# Receiving health data updates (events)
Terra API simplifies health & fitness data syncing: once you connect a user, Terra automatically manages **token** **refreshes**, **authentication** **updates**, and delivers all **health** **and** **fitness** **data** directly to your Webhook/DB as soon as it’s available.
Requesting data is not required unless you need to backfill historical data, to debug, or as a fallback. This lets you focus on your app while Terra handles the data flow and reliability.
In this section, you will learn about:
1. [**Health Data Events**](#data-events)**:** sent to your destination when new data is available on the user's account.
2. [**How to test your Destination**](https://dashboard.tryterra.co/dashboard/generate)**:** Terra sends [events](/introduction/core-concepts.md#event) to your [destination](/introduction/core-concepts.md#destination), learn how to test this.
3. [**Common errors and troubleshooting**](#common-errors-and-troubleshooting)**:** when not receiving expected data.
{% hint style="success" %}
### **Prerequisites**
In order to receive Data as **Events**, you'll need to:
1. [**API Key**:](https://dashboard.tryterra.co/) Obtain your API Key from your Terra Dashboard
2. [**Destination Configured**:](/health-and-fitness-api/integration-setup.md#set-up-your-data-sources-and-destinations) Set up a data destination where Terra will send event and data updates.
3. [**Data Sources Enabled**:](/health-and-fitness-api/integration-setup.md#set-up-your-data-sources-and-destinations) Enable the specific data sources your app requires (e.g., oura, garmin, etc).
4. **Connected at least a user.**
1. If not, then no worries, you can use the [Payload Simulator](https://dashboard.tryterra.co/dashboard/generate) to test sending data to your destination!
2. However, make sure to familiarize yourself with [Authentication Events](broken://pages/j6nBtfGYuTZY8Spl4Abk).
{% endhint %}
***
## 1. Types of Health Data Events
Whenever a [User](/reference/health-and-fitness-api/core-concepts.md#user) has new data available on the respective platform they use, Terra will send a Data Event to your **Data** **Destination**.
Data Events fall under one of the following categories:
(1) Activity: A tracked workout, with a defined start and end time.
Unique identifier (per [User](/reference/health-and-fitness-api/core-concepts.md#user)): `metadata.summary_id`
For example, an [End User](https://github.com/tryterra/gitbook-docs/blob/master/health-and-fitness-api/broken-reference/README.md) pressing **"start run"** on their watch, going for a 5k run, and pressing **"end run"**
See [GET activity](/reference/health-and-fitness-api/readme.md#activity) for the full Schema & descriptions of each field
(2) Daily: the total daily summary of the user's activity up to the point in time of the event
Unique identifier (per [User](/reference/health-and-fitness-api/core-concepts.md#user)): `metadata.start_time`
This can be the cumulative number of steps, calories burned, etc. `daily` payloads are always relevant to a given 24 hour period, defined by the `start_time` and `end_time` of the `metadata` key. When parsing, only consider the **date** part of the field, and ignore the time.
See [GET daily](/reference/health-and-fitness-api/readme.md#daily) for the full Schema & descriptions of each field
(3) Body: the recorded body metrics for the user for a given day
Unique identifier (per [User](/reference/health-and-fitness-api/core-concepts.md#user)): `metadata.start_time`
`body` payloads are always relevant to a given 24 hour period, defined by the `start_time` and `end_time` of the `metadata` key.
See [GET body](/reference/health-and-fitness-api/readme.md#body) for the full Schema & descriptions of each field
(4) Sleep: a tracked sleep session, with a defined start and end time.
Unique identifier (per [User](/reference/health-and-fitness-api/core-concepts.md#user)): `metadata.summary_id`
This can include time spent in bed while awake, if recorded by the wearable.
See [GET sleep](/reference/health-and-fitness-api/readme.md#sleep) for the full Schema, example, & descriptions of each field
(5) Menstruation: menstrual metrics for the user for a given day
Unique identifier (per [User](/reference/health-and-fitness-api/core-concepts.md#user)): `metadata.start_time`
E.g. the phase they're currently on, their blood flow for the day, etc. `menstruation` payloads are always relevant to a given 24 hour period, defined by the `start_time` and `end_time` of the `metadata` key.
