Source: https://databento.com/docs/api-historical/basics/versioning


### Versioning

Our historical and live APIs and their client libraries adopt `MAJOR.MINOR.PATCH` format
for version numbers. These version numbers conform to
[semantic versioning](https://semver.org). We are using major version `0` for
initial development, where our API is not considered stable.

Once we release major version `1`, our public API will be stable. This means that
you will be able to upgrade minor or patch versions to pick up new functionality,
without breaking your integration.

Starting with major versions after `1`, we will provide support for previous
versions for one year after the date of the subsequent major release.
For example, if version `2.0.0` is released on January 1, 2024, then all versions
`1.x.y` of the API and client libraries will be deprecated. However, they will
remain supported until January 1, 2025.

We may introduce backwards-compatible changes between minor versions in the form of:

- New data [encodings](https://databento.com/docs/api-historical/basics/encodings.md)
- Additional fields to existing data [schemas](https://databento.com/docs/api-historical/basics/schemas-and-conventions.md)
- Additional batch download [customizations](https://databento.com/docs/api-historical/batch.md)

Our [Release notes](https://databento.com/docs/release-notes/release-notes-python.md) will contain information about
both breaking and backwards-compatible changes in each release.

Our API and official client libraries are kept in sync with same-day releases
for major versions. For instance, `1.x.y` of the C++ client
library will use the same functionality found in any `1.x.y` version of the Python client.

Related: [Release notes](https://databento.com/docs/release-notes/release-notes-python.md).