Open Session started as an internal app at Tella (YC S20). It’s become our most important tool. The whole team uses it, and not just for product development. It’s also great for customer support, operations, and data analysis.
In the last couple months we turned it into something that other teams might want to use and adapt.
When we started working on it earlier this year, our main frustrations with existing tools were (1) the lack of adaptability, (2) lack of good cloud-based workflows, (3) price (e.g. on Devin you couldn’t use your existing Claude sub). Open Session solves all three of these things for us:
It’s open-source, so you can do what you want with it. But it also has extensibility built into the product. You can connect MCPs, skills, integrations, sandbox providers and more. Our team relies heavily on its Slack, Plain and GitHub integrations.
It’s designed to run on your cloud (Mac mini also works). So you can close your laptop, run as many agents as your server can handle, and code from your phone. We’ve also made it easy to work together with your team. You can share a session with others as a link. They can steer the agent in the same session with you, or start a related session in a new tab.
It’s self-hosted, so you only need to pay for your servers and the token costs. It also has some nice tools for managing AI subscriptions across your team.
You can use Open Session in your browser or as a desktop app. You can also use it on your phone with the iOS app (coming soon) or PWA.
Yes, we know everyone is building a harness right now. But so much is changing about how we build software and the best way to figure out where it’s all headed is to help decide the direction yourself.
We hope your team enjoys using Open Session as much as ours.