> ## Documentation Index
> Fetch the complete documentation index at: https://docs.flipt.io/llms.txt
> Use this file to discover all available pages before exploring further.

# API Overview

> Learn how to interact with the Flipt REST API to manage flags, segments, rules, and evaluate feature flags programmatically.

Flipt's API is the primary way to interact with Flipt Open Source outside of the UI. It's used to create, update, and delete entities such as namespaces, flags, segments, rules, and also to evaluate flags.

The Flipt UI is completely backed by this same API. This means that anything that can be done in the Flipt UI can also be done via the REST API.

The latest version of the [management REST API](https://raw.githubusercontent.com/flipt-io/flipt/refs/heads/v2/rpc/v2/environments/openapi.yaml) and [evaluation REST API](https://raw.githubusercontent.com/flipt-io/flipt/refs/heads/v2/rpc/v2/evaluation/openapi.yaml) are documented using the OpenAPI v3 specification.