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Feature Flags

Control available features during development via features.json or a cloud-based feature flag service.

Provider Selection​

The feature gate system supports two providers, selected via the FEATURE_GATE_PROVIDER environment variable:

  • server (default): File-based feature flags using features.json in the project root. Intended for on-premise Tableau Server deployments.
  • cloud: Cloud-based feature flag service. Currently returns false for all features.

Configuration​

Server Provider (File-Based)​

Create a features.json file in the project root:

{
  "mcpapps": true,
  "pulse": true,
  "oauth-embedded": false
}

Location: features.json in project root (no environment variable needed)

Usage in Code​

import { getFeatureGate } from './features/init.js';

if (getFeatureGate().isFeatureEnabled('mcpapps')) {
  // MCP Apps logic here
}

Behavior​

  • Lazy initialization: Feature gate loads config on first access
  • Features not listed: Disabled by default
  • Invalid JSON or missing file: All features disabled, error logged
  • Partial validation: Invalid key-value pairs are skipped with a warning, valid pairs are loaded

Adding a New Feature Flag​

  1. Add the feature name and default value to features.json (for server provider)
  2. Use getFeatureGate().isFeatureEnabled('your-feature') in your code
  3. No code changes needed to enable/disable - just update the JSON file (server provider) or the cloud service configuration (cloud provider)