See [GET menstruation](/reference/health-and-fitness-api/readme.md#menstruation) for the full Schema, example, & descriptions of each field
(6) Planned Workout: a step by step workout plan for the end user
Unique identifier (per [User](/reference/health-and-fitness-api/core-concepts.md#user)): `metadata.summary_id`
A planned workout, with a defined set of steps/reps/sets to be followed. For example, 15 min running at 7:00 pace, followed by 3x repetitions of 100m sprints with 45s jog at 8:00 min pace in between. See [here](/health-and-fitness-api/managing-user-health-data/write-data.md#writing-planned-workouts) for more info
You can find more details about these **Data Events** in the [Event Type](/reference/health-and-fitness-api/event-types.md) reference.
You can find all your received events (payloads) in:
* Your [Terra Dashboard > Payload History](https://dashboard.tryterra.co/dashboard/debug).
{% hint style="warning" %}
**Overwriting/Updating data**
* Whenever you receive an event for a [User](/reference/health-and-fitness-api/core-concepts.md#user) which constitutes a duplicate, based on the data type's unique identifier (detailed in each section below), the received data will always be a **superset** of any previous data received.
* This means you should always **overwrite** data stored on your end with the most up-to-date version.
* Depending on the event type, use the **unique** **identifier** for each payload to overwrite data appropriately upon receiving an update (e.g. `metadata.start_date`, `metadata.summary_id`, etc). These **unique** **identifiers** are found in the category descriptions listed above.
{% endhint %}
#### **Example of a Health & Fitness Payload**
Data Events will take the following form:
{% code title="ActivityPayload.json" lineNumbers="true" %}
```json
{
"type": "activity",
"data": [
{
"metadata": {
"type": 45,
"start_time": "2024-10-03T18:17:45.000000+08:00",
"city": null,
"name": "MEDITATION",
"state": null,
"upload_type": 1,
"country": null,
"summary_id": "f09554ca56fde426de5d7f9c34fc0e1e3ff015c2ae253b39",
"end_time": "2024-10-03T18:38:39.000000+08:00"
},
..... ommitted for brevity
}
],
"user": {
"reference_id": "2397",
"active": true,
"user_id": "9d5dc9eb-3e02-4b37-9a7b-b14b5a5a2b93",
"last_webhook_update": "2024-10-03T11:13:43.360227+00:00",
"created_at": null,
"scopes": "fitness.sleep.read,fitness.body.read,fitness.body_temperature.read,fitness.activity.read,fitness.blood_pressure.read,fitness.location.read,calendar.settings.readonly,fitness.reproductive_health.read,userinfo.email,user.birthday.read,user.gender.read,fitness.oxygen_saturation.read,fitness.heart_rate.read,userinfo.profile,fitness.nutrition.read,fitness.blood_glucose.read",
"provider": "GOOGLE"
},
"version": "2022-03-16"
}
```
{% endcode %}
## 2. How to test your Destination?
For testing out the different event types mentioned above, you may also use [the payload simulator](https://dashboard.tryterra.co/dashboard/generate) in the Terra Dashboard. See the tutorial below for a step by step guide.
{% embed url="" %}
## 3. FAQ: Common errors & troubleshooting
Found in [**Debugging FAQ.**](https://app.gitbook.com/o/FSHKsjH8Q1Ejnax0ajY6/s/VGMJVuZnZyOtvV4b53cY/~/changes/96/debugging-faq)
***
## ✅ Checklist
{% hint style="success" %}
### Receiving data Updates
1. **Set-up**: Have you tested that your destination can receive data payloads from Terra?
2. **Connect a User**: Have you connect a user via Terra? Have you received an Authentication Event?
3. **Receiving** **Data**: After completing an event (e.g. activity), did you receive a Data Event "Activity"?
If you didn't receive an expected payload after a long time, please refer to our [**Debugging FAQ**](https://app.gitbook.com/o/FSHKsjH8Q1Ejnax0ajY6/s/VGMJVuZnZyOtvV4b53cY/~/changes/96/debugging-faq) to ensure the user's data is synced properly.
{% endhint %}
---
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```
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