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

# Overview

> This section provides an overview of the Upsun REST API.

Upsun, formerly Platform.sh, is a container-based Cloud Application Platform. Our main API is simply Git. With a single `git push` and a couple of YAML files in your repository you can deploy an arbitrarily complex cluster. Every Project can have multiple applications (PHP, Node.js, Python, Ruby, Go, etc.) and managed, automatically provisioned services (databases, message queues, etc.).

Each project also comes with multiple concurrent live staging/development Environments. These ephemeral development environments are automatically created every time you push a new branch or create a pull request, and each has a full copy of the data of its parent branch, which is created on-the-fly in seconds.

Our Git implementation supports integrations with third party Git providers such as GitHub, Bitbucket, or GitLab, allowing you to simply integrate Upsun into your existing workflow.

## Using the REST API

In addition to the Git API, we also offer a REST API that allows you to manage every aspect of the platform, from managing projects and environments, to accessing accounts and subscriptions, to creating robust workflows and integrations with your CI systems and internal services.

These API docs are generated from a standard **OpenAPI (Swagger)** Specification document which you can find here in [JSON](https://meta.upsun.com/openapi-spec) format.

This RESTful API consumes and produces HAL-style JSON over HTTPS, and any REST library can be used to access it.

In order to use the API you will first need to have an <a class="link" href="https://auth.upsun.com/register/">Upsun account</a> and [create an API Token](/api/rest/authentication).

<OpenApiIntroduction />