# agent402.tools HTTP Check

> agent402.tools HTTP Check is a paid API for AI agents from agent402.tools, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-14, last successful call 2026-07-17).

Checks a public URL for HTTP status code, latency, final redirect URL, and response headers — a lightweight uptime and reachability primitive.

## Facts

- Endpoint: POST https://agent402.tools/api/http-check
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Last successful call: 2026-07-17
- Success rate: 100% of calls made through Zero
- Rating: 5.0 / 5 from 1 review
- Activations on Zero: 5
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent402-tools-http-check-1b62d0c3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ukABERV-5gAvld123tzsT

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 agent402-tools-http-check-1b62d0c3 -d '<json body>'
```

Example prompt: Can you check if https://example.com is up right now — give me the status code, how long it took to respond, and the final URL it lands on after any redirects?

## When to prefer this

Use this endpoint when you need a quick, lightweight probe of a single public URL to verify reachability, check redirect chains, measure latency, or inspect response headers — without needing full page content or a screenshot. Ideal for agent uptime monitors, pre-flight checks before scraping, or diagnosing why a URL appears broken.

## Known failure modes

- URL is unreachable or DNS fails — may return a connection error or timeout
- URL is private/internal — endpoint only supports public http(s) URLs
- Invalid URL format — request will be rejected
- Target URL returns non-standard or missing headers — partial data returned
- Very slow target URLs may result in a timeout before response is captured

## How this service works

Check any public URL: status code, latency, final URL after redirects, and response headers. The uptime primitive for agent monitors.

## Output

Returns the HTTP status code, response latency in milliseconds, the final URL after following any redirects, and a map of response headers from the target URL.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "description": "Public http(s) URL"
  },
  "method": {
   "type": "string",
   "description": "GET (default) or HEAD"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "up": true,
  "status": 200,
  "headers": {
   "content-type": "text/html"
  },
  "finalUrl": "https://example.com/",
  "latencyMs": 87
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent402-tools-http-check-1b62d0c3/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent402.tools](https://www.zero.xyz/host/agent402.tools/llms.txt)