Tool: OPFS + Pyodide test harness
Simon Willison’s Weblog
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23rd June 2026
Tool
OPFS + Pyodide test harness
I've been pondering if Datasette Lite - the Python Datasette application run entirely in the browser using Pyodide and WebAssembly - might be able to edit persistent SQLite files stored on the user's computer.
That's what OFPS (Origin Private File System) is for, so I had Claude Code for web build me this playground UI to try it out in different browsers.
Recent articles
Porting the Moebius 0.2B image inpainting model to run in the browser with Claude Code - 22nd June 2026
sqlite-utils 4.0rc1 adds migrations and nested transactions - 21st June 2026
Datasette Apps: Host custom HTML applications inside Datasette - 18th June 2026
This is a beat by Simon Willison, posted on 23rd June 2026.
browsers 105
pyodide 30
datasette-lite 22
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