About 143

How it started

143 started as an internal project at Assembled. We wanted to speed up our engineering team and looked at everything out there. None of the existing tools had what we needed: agentic thinking, cloud-based coding, and a way for non-technical people to build product too.

Built for ourselves first

So we built it ourselves. 143 is an autopilot for coding agents that lets anyone on the team spin up a cloud session, describe what they need, and watch it get built. Engineers use it to move faster day to day. PMs and designers use it to prototype features and ship fixes without waiting on a sprint.

The name comes from the 143 days it took a small team of Lockheed engineers to build the XP-80 Shooting Star, America's first jet fighter, in 1943. A small focused team with the right tools doing the impossible. That's the spirit we wanted to capture.

Open source from day one

We built 143 as open source from the start. Our founders have been in open source for a long time and always wanted to contribute back to the community. 143 was that chance. We think the best developer tools are built in the open and shaped by the people who use them. We hope it helps other teams move faster and bring more people into the building process.

One platform, every model, every agent

Every model provider only supports their own models. That frustrated us. We wanted one place where different people on the team could use whatever coding agent they preferred, whether that's Claude, GPT, Gemini, or something else, without getting locked into a single vendor.

It's not just about model choice though. We wanted a single experience for the whole team where you can see all coding agent usage in one place, collaborate on projects that span multiple PRs and commits, and keep context alive across sessions instead of starting from scratch every time.

We also wanted to build a PM agent that actually knows your company's context. Your codebase, your product, your priorities. One that keeps building on that knowledge over time and gets smarter the more your team uses it.

About Assembled

Assembled is a workforce management platform that helps support teams deliver better customer experiences. 143 is a piece of the engineering culture behind Assembled that we wanted to share with everyone.