# Versioning

> For the complete machine-readable documentation index, see [llms.txt](https://apidocs.chargebee.com/llms.txt).


The Chargebee API has two major versions: v1 and v2. Use the toggle at the top of the page to switch between these versions.

## Checking the API version

There are three ways to know the API version you're using:

-   **Endpoints**: The version of the API can be seen in the API endpoint path: For v2 the path begins with `/api/v2` whereas for v1, it begins with `/api/v1`.
-   **Client library**: The API version used can be found assigned to the `const` named `APIVersion` in the file `environment.{extension}`. Moreover, if you know the version of the library, you can find the compatible API versions listed in [the readme](https://github.com/chargebee/chargebee-go#readme).
-   **Webhooks**: In webhook payloads, the API version can be found in the value of the attribute [`api_version`](/docs/api/events#event_api_version). The schema of the payload is determined by the API version.

**Note**

Ensure that you do not upgrade the SDK to version that is not compatible with your API version. See [the readme](https://github.com/chargebee/chargebee-go#readme) for compatibility information.

## Backward compatible changes

Chargebee considers the following changes as backward compatible:

-   Adding new API resources.
-   Adding new attributes to existing API resources.
-   Changing the order of attributes in existing API responses.
-   Adding new endpoints.
-   Adding new optional input parameters to existing endpoints.
-   Adding new event types.