jonnyzzz/mcp-steroid/prompt

IntelliJ API Power User Guide

RECOMMENDED: Execute Kotlin code directly in IntelliJ IDEA's runtime with full access to IntelliJ Platform APIs.

MCP Steroid - IDE API Access for AI Agents

Execute Kotlin code directly in IntelliJ IDEA's runtime with full access to the IntelliJ Platform API.

Important Notes for AI Agents

Learning Curve: Writing working code for IntelliJ APIs may require several attempts. This is normal! The API is vast and powerful. Keep trying - each attempt teaches you more about the available APIs. Use printException() to see stack traces when errors occur.

Drop-in replacement for LSP: This MCP server replaces LSP (Language Server Protocol) tools with IntelliJ's native APIs — same operations, deeper understanding:

• PSI (Program Structure Interface) instead of LSP document symbols — full semantic analysis
• IntelliJ inspections, refactorings, intentions instead of LSP code actions
• Full project model with module dependencies instead of workspace folders
• Platform-specific indices for O(1) code search instead of filesystem scans

Common task → resource cheat sheet

Before reading further, if your task matches one of these, skip straight to the linked recipe:

The full index is in the "MCP Resources (Use Them)" section below.

Quickstart Flow

1. steroid_list_projects → get list of open projects
2. Empty on a clean machine? Run `devrig backend download --json`, install the required product, then
   call steroid_open_project. It auto-starts a sole installed backend; no separate start is required.
3. Poll steroid_list_projects until the path appears, then pick its `project_name` (the unique routing
   key — NOT the human-readable `name`). Do not reuse a key from before an IDE/project restart.
4. On a first Maven/Gradle open, fetch `mcp-steroid://skill/execute-code-maven` or
   `mcp-steroid://skill/execute-code-gradle`, then trigger and await external-system configuration exactly
   as that recipe shows.
5. steroid_execute_code → run Kotlin code with that project_name
6. steroid_execute_feedback → report success/failure for tracking

For unattended Java/JVM work on 2026.2, install IDEA Ultimate with a pinned 2026.2 version. devrig launches it as a frontendless Remote Development backend with MCP Steroid included, so a window or screenshot is not a readiness requirement. Full lifecycle details: mcp-steroid://open-project/managing-backends (fetch it after steroid_list_projects supplies a project_name).

Each steroid_list_projects entry has TWO name fields: project_name (the within-IDE-unique, opaque routing KEY you pass back to every project-scoped tool) and name (the human-readable folder name, informational/display only). Always route by project_name. To find the right project for a file or directory path, pick the project whose path is the longest prefix of your target path (this disambiguates nested checkouts and git worktrees).

Example session:

→ steroid_list_projects
← {"projects":[{"project_name":"my-app-9fk2a0xq","name":"my-app","path":"/path/to/my-app","backend_name":"iu-9fk2a0xq"}],
   "backends":[{"backend_name":"iu-9fk2a0xq","intellij":{"name":"IntelliJ IDEA 2026.1.3","version":"2026.1.3","build":"IU-261.25134.95"}}]}
 
→ steroid_execute_code(project_name="my-app-9fk2a0xq", code="println(project.name)", ...)
← "my-app"
 
→ steroid_execute_feedback(project_name="my-app-9fk2a0xq", task_id="...", execution_id="...", success_rating=1.0, explanation="Got project name")

When to Use This Skill

ALWAYS prefer IntelliJ APIs over file-based operations:

The IDE has indexed everything. It knows the code better than any file search.

Available Tools

steroid_list_projects

List all open projects. Each entry has project_name (the unique routing key to pass to steroid_execute_code and the other project-scoped tools), name (the human-readable folder name, informational only), and path. To map a file/dir path to a project, pick the project whose path is the longest prefix of your target path.

steroid_list_windows

List open IDE windows (and background tasks) and their associated projects. Some windows may not be tied to a project and a project can have multiple windows. Use this in multi-window setups to pick the correct window_id for screenshot/input tools. Each window and task entry references its project by project_name — the single routing key. Look up that project's human-readable name and path via steroid_list_projects by that key (they are not duplicated on window/task entries).

steroid_take_screenshot

Capture a screenshot of the IDE frame and return image content.

