Prompt Studio

Prompt Studio is a VS Codium extension for writing, testing, and iterating on LLM prompts without leaving the editor — no separate playground tab, no copy-pasting between a text file and a browser. It supports multiple AI providers through a shared router, so the same prompt can be tried against different models side by side.

It grew out of a parity project alongside a standalone Prompt Workbench web app, and shares the same underlying domain model.