# is-port-139-open

> is-port-139-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 139 (NetBIOS) 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/139?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-139-open-d01bf756
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_gpVsOtvhi9aGcRmYpE8t0

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-139-open-d01bf756
```

Example prompt: Can you check if TCP port 139 (NetBIOS) is open or closed on the host 203.0.113.45 — I want to know if it's exposed to the internet without me having to run a scanner.

## When to prefer this

Use this endpoint when you need a quick, lightweight check of NetBIOS port 139 exposure from an external vantage point (Cloudflare's edge) without deploying a network scanner. Ideal for security audits, compliance checks, and post-firewall-change verification on individual hosts. Prefer this over general-purpose port scanners when you specifically need NetBIOS exposure confirmation via a pay-per-use API with no setup.

## Known failure modes

- Host is Cloudflare-fronted — result returned as inconclusive rather than open/closed
- Host unreachable or DNS resolution failure — may return filtered or an error
- Firewall silently drops packets — may report filtered rather than closed
- Rate limiting or payment failure — check rejected before execution
- Invalid hostname or IP format — request rejected

## How this service works

Is TCP port 139 (NetBIOS) 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 NetBIOS without running a scanner. $0.01 per check.

## Output

Returns a status of open, closed, or filtered for TCP port 139 on the target host, along with the connection time in milliseconds. If the host is behind Cloudflare's edge, the result is marked inconclusive because Cloudflare's infrastructure 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-139-open-d01bf756/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)