# Fundamentals

- [API and client libraries](/developer-documentation/fundamentals/api-and-client-libraries.md)
- [Search UI widgets](/developer-documentation/fundamentals/search-ui-widgets.md): Search.io comes with a set of easy to integrate search widgets. Learn how to customize the widgets.
- [Search results widget](/developer-documentation/fundamentals/search-ui-widgets/search-results-widget.md)
- [Search input widget](/developer-documentation/fundamentals/search-ui-widgets/search-input-widget.md)
- [Takeover Search Input Widget](/developer-documentation/fundamentals/search-ui-widgets/takeover-search-input-widget.md)
- [Configuration Objects](/developer-documentation/fundamentals/search-ui-widgets/configuration-objects.md)
- [Pipelines](/developer-documentation/fundamentals/pipelines.md)
- [Steps](/developer-documentation/fundamentals/pipelines/steps.md)
- [Record Pipelines](/developer-documentation/fundamentals/pipelines/record-pipelines.md)
- [Query pipelines](/developer-documentation/fundamentals/pipelines/query-pipelines.md)
- [Fundamental steps](/developer-documentation/fundamentals/pipelines/fundamental-steps.md)
- [Variable manipulation](/developer-documentation/fundamentals/pipelines/variable-manipulation.md)