Developers

Build your own apps inside the classroom.

Built for schools, tutoring companies and edtech teams with developers. Custom Apps are web apps you build and host that run inside a Space. Our @pncl/mario library keeps state in sync for everyone in the room, so the whole class uses your app together.

Talk to us Read the docs

Want developer access? Email support@pencilspaces.com and we’ll set you up.

Your appflashcards.tsx

import { MarioClient } from "@pncl/mario";

const mario = new MarioClient("*");

// Everyone in the Space gets the same state

fromEvent(mario, "Sync").subscribe(render);

mario.sync({ card: 3, flipped: true });

Flashcards · Spanish 2

Flip a card, and everyone sees it flip.

How it works

You write the app. Mario keeps everyone in sync.

The @pncl/mario client library handles sign-in, real-time sync and storage, so you can focus on the activity.

In the libraryWhat it gives you

SyncShared stateSame for everyone, even after a disconnect

EventsBroadcast messagesInstant signals to everyone else

UsersSpaceUsersInfoWho’s here, with names and pictures

Pencil Spaces’ own polls, timer and YouTube player are built the same way.

Ideas

What your team could build.

Anything that runs in a browser can run in a Space. A few starting points:

Sync→Everyone

Shared flashcards

Keep the deck and the current card in shared state, so the whole class moves together.

Event→Everyone

Live check-ins

Send a quick prompt to everyone in the room and collect answers as they come in.

SpaceUsersInfo→Your app

Turn-taking games

Use who’s in the Space, with names and pictures, to run turns and teams.

Get started

From idea to classroom in three steps.

You build and host the app. We review it and add it to your institution’s Spaces.

Get developer access.

Email support@pencilspaces.com. We’ll enable you on our staging environment.

Build and test.

Build with any web stack and @pncl/mario, then import your local app into a staging Space to test it.

Ship it.

Host it anywhere and send us its name, a short subtitle, an icon and its URLs. After a security review, it appears under Your institution’s apps.

Read the docs See the example app

FAQ

Questions, answered.

Who can use my app?

Your institution. Once approved, it appears in the App Library under Your institution’s apps, in Spaces your institution owns.

What can I build it with?

Any web stack. The example app uses React and Vite, and plain JavaScript works too.

Where is it hosted?

Wherever you like, such as Firebase Hosting. You send us the URL.

Is there a review?

Yes. We do a security review before an app goes live in production.

Are events stored?

No. Events are instant messages and aren’t replayed. Use Sync for anything that needs to persist.

How is student data protected?

Pencil Spaces is FERPA, COPPA, GDPR and SOC 2 Type II compliant, and ISO 27001 certified.

Get started

Put your own tools in the classroom.

Tell us what you want to build, and we’ll get you set up.

Have an idea

Talk it through with us.

Book a call and we’ll help you scope your app and how it fits in a Space.

Talk to us

Ready to build

Start with the docs.

Read the guide, clone the example app, and email support for developer access.

Custom Apps docs Example app