Skip to main content

​
0. Prerequisites

Docker 24.0+ with Compose v2. See Requirements for hardware.

​
1. Clone and configure

Open .env and set at minimum:
Full reference: Configuration.

​
2. Start the Computer Use Server

The first build downloads tooling and assembles the workspace image (~15 min on a decent connection). Subsequent starts take seconds. When you see Uvicorn running on http://0.0.0.0:8081, the orchestrator is live. Smoke test in another terminal:

​
3. Start Open WebUI

In a second terminal:
The init script auto-installs the Computer Use tool + filter, creates your admin user, and sets function_calling: native + stream_response: true as the default model params. Open http://localhost:3000 and sign in with ADMIN_EMAIL / ADMIN_PASSWORD.

​
4. Add a model

  1. Go to Admin → Settings → Connections and add your LLM provider (the same OPENAI_API_KEY you set in .env, or a separate dedicated key).
  2. Go to Workspace → Models and enable at least one model.
  3. Verify Function Calling = Native and Stream Chat Response = On — set globally in Admin → Settings → Models → Advanced Params if you want these to be the default for every model.
If tool calls silently don’t fire, 99% of the time it’s because Function Calling is set to Default instead of Native. See Model settings.

​
5. Chat

Start a new chat and ask for something tool-worthy:
“Create a professional cover letter for a Senior Software Engineer applying to a startup in .docx, three paragraphs.”
You should see:
  • The model picks the docx skill.
  • bash_tool and create_file calls execute inside a fresh sandbox container.
  • A file link appears. A preview iframe auto-inserts below it.
If any of that fails, check Known bugs and Open WebUI integration traps.

​
Two compose files, on purpose

They’re split so the MCP server and the UI can run on different hosts in production — the split matches how real deployments look. Both files attach to the same external network (computer-use-net) that the server creates on first up.

​
Next

Configuration

Full env var reference.

Docker details

Why the server needs the Docker socket, resource limits, image layout.

Model settings

Why Function Calling = Native and streaming matter.

Open WebUI traps

Four things that silently break Computer Use in custom deployments.