# ClientContextClient

**Kind:** Interface

**Source:** [`src/adapter/aws-lambda/types.ts`](https://github.com/honojs/hono/blob/main/src/adapter/aws-lambda/types.ts#L15)

**Part of:** [Adapter](subsystem-src-adapter)

`ClientContextClient` models client application metadata carried by the AWS Lambda adapter. It provides typed fields for the installation, application identity, and version information associated with a request.

## Properties

| Property | Type |
|---|---|
| `installationId` | `string` |
| `appTitle` | `string` |
| `appVersionName` | `string` |
| `appVersionCode` | `string` |
| `appPackageName` | `string` |

## Diagram

```mermaid
graph LR
  ClientContextClient --> installationId
  ClientContextClient --> appTitle
  ClientContextClient --> appVersionName
  ClientContextClient --> appVersionCode
  ClientContextClient --> appPackageName
```

## Usage

```ts
import type { ClientContextClient } from './types';

const client: ClientContextClient = {
  installationId: 'device-token',
  appTitle: 'Example App',
  appVersionName: 'release-name',
  appVersionCode: 'release-code',
  appPackageName: 'com.example.app',
};

function getClientLabel(context: ClientContextClient): string {
  return `${context.appTitle} (${context.appPackageName})`;
}

console.log(getClientLabel(client));
```

## AI Coding Instructions

- Keep every property as a string, including version codes and installation identifiers.
- Preserve the field names when mapping AWS Lambda client-context data into this interface.
- Treat client-provided values as request metadata and validate them before using them for authorization or persistence.
- Handle missing client context before constructing a `ClientContextClient` value.

## How it works

`ClientContextClient` is an exported TypeScript interface describing the `client` portion of a Lambda client context. [`src/adapter/aws-lambda/types.ts:8-20`](src/adapter/aws-lambda/types.ts#L8-L20)

An object typed as `ClientContextClient` has five required string fields:

- `installationId` — [`src/adapter/aws-lambda/types.ts:16`](src/adapter/aws-lambda/types.ts#L16)
- `appTitle` — [`src/adapter/aws-lambda/types.ts:17`](src/adapter/aws-lambda/types.ts#L17)
- `appVersionName` — [`src/adapter/aws-lambda/types.ts:18`](src/adapter/aws-lambda/types.ts#L18)
- `appVersionCode` — [`src/adapter/aws-lambda/types.ts:19`](src/adapter/aws-lambda/types.ts#L19)
- `appPackageName` — [`src/adapter/aws-lambda/types.ts:20](src/adapter/aws-lambda/types.ts#L20)

`ClientContext` requires its `client` field to conform to this interface. [`src/adapter/aws-lambda/types.ts:8-13`](src/adapter/aws-lambda/types.ts#L8-L13) `LambdaContext` may contain that enclosing `ClientContext` through its optional `clientContext` field. [`src/adapter/aws-lambda/types.ts:35-45`](src/adapter/aws-lambda/types.ts#L35-L45)

The interface declares no methods, runtime validation, error handling, or side effects. [`src/adapter/aws-lambda/types.ts:15-21`](src/adapter/aws-lambda/types.ts#L15-L21)