The VS Code extension¶

GMAT Script brings the grammar, linter, and language server to Visual Studio Code: syntax highlighting, hover docs, live diagnostics, completion, go-to-definition, an outline, and format-on-save for .script and .gmf files.

Installing¶

Install GMAT Script from either marketplace:

Visual Studio Marketplace — search GMAT Script in the Extensions view, or run code --install-extension astro-tools.gmat-mission-script.
Open VSX — for VSCodium, Cursor, Gitpod, and other Open VSX–based editors.

The extension bundles syntax highlighting as a TextMate grammar, so colouring works the moment it is installed — no Python, no further setup.

Everything richer — hover, diagnostics, completion, definition, references, the outline, and formatting — is served by the gmat-script language server, which runs on Python. Install it into a Python environment the extension can reach:

$ pip install "gmat-script[lsp]"

This puts a gmat-script-lsp command on your PATH, which the extension launches automatically. If it is not found, highlighting still works and the extension points you here. To use a specific interpreter or virtual environment, set gmatScript.server.pythonPath (see Settings).

Features¶

Feature	Needs the server?
Syntax highlighting — resources, commands, fields, control flow, solver blocks, GmatFunction headers	no
Hover — a field's type, default, allowed values, units, and reference target	yes
Live diagnostics as you type — syntax errors plus linter findings	yes
Completion — resource names, the fields valid for the resource under the cursor, and enum values	yes
Go to definition / find all references for resources	yes
Document outline — every `Create`'d resource and GmatFunction header	yes
Format on save — canonical, idempotent re-emission	yes

The server-backed features are exactly those of the language server; the extension is the VS Code client that launches and talks to it. A half-typed buffer never breaks them — the error-recovering parse keeps hover and completion working while you edit.

Format on save¶

Format-on-save is enabled for GMAT files by default: the extension sets editor.formatOnSave for the gmat language, so saving a .script or .gmf rewrites it into canonical form via the same formatter the CLI and library use. Turn it off per-language if you prefer:

"[gmat]": { "editor.formatOnSave": false }

Settings¶

Setting	Default	Description
`gmatScript.server.path`	`gmat-script-lsp`	Command used to launch the language server. Set an absolute path if it is not on your `PATH`.
`gmatScript.server.pythonPath`	(empty)	A Python interpreter with `gmat-script[lsp]` installed; when set, the server runs as `<python> -m gmat_script.lsp` and takes precedence over `server.path`. Point it at a virtual environment.
`gmatScript.server.args`	`[]`	Extra arguments passed to the server on launch.
`gmatScript.trace.server`	`off`	Trace JSON-RPC traffic to the output channel (`off` / `messages` / `verbose`) when debugging.

Other editors¶

The same server powers any LSP-capable editor — Neovim, Emacs, Helix, and the rest. See the language server guide for editor-agnostic setup.