Announcing Extension.js 3.0.0

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What ships in v3

• Stronger cross-browser workflows across Chrome, Edge, and Firefox with one command surface.
• Expanded template experience for modern stacks including TypeScript, React, Vue, Svelte, and Preact.
• Improved development update behavior with clearer hot module replacement (HMR), hard-reload, and restart-required boundaries.
• Better production confidence workflows across troubleshooting, security checks, performance checks, continuous integration (CI) templates, and Playwright end-to-end (E2E) testing.
• More predictable project configuration through extension.config.js and browser-aware build output.
• A cleaner documentation and homepage experience designed for faster onboarding and lower cognitive load.

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The day-one flow is simpler

1. create to scaffold.
2. dev to iterate quickly.
3. build to generate production artifacts.
4. start or preview to validate production behavior.

npx extension@latest create my-extension --template=new-typescript
cd my-extension
pnpm dev
pnpm build

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Better for teams, not just demos

• Typed templates and framework-first baselines reduce setup drift.
• Browser-targeted builds and flags make compatibility checks explicit.
• Workflow docs now map directly to release confidence tasks.
• The standard delivery flow now includes security and performance guidance.

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Who this release is for

• You are migrating from custom extension build scripts.
• You are moving from app development to extension development.
• You are standardizing extension developer experience across multiple repos and contributors.

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Upgrade notes

• update the package to latest,
• prefer canonical template slugs (new-react, new-typescript, new-vue, etc.),
• keep your command flow aligned with create → dev → build.

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Thanks