Debugger MCP Server
A JetBrains IDE plugin that hands the debugger to an agent: breakpoints, stepping, variables and expression evaluation over MCP.
- 118 ★ on the repository
- Last commit
- MIT
Broad access
Why this level
- The agent evaluates arbitrary expressions and changes variable values in the running program.
- With the address 0.0.0.0 the debugger port is reachable across the whole local network.
Install
- Works in
Manual install
claude mcp add --transport http intellij-debugger http://127.0.0.1:29190/debugger-mcp/streamable-http --scope userExample for IntelliJ IDEA. Server name and port differ per IDE; the Install on Coding Agents button fills them in.
Access and checks
How we reviewBroad accessThe tool can change data, run commands or handle secrets.
- The agent evaluates arbitrary expressions and changes variable values in the running program.
- With the address 0.0.0.0 the debugger port is reachable across the whole local network.
This is third-party code. Review the repository files before installing.
What it does
Debugger MCP Server is a plugin for IntelliJ Platform IDEs. It runs an MCP server inside the IDE, and the agent drives the standard debugger: it starts run configurations in debug mode, sets conditional breakpoints and tracepoints, steps through code, reads stacks and threads, and reads and changes variables. A single call returns variables, stack and a source snippet. There are 27 tools. Expression evaluation has three modes: unrestricted, a default blocklist of risky operations, and a conservative read-only mode with custom regex block rules. A companion skill with debugger tips ships with the plugin: install it into `.claude/skills/` or export it as `.skill` and `.zip`.
Who it is for. Developers in IntelliJ IDEA, PyCharm, WebStorm or GoLand who want an agent to track down a failure in running code.
Good fit when
- A test fails on a non-obvious value and the agent should stop at line 42 and show the variables.
- A bug appears after several calls, so a conditional breakpoint is set.
- Log messages are needed without pausing the program: the agent sets tracepoints.
- An Android app is already running and the agent has to attach to its process.
Not a fit when
- The IDE is not from the JetBrains family or lacks XDebugger support.
- The code touches production data and the agent could change variables.
- A log or a crash stack is enough and no program run is needed.
Example request
Run the UserService tests under the debugger, stop at line 42 and show the call stack and local variables.MCP
- Transport
- http, sse
- Authentication
- not required
Limitations
A JetBrains IDE version 2025.2 or newer is required. Each IDE has its own port: 29190 for IntelliJ IDEA, 29192 for PyCharm, 29193 for WebStorm. The server listens on `127.0.0.1` by default, and the value `0.0.0.0` exposes it to the whole network. IntelliJ IDEA, PyCharm, WebStorm and GoLand are verified in CI; other IDEs are community-tested or untested. Moving the execution point to another line works only for Python on pydevd.
How to disable. Run `claude mcp remove intellij-debugger` with your IDE's server name and disable the plugin in the IDE settings.
FAQ
How do I connect the server to Claude Code?
Run `claude mcp add --transport http intellij-debugger http://127.0.0.1:29190/debugger-mcp/streamable-http --scope user`. The name and port depend on the IDE; the plugin's tool window shows the right values.
Can risky expressions be restricted?
Yes. Settings offer three evaluation modes: unrestricted, a blocklist of risky operations, or read-only. Custom block rules can be added on top of a mode.
Which IDEs does the plugin support?
Any IntelliJ Platform IDE with XDebugger. IntelliJ IDEA, PyCharm, WebStorm and GoLand are verified in CI; the community confirmed RustRover, Android Studio and PhpStorm.
Which transport does the server use?
Streamable HTTP at an address like `http://127.0.0.1:{PORT}/debugger-mcp/streamable-http`. Older clients can use HTTP+SSE.
What does the companion skill do?
It tells the agent how to use the debugger tools. Install it into `.claude/skills/` with one click or export it as `.skill` and `.zip`.
Discussion
No questions or reviews yet.
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Comparison with similar tools
Cards that share the main search query, and how they differ.
| Tool | Official | Authentication | Repository stars | Main difference |
|---|---|---|---|---|
| Debugger MCP Server (this card) | no | not required | 118 | |
| Claude Debugs For You | no | not required | 515 | a VS Code extension; Debugger MCP Server runs inside JetBrains IDEs |
| DebugMCP | yes | not required | 581 | a VS Code extension and CLI from Microsoft; here the debugger comes from a JetBrains IDE |
README in short
The plugin installs from JetBrains Marketplace. After an IDE restart the server starts on its own at the port of that IDE. The Install on Coding Agents button in the tool window configures Claude Code and Codex CLI and copies a JSON config for other clients.