Data is sent to the tracker as track events. The [Tracking API](🔗) is used for **recording** track events, whereas the [Profile Store API](🔗) is used for **querying** track events. The Profile Store API is separated from the Tracking API so that it has independent processing loads.

## Authentication

Use the Authorization header for authentication with a value in the following format: epi-single key; it contains the subscription key that is passed to the tracker with each request.

## Endpoints

Post is the default and preferable method to track, and allows sending additional payload data.

You can track and send single or batch messages to and from the Tracking API. Batch tracking works the same way as single tracking, and takes a list of track events. You can have up to 100 track events in each batch, with a limit of 256KB for each track event.

Endpoint for tracking API single track event is POST https://example.com/api/v1.0/Track.

Endpoint for tracking many events in batches is POST https://example.com/api/v1.0/TrackBulk.