Caroster

Caroster is a free, open-source carpooling web application for organizing shared trips to events, built with Next.js and Strapi by the Geneva-based startup studio Octree.

What is Caroster?

Caroster is a free, open-source carpooling app that lets event organizers create a dedicated carpool page for an event, where drivers can propose trips and passengers can join in a few clicks. The app displays proposed trips on a map, supports round trips, waiting lists, email notifications, and weekly organizer summaries. It is built as a monorepo with a Next.js frontend and a Strapi backend, and is developed and provided by Octree, a sustainable startup studio in Geneva. Caroster is licensed under GNU AGPL v3.0, and the hosted service is scheduled to shut down on November 30, 2026.

Key Features

• Event carpool pages — Create a dedicated carpool page for each event and customize its description, location, and date.
• Map-based trip visualization — See all proposed trips on a map powered by Mapbox geocoding and OpenStreetMap tiles (default).
• Driver and passenger flows — Propose a trip as a driver or add yourself as a passenger in just a few clicks.
• Waiting list — Passengers can request a trip that isn't available yet and join a waiting list menu.
• Round trip management — Manage round trips for an event (outbound and return legs).
• Search by departure location — Use the search bar to find a trip based on where it departs.
• Email notifications — Get email notifications when a new trip is available; organizers receive weekly summary emails.
• Administrator roles — Manage an event with administrator roles (available in the Caroster paid plan only).
• Tech stack — Next.js frontend, Strapi backend, GraphQL endpoints, and Docker Compose for local deployment.

Who is it for?

• Event organizers — Create a carpool page for a party, seminar, sport game, or camp and share it so attendees can arrange shared rides.
• Drivers — Propose a trip as a driver in a few clicks, setting departure location and seats, and help fill their car.
• Passengers — Find or request a ride to an event, either by searching departure locations or joining the waiting list.
• Open-source contributors — Developers who want to contribute to a project with a Contributor Covenant code of conduct and a GitLab reference repository.

What can you do with Caroster?

• Party and event hosts: set up a carpool page for your gathering, customize date and location, and let guests coordinate rides.
• Commuter groups: organize home-to-work carpooling with round-trip management and recurring events.
• Club and sports teams: coordinate transport to away games or camps by embedding the carpool page and sharing the link.
• Self-hosters: deploy Caroster locally with Docker Compose, configure SMTP and (optionally) Mapbox, and run the app on your own server.

How does Caroster work?

Organizers create an event carpool page and share its link. Drivers propose trips by specifying departure and arrival, and passengers join existing trips or request a new one. Trips appear on a map, and email notifications keep everyone updated. The application consists of a Next.js frontend and a Strapi backend, and you can run it with Docker Compose or in development mode with Yarn.

Pricing

Caroster is free and open source under the GNU AGPL-3.0 license. The page indicates a paid plan exists that unlocks administrator role management for events; no pricing amounts are published.

Alternatives

Mobicoop — an ethical, open-source carpooling solution that the Caroster team recommends as a replacement, offering similar features for home-to-work commutes and events.

FAQ

Is Caroster still available?

The hosted Caroster service will shut down on November 30, 2026. Until then the service remains available, and Octree recommends switching to Mobicoop. Because the code is open source, you can self-host Caroster after the shutdown.

Is Caroster free?

Yes, Caroster is free and open source under the GNU AGPL-3.0 license. There is also a paid plan that adds administrator role management for events, but no pricing details are published.

What tech stack does Caroster use?

Caroster is composed of a Next.js frontend and a Strapi backend, with GraphQL endpoints for e2e tests. It uses Mapbox for geocoding and maps, with OpenStreetMap as the default tile server.

Can I self-host Caroster?

Yes. You can clone the repository from GitLab and run it with Docker Compose, providing SMTP configuration and an optional Mapbox token. For development, you can run the frontend and backend separately with Yarn, and tests are available in the e2e directory.

What license does Caroster use?

Caroster is licensed under the GNU Affero General Public License v3 (AGPL-3.0), which allows free use, modification, and duplication while requiring derivative works to be open source.