Flag Engine Overview
The FeatureSignals Flag Engine is a Next.js web application that provides a visual interface for managing feature flags, environments, team members, and more.
Accessing the Flag Engine
After starting FeatureSignals, open https://app.featuresignals.com.
Navigation
The sidebar provides access to all major sections:
| Section | Description |
|---|---|
| Flags | Create, view, and manage feature flags with category and status tracking |
| Segments | Define reusable user segments |
| Environments | View and manage deployment environments |
| Eval Metrics | Monitor flag evaluation statistics |
| Flag Health | Identify stale or problematic flags with category-aware thresholds |
| Env Comparison | Compare and sync flag states across environments |
| Target Inspector | See what a specific user experiences across all flags |
| Target Comparison | Compare flag evaluations between two users side-by-side |
| Usage Insights | View flag value distributions (true/false percentages) |
| Webhooks | Configure event notifications |
| Audit Log | Review change history |
| Team | Manage organization members and roles |
| Approvals | Review and approve pending changes |
| Settings | API keys and project configuration |
Key Features
Flag Management
- Create flags with different types (boolean, string, number, JSON, A/B)
- Classify flags by category (release, experiment, ops, permission) and track lifecycle status
- Toggle flags per environment
- Configure targeting rules with a visual editor
- Set percentage rollouts
- Configure A/B experiment variants
- Manage mutual exclusion groups
- Set up prerequisite dependencies
- Schedule enable/disable times
- Compare and sync flag states across environments
- Kill switch for emergency disable
Flag Intelligence
- Target Inspector — See all flag evaluations for a specific user
- Target Comparison — Compare what two different users experience
- Usage Insights — View value distribution percentages per flag
Real-Time Updates
The Flag Engine uses polling to keep flag states current. Changes made via API or by other team members appear automatically.
Multi-Environment View
The flag detail page shows per-environment configuration in tabs, making it easy to compare dev, staging, and production settings side by side.