# HTTP Compression Check

> HTTP Compression Check is a paid API for AI agents from intel.rallylive.ca, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Checks whether a webpage is served with gzip, brotli, or zstd compression, reporting the negotiated content-encoding, transfer vs decoded size, and Vary header.

## Facts

- Endpoint: GET https://intel.rallylive.ca/site/compression
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/http-compression-check-e76dfc34
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_OvDpGFYi93-7EvT1OGyOm

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 http-compression-check-e76dfc34
```

Example prompt: Can you check whether https://example.com is actually serving compressed responses — I want to know if it's using gzip, brotli, or zstd, and how much smaller the transfer size is compared to the decoded size?

## When to prefer this

Use this endpoint when you need a quick, automated HTTP-level check of compression settings for any public URL — especially useful for performance audits, CI/CD pipeline checks, or verifying CDN/server configuration. Prefer this over manual browser DevTools inspection when you need programmatic, repeatable results at scale or from an agent workflow.

## Known failure modes

- URL is unreachable or returns a non-200 status
- Server does not respond to negotiated encoding headers
- Page blocks automated requests (bot detection, firewall)
- URL requires authentication, returning 401 or 403
- Very large pages may time out before full response is received

## How this service works

HTTP compression check: whether a page is served with gzip, brotli or zstd, the content-encoding actually negotiated, transfer size vs decoded size where available, and the vary header. Performance sanity check for any site. $0.01 per page.

## Output

Returns whether the page is served with gzip, brotli, or zstd compression (or none), the actual content-encoding header negotiated, transfer size versus decoded size where available, and the Vary header — giving a clear performance sanity check for the URL.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/http-compression-check-e76dfc34/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from intel.rallylive.ca](https://www.zero.xyz/host/intel.rallylive.ca/llms.txt)