# User Guide ```{admonition} Backwards Compatibility and Deprecations :class: info BayBE is in a constant state of development. As part of this, interfaces and objects might change in ways breaking existing code. We aspire to provide backwards **support for deprecated code of the last three minor versions**. After this time, old code will generally be removed. Both the moment of deprecation and full removal (deprecation expiration) will be noted in the [changelog](/misc/changelog_link). ``` The most commonly used interface BayBE provides is the central [`Campaign`](baybe.campaign.Campaign) object, which suggests new measurements and administers the current state of your experimental operation. The diagram below explains how the [`Campaign`](baybe.campaign.Campaign) can be used to perform the bayesian optimization loop, how it can be configured and how the results can be post-analysed. ```{image} ../_static/api_overview_dark.svg :align: center :class: only-dark ``` ```{image} ../_static/api_overview_light.svg :align: center :class: only-light ``` Detailed examples of how to use individual API components can be found below: ```{toctree} Getting Recommendations Campaigns Active Learning Asynchronous Workflows Constraints Environment Vars Insights Objectives Parameters Recommenders Search Spaces Serialization Simulation Surrogates Targets Transformations Transfer Learning Utilities ```