# Saylor Innovations Cache-Control Header Analyzer

> Saylor Innovations Cache-Control Header Analyzer is a paid API for AI agents from saylorinnovations.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-30).

Parses and analyzes a Cache-Control header value, returning browser and CDN cacheability, freshness durations, directive breakdown, and warnings about conflicting or ineffective directives

## Facts

- Endpoint: GET https://saylorinnovations.com/api/dev/cache-control?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/saylor-innovations-cache-control-header-analyzer-3dd1c3dd
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_WcvrZXHn1da7Lh29y96Rd

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 saylor-innovations-cache-control-header-analyzer-3dd1c3dd
```

Example prompt: Can you analyze this Cache-Control header for me: 'public, max-age=3600, stale-while-revalidate=60' — tell me how long browsers and CDNs will cache it, and whether there are any conflicting or problematic directives?

## When to prefer this

Use this endpoint when you need a quick, structured analysis of a Cache-Control header value without building your own parser — especially useful for diagnosing caching misconfigurations, checking CDN vs browser freshness differences, detecting conflicting directives, or explaining caching behavior to non-experts. Prefer it over manual parsing when you need both human-readable verdicts and machine-readable directive breakdowns in one call.

## Known failure modes

- Missing or empty 'header' query parameter returns an error
- Malformed or non-standard directive strings may produce incomplete parsed output
- Highly unusual or vendor-specific extensions may not be recognized
- Network or payment authorization failure returns a 402 or 4xx error

## How this service works

Analyze a Cache-Control header - browser and CDN freshness, no-store and no-cache handling, stale-while-revalidate and conflicting directive warnings

## Output

A JSON object containing the original header string, an overall verdict, a list of warnings about conflicting or ineffective directives, a breakdown of parsed directive values (max-age, s-maxage, public, stale-while-revalidate, etc.), boolean flags for browser_cacheable and shared_cache_cacheable, human-readable freshness durations for both browser and shared cache, and additional fields like immutable, revalidate_every_time, and stale_if_error_seconds.

## 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",
     "required": [
      "header"
     ],
     "properties": {
      "header": {
       "type": "string",
       "description": "Cache-Control header value, e.g. public, max-age=3600"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "json"
    },
    "example": {
     "type": "object",
     "required": [
      "header",
      "verdict",
      "warnings"
     ],
     "properties": {
      "header": {
       "type": "string",
       "description": "Header as supplied"
      },
      "source": {
       "type": "string",
       "description": "Data source the values come from"
      },
      "verdict": {
       "type": "string",
       "description": "Overall assessment derived from the listed reasons"
      },
      "warnings": {
       "type": "array",
       "description": "Conflicting or ineffective directives"
      },
      "immutable": {
       "type": [
        "boolean",
        "null"
       ],
       "description": "True when the immutable directive is set"
      },
      "directives": {
       "type": "object",
       "properties": {
        "public": {
         "type": [
          "boolean",
          "null"
         ],
         "description": "public directive present"
        },
        "max-age": {
         "type": [
          "string",
          "null"
         ],
         "description": "max-age in seconds"
        },
        "s-maxage": {
         "type": [
          "string",
          "null"
         ],
         "description": "s-maxage in seconds"
        },
        "stale-while-revalidate": {
         "type": [
          "string",
          "null"
         ],
         "description": "stale-while-revalidate in seconds"
        }
       },
       "description": "Parsed directives and values"
      },
      "browser_cacheable": {
       "type": "boolean",
       "description": "Browser cacheable"
      },
      "browser_fresh_for": {
       "type": "string",
       "description":
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/saylor-innovations-cache-control-header-analyzer-3dd1c3dd/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from saylorinnovations.com](https://www.zero.xyz/host/saylorinnovations.com/llms.txt)