Cobalt — Hand off a coding task, get working software

From task to working software

Describe the change you need. Cobalt does the work on its own computer, shows you the result running in your browser, and opens a pull request when you are happy with it.

Nothing to install. The repository, dependencies, and services live on Cobalt's computer.
A running app, not just a diff. Click through the change before anyone reviews the code.
Codex, Cursor, OpenCode, or Pi. Choose the coding agent when the task starts.

Cobalt showing a running notes application inside its live preview — Your conversation and your running app, in one place.

How it works

A request becomes running software, then a normal pull request.

Describe the change in plain language. A coding agent gets its own computer, builds it, and runs the tests. You review the live result and merge - the same loop whether you write code or not.

Review the result

Try the change before you review the code.

Open the running app and use it. A wrong interaction is obvious in ten seconds and invisible in a diff.

Keep the task running

Close the tab. The task stays ready.

The computer keeps running after you leave - dependencies installed, services up, branch intact. Come back on any device to the same conversation and the same running app.

For the whole team

The bottleneck moved. So should the interface.

Testers, analysts, and product managers can request a change and review the result from the browser - without a local environment or a shared agent credential. Developers keep the work that needs their judgment.

Run work in parallel

Run more than one task at a time.

Every task gets its own computer, so a feature build, a bug fix, and a spike can run at once - no extra checkouts or branches juggled on your machine.

Coding agents

Choose the agent. Keep the workflow.

Codex, Cursor, OpenCode, or Pi - pick one when the task starts. The computer, the live preview, the tests, and the pull request stay exactly the same underneath.

What’s new in Cobalt

Product updates and practical examples from the Cobalt team.

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Start with one task

Turn the next request into working software.

Give Cobalt the change your team needs and review the result in your browser.

Start a task