Give AI the whole IntelliJ, not just the files
AI agents can finally SEE your IDE — not just read code
Website • Demo Videos • Blog Post • TeamCity (JetBrains internal) • Discord
MCP Steroid is an open-source Model Context Protocol server that runs inside JetBrains IDEs and exposes the full power of the IntelliJ Platform to AI agents.
Unlike file-only assistants, MCP Steroid gives AI agents the same capabilities developers use: semantic code understanding, advanced refactorings, debugging, test running, visual awareness, and the entire IntelliJ API surface — all accessible via standard MCP over HTTP.
MCP Steroid is the only MCP server offering ALL of:
- Visual IDE understanding — Screenshots + OCR + component tree
- UI automation — Control the IDE like a human developer
- Native IntelliJ APIs — PSI, inspections, refactorings, and more
- Kotlin scripting — Full platform access at runtime
- Human-in-the-loop safety — Review modes (ALWAYS / TRUSTED / NEVER)
- Standard MCP protocol — Works with ANY MCP-compatible AI agent
On DPAIA Spring Boot tasks, agents with MCP Steroid are 20–54% faster than file-only workflows on complex multi-file operations:
| Case | Task | MCP Time | No-MCP Time | Δ |
|---|---|---|---|---|
| dpaia_jhipster_sample_app-3 | Rename ROLE_ADMIN across app (9 files) | 202s | 440s | -54% |
| dpaia_empty_maven_springboot3-1 | JWT auth from scratch (5+ new files) | 288s | 396s | -27% |
| dpaia_feature_service-25 | Parent-child JPA + Flyway (10 files) | 382s | 523s | -27% |
| dpaia_feature_service-125 | Multi-layer JPA+service+controller (15 files) | 788s | 1002s | -21% |
| dpaia_spring_petclinic_rest-14 | Simple URL prefix replace (7 files) | 188s | 181s | +4% |
| dpaia_train_ticket-1 | Extend OrderRepository JPQL (4 files) | 727s | 633s | +15% |
Tasks requiring semantic understanding show the largest speed gains. Simple text replacements perform similarly with or without IDE access.
Requirements: IntelliJ IDEA 2025.3+ (or any IntelliJ-based IDE: Rider, Android Studio, GoLand, WebStorm, PyCharm, CLion, etc.)
Search for MCP Steroid in Settings > Plugins > Marketplace, or install from plugins.jetbrains.com.
Add this URL in Settings > Plugins > Gear icon > Manage Plugin Repositories...:
https://mcp-steroid.jonnyzzz.com/updatePlugins.xml
Download the latest ZIP from GitHub Releases and install via Settings > Plugins > Gear icon > Install Plugin from Disk.
When the plugin starts, it writes the server URL to .idea/mcp-steroid.md in each open project. Connect any MCP-compatible client to it:
# Claude Code
claude mcp add --transport http mcp-steroid http://127.0.0.1:6315/mcp
# Or verify with any agent
claude -p "List all open projects using steroid_list_projects"Any MCP client can connect using the Streamable HTTP transport at http://127.0.0.1:6315/mcp.
Works with ANY MCP-compatible client:
- Claude (Claude Code, Claude Desktop)
- ChatGPT with MCP support
- Gemini CLI
- Codex CLI
- Cursor IDE
- Junie
- OpenCode
- Any other MCP-compatible client
| Tool | Description |
|---|---|
| Execute Code | Run Kotlin code inside the IDE's JVM with full API access |
| Execute Feedback | Provide execution ratings back to agents |
| Vision Screenshot | Capture IDE screenshots with component metadata |
| Vision Input | Send keyboard/mouse events, OCR analysis |
| Action Discovery | Find and invoke IDE actions and quick-fixes |
| Capabilities Discovery | Explore available IDE features |
| List Projects | Discover all open IntelliJ projects |
| List Windows | Enumerate IDE windows and components |
| Open Project | Open projects programmatically |
Comprehensive guides and examples covering:
- LSP Operations (11) — Go to definition, find references, hover, completion
- IDE Power Operations (22) — Refactorings, code generation, project analysis
- Debugger Integration (7) — Breakpoints, thread control, debugging workflows
- Test Runner (10) — Run tests, inspect results, navigate test trees
- VCS Operations (3) — Git annotations, file history
- Project Workflows (4) — Open projects with trust levels
- Skill Guides (3) — IntelliJ API, debugger, and test runner guides
| Video | Description | Duration |
|---|---|---|
| Codex Debugs in IntelliJ IDEA | Full debugging session with Codex | 1:03:24 |
| CodeDozer Demo 5 | Most popular demo | 1:00 |
| CodeDozer & IntelliJ Debugger | Debugger integration showcase | 8:25 |
| Now we call tasks in IntelliJ | Task execution demo | 2:21 |
| Real Work in Monorepo Part 2 | Deep dive into real workflow | 18:37 |
| Cursor Talks with IntelliJ | Cursor integration | 0:44 |
Watch all demos: MCP Steroid Playlist
MCP Steroid can be configured via IntelliJ's Registry (Help > Find Action > Registry) or JVM system properties.
| Registry Key | Default | Description |
|---|---|---|
mcp.steroid.server.port |
6315 | MCP server port (0 for auto-assign) |
mcp.steroid.server.host |
127.0.0.1 | Bind address (use 0.0.0.0 for Docker) |
mcp.steroid.review.mode |
ALWAYS | Review mode: ALWAYS, TRUSTED, or NEVER |
mcp.steroid.storage.path |
(empty) | Custom storage path (default: .idea/mcp-steroid/) |
See the full Configuration Documentation on the website.
- Technology: Kotlin 2.2.21 on Java 21
- HTTP Server: Ktor 3.1.0 (Streamable HTTP + SSE)
- Protocol: Model Context Protocol (MCP)
- Default Port: 6315
- OCR: Tesseract 5.5.1
- Platform: IntelliJ Platform Plugin SDK
The server runs inside the IDE's JVM process — no inter-process communication. Direct access to the project model, semantic index, PSI tree, test runner, debugger, and VCS layer.
MCP Steroid is an open-source project by Eugene Petrenko (@jonnyzzz), licensed under Apache 2.0.
Read more:
- MCP Steroid Is Now Open Source — announcement and project history
- IntelliJ as a Skill Factory — build custom agent skills without plugin development
- Project Assessment: 75 Days, 1300+ Commits — architecture and quality deep dive
IntelliJ IDEA, IntelliJ Platform, PyCharm, WebStorm, and JetBrains are trademarks of JetBrains s.r.o.
We welcome contributions! See CONTRIBUTING.md for guidelines on how to get started, and CONTRIBUTORS.md for the list of people who have helped make MCP Steroid better.
MCP Steroid is open-source software licensed under the Apache License 2.0.
- Website: mcp-steroid.jonnyzzz.com
- JetBrains Marketplace: plugins.jetbrains.com
- Discord: discord.gg/e9qgQ7NeTC
- GitHub Issues: github.com/jonnyzzz/mcp-steroid/issues
- GitHub Sponsors: github.com/sponsors/jonnyzzz
- Blog: jonnyzzz.com
- YouTube: @jonnyzzz
- LinkedIn: jonnyzzz
- X/Twitter: @jonnyzzz
Built with care for the AI agent developer community