Simon Willison built web-edit to edit files from a phone without passing their contents through an AI conversation. The immediate need was a credentials file. The small Python application provides a browser interface for viewing and editing a folder, intended to be reached through Willison's own Tailscale network. An AI agentAn AI system that doesn't just answer once but works toward a goal in a loop — taking actions, reading the results, and deciding what to do next.Full definition → can start the application, and the person then makes the edit directly. That separates the agent's setup work from the sensitive text the person wants to enter. Release account.
Key takeaways · AI-distilled
Willison built the tool so he could edit a credentials file from his phone without sending those secrets through the LLMA large language model — the neural network behind tools like Claude and ChatGPT, trained on huge amounts of text to predict what comes next.Full definition →: the agent starts the editor, but the secret goes straight from the human to the file.
web-edit is a small Python web app that lists the files in a folder and lets you edit them. It is meant to run over Tailscale, so it can be reached from the author's phone on his private network rather than the public internet.
Willison says he had Codex with GPT-6 Astra Extra High build the app. Editing uses CodeMirror 6, which he chose over Monaco because Monaco still lacks a good mobile experience.
Terms in this piece · Glossary
AI agent — An AI system that doesn't just answer once but works toward a goal in a loop — taking actions, reading the results, and deciding what to do next.
LLM — A large language model — the neural network behind tools like Claude and ChatGPT, trained on huge amounts of text to predict what comes next.
