# SiteCheck Uptime / URL Health Check

> SiteCheck Uptime / URL Health Check is a paid API for AI agents from api.sitecheck-api.workers.dev, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-20).

Checks whether 1–5 URLs are reachable, returning HTTP status, TLS status, response time, final URL after redirects, and content type for each.

## Facts

- Endpoint: GET https://api.sitecheck-api.workers.dev/api/uptime?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/sitecheck-uptime-url-health-check-6996feb5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_tDLKsS4txYF44GGD3oiUv

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 sitecheck-uptime-url-health-check-6996feb5
```

Example prompt: Can you check if https://example.com and https://api.example.com are currently up and responding correctly, and tell me their HTTP status codes and how fast they're responding?

## When to prefer this

Use this endpoint when you need a quick, pay-per-call HTTP reachability check for up to 5 URLs simultaneously, with redirect-following, TLS verification, and response-time measurement — without setting up infrastructure. Ideal for agents that need on-demand uptime verification rather than continuous scheduled monitoring.

## Known failure modes

- URL is unreachable — up: false, error message returned
- TLS certificate invalid — tls: false
- Redirect loop or >5 hops — error reported
- Non-HTTP/HTTPS URL provided — validation error
- More than 5 URLs submitted — schema validation failure
- Timeout after 9 seconds — error field populated
- Malformed URL — request rejected

## How this service works

Checks up to five public URLs now from this Worker: up or down, HTTP status, the final URL after up to five redirects, response time in milliseconds, whether TLS was used, content type and length, and the Cloudflare data centre (colo) the check ran from. A down site is a valid 200 answer with up false and the error, not a failure. The check is one GET per hop, so it measures the first response, not the full page.

## Output

Returns a JSON object with a checks array — one entry per URL — each containing: up (boolean), tls (boolean), status (HTTP code), finalUrl (after redirects), redirects (count), responseTimeMs, contentType, and error (if any). Also includes checkedAt timestamp, total count, and the data-center colo where the check ran.

## 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": [
      "urls"
     ],
     "properties": {
      "urls": {
       "type": "string",
       "description": "Comma-separated public http or https URLs, 1 to 5"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "colo": null,
  "count": 1,
  "checks": [
   {
    "up": true,
    "tls": true,
    "url": "https://example.com/",
    "error": null,
    "status": 200,
    "finalUrl": "https://example.com/",
    "redirects": 0,
    "contentType": "text/html; charset=utf-8",
    "contentLength": null,
    "responseTimeMs": 81
   }
  ],
  "source": "Checked from this Worker (GET, redirects followed up to 5 hops, 9 s timeout)",
  "checkedAt": "2026-10-15T14:07:52.571Z"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/sitecheck-uptime-url-health-check-6996feb5/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.sitecheck-api.workers.dev](https://www.zero.xyz/host/api.sitecheck-api.workers.dev/llms.txt)