MV3, minimal permissions, two stores

The AI extension builder for the missing button

Some products are a button that lives in the toolbar: clean this page, watch this price, save this thing. Describe the moment it acts — the builder handles MV3, permissions, the popup, the icons, and the path to both stores.

Start building free Try a prompt on the homepage

Reading & researchPage monitorsProductivityPrivacy toolsShopping helpersDeveloper utilities

The fastest idea-to-shipped path

Real extensions, store-ready by construction

Extensions live or die on store review — and store review cares about permissions, manifests and privacy claims. The builder treats those as first-class, not paperwork.

Built right

MV3 without reading a single migration doc

The current manifest standard both stores require, the service-worker background model it implies, and a popup/options UI styled like a product — from a plain-language description of the behavior.

Manifest V3, correct from generation
Popup, content scripts or background watcher — shaped by your description
Icon family at every size the stores demand

Plainread — a decluttered reading mode extension

Minimal permissions

Ask for less, pass review faster

Over-asking is the top review trap and an accidental privacy claim. The build requests only the permissions the behavior needs — and every request comes with a written justification for the listing.

Permissions derived from behavior, not templates
Per-permission justifications generated
Privacy answers checked against the actual code

Two stores, one click each

Chrome and Firefox, through your accounts

The listing kit — screenshots, copy, permission justifications, a published privacy policy — generates from the build. Firefox ships fully hands-off via API; Chrome gets console autofill down to the last checkbox.

Firefox Add-ons: upload to listing with no console visit
Chrome Web Store: kit + autofill, you click publish
Re-ships bump versions and update listings automatically

Watchtower — a page-change monitor extension

How it works

From itch to installed

Describe the moment it acts; the shape follows.

Describe the action

“Strips clutter from articles when I click it” — the trigger moment decides the architecture.

Approve the plan

Popup vs content script vs background watcher, and the minimal permission set, proposed upfront.

Watch it build

UI, logic, manifest, icons. Preview in chat; load it unpacked for a real-browser test.

Verification runs

Functional checks, code review, security — and permission minimality is part of the bar.

Ship to stores

The kit generates; Firefox ships via API, Chrome autofills. Your developer accounts, your listing.

After the build

After it ships

Store distribution has its own afterlife: reviews, updates, analytics. Covered.

Store status tracing

Submissions land in your Shipped hub with per-store state; store analytics snapshots (installs, listing performance) collect daily.

Painless updates

Iterate in the chat; re-ships rebuild the zip, bump the version past the published one automatically, and refresh the listing.

A landing page in minutes

Pair the extension with a website build for SEO reach the stores don't give you — same platform, one more sentence.

Honest privacy forever

Privacy declarations stay code-checked on every re-ship — your listing never drifts from what the code does.

Built in

Everything the extension builder ships with

Both store formats

One build, Chrome and Firefox zips — quirks per store handled.

Local testing

Load-unpacked instructions right on the build card for a real browser check.

The listing kit

Screenshots, promo tiles, copy, justifications, privacy page — generated, editable, never overwritten once you touch it.

Options & storage

Settings pages and synced storage wired like a real product.

Versions & rollback

Every iteration is a version; any version re-ships.

Verification record

The audit trail per version, permissions included.

Ideas

Extensions people ship

A decluttered reading modeA page-change monitor with badgesA privacy inspectorA price-drop watcherA tab organizerA form-filling assistant for your team

FAQ

extension builder FAQs

Which browsers are supported?+

Chrome (and Chromium family) and Firefox — one build produces both store-ready zips. Both ship through your own developer accounts.

How fast is store review?+

Firefox typically lists quickly; Chrome's queue runs days. Neither is under anyone's control but the store's — plan launches accordingly.

Is the build checked before I get it?+

Yes — every build runs a verify → fix → re-verify loop (code review, security audit, links/SEO, accessibility, conformance, an in-browser run) and the loop keeps iterating until the verifiers find nothing left to fix. Details: How builds verify themselves.

Why do permissions matter so much?+

Stores review them, users fear them, and every permission is a privacy claim. The builder requests the minimum and writes the justification for each — see the extension manual.

Can I test before shipping?+

Yes — preview in the chat, then load the zip unpacked (developer mode) for a real-browser test before any store sees it.

Do I own what I build?+

Yes — prompts, content, and the built product are yours, including commercial use (Terms §5). Publishing and store accounts are in your name, not ours.

Can I try it for free?+

Yes — the free plan includes every builder and the full verification chain, with a monthly credit allowance and no card at signup. See what the free plan actually includes.

More answers in the full Q&A and the handbook series.