MPS: Skill for Claude Code

MPS IDE Plugin Language

Loading companion skills

Companion names in this skill are lazy dependencies: load only those relevant to the current task. If this skill came from an MCP server, use the host's skill loader to resolve the companion's unique discovered entry URI on the same host-assigned originating server. If the host has no server-backed skill loader, stop and report that limitation; do not silently fall back to a filesystem copy. If this skill came from a filesystem catalog, load the named sibling from that same catalog at <skills-root>/<skill-name>/SKILL.md, even if remote skill loaders are also available. Do not invent a tool name or server endpoint.

This skill covers IDE plugins: code that integrates with the MPS/IntelliJ host IDE — menu actions, tool windows, shortcuts, settings panels. Plugin code lives in a regular Solution module (compilation mode: "Regular MPS module contributing extensions to MPS") with model(s) using jetbrains.mps.lang.plugin and jetbrains.mps.lang.plugin.standalone. The canonical model name is <solution_name>.plugin — MPS auto-registers it on that convention.

Official documentation: https://www.jetbrains.com/help/mps/plugin.html

Critical Directives

• Disambiguate the overloaded vocabulary first. "Plugin", "tool", "action group" each mean two or three different things. See references/terminology.md before naming anything.
• A plugin solution is NOT an IntelliJ plugin jar. The solution contains MPS models; the jar is what the MPS Build Language packages from it. Don't conflate.
• A Tool is a tool window — a dockable panel — not a CLI tool or an action.
• Use MPS MCP tools for edits. mps_mcp_insert_root_node_from_json, mps_mcp_update_node, mps_mcp_print_node. Resolve concept names with mps_mcp_search_concepts / mps_mcp_get_concept_details; never guess.
• ModificationStatement.modifiedGroup is a node reference (r:...), not a concept reference (c:...). Look up the target group via mps_mcp_search_root_node_by_name to obtain the node ref.
• Add a model dependency on jetbrains.mps.ide.actions before referencing built-in groups (MainMenu, EditorPopup, NodeActions, ModelActions, ModuleActions, MainToolbar, ProjectViewPopupMenu).
• Pick requiredAccess deliberately: none (no model touch), read (safe traversal), command (mutates with undo + write lock — never open modal dialogs from here), editorCommand (correct undo scope for editor-driven edits).
• A node known at design time (one sample or library root that an action opens or edits) is node-ptr/<name>/.resolve(<the MPS project's repository>) inside the action's read or command access, never a search for its name. Blueprint and the model import it needs: references/link-and-concept-literals.md in the mps-model-manipulation skill root after loading that companion skill from the same origin.
• Don't call project.tool<…> from dispose. The lookup can fail during teardown.
• Mac keymap trap: with Keymap = Default, MPS translates ctrl → cmd on macOS. If you specifically want ctrl on Mac, add a separate Mac_OS_X KeymapChangesDeclaration.
• After edits, rebuild the module (mps_mcp_alter_nodes MAKE) so generated Java is current, then Reload All in MPS for hot-load.
• Validate every new root with mps_mcp_check_root_node_problems.