Backends for
realtime apps

The painless session backend platform.
Serverless like Lambda, built for WebSockets.

What are
session backends?

Session backends are server processes that you can start instantly with an API call. Your application connects to them from client-side code. When it closes the connection, the session backend is shut down.

This architecture is commonly used for multiplayer collaboration, sandboxed user code execution, and more.

Multiplayer
Jamsocket’s session backend implementation was influenced by Figma’s multiplayer architecture and multiplayer game servers.
Read docs
Rayon
Rayon uses Jamsocket as the realtime data backend for its CAD software.
When a user opens a document, Rayon spins up a Jamsocket backend, which serves as the source-of-truth for all clients connected to that document. The session backend is responsible for persisting changes to the database.
“We love using Jamsocket at Rayon. It just works!”
Bastien Dollaco-founder, Rayon
Sandboxed code execution
Jamsocket runs each session backend in an isolated sandbox with abuse detection, so you can run code from your users or an LLM without losing sleep.
Read docs
Op
Op lets users analyze data with Pandas within the browser.
When a user opens a sheet, Op spins up a Jamsocket backend to load the user’s dataset into memory. It then allows the user to answer questions about the dataset using plain language (by invoking an LLM) or directly in Python.
“I wanted the easiest way to set up a code execution backend for every user. Jamsocket had the simplest API.”
Samuel Quinnfounder, Op
Jupyter notebooks
You can run almost anything in a session backend, including a full Jupyter notebook server.
We provide a git repo that you can clone, add pip dependencies to, and build automatically with a GitHub Action.
Try it now
Toolchest
Toolchest uses Jamsocket to create ephemeral demo notebooks for its computational biology platform.
When propective customers click the link, Toolchest starts a Jupyter server inside a Jamsocket session backend. When the tab is closed, we shut the notebook down.
“Before Jamsocket, we set up demo environments manually for each lead. Now, setting up a demo environment is as easy as sharing a link.”
Noah Lobovicfounder, Toolchest

HOW IT WORKS

> docker build . -t hello-app-image

Successfully built 33fe99c5649e
Successfully tagged hello-app:latest

> jamsocket push hello-app hello-app-image

Tagging.
Pushing.
Using default tag: latest
The push refers to repository [jamcr.io/paul/hello-app]
5c4dd8c6a493: Pushed
6150b9c49004: Pushed
e83d4114481d: Pushed
0b3d0512394d: Pushed
5b1fa8e3e100: Pushed
Done.

> jamsocket spawn hello-app # or spawn via API

backend name: 1e9w4
backend url: https://1e9w4.jamsocket.run
status url: https://api.jamsocket.com/backend/1e9w4/status
ready url: https://api.jamsocket.com/ready/1e9w4

Containerize your server

Upload it to Jamsocket

Spawn instances by API

Session
Backends

Jamsocket lets you spin up session backends on the fly, making hard things easy.

Real-time collaboration

Share backends among users to build multiplayer collaboration that scales effortlessly.

Data-intensive apps

Build desktop-class data apps that run in the browser by running memory-intensive work in a session backend.

Developer tools

Run user code and compiler toolchain components in a per-user sandbox.

Want to learn more? Read our blog post about session backends.

Serverless,
or not.

You can use Jamsocket to start session backends on our managed cluster and never think about servers.

If you prefer to run backends on-prem, you can use Jamsocket as a managed control plane to run backends on your own servers with our bring-your-own-compute model. We manage scheduling, DNS, certificates, and observability so you don’t have to.