---
title: Feature Flags module
description: Rollout rules, cohort targeting, kill switches, and SDK-side local evaluation.
section: Modules
order: 11
updatedAt: 2026-05-07
slug: modules/feature-flags
---
# Feature Flags module

The feature-flags module manages flag definitions, rollout percentages, cohort gates, kill switches, and transactional history.

## Evaluation

SDK helpers evaluate locally using the same rule as the server:

1. Killed flags return false.
2. Disabled flags return false.
3. Non-empty cohort dimensions must match the evaluation context.
4. Percentage rollouts use SHA-256 of `flagKey:userId`, bucketed into 0-99.

## API

| Endpoint | Returns |
| --- | --- |
| `GET /api/flags/status` | Module health |
| `GET /api/flags?project_id=...` | Flags for a project |
| `GET /api/flags/{key}?project_id=...` | A single flag |
| `GET /api/flags/stream?project_id=...` | Server-sent update stream |

Product page: [Feature Flags](/product/modules/feature-flags).