# AWS ParallelCluster API
<a name="api-reference-v3"></a>

**What is AWS ParallelCluster API?**

AWS ParallelCluster API is a serverless application that, once deployed to your AWS account, provides programmatic access to AWS ParallelCluster features through an API. 

AWS ParallelCluster API is distributed as a self-contained [CloudFormation](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/Welcome.html) template that includes an [Amazon API Gateway](https://docs.aws.amazon.com/apigateway/latest/developerguide/welcome.html) endpoint, that exposes AWS ParallelCluster features, and an [AWS Lambda](https://docs.aws.amazon.com/lambda/latest/dg/welcome.html) function, that takes care of processing the invoked features. 

The following image shows a high-level architecture diagram of the AWS ParallelCluster API infrastructure.

 ![a high-level architecture diagram of the ParallelCluster API infrastructure](http://docs.aws.amazon.com/parallelcluster/latest/ug/images/API-Architecture-r2.png) 

## AWS ParallelCluster API Documentation
<a name="api-reference-documentation-v3"></a>

The OpenAPI specification file that describes the AWS ParallelCluster API can be downloaded from: 

```
https://{{<REGION>}}-aws-parallelcluster.s3.{{<REGION>}}.amazonaws.com/parallelcluster/{{<VERSION>}}/api/ParallelCluster.openapi.yaml
```

Starting from the OpenAPI specification file, you can use one of the many available tools such as [ Swagger UI](https://swagger.io/tools/swagger-ui/) or [Redoc](https://github.com/Redocly/redoc) to generate documentation for the AWS ParallelCluster API. 

**How to deploy AWS ParallelCluster API**

To deploy AWS ParallelCluster API you need to be an Administrator of the AWS account. 

The template used to deploy the API is available at the following URL:

```
https://{{<REGION>}}-aws-parallelcluster.s3.{{<REGION>}}.amazonaws.com/parallelcluster/{{<VERSION>}}/api/parallelcluster-api.yaml
```

where `{{<REGION>}}` is the AWS Region where the API needs to be deployed to and `{{<VERSION>}}` is the AWS ParallelCluster version (e.g. 3.15.0). 

AWS Lambda uses a Lambda layer interface with the [AWS ParallelCluster Python library API](pc-py-library-v3.md) to process the API invoked features.

**Warning**  
Any user in the AWS account, that has privileged access to AWS Lambda or Amazon API Gateway services, automatically inherits permissions to administer AWS ParallelCluster API resources.