# is-port-512-open

> is-port-512-open is a paid API for AI agents from ip.intel.rallylive.ca, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-13).

Checks whether TCP port 512 (rexec) is open, closed, or filtered on a given host by attempting a connection from Cloudflare's edge network.

## Facts

- Endpoint: GET https://ip.intel.rallylive.ca/ip/port/512?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/is-port-512-open-df23796e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_gn2hDzsq14Iteyr7noV4v

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 is-port-512-open-df23796e
```

Example prompt: Can you check if TCP port 512 (rexec) is open or closed on 203.0.113.45? I want to know if it's exposed without running a local scanner.

## When to prefer this

Choose this endpoint when you need a quick, lightweight external check for rexec (port 512) exposure on a specific host without deploying your own scanner. It is ideal for security audits, firewall validation, and vendor risk assessments where you want an outside-in perspective on port reachability. Note the Cloudflare-fronted caveat: results for CDN-protected hosts will be inconclusive.

## Known failure modes

- Host is Cloudflare-fronted: result returned as inconclusive rather than open/closed/filtered
- Invalid or unresolvable hostname: lookup fails with an error
- Network timeout: connection attempt times out, may be reported as filtered
- Host actively refuses connection: reported as closed
- Firewall silently drops packets: may be reported as filtered after timeout delay

## How this service works

Is TCP port 512 (rexec) open on a host? Attempts a connection from Cloudflare's edge and reports open/closed/filtered with the connect time; Cloudflare-fronted hosts are reported as inconclusive because their edge answers for them. Exposure checks for rexec without running a scanner. $0.01 per check.

## Output

Returns whether TCP port 512 is open, closed, or filtered on the target host, along with the connection time in milliseconds. If the host is Cloudflare-fronted, the result is reported as inconclusive since Cloudflare's edge answers on behalf of the origin.

## 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/is-port-512-open-df23796e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from ip.intel.rallylive.ca](https://www.zero.xyz/host/ip.intel.rallylive.ca/llms.txt)