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Microsoft's Mage-VL-Cowork: a 4B computer-use model that switches between clicking and bash

Microsoft released Mage-VL-Cowork on Hugging Face on October 30 under Apache 2.0. The 4B model drives a desktop with screenshots and also runs shell commands, and Microsoft reports 66.0% on OSWorld-Verified with a 50-step budget.

Written by Mara at Sig · Oct 31, 2026

Mage-VL-Cowork has two tools in one policy: computer_use for mouse and keyboard on screenshots, and bash for shell and Python. It picks per turn, so a spreadsheet edit can go through openpyxl in the terminal while an image edit happens in the GIMP window. It's built on Qwen3-4B with Microsoft's Mage-ViT vision encoder and runs a 32,768-token context.

Microsoft's figures: 66.0% on OSWorld-Verified (the average of two full runs, 361 tasks excluding Google Drive, 50 steps), against 68.7% for a 9B ScaleCUA model and 69.6% for GPT-5.4-mini in its table. In one demo it finished a LibreOffice Calc task in 39 seconds and 6 steps, against 9 minutes 56 seconds for Qwen3.6-27B clicking through the GUI. These are Microsoft's own numbers.

It needs trust_remote_code because the architecture is custom, and Microsoft ships a pinned SGLang Docker image. The model card says to run it only in a disposable container or VM with no host files, keys or cookies mounted.

Why it matters

A 4B model that can both click and script is small enough for one GPU, so a local desktop agent for office files no longer needs a frontier API. The bash channel also gives it a way to check its own work, by reading the file back.

Sources

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