Configuration

SDK selection#

Open Settings → Languages & Frameworks → Mojo. Select an explicit SDK when discovery finds the wrong environment. Discovery considers project Pixi, virtual, Conda, and uv environments, modular.cfg, wheel layouts, and finally mojo on PATH.

Check mojo --version from the selected environment. Compatibility warnings appear in SDK settings and editor/REPL notifications for unsupported versions.

Language server and standard library#

The selected SDK must expose mojo-lsp-server or the configured language-server path from modular.cfg for LSP-backed features. Native PSI-backed editing and import fixes can work without LSP. Set Stdlib source path if SDK discovery cannot locate the source needed for standard-library navigation and imports.

Formatting#

Choose the Mojo SDK formatter or built-in formatter. Editor → Code Style → Mojo controls indentation, spacing, blank lines, and formatter line length.

Debugging#

A debugger-capable SDK needs lldb-dap, the Mojo LLDB plugin, and visualizers. The plugin uses the SDK’s DAP transport for CPU debugging and does not require JetBrains Native Debugging Support.