# Get started with Celonis APIs

Every Celonis customer has access to a range of APIs that provide access to ingest data into Celonis, consume process intelligence from Celonis, and administer the Celonis team.

## Reading this documentation

Each API endpoint in this documentation is described using several parts:

- **The HTTP method.**  Includes  `GET`,  `POST`,  `PUT`,  `PATCH`,  and `DELETE`.
- **The base path.**  All URLs referenced in the documentation have the base path `https://{team_domain}.{realm}.celonis.cloud`. This base path goes *before* the endpoint path.
- **The endpoint path.**  The endpoint path is resource-oriented. For example, `/intelligence/api/knowledge-models/{km-id}/records/{record-id}`.
- **Required parameters.**  These parameters must be included in a request. In the example above,  `{km-id}`  and  `{record-id}`  are required parameters representing the resources to be accessed. In a request, you will replace the placeholders with real values.
- **Optional parameters.**  These parameters can be included in a request to customize the query. Query parameters are added to the end of the URL with  [query string encoding](https://en.wikipedia.org/wiki/Query_string).
- **A token scope.**  If an API endpoint requires a [token scope](/celonis-apis/auth#authorization) that the default access token does not have, the token scope will be listed instead.
- **Code examples.**  Each endpoint has example requests in [cURL](http://curl.haxx.se/) format and in the following programming languages: [JavaScript](https://www.w3schools.com/js/default.asp), [Java](https://www.w3schools.com/java/default.asp), [Python](https://www.w3schools.com/python/default.asp), and [PHP](https://www.w3schools.com/php/default.asp).
- **API Essentials.** Features applicable to all APIs such as Authentication/Authorization, Pagination, Quotas and Rate limiting, and Error Message Standardization are handled in the [API Essentials](/celonis-apis/get-started-with-celonis-apis#api-essentials) section below.


## API Essentials

### [Install a REST Client](/celonis-apis/rest-client)

How to [install a REST client](/celonis-apis/rest-client) to access Celonis APIs.

### [Authentication/Authorization](/celonis-apis/auth)

The user security and permissions [framework](/celonis-apis/auth) to access Celonis platform via Celonis APIs.

### [Result Pagination](/celonis-apis/pagination)

When you call a Celonis API method to retrieve a collection of objects, they are usually returned in portions. Check out the details on [pagination in API methods](/celonis-apis/pagination), including how to use them and which methods follow the pattern.

### [Quotas and Rate Limiting](/celonis-apis/rate-limiting)

Celonis Platform features and APIs rely on rate limits to help provide a predictable experience for users. The details of how and when rate limiting works differs between API families and features. This [article](/celonis-apis/rate-limiting) gives an overview of the rate limits you're likely to encounter for Celonis API families and notes how the limits apply to each family.

### [Common Error Messages](/celonis-apis/api-reference/common-error-catalog)

This article identifies some of the error codes and messages that Celonis APIs return. Specifically, [the errors listed here](/celonis-apis/api-reference/common-error-catalog) are in the global, or default, domain for Celonis APIs. Many APIs also define their own domains, which identify API-specific errors that are not in the global domain.