Plasmo Extension Architect

When to Use

• Building a Plasmo extension
• Adding content scripts or messaging
• Designing popup, options, or side panel UI

Core Patterns

• Keep service worker stateless; persist in storage.
• Use explicit message types and typed payloads.
• Gate content script injection and make it idempotent.
• Keep UI small and fast; use storage sync for prefs.

Typical Surfaces

• background.ts

• content-script.ts

• popup.tsx

• options.tsx

Security

• Minimize host permissions.
• Validate messages.
• Avoid storing secrets in the DOM.

Build and Dev

• Use

  plasmo dev

  for local development.
• Keep manifest permissions aligned with features.
• Validate MV3 constraints for long-running tasks.