I Built a GitHub Alternative

I built an open source GitHub alternative called Stratum. It’s a code platform designed for a world where AI agents write most of the code. I work at Cloudflare as a Developer Success Engineer, and it’s built on [Cloudflare Artifacts](https://blog.cloudflare.com/artifacts-git-for-agents-beta/), which shipped during Agents Week in April.

Let me explain why.

The workflow problem

I’ve been using AI coding agents for real work for a while now. Mostly Claude Code and opencode. They write solid code fast. But every single one of them ends up pushing code through GitHub’s pull request model. An agent writes 200 lines in 30 seconds, opens a PR, and then I have to click through a diff view, read everything line by line, maybe leave some comments, and hit Approve.

That flow was built for humans reviewing code that other humans wrote. It made sense ten years ago. It doesn’t make sense when I just need to know if the tests pass and whether the change matches what I asked for.

I’m not the only one feeling this. Mitchell Hashimoto [recently announced](https://mitchellh.com/writing/ghostty-leaving-github) that Ghostty is leaving GitHub. He’d been keeping a journal of every day a GitHub outage blocked his work, and almost every day had an X. His complaint was about reliability, but I think the problem goes deeper than that. The platform was designed for a different era.

I kept asking myself what I’d build if I could start from scratch. So I built it.

What my day actually looks like now

I describe what I want done. The agent forks a workspace in Stratum, writes the code, and pushes it. Stratum runs a set of evaluators against the change. Tests, type checking, static analysis, LLM review. Each one produces a score. If everything passes and the repo’s policy allows it, the change merges automatically. I get a notification that it was evaluated and merged.

If something needs my attention, it shows up in the exception queue with the evaluation data attached so I can see what happened and why.

Most changes merge without me looking at them. When I do review something, I’m looking at structured data, not raw diffs. I know the tests passed, I know the type checker is clean, I know what the LLM reviewer thought. That context makes review way faster than staring at green and red lines in GitHub.

How it works

Stratum is a code platform where agents and humans can both do their thing without one slowing down the other. Humans get a reliable place to host code, browse files, review changes. Agents get programmatic access to create isolated workspaces, push code, and have it automatically evaluated before it ever touches the main branch.

Every change gets scored by multiple evaluators running at the same time. Test results, static analysis, diff checks, LLM review. All of that gets attached to the change so when a human does look at it, they have real data instead of a green checkmark.

You configure all of this in a `.stratum/policy.yaml` file in your repo. What evaluators to run, what scores qualify for auto-merge, which file paths always require a human to sign off. Everything is explicit.

Why Cloudflare

Artifacts is a Git storage primitive built on Durable Objects. You can create millions of repos programmatically, fork them instantly, and access them through normal Git or a REST API.

That’s what makes the workspace model work. Spinning up hundreds of isolated forks for agent tasks and tearing them down when they’re done is just an API call. GitHub doesn’t give you that as a primitive.

The isolation also solves the reliability problem. Every repo is its own Durable Object, so one repo can’t take down another. Not because of monitoring or incident response. Because the architecture doesn’t allow it.

Open source

The whole thing is open source. Deploy it on your own Cloudflare account and just pay for the infrastructure. There’s also a managed version if you don’t want to deal with that. But the code is there for you to read. If I’m going to ask you to move your repos somewhere, you should be able to see exactly what you’re trusting.

If you need deployment pipelines, hook into your existing CI from Stratum’s webhooks. I didn’t try to clone every GitHub feature. Code hosting, change management, and evaluation. That’s the scope.

Try it

Stratum is live at [usestratum.dev](https://usestratum.dev). Import a GitHub repo and have it running in a few minutes. I’m [@i_am_jlmx](https://x.com/i_am_jlmx) on X and [@jlmx.dev](https://bsky.app/profile/jlmx.dev) on Bluesky.