Folders and files
| Name | Name | Last commit date | ||
|---|---|---|---|---|
VS Code extension for analyzing JVM thread dumps (.tdump files).
- Tree View Sidebar — Threads grouped by state (RUNNABLE, BLOCKED, WAITING, etc.) with counts and icons
- Dashboard — Pie chart of thread states, top 10 hot methods, deadlock alerts
- Click-to-Navigate — Click a thread in the tree to jump to its location in the dump file
- Deadlock Detection — Automatic cycle detection in lock wait graphs
- Method Search — Find all threads running a specific method, with state breakdown and lock info
- MCP Server — Expose analysis tools to AI assistants (Claude, Copilot, Cursor) via the Model Context Protocol
- Java 8 & 11+ Support — Parses both formats (with and without cpu=/elapsed= fields)
- Open a .tdump file in VS Code
- The tree view populates automatically in the Fast Java Thread sidebar
- Right-click in the editor and select Analyze Thread Dump for full analysis
- Run Fast Java Thread: Show Dashboard from the command palette for the webview dashboard
| Command | Description |
|---|---|
| Fast Java Thread: Analyze Thread Dump | Parse the active .tdump file and populate the tree view |
| Fast Java Thread: Show Dashboard | Open the webview dashboard with charts and deadlock alerts |
The extension includes an MCP server that lets AI assistants analyze thread dumps directly. It works with any MCP-compatible client — Claude Code, Claude Desktop, GitHub Copilot Chat, Cursor, etc.
| Tool | What it does |
|---|---|
| analyze_thread_dump | Full analysis: thread states, hot methods, and deadlock detection |
| detect_deadlocks | Focused deadlock cycle detection with lock chain details |
| get_hot_methods | Most frequently occurring methods across all stack traces |
| get_thread_summary | Quick overview: thread count, state breakdown, deadlock count |
| find_threads_by_method | Find threads running a specific method, with state and lock info |
Point your MCP client at the server:
node out/src/mcp/server.jsFor Claude Code, add to your .mcp.json:
{
"mcpServers": {
"fast-java-thread": {
"command": "node",
"args": ["path/to/FastJavaThread/out/src/mcp/server.js"]
}
}
}For network access (e.g. from a Tauri app), run with HTTP transport:
node out/src/mcp/server.js --transport http --port 3100 --auth-token mytoken| Setting | Default | Description |
|---|---|---|
| fastJavaThread.mcp.transport | stdio | Transport mode: stdio or http |
| fastJavaThread.mcp.port | 3100 | Port for HTTP transport |
| fastJavaThread.mcp.auth.enabled | false | Enable Bearer token auth (HTTP only) |
| fastJavaThread.mcp.auth.token | "" | Bearer token value |
npm install
npm run compile
npm testPress F5 in VS Code to launch the Extension Development Host.
The extension expects .tdump files containing standard JVM thread dump output, as produced by jstack, kill -3, or JMX ThreadMXBean.dumpAllThreads().