Convert IP addresses across Dot-Decimal
Convert IP addresses across Dot-Decimal, IPv6, Integer, Hex, and Binary, and compute CIDR subnet math and IANA scopes
Request
- x-api-key: <your-api-key>
- Content-Type: application/json
Response
{
"ipDetails": {
"binary": "<binary>",
"compressed": "<compressed>",
"dotDecimal": "<dot decimal>",
"expanded": "<expanded>",
"hex": "#7C4DFF",
"integer": "<integer>",
"scope": "<scope>"
},
"status": "success",
"subnet": {
"broadcastAddress": "Powstańców Śląskich 5/212, 53-332 Wrocław",
"cidr": "10.0.0.0/24",
"firstUsableIp": "83.136.251.156",
"lastUsableIp": "83.136.251.156",
"netmask": "<netmask>",
"networkAddress": "Powstańców Śląskich 5/212, 53-332 Wrocław",
"prefixLength": 16,
"totalIps": "3",
"totalUsableIps": "3",
"wildcardMask": "<wildcard mask>"
},
"tokensDeducted": 1,
"version": "1.0.0"
}What it does
Convert IP addresses across Dot-Decimal, IPv6, Integer, Hex, and Binary, and compute CIDR subnet math and IANA scopes
Request
Body
| Field | Type | Required | Description |
|---|---|---|---|
ip | string | yes | IP address or network string (e.g. "192.168.1.1", "10.0.0.1/24", "2001:db8::1", "3232235777", "0xc0a80101"). |
prefix | integer | no | Optional explicit CIDR prefix length (0-32 for IPv4, 0-128 for IPv6). Overrides prefix in IP string if provided. |
Example request
{
"ip": "83.136.251.156",
"prefix": 15
}Response
| Field | Type | Description |
|---|---|---|
ipDetails | object | |
↳ binary | string | |
↳ compressed | string | |
↳ dotDecimal | string | |
↳ expanded | string | |
↳ hex | string | |
↳ integer | string | |
↳ scope | string | |
status | string | |
subnet | object | |
↳ broadcastAddress | string | |
↳ cidr | string | |
↳ firstUsableIp | string | |
↳ lastUsableIp | string | |
↳ netmask | string | |
↳ networkAddress | string | |
↳ prefixLength | integer | |
↳ totalIps | string | |
↳ totalUsableIps | string | |
↳ wildcardMask | string | |
tokensDeducted | integer | |
version | string |
Example response
{
"ipDetails": {
"binary": "<binary>",
"compressed": "<compressed>",
"dotDecimal": "<dot decimal>",
"expanded": "<expanded>",
"hex": "#7C4DFF",
"integer": "<integer>",
"scope": "<scope>"
},
"status": "success",
"subnet": {
"broadcastAddress": "Powstańców Śląskich 5/212, 53-332 Wrocław",
"cidr": "10.0.0.0/24",
"firstUsableIp": "83.136.251.156",
"lastUsableIp": "83.136.251.156",
"netmask": "<netmask>",
"networkAddress": "Powstańców Śląskich 5/212, 53-332 Wrocław",
"prefixLength": 16,
"totalIps": "3",
"totalUsableIps": "3",
"wildcardMask": "<wildcard mask>"
},
"tokensDeducted": 1,
"version": "1.0.0"
}Errors
Every error answers with the same envelope: an HTTP status, a machine code and a sentence.
400 | The body or a parameter failed validation. The details array names the field. |
401 | No key, a revoked key or a wrong header. Send x-api-key. |
402 | The wallet cannot cover this call. Top up or wait for the monthly grant. |
404 | The resource does not exist, or it is not yours. Both answer identically and cost nothing. |
429 | Over the per-minute quota of your tier. Back off and retry. |
5xx | Upstream refused or timed out. The call is not billed. |
Code
curl -X POST 'https://app.castomapi.com/v1/convert/network-ip' \
-H 'x-api-key: <your-api-key>' \
-H 'Content-Type: application/json' \
-d '{"ip": "83.136.251.156", "prefix": 15}'const res = await fetch('https://app.castomapi.com/v1/convert/network-ip', {
method: 'POST',
headers: { 'x-api-key': '<your-api-key>', 'Content-Type': 'application/json' },
body: JSON.stringify({"ip": "83.136.251.156", "prefix": 15})
});
const data = await res.json();
console.log(data);import { request } from 'node:https';
// Node 18+ has fetch built in
const res = await fetch('https://app.castomapi.com/v1/convert/network-ip', {
method: 'POST',
headers: { 'x-api-key': '<your-api-key>', 'Content-Type': 'application/json' },
body: JSON.stringify({"ip": "83.136.251.156", "prefix": 15})
});
const data = await res.json();
console.log(data);import requests
res = requests.post(
'https://app.castomapi.com/v1/convert/network-ip',
headers={'x-api-key': '<your-api-key>'},
json={"ip": "83.136.251.156", "prefix": 15},
timeout=30,
)
print(res.json())<?php
$ch = curl_init('https://app.castomapi.com/v1/convert/network-ip');
curl_setopt_array($ch, [
CURLOPT_CUSTOMREQUEST => 'POST',
CURLOPT_RETURNTRANSFER => true,
CURLOPT_HTTPHEADER => ['x-api-key: <your-api-key>', 'Content-Type: application/json'],
CURLOPT_POSTFIELDS => json_encode(['ip' => '83.136.251.156', 'prefix' => 15]),
]);
$data = json_decode(curl_exec($ch), true);
print_r($data);Cost and limits
This operation needs no API key and costs nothing: called without a key it answers 200 and deducts zero tokens, up to 10 requests a minute per IP address.
Rate limits per minute
| No key | 10 |
| Free | 60 |
| Pro | 300 |
| Enterprise | 1200 |
Questions
What does Convert IP addresses across Dot-Decimal cost?
This operation needs no API key and costs nothing: called without a key it answers 200 and deducts zero tokens, up to 10 requests a minute per IP address.
How do I authenticate?
Send your key in the x-api-key header. One key covers every metered endpoint; there is nothing to enable per endpoint.
Can I send an Authorization: Bearer token instead?
Not for a metered endpoint — those take the x-api-key header and nothing else. Bearer tokens belong to the account side: the dashboard and account APIs accept a JWT session, and castomapi-auth issues those through a standard OAuth2 handshake, with authorization code, client credentials and refresh grants. The auth service page covers it.
What are the limits?
10 requests a minute per IP with no key at all, 60 a minute on the free tier, 300 on Pro, 1200 on Enterprise. Above the no-key tier the quota is per account, across every endpoint.
OpenAPI: https://app.castomapi.com/docs/json