# ipRestriction

**Kind:** Function

**Source:** [`src/middleware/ip-restriction/index.ts`](https://github.com/honojs/hono/blob/main/src/middleware/ip-restriction/index.ts#L218)

**Part of:** [Middleware](subsystem-src-middleware)

IP Restriction Middleware for Hono.

`ipRestriction` creates Hono middleware that checks a request’s client IP address against configured allow and deny lists. Attach it to an application or route to reject requests from disallowed addresses before route handlers run.

## Signature

```ts
function ipRestriction(getIP: GetIPAddr, { denyList = [], allowList = [] }: IPRestrictionRules, onError: ( remote: { addr: string; type: AddressType }, c: Context ) => Response | Promise<Response>): MiddlewareHandler
```

## Parameters

| Name | Type |
|---|---|
| `getIP` | `GetIPAddr` |
| `{ denyList = [], allowList = [] }` | `IPRestrictionRules` |
| `onError` | `( remote: { addr: string; type: AddressType }, c: Context ) => Response | Promise<Response>` |

**Returns:** `MiddlewareHandler`

## Diagram

```mermaid
graph LR
  Request[Incoming request] --> Middleware[ipRestriction middleware]
  Middleware --> IP[Read client IP]
  IP --> Lists[Check allowList and denyList]
  Lists -->|Allowed| Handler[Route handler]
  Lists -->|Denied| Forbidden[Forbidden response]
```

## Usage

```ts
import { Hono } from 'hono'
import { ipRestriction } from 'hono/ip-restriction'

const app = new Hono()

app.use(
  '*',
  ipRestriction({
    allowList: ['192.168.0.2', '10.0.0.0/24'],
    denyList: ['192.168.0.10'],
  })
)

app.get('/', (c) => c.text('Access granted'))

export default app
```

## AI Coding Instructions

- Register `ipRestriction` with `app.use()` before routes that require IP checks.
- Keep IP addresses and CIDR ranges in `allowList` and `denyList` aligned with the deployment network.
- Test requests from both allowed and denied addresses when changing list rules.
- Account for proxies and platform networking when determining the client IP visible to Hono.