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

# Sources

> Manage hosted extractor sources in Cognite Data Fusion (CDF).

Sources define where a hosted extractor reads data from. Each source specifies the connection details for an external system. You create and configure sources, then reference them via `sourceId` when creating jobs.

## What sources are

A source is a configuration object that describes how to connect to an external system. It includes connection parameters such as host, port, credentials, and protocol-specific settings. Once created, a source can be reused by multiple jobs.

## Supported source types

| Type          | Description               |
| ------------- | ------------------------- |
| `mqtt3`       | MQTT v3 broker            |
| `mqtt5`       | MQTT v5 broker            |
| `eventhub`    | Azure Event Hub           |
| `rest`        | HTTP/HTTPS REST API       |
| `kafka`       | Kafka broker              |
| `mqtt_broker` | MQTT broker hosted by CDF |

Each type has its own configuration schema, and credentials are included as part of the source configuration.

## Creating and managing sources

You create a source by specifying its `type`, `externalId`, and the required connection parameters for that type. After creation, you reference the source in a job via `sourceId`. You can update a source to change its configuration or credentials, and delete it when it is no longer in use.