# agentshelf.syntexa.ch Link rel=preload Extractor

> agentshelf.syntexa.ch Link rel=preload Extractor is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.007/call, status unknown (last checked 2026-10-02).

Extracts all link rel=preload href values from a given public web page URL or raw HTML, in an SSRF-safe manner.

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/profile-rel-preload?utm_source=zero.xyz
- Price: $0.007/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agentshelf-syntexa-ch-link-rel-preload-extractor-5f6c122e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_hSowAU9SH5_Oo41RrV790

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 agentshelf-syntexa-ch-link-rel-preload-extractor-5f6c122e -d '<json body>'
```

Example prompt: Can you extract all the link rel=preload hrefs from https://example.com so I can see what resources that page is preloading?

## When to prefer this

Use this endpoint when you need to programmatically extract link rel=preload resource hints from a public web page or a block of raw HTML. It is SSRF-safe, making it suitable for agent pipelines that cannot run untrusted fetches internally. Prefer the free sandbox endpoint (/v1/sandbox/profile-rel-preload) for testing; use this paid endpoint ($0.007 USDC) for production or when the sandbox is unavailable.

## Known failure modes

- URL is not publicly accessible or requires authentication — returns error
- SSRF-blocked URL (private IP ranges, localhost) — rejected for safety
- HTML input exceeds 200,000 character limit — returns validation error
- No rel=preload links found on the page — returns empty list
- Malformed URL format — returns validation error
- Page fetch timeout or network error for URL-based requests

## How this service works

Call when an agent needs link rel=preload hrefs extracted from a public page or HTML (SSRF-safe). Exact $0.007 USDC. Prefer unpaid POST /v1/sandbox/profile-rel-preload first.

## Output

A list of href values found in link rel=preload tags on the target page or HTML — typically an array of URLs pointing to preloaded scripts, stylesheets, fonts, or other assets.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "maxLength": 2048,
   "minLength": 8,
   "description": "Public page to fetch. The selector or profile is fixed by the SKU. Provide url or html."
  },
  "html": {
   "type": "string",
   "examples": [
    "<!doctype html><html lang=\"en\"><head><title>Hello</title>\n<meta name=\"description\" content=\"Desc\"><meta property=\"og:title\" content=\"OG\">\n<link rel=\"canonical\" href=\"https://example.com/\"><link rel=\"icon\" href=\"/favicon.ico\">\n</head><body><h1>Hello</h1><a href=\"https://example.com/a\">A</a></body></html>"
   ],
   "maxLength": 200000,
   "minLength": 1,
   "description": "HTML to extract from locally. Provide html or url. When both are set, html is used."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agentshelf-syntexa-ch-link-rel-preload-extractor-5f6c122e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agentshelf.syntexa.ch](https://www.zero.xyz/host/agentshelf.syntexa.ch/llms.txt)