Guidelines for writing IntelliJ actions, which are commands users trigger from menus, toolbars, or keyboard shortcuts in IntelliJ-based IDEs. They cover how actions should be declared, named, translated, and connected to icons.

Use it when creating or changing an IntelliJ action, including its Kotlin class, plugin.xml registration, icon, identifier, and message-bundle text.

Following these conventions helps actions appear correctly in the IDE and keeps their labels and descriptions maintainable. It also avoids common construction and configuration mistakes.

actions — Skill by JetBrains

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods

npx agentmods add skills/jetbrains/mps/actions

Any agent

npx skills add JetBrains/MPS --skill actions

Clone the repo

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

Made for: Claude Code, Codex.

Per session 31 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 298 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. Scan, not verified.

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	$0.00031	$0.00298
Opus 5	$0.00015	$0.00149
Sonnet 5	$0.00006	$0.00060
Haiku 4.5	$0.00003	$0.00030

Measured 2d ago against content hash 6c2c742437cb, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

actions 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 2d 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/actions/SKILL.md · 44 lines

What it actually says

Actions

Guidelines for implementing IntelliJ actions (AnAction).

Documentation

Action System - Architecture and usage of the action system

Best Practices

NEVER instantiate Presentation in action constructors - Use no-argument constructors
Define text, description, and icon in plugin.xml - Not in constructor parameters
Follow the convention:
1. Set the id attribute for the action in plugin.xml
2. Optionally set the icon attribute if an icon is needed
3. Set text and description in the message bundle (e.g., GitBundle.properties):
- action.<action-id>.text=Translated Action Text
- action.<action-id>.description=Translated Action Description

Good example:

Kotlin:

class MyAction : AnAction()

plugin.xml:

<action id="My.Action.Id"
        class="my.package.MyAction"
        icon="my.package.MyIcons.ICON"/>

Bundle.properties:

action.My.Action.Id.text=My Action
action.My.Action.Id.description=Description of my action

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.

2d ago First seen · 44 lines · 31 tokens per session scan A 6c2c742437cb

Subscribe to this mod's changes

actions is a skill published in the GitHub repository JetBrains/MPS (1,657 stars, last pushed today), licensed Apache-2.0. It adds 31 tokens to every session and 298 once invoked, about $0.0002 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.

domain-specific-language dsl

langium

A comprehensive skill to understanding how Langium-based projects work — from grammar definition through code generation, runtime parsing, linking, validation, and LSP integration.

eclipse-langium/langium-ai · 33 tokens

lai-gen-evals

Expand and refine the evaluation suite for a Langium DSL project. Generates comprehensive eval files that cover syntactic correctness, semantic validity, user intent matching, edge cases, and language understanding.

eclipse-langium/langium-ai · 42 tokens

lai

Guide for using the langium-ai (LAI) CLI to generate language descriptors, synthesize system prompts, run evaluations, and iteratively refine AI-powered tooling in Langium projects. Use when working with lai commands, descriptors, or evaluation files.

eclipse-langium/langium-ai · 52 tokens

actions