# Port Reference Guide — REST API endpoint `port-reference-guide`

Return well-known network ports that match a port number, service name, protocol, or category, with a security note (safe / caution / insecure) for each. Call with no filters to list every port in the reference table.

- Category: network
- MCP server: https://mcp.findutils.com/ (Streamable HTTP, no API keys, 120 req/min per IP)
- REST endpoint: POST https://api.findutils.com/api/tools/port-reference-guide/execute (no API keys, 60 req/min per IP)
- Reference page: https://findutils.com/api/port-reference-guide/
- Same tool on the other surface: https://findutils.com/mcp/port-reference-guide/

## Call the endpoint (verified example)

```bash
curl -X POST https://api.findutils.com/api/tools/port-reference-guide/execute \
  -H "Content-Type: application/json" \
  -d '{
    "port": 443
  }'

# Parameter schema
curl https://api.findutils.com/api/tools/port-reference-guide
```

## Input schema

| Argument | Type | Required | Description |
|---|---|---|---|
| `query` | string | no | Free-text search over port number, service, description, and category, e.g. "ssh", "443", "database". |
| `port` | integer | no | Exact port number to look up (0-65535). |
| `protocol` | string (TCP \| UDP \| TCP/UDP) | no | Restrict to one transport protocol. |
| `category` | string (Web \| Email \| File Transfer \| Remote Access \| DNS & Network \| Database \| Security & VPN \| Messaging \| Development \| Container & Orchestration \| Media \| Proxy & Load Balancing \| Monitoring \| CI/CD \| Message Queues) | no | Restrict to one category. |
| `limit` | integer | no | Maximum number of entries to return (1-200). Default 50. Default: `50`. |

Example arguments (verified):

```json
{
  "port": 443
}
```

OpenAPI 3.1 spec: https://findutils.com/api/openapi.json · Interactive docs: https://findutils.com/api/docs/

## Also an MCP tool

```bash
claude mcp add findutils --transport http https://mcp.findutils.com/
```

Then ask the client to call `findutils:port_reference_guide`. Full MCP reference: https://findutils.com/mcp/port-reference-guide/

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