Claude Code ports an inpainting model into a browser
Willison delegated a Moebius model port to Claude Code using local repositories and a research note. He tested the browser UI and returned errors while the agent iterated on ONNX and WebGPU support.
simonwillison.net
Prompt to try
Editorial adaptation, not the source author’s exact prompt. Replace bracketed inputs and review tool permissions first.
In an isolated workspace, assess whether [model] can run in a browser. Inspect code, weights and licensing. Plan a small conversion and UI demo; record errors and limitations. Give me a local URL to test. Stop before uploading weights or creating public resources.
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See placements →What happened
Willison reports a working browser demo and published converted weights.
Reported by Simon WillisonHow the agent did it
- Gather the model code, weights and feasibility notes in a scratch workspace.
- Have Claude Code plan and implement an ONNX and WebGPU browser version.
- Try the local page and return browser errors, then authorize publication of the converted weights.
Where a person stepped in
Willison tested in Chrome and supplied a repository-scoped publishing token only after deciding to publish.
A person approved each step before the agent continued.
More details
About this account
The agent explored conversion and implementation choices, maintained notes and revised the browser build from feedback.
Firsthand account with repository, notes and demo links. A working demo is not a claim of parity across all hardware.
Credit: Simon Willison
Source published 22 Jun 2026
Source checked 14 Oct 2026
Tools and topics
Claude Code · ONNX Runtime Web · WebGPU · PyTorch · Hugging Face CLI
Code · Testing
Editorial completeness: 100/100. Measures documented fields, not agent performance or verified outcomes.