Applicability
When to Use
✓When decoupling deployment from release
✓When testing features with specific user segments
✓When you need instant kill switches for new features
Overview
How It Works
Feature flags let you deploy code that is dormant until the flag is enabled. Using LaunchDarkly or Statsig MCP Server, the agent checks flag status before executing new functionality. This decouples deployment (shipping code) from release (enabling for users).
Flags can target specific users, percentage rollouts, or segments. The MCP agent evaluates flags in real-time and routes code execution accordingly. This enables A/B testing, gradual rollouts, and instant rollbacks without code deployment.
Implementation
Code Example
typescript
async function handleRequest(user, request) {
const flags = await launchDarkly.evaluate({ user: { key: user.id, email: user.email, plan: user.plan } });
if (flags["new-search-algorithm"]) {
return await newSearchAlgorithm(request);
} else {
return await legacySearch(request);
}
}
// Percentage rollout check
async function isFeatureEnabled(flagKey, userId) {
return await launchDarkly.variation({
flagKey,
user: { key: userId },
defaultValue: false
});
}Quick Info
Categorydeployment
ComplexityEasy