# CLIENT_IP_INVALID

# CLIENT_IP_INVALID

`client.ip` is not a usable public address for an end user.

## Summary

| Field | Value |
|---|---|
| HTTP status | `400` |
| `errorCategory` | `validation` |
| `retryable` | `false` |

## When This Fires

- **`POST /v1/marketfront/orders/validate`**
- **`POST /v1/marketfront/orders/place`**

…when `client.ip` does not parse as a single IP address, or parses but sits in a range no customer can originate from.

### Rejected values

| Kind | Examples |
|---|---|
| Private (RFC 1918) | `10.0.0.1`, `172.16.0.5`, `192.168.1.1` |
| Loopback | `127.0.0.1`, `::1` |
| Unspecified / placeholder | `0.0.0.0`, `::` |
| Link-local | `169.254.10.1`, `fe80::1` |
| Carrier-grade NAT (RFC 6598) | `100.64.0.1` |
| Unique-local IPv6 | `fd00::1` |
| Reserved / documentation | `192.0.2.0/24`, `198.18.0.0/15`, `240.0.0.0/4` |
| Not a single address | `203.0.113.7, 70.41.3.18`, `203.0.113.7:8080`, `not-an-ip` |

An IPv4-mapped IPv6 address (`::ffff:10.0.0.1`) is evaluated as the IPv4 address it wraps, so it cannot be used to route around the list above.

## Recommended Action

Two mistakes account for almost all of these:

1. **Sending your own server's address.** Your backend's outbound address is usually private or a load-balancer address. Take the customer's address from the request your front end received.
2. **Sending the whole forwarded-for chain.** `client.ip` is one address. If you have `X-Forwarded-For: 203.0.113.7, 70.41.3.18`, send the **first** entry — the client — not the joined string.

```jsonc
{
  "client": {
    "ip": "203.0.113.7",          // one address, publicly routable
    "userAgent": "Mozilla/5.0 …"
  }
}
```

We validate that the address is *shaped* like a real client address. We cannot verify that it belongs to the person ordering — that remains your responsibility under the integration agreement.

## Example

```json
{
  "type": "https://developer.gett-tech.com/errors/CLIENT_IP_INVALID",
  "title": "Bad Request",
  "status": 400,
  "detail": "client.ip must be the end user's publicly routable address. Private, loopback, link-local and reserved addresses are rejected — if your front end sits behind a proxy, forward the first address in the chain rather than your own server's.",
  "instance": "/v1/marketfront/orders/place",
  "requestId": "req_abc123",
  "timestamp": "2026-08-10T14:30:00.000Z",
  "errorCode": "CLIENT_IP_INVALID",
  "errorCategory": "validation",
  "retryable": false
}
```