# IPv4 Private Check

> IPv4 Private Check is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Determines whether a given IPv4 address falls within RFC1918 private address ranges using local computation only.

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/ip-v4-private-check
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/ipv4-private-check-095a5426
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_xgKKp-SDXN2DbpO2SrbUb

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 ipv4-private-check-095a5426 -d '<json body>'
```

Example prompt: Is 192.168.1.55 a private IP address? I need to know before deciding whether to run a whois lookup on it.

## When to prefer this

Choose this endpoint when an agent needs a fast, cheap, deterministic classification of an IPv4 address as private or public before committing to more expensive operations like whois lookups, geolocation queries, or network reachability checks. Ideal for pre-filtering pipelines where private IPs should be excluded from external API calls. Preferred over rolling your own RFC1918 logic when operating in a tool-calling context where simplicity and determinism matter.

## Known failure modes

- Invalid or malformed IPv4 string returns an error response
- IPv6 addresses or hostnames not accepted — input must be a dotted-decimal IPv4 string
- Payment failure (x402) results in 402 response before computation occurs
- Empty or missing `ip` field causes a validation error

## How this service works

Detect RFC1918 private IPv4 addresses. Call when agents classifying IPs before whois/network calls. Returns is_private as deterministic JSON for $0.001 USDC via x402 on Base. First-party local math only—no RPC, live market feed, API keys, storage, or mediagen. Advisory only; the caller owns capital, risk, and production controls.

## Output

Returns a deterministic JSON object containing an `is_private` boolean indicating whether the supplied IPv4 address falls within RFC1918 private ranges (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16). Computed locally with no external calls.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "ip": {
   "type": "string",
   "description": "IPv4 address string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "schema": "delx/util-ip-v4-private-check/v1",
  "is_private": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/ipv4-private-check-095a5426/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.delx.ai](https://www.zero.xyz/host/api.delx.ai/llms.txt)