Try the plugin

Use this short user check after installation.

Create test.algo:

# language: fr

Fonction double(x: entier) -> entier:
    Renvoyer x * 2
Fin

Afficher double(21)

Then verify:

1. syntax coloring appears;
2. F5 runs the file and prints 42;
3. an intentional undefined variable appears in Diagnostics and its line link jumps to the source;
4. Ctrl+Space shows localized completions;
5. Ctrl+click on double jumps to its definition;
6. Pseudocode → Formater formats the file;
7. Algorigramme renders in Mermaid and Graphviz;
8. Exécution pas à pas follows the source and state;
9. switching to a .py file restores normal Thonny behavior.

For failures, use Troubleshooting.