Flag management in the VS Code extension

The VS Code extension lets you create, toggle, edit, and manage feature flags without leaving your editor.

Toggling flags

You can toggle a feature flag on or off from multiple places:

• CodeLens — Click the toggle action above a flag call in your code
• Right-click context menu — Right-click on a flag key string and select the toggle option
• Sidebar Flags tab — Click the toggle next to any flag in the list

A confirmation dialog appears before the change is applied to prevent accidental toggles. The change takes effect in PostHog immediately.

Editing rollout and variants

From the flag detail panel (accessible via PostHog: Show Flag Detail or clicking a flag in the sidebar), you can edit:

• Rollout percentage — Adjust the percentage of users who see the flag
• Variant configuration — Modify variant names, weights, and distribution
• Payloads — Update the JSON payload associated with each variant

Changes are saved directly to PostHog.

Creating flags from unrecognized keys

When the extension detects a flag key in your code that doesn't exist in your PostHog project, it shows a yellow underline warning. Hover over the warning to see a quick-fix action:

1. Click Create Feature Flag in the quick-fix menu
2. The extension creates the flag in PostHog using the key from your code
3. The warning disappears after the next sync

This lets you write code with new flags first and create them in PostHog without switching context.

Generating TypeScript types

The extension can generate TypeScript types from your feature flag payload configurations, giving you type safety when working with flag values.

All flags at once

Run PostHog: Generate Flag Types from the command palette to generate types for all flags in your project that have payload schemas defined.

Individual flags

Right-click on a flag key in your code and select PostHog: Generate Type to generate a type for just that flag's payload.

The generated types reflect the structure of your flag payloads as configured in PostHog.

Wrapping code in flag checks

Select a block of code, then use the context menu or command palette to wrap it in a feature flag check. The extension inserts the appropriate isFeatureEnabled() or getFeatureFlag() call around your selection, prompting you to choose which flag to use.

Other flag actions