What is Arc CMS

Arc CMS is an open-source content management system that runs on your own Firebase project. You use it to build a website, or you copy it and build your own app on top of it.

In plain words

Arc CMS gives you an admin area where you define content types, write and publish content, design how it looks with HTML templates, collect sign-ups and send email. Everything it stores lives in your Firebase project: Firestore for data, Firebase Authentication for accounts, Cloud Storage for files and Cloud Functions for the work that has to happen on a server.

When you publish, Cloud Functions write the page as a static HTML file to Firebase Hosting. Visitors get plain, fast pages; the admin area and the member area are an Angular app served from the same site.

What you get

Most capabilities are always on. Eleven switchable features can be turned on or off per app in src/custom/features.ts: ten are on unless you turn them off, and the installable app (pwa) is off until you turn it on (see Feature ids). The last column says which switch a capability belongs to.

Capability	What it does	Switch
Content	Your own content types with their own fields, drafts, a publish queue and bulk import, plus ready-made About, Contact and policy pages.	`content`
Templates	Plain HTML and CSS files that decide how lists and single items look.	Part of `content`
Media	A media library for images, stored at several sizes and converted to WebP on upload.	Always on
Authors and tags	Author profiles and tags for grouping content.	Part of `content`
Search	Site search for visitors and search inside the admin area.	`search`
SEO and discoverability	Meta tags, sitemap, robots file, RSS feed and `llms.txt`, written for you.	`seo`
Languages	Content in more than one language, and an admin area in more than one language.	Always on
Signup forms	Waitlists and signup forms, with a verification code and a welcome email.	`forms` (needs `audience`)
Contact form	A contact form on your site, with a Messages inbox in the admin.	`contact`
Audience	Contacts, lists, tags and fields for everyone who signed up.	`audience`
App audience	The users of an app as a live audience you can email.	Part of `audience`
Email engine	Sending through Gmail, SMTP or Resend, with logs and a shared brand kit.	Always on
Email marketing	Broadcasts, drip series and announcements to lists and audiences.	`email-marketing` (needs `audience`)
Automations	Rules that send an email, add a notification or change list membership when something happens.	Always on
SMS	Text messages, such as sign-in codes.	`sms`
Sign-in methods	Email and password, Google and phone sign-in.	Always on; phone sign-in is part of `sms`
Payments	Checkout, plans and payment events through Dodo Payments.	`payments`
Premium entitlements	Premium access and credits that follow from payments.	Part of `payments`
Users and roles	Accounts, roles and who may do what.	Always on
Installable app (PWA)	An app people can install on their phone.	`pwa` (off by default)
Feedback button	A button that sends feedback with a screenshot to the admins.	Core, with its own switch on the Feedback page (off by default)
Notifications	Notifications inside the admin and member areas.	Always on
Analytics	A Google Analytics connection and dashboard.	Always on
Banners	A site-wide message banner and a site usage banner.	Always on
Data import and export	Exporting and importing your data.	`data`

The full list, with what each feature needs, is in All features.

What it is built with

Layer	Technology
Framework	AnalogJS 2 (full-stack Angular) on Angular 21
Interface	Angular Material and Bootstrap 5
State	NgRx Signals
Editor	TipTap 3
Build and dev server	Vite 7
Backend	Firebase: Firestore, Authentication, Cloud Storage, Cloud Functions (Node 22), Hosting
Tests	Vitest

There is no server of your own to run. The build ships the app as static files. Your home page and content are published as static pages, and all server work happens in Cloud Functions. See Architecture for how the parts fit.

Who it is for

Developers who know web development and want a content site, or an app with sign-in, email and payments, without building those parts again.
Teams that run the site: editors and admins who write content, manage sign-ups and send email from the admin area, without touching code.

What it is not

Not a hosted service. You run it on your own Firebase project and pay Google for what it uses.
Not a drag-and-drop page builder. Pages are shaped by HTML templates that a developer writes once.
Not for another backend. It is built on Firebase and needs a Firebase project; it does not run on another database or host.
Not something you edit freely in an app. An app built on a copy keeps its own code in the custom space and leaves the Arc CMS files alone, so updates merge cleanly (see Core and custom).