What is mps-aspect-editor-menus-and-keymaps?

A guide for defining how users interact with editors in JetBrains MPS, a tool for building custom programming languages. It covers keyboard shortcuts, typing behavior, completion, paste actions, and context menus.

Use it to add keybindings, configure actions, provide completion or transformation options, and control paste and context-menu behavior.

It helps map a desired editor behavior to the correct MPS interaction definition instead of changing the wrong part of the editor.

How JetBrains/MPS configures Claude Code and Codex

About the project

JetBrains MPS is a development environment for creating domain-specific languages, which are programming languages designed for a particular field or task. It provides editors with features such as completion, semantic checks, and type checking, and can generate code in languages including Java and XML.

JetBrains/MPS · 1,658 stars · on GitHub · jetbrains.com

Reuse

Borrowing it

Nothing to install: this file belongs to JetBrains/MPS. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/JetBrains/MPS/master/.agents/skills/mps-aspect-editor-menus-and-keymaps/SKILL.md

Clone the repo

git clone --depth 1 https://github.com/JetBrains/MPS

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/jetbrains/mps/mps-aspect-editor-menus-and-keymaps/github.svg)](https://agentmods.dev/skills/jetbrains/mps/mps-aspect-editor-menus-and-keymaps)

Your own site

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Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/jetbrains/mps/mps-aspect-editor-menus-and-keymaps"><img src="https://agentmods.dev/badge/skills/jetbrains/mps/mps-aspect-editor-menus-and-keymaps.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 224 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 3,272 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits

NVIDIA SkillSpector pass 7 Sept 2026

How audits are shown

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00224	$0.03272
Opus 5	$0.00112	$0.01636
Sonnet 5	$0.00045	$0.00654
Haiku 4.5	$0.00022	$0.00327

Measured 11d ago against content hash 9175c46a487b, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

mps-aspect-editor-menus-and-keymaps scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 11d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.agents/skills/mps-aspect-editor-menus-and-keymaps/SKILL.md · 85 lines

How it starts

The opening of the file, as written. The whole thing — 85 lines — stays where its author put it; the contents beside it link to each section on GitHub.

MPS Editor Aspect — Menus, Keymaps and Actions

This skill covers the non-layout parts of the MPS editor aspect: everything that controls user interaction (typing, keystrokes, completion, paste, context actions). Most concepts belong to jetbrains.mps.lang.editor.structure; paste wrappers / node factories / copy-paste handlers live in jetbrains.mps.lang.actions.structure. Roots typically live in <lang>/languageModels/editor.mps or actions.mps.

Where these roots go. Menus / keymaps / action maps live in the same editor aspect model as the layout cell models — there is no separate aspect ID. Paste wrappers, copy-paste handlers and node factories live in the actions aspect model. Both aspect IDs (editor, actions) are case-sensitive and carry no @ suffix — see aspect-model-stereotypes.md.

For the layout side (concept editors, cell models, style sheets, editor components) see mps-mcp-workflow and mps-aspect-editor.

Critical Directives

Pick the right artefact for the user-visible behaviour. "Change what Delete does" → action map. "Add Ctrl+Shift+I" → keymap. "Offer + after a number" → side transform in a transformation menu. "Hide / reorder completion" → substitute menu. "Wrap pasted node" → paste wrapper. See references/landscape.md for the full mapping.
Author by convention. Name roots <Concept>_ActionMap, <Concept>_KeyMap, <Concept>_TransformationMenu, <Concept>_<Position>_SubstituteMenu, <Concept>_Factory, <Concept>Styling for automatic discovery. MPS walks the super-concept chain to find them.
Use MPS MCP tools for edits. mps_mcp_insert_root_node_from_json, mps_mcp_update_node. Resolve concept names with mps_mcp_search_concepts / mps_mcp_get_concept_details — never guess concept IDs.
Define a substitute menu before a transformation menu. The default BaseConcept_TransformationMenu already includes the substitute menu; for most "make my concept completable" tasks, only a substitute menu is required.
An empty default substitute menu HIDES the concept from completion. Either remove it or fill it. See references/substitute-menus.md §"Empty default suppresses".
Side-transform items are NOT automatically in Ctrl+Space. Either list TransformationLocation_Completion alongside TransformationLocation_SideTransform, or add a separate completion section.
Use action maps for DELETE/BACKSPACE instead of keymaps bound to VK_DELETE. They integrate with two-step deletion and action inheritance.
TransformationMenu field name is conceptDeclaration, not applicableConcept. Real role names: sections, parts, locations, textFunction. Older docs lie.
Contributions must live in a different language from the menu they extend. TransformationMenuContribution / SubstituteMenu_Contribution are cross-language only.
Write bodies with mps-model-manipulation idioms. node.replace with(...), node.parent.<role>.set(...), node.children<X>.add new(...). Implicit params: node, editorContext (+ model, scope, operationContext depending on function kind).
After edits run mps_mcp_check_root_node_problems and rebuild the language.
Trace missing completion items with Ctrl+Alt+B on the offending item — MPS shows the menu → menu-part → action chain.

Read the full file on GitHub · 85 lines

Files

What ships with it

15 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

11d ago First seen · 85 lines · 224 tokens per session scan A 9175c46a487b

Subscribe to this mod's changes

mps-aspect-editor-menus-and-keymaps is a skill published in the GitHub repository JetBrains/MPS (1,658 stars, last pushed today), licensed Apache-2.0. It adds 224 tokens to every session and 3,272 once invoked, about $0.0011 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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