llms.txt)