HEAVY ENDPOINT: Use only for debugging and tricky configuration. Prefer steroid_execute_code for regular automation.

Parameters:

• project_name (required): the project_name from steroid_list_projects (a unique routing key, NOT the raw folder name)
• task_id (required): Task identifier for logging
• reason (required): Why the screenshot is needed
• window_id (optional): Window id from steroid_list_windows to target a specific window

Artifacts (saved under the execution folder):

• screenshot.png
• screenshot-tree.md
• screenshot-meta.json

The response includes window_id (also stored in screenshot-meta.json); pass it to steroid_input to target the same window. window_id is also returned by steroid_list_windows.

steroid_input

Send input events (keyboard + mouse) using a sequence string.

HEAVY ENDPOINT: Use only for debugging and tricky configuration. Prefer steroid_execute_code for regular automation.

Parameters:

• project_name (required): the project_name from steroid_list_projects (a unique routing key, NOT the raw folder name)
• task_id (required): Task identifier for logging
• reason (required): Why the input is needed
• window_id (required): Window id from steroid_list_windows (also returned by steroid_take_screenshot)
• sequence (required): Comma-separated or newline-separated input sequence (commas inside values are allowed unless they look like , <step>:; commas are optional when using newlines)

Sequence examples:

• stick:ALT, delay:400, press:F4, type:hurra
• click:CTRL+Left@120,200
• click:Right@screen:400,300

Notes:

• Comma separators are detected by , <step>: patterns, so avoid typing , delay: etc in text.
• Trailing commas before a newline are ignored.
• Use # for comments until the end of the line.
• Targets default to screenshot coordinates; use screen: for absolute screen pixels.
• Input focuses the screenshot window before dispatching events.

steroid_execute_code

Execute code with IntelliJ's brain, not just text files.

Give your AI agent a senior developer's toolkit: semantic code understanding, automated refactorings, and IDE intelligence that LSP can't provide.

Parameters: project_name, code (Kotlin suspend function body), task_id, reason, timeout (optional)

Returns: execution_id plus ONLY what the script explicitly prints (println / printJson / printCsv / printToon). The last expression's value is ignored by the runtime — a script that computes but never prints returns no data, just a HINT: about the missing print.

Complete guide: mcp-steroid://skill/coding-with-intellij (API reference, patterns, examples, best practices)

steroid_execute_feedback

Rate execution results. Use after steroid_execute_code.

steroid_open_project

Open a project in the IDE. A managed backend cold start may block until MCP is reachable; only the project-open phase is asynchronous.

Through devrig, a sole installed managed backend is selected and started automatically; backend startup waits until MCP is reachable. The project-open request itself remains asynchronous.

Parameters:

• project_path (required): Absolute path to the project directory to open
• task_id (required): Task identifier for logging
• reason (required): Why you are opening the project
• trust_project (optional): If true, trust the project path before opening (skips trust dialog). Default: true

Workflow:

1. Call steroid_open_project with the project path
2. If trust_project=true, the project will be trusted automatically (no trust dialog)
3. Poll steroid_list_projects until the path appears and keep its fresh project_name
4. If a frontend exists, use steroid_list_windows; only use screenshot/input when it reports a modal
5. A frontendless Remote Development backend has no required window. For a first Maven/Gradle open, await

the build-system model using its execute-code sync recipe before indexed semantic queries

MCP Resources (Use Them)

This server exposes built-in articles through steroid_fetch_resource. These are the fastest way to load full examples and guides without guessing or copy/pasting from the web.

How to access resources:

1. Call steroid_fetch_resource with a mcp-steroid:// URI to load the content.

The fetch tool is project-scoped because articles render for the target IDE. On a clean machine, use the initialize instructions and open-project description to bootstrap; fetch articles after a project appears.