browser-extension-builder

Create a manifest.json with manifest_version 3, declare permissions like storage and activeTab, and register your popup, content scripts, and background service worker. Organize the project into popup, content, background, options, and icons directories.

Content scripts communicate with popups through the background service worker using chrome.runtime.onMessage listeners and sendResponse callbacks. Return true from the listener to keep the message channel open for asynchronous responses.

chrome.storage.local stores up to 5MB on the local device, while chrome.storage.sync is limited to 100KB total with 8KB per item but syncs across the user's signed-in devices. Use sync for small settings and local for larger data.

Manifest V3 service workers are terminated when idle, unlike persistent background pages in MV2. Keep background logic minimal, use chrome.alarms for periodic tasks, and offload heavy work to content scripts.

Request only the minimum permissions needed, such as storage and activeTab, since broad permissions reduce installs and risk store rejection. Use optional permissions and request them at the time of use with an explanation in the description.