# is-port-137-open

> is-port-137-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 2026-10-12).

Checks whether TCP port 137 (NetBIOS-NS) is open, closed, or filtered on a given host, returning the connection result and connect time from Cloudflare's edge.

## Facts

- Endpoint: GET https://ip.intel.rallylive.ca/ip/port/137?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/is-port-137-open-a239103f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_nFnOoQjDy3d_yCWDp9AbT

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-137-open-a239103f
```

Example prompt: Can you check whether TCP port 137 (NetBIOS-NS) is open or closed on 203.0.113.45 — I want to know if NetBIOS name service is exposed without running a scanner?

## When to prefer this

Choose this endpoint when you need a lightweight, agentless check of NetBIOS-NS (port 137) exposure on a host without deploying a network scanner. It is ideal for security audits, compliance checks, or pre/post-hardening verification where a fast, remote probe from a well-known edge network (Cloudflare) is acceptable. Prefer alternatives if you need scanning from multiple vantage points, UDP port checks, or scanning at scale (consider bulk endpoints if available).

## Known failure modes

- Cloudflare-fronted hosts return 'inconclusive' because Cloudflare's edge intercepts the connection
- Filtered ports may time out and take longer to return a result
- Invalid or unresolvable hostnames may result in an error response
- The check reflects reachability from Cloudflare's edge, not the broader internet — results may differ from other vantage points

## How this service works

Is TCP port 137 (NetBIOS-NS) 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-NS without running a scanner. $0.01 per check.

## Output

Returns whether TCP port 137 is open, closed, or filtered on the target host as seen from Cloudflare's edge, along with the TCP connect time in milliseconds. If the host is Cloudflare-fronted, the result is marked inconclusive because 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-137-open-a239103f/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)