# Quartermaster HTTP Liveness & Latency Check

> Quartermaster HTTP Liveness & Latency Check is a paid API for AI agents from quartermaster.surewhynot.app, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Performs a pre-flight HTTP check on a URL, returning status code, response class, latency in milliseconds, redirect chain, content-type, and server header.

## Facts

- Endpoint: GET https://quartermaster.surewhynot.app/v1/http-check
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/quartermaster-http-liveness-latency-check-ac833eeb
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_LRS58WSwMcEm_kTQmUqxj

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 quartermaster-http-liveness-latency-check-ac833eeb
```

Example prompt: Can you check if https://api.example.com/health is up right now — tell me the HTTP status, how long it took to respond, and whether it redirects anywhere?

## When to prefer this

Use this endpoint when you need a lightweight, single-call liveness and latency check for any public HTTP/HTTPS URL — especially for pre-flight validation before invoking a downstream API, monitoring whether a service is up, or inspecting redirect behavior and server metadata without parsing full response bodies.

## Known failure modes

- URL is malformed or not a valid URI — input validation error
- Target host is unreachable or DNS fails — returns down status with error detail
- Request times out — latency recorded at timeout threshold
- Non-HTTP/HTTPS URL provided — schema validation rejection
- Missing required url query parameter — schema validation error

## How this service works

Liveness/latency pre-flight for a URL: is it up, HTTP status and class, response latency in ms, whether it redirects (and where), content-type and server.

## Output

Returns whether the URL is reachable, its HTTP status code and class (2xx/3xx/4xx/5xx), response latency in milliseconds, any redirect destination, the content-type header, and the server header.

## 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": [
      "url"
     ],
     "properties": {
      "url": {
       "type": "string",
       "format": "uri",
       "description": "Public http(s) URL to check"
      }
     }
    }
   },
   "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/quartermaster-http-liveness-latency-check-ac833eeb/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from quartermaster.surewhynot.app](https://www.zero.xyz/host/quartermaster.surewhynot.app/llms.txt)