> ## Documentation Index
> Fetch the complete documentation index at: https://upstash.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

#  AWS Lambda

<Snippet file="redis/start-redis-snippet.mdx" />

<Card title="GitHub Repository" icon="github" href="https://github.com/upstash/redis-js/tree/main/examples/aws-cdk-python" horizontal>
  You can find the project source code on GitHub.
</Card>

### Prerequisites

* Complete all steps in [Getting started with the AWS CDK](https://docs.aws.amazon.com/cdk/v2/guide/getting_started.html)

### Project Setup

Create and navigate to a directory named `counter-cdk`. CDK CLI uses this directory name to name things in your CDK code, so if you decide to use a different name, don't forget to make the appropriate changes when applying this tutorial.

```shell theme={"system"}
mkdir counter-cdk && cd counter-cdk
```

Initialize a new CDK project.

```shell theme={"system"}
cdk init app --language typescript
```

### Counter Function Setup

Create a folder named `api` under `lib`

```shell theme={"system"}
mkdir lib/api
```

Create `/lib/api/requirements.txt`

```txt /lib/api/requirements.txt theme={"system"}
upstash-redis
```

Create `/lib/api/index.py`

```py /lib/api/index.py theme={"system"}
from upstash_redis import Redis

redis = Redis.from_env()

def handler(event, context):
    count = redis.incr('counter')
    return {
        'statusCode': 200,
        'body': f'Counter: {count}'
    }
```

### Counter Stack Setup

Update `/lib/counter-cdk-stack.ts`

```ts /lib/counter-cdk-stack.ts theme={"system"}
import * as cdk from 'aws-cdk-lib';
import { Construct } from 'constructs';
import * as lambda from 'aws-cdk-lib/aws-lambda';
import * as path from 'path';

export class CounterCdkStack extends cdk.Stack {
  constructor(scope: Construct, id: string, props?: cdk.StackProps) {
    super(scope, id, props);

    const counterFunction = new lambda.Function(this, 'CounterFunction', {
      code: lambda.Code.fromAsset(path.join(__dirname, 'api'), {
        bundling: {
          image: lambda.Runtime.PYTHON_3_9.bundlingImage,
          command: [
            'bash', '-c',
            'pip install -r requirements.txt -t /asset-output && cp -au . /asset-output'
          ],
        },
      }),
      runtime: lambda.Runtime.PYTHON_3_9,
      handler: 'index.handler',
      environment: {
        UPSTASH_REDIS_REST_URL: process.env.UPSTASH_REDIS_REST_URL || '',
        UPSTASH_REDIS_REST_TOKEN: process.env.UPSTASH_REDIS_REST_TOKEN || '',
      },
    });

    const counterFunctionUrl = counterFunction.addFunctionUrl({
      authType: lambda.FunctionUrlAuthType.NONE,
    });

    new cdk.CfnOutput(this, "counterFunctionUrlOutput", {
      value: counterFunctionUrl.url,
    })
  }
}
```

### Database Setup

Create a Redis database using [Upstash Console](https://console.upstash.com) or [Upstash CLI](https://github.com/upstash/cli) and export `UPSTASH_REDIS_REST_URL` and `UPSTASH_REDIS_REST_TOKEN` to your environment.

```shell theme={"system"}
export UPSTASH_REDIS_REST_URL=<YOUR_URL>
export UPSTASH_REDIS_REST_TOKEN=<YOUR_TOKEN>
```

### Deploy

Run in the top folder:

```shell theme={"system"}
cdk synth
cdk bootstrap
cdk deploy
```

Visit the output url.