---

Necode is a highly modular educational programming environment for collaborative in-class activities. It has several features which sets it apart from existing solutions:

• Peer-to-peer communication: Most collaborative programming environments operate by having each user send data to a server, and then the server sends their data to each other user they are connected to. Necode bypasses this, only using a server for initial linking and signalling, and then having users talk directly through peer-to-peer connections. This makes Necode require significantly fewer server resources.
• Client-side compuatation: All execution of user code is performed client-side rather than on a server in the cloud. This has some drawbacks such as making it significantly more challenging to implement support for many languages. However, not only does this approach significantly reduce the necessary server resources to run Necode, but it also enables use of the built-in browser development tools (such as for reading logs or debugging JavaScript) and allows code in some languages to directly interact with the DOM.
• Communication with non-code artifacts: Usually when environments advertise collaborative programming, they are referring to shared editors, one kind of collaborative programming in which each user's edits to their code gets propagated to all of the other users. Necode abstracts this, allowing not just code artifacts, but any artifacts to be shared, and to be shared asymmetrically with only certain individuals rather than everyone.
• Plugin API: New language support, activities (i.e. frontend experiences), and RTC-linking policies can be developed by third-party developers and dynamically plugged into existing Necode instances.

Screenshots

Papers

• MQP Report (2022) (no peer review)
• Master's Thesis (2023) (no peer review)

Offshoot projects

Necode has spawned a number of projects which, though originally designed for use in Necode, exist independently from it. These include:

• mike-language (plus mike-vscode): a programming language for defining simple event-based programs with serializable state.
• use-dnd: a minimal library for using HTML5 drag-and-drop in React, based on react-dnd.
• scheme-js: a library for using a WASM build of Chez Scheme on the web.

How to run

Pre-requisites

There are a few things you need to run Necode

• Node.js 16+
• A PostgreSQL database with an appropriate user role attached
• SSL Certificates (not necessary for local development)

Necode uses PNPM. For detailed instructions on how to install PNPM, see the docs. However, for most users who have Node.js 16+ installed, you will want to run one of the following commands:

# either
corepack enable
# or
npm install -g pnpm

Once PNPM is installed, to install the necessary dependencies for Necode, run:

pnpm install

Then you will need to configure .env. Copy template.env to .env, and fill out the fields.

After doing so, to populate your database with the necessary tables, run:

pnpm db:migrate:dev

Development

To start up the Necode frontend and the websocket server in development mode, run:

pnpm dev

This will also watch for changes and automatically recompile and reload when files are changed.

If you wish to serve the Next.js server over HTTPS, also run:

pnpm ssl-proxy

It will now also be available at https://localhost:3010/. Note that without valid SSL certificates, you may have to bypass browser security warnings, including for the websocket server. To bypass websocket security warnings, go to https://localhost:3001/socket.io/.

To log in to the development environment, click "Sign In" and log in with a username and the DEV_PASSWORD you defined in .env. To create an administrator account, either follow the instructions in the "First-Time Setup" section, or run:

pnpx turbo db:seed

Then log in with the username admin.

Production

Necode Next.js

Necode uses Vercel in production, and does not have pre-packaged instructions for running it on your own infrastructure. However, running pnpm vercel-build in the root directory will generate a .next folder in apps/necode that can be used even without Vercel. This page has some details on how to accomplish this.

Necode Websocket Server

Necode also has a required websocket server, which can be built with wsserver:build. This cannot be hosted on Vercel, and should be run on a server somewhere. pm2 is a decent option for daemonizing it. It will also require a copy of the .env file in your working directory (process.cwd()), which may or may not be the same directory that the build is contained in.

First-Time Setup

If you are in production and using Azure Active Directory, see "Using Azure Active Directory" below. If you are working in a development environment, you can log in with any username using the password you defined with the DEV_PASSWORD environment variable.

You will now need to make a manual database change. While you can do this through psql or pgAdmin, it may be easier to use Prisma Studio:

1. Navigate to the packages/database directory and run pnpm studio. Open the link it puts in the console.
2. Click "User".
3. Find the record for the user you just logged in as. Scroll to the right until you see a column called "rights".
4. Double click the "rights" field on the record for your user and change the value to "Admin".
5. Click "Save 1 change" on the top.

Now navigate to /admin/createClassroom. You should see a field asking for a display name. If you see an error instead, refresh. Enter a display name for the classroom you are about to create. For example, "Test Classroom".

Once you've chosen a display name, press "Create" and wait a few moments. It may take some time to load the newly created classroom, especially in a development environment. Eventually you should come to the manage classroom page. From here you can create activities and manage your classroom.

Using Azure Active Directory

To set up azure active directory, you will first need to create an application. This page has some instructions on getting this set up: https://learn.microsoft.com/en-us/azure/active-directory/develop/quickstart-web-app-nodejs-msal-sign-in The redirect URIs are:

{protocol}://{origin}/api/auth/signin/wpi
{protocol}://{origin}/api/auth/callback/wpi

To link this new application Necode, you will need to make some direct database changes. The easiest way to do this is through Prisma Studio.

1. Navigate to the packages/database directory and run pnpm studio. Open the link it puts in the console.
2. Click "SystemConfiguration".
3. Add the following four records with the appropriate values:

| key                       | value                                 |
|-------------------------------------------------------------------|
| auth.azure.loginName      | Your organization's name (e.g. WPI)   |
| auth.azure.clientId       | <your app's client/application ID>    |
| auth.azure.clientSecret   | <your app's client secret>            |
| auth.azure.tenantId       | <your organization's tenant ID>       |

4. Then make sure to save your changes.

You should now be able to log in using your Microsoft account.

Contributing

Changing the database

To make a change to the database, modify packages/database/schema.prisma. Run pnpm i or pnpx turbo run generate to update the generated code and then run pnpm db:push in packages/database to apply the changes to your local database.

Once you're done and would like to make a PR, run pnpm db:migrate:dev to generate the migration file. This may require resetting your local database, though it should get re-populated with some minimal seed data. You can reset your development database to the initial seeded state with pnpm db:migrate:reset.