# NetIntel Subnet Calculator

> NetIntel Subnet Calculator is a paid API for AI agents from netintel.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15).

Calculates detailed subnet information for a given CIDR notation, including network range, broadcast address, usable hosts, subnets, and RFC classification

## Facts

- Endpoint: GET https://netintel.dev/subnet/calc
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/netintel-subnet-calculator-0cf57df9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_uWD8P4QfxahwkaT13bUV3

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 netintel-subnet-calculator-0cf57df9
```

Example prompt: Can you give me the full subnet breakdown for 10.0.1.0/24 — broadcast address, first and last usable IP, total hosts, netmask, supernet, and whether it's a private range?

## When to prefer this

Use this endpoint when you need comprehensive, structured subnet metadata for a given CIDR block — especially when you need multiple fields at once (netmask, broadcast, host counts, subnets, RFC classification) rather than computing them manually. Ideal for network planning, infrastructure automation, documentation generation, or validating IP address space allocations.

## Known failure modes

- Invalid CIDR notation returns an error response
- Missing required 'cidr' query parameter returns 400-level error
- Malformed IP address in CIDR (e.g. 999.0.0.0/24) returns validation error
- Payment not included or insufficient results in 402 Payment Required response

## How this service works

Calculates IPv4/IPv6 subnet details from CIDR notation — network/broadcast, netmask, wildcard (Cisco ACL) mask, binary/hex masks, usable host range, RFC classification (private/loopback/multicast), supernet, and subnet-split counts. Pass comma-separated CIDRs to detect overlaps and classify each pair (subnet/supernet/partial overlap/disjoint); multi-CIDR responses return {subnets, overlaps}.

## Output

Returns a JSON object with complete subnet details: CIDR, netmask, hex/binary/wildcard masks, network and broadcast addresses, first/last usable IPs, total and usable host counts, prefix length, IP version, supernet, a list of possible sub-division subnets with counts, and RFC classification (e.g. Private RFC 1918).

## 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",
     "required": [
      "cidr"
     ],
     "properties": {
      "cidr": {
       "type": "string",
       "description": "CIDR block, e.g. 10.0.1.0/24 or 2001:db8::/48 (IPv6). Comma-separate multiple CIDRs for overlap/containment analysis, e.g. 10.0.0.0/16,10.0.1.0/24"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "cidr": {
       "type": "string"
      },
      "netmask": {
       "type": "string"
      },
      "network": {
       "type": "string"
      },
      "subnets": {
       "type": "array"
      },
      "hex_mask": {
       "type": "string"
      },
      "supernet": {
       "type": "string"
      },
      "wildcard": {
       "type": "string"
      },
      "broadcast": {
       "type": "string"
      },
      "ip_version": {
       "type": "number"
      },
      "is_private": {
       "type": "boolean"
      },
      "binary_mask": {
       "type": "string"
      },
      "last_usable": {
       "type": "string"
      },
      "total_hosts": {
       "type": "number"
      },
      "first_usable": {
       "type": "string"
      },
      "usable_hosts": {
       "type": "number"
      },
      "prefix_length": {
       "type": "number"
      },
      "rfc_classification": {
       "type": "string"
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "cidr": "10.0.1.0/24",
  "netmask": "255.255.255.0",
  "network": "10.0.1.0",
  "subnets": [
   {
    "count": 2,
    "prefix": "/25"
   },
   {
    "count": 4,
    "prefix": "/26"
   },
   {
    "count": 8,
    "prefix": "/27"
   },
   {
    "count": 16,
    "prefix": "/28"
   }
  ],
  "hex_mask": "ffffff00",
  "supernet": "10.0.0.0/23",
  "wildcard": "0.0.0.255",
  "broadcast": "10.0.1.255",
  "ip_version": 4,
  "is_private": true,
  "binary_mask": "11111111111111111111111100000000",
  "last_usable": "10.0.1.254",
  "total_hosts": 256,
  "first_usable": "10.0.1.1",
  "usable_hosts": 254,
  "prefix_length": 24,
  "rfc_classification": "Private (RFC 1918)"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/netintel-subnet-calculator-0cf57df9/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from netintel.dev](https://www.zero.xyz/host/netintel.dev/llms.txt)