# AppSync GraphQL API Acting on DynamoDB
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![Stability: Experimental](https://img.shields.io/badge/stability-Experimental-important.svg?style=for-the-badge)

> **This is an experimental example. It may not build out of the box**
>
> This examples is build on Construct Libraries marked "Experimental" and may not be updated for latest breaking changes.
>
> If build is unsuccessful, please create an [issue](https://github.com/aws-samples/aws-cdk-examples/issues/new) so that we may debug the problem 

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This an example of an AppSync GraphQL API, pointing to four resolvers doing CRUD operations with a single DynamoDB table.

![Detailed diagram](diagram.png)

## Build

To build this app, you need to be in this example's root folder. Then run the following:

```bash
$ python3 -m venv .env
$ source .env/bin/activate
$ pip install -r requirements.txt
```

This will install the necessary CDK, then this example's dependencies, and then build your Python files and your CloudFormation template.

Install the latest version of the AWS CDK CLI:

```shell
$ npm i -g aws-cdk
```

## Deploy

Run `cdk deploy`. This will deploy / redeploy your Stack to your AWS Account.

After the deployment you will see the API's URL, which represents the url you can then use.

## Synthesize Cloudformation Template

To see the Cloudformation template generated by the CDK, run `cdk synth`, then check the output file in the "cdk.out" directory.

## The Component Structure

This Stack contains:

- a __GraphQL API__ with an API Key (Use with caution, each key is only valid for 7 days.)
- a __GraphQL Schema__ with Queries to get one and all items and two mutations to save and delete an item
- a __DynamoDB table__ `items` that stores the data with a Pay Per Request Billing Mode
- an __IAM Role__ that allows AppSync to invoke your DynamoDB table.
- an __AppSync DataSource__, connecting your API to the DynamoDB table with the previously specified role.
- a __AppSync Resolver__ for a Query `getOne` to get one item from the DynamoDB table.
- a __AppSync Resolver__ for a Query `all` to get all items from the DynamoDB table.
- a __AppSync Resolver__ for a Mutation `save` to put an item into the DynamoDB table (the id is autogenerated, you need only name).
- a __AppSync Resolver__ for a Mutation `delete` to delete one item from the DynamoDB table.