syncause-debugger

# Syncause Debugger

Use runtime traces to enhance bug fixing: collect runtime data with the SDK, then analyze with MCP tools.

**Before fix, create a detailed plan** to ensure no details are missed, always include 4 phases: Setup → Analyze → Summary → Teardown.

## Phase 1: Setup

### Pre-check

1. **MCP Server**: This skill depends on `debug-mcp-server` MCP server. If it is not present, **STOP** and request the user to install the MCP server ([Anonymous Mode (Default)](./references/install/mcp-install-anonymous.md) or [Login Mode](./references/install/mcp-install-login.md)).
2. **Authentication**: If any MCP Tool returns a `Unauthorized` error, **STOP** and request the user to configure the `API_KEY` ([Login Mode Guide](./references/install/mcp-install-login.md)).

Verify SDK NOT already installed by checking dependency files:
- Java: `pom.xml` or `build.gradle`
- Node.js: `package.json`
- Python: `requirements.txt` or `pyproject.toml`

**WARNING:** `.syncause` folder is NOT a reliable indicator.

### Steps
1. **Initialize Project**: Use `setup_project(projectPath)` to get the `projectId`, `apiKey`, and `appName`. These are required for SDK installation in the next step.
   - **WARNING:** If tool not found or returns `Unauthorized`, **STOP** and follow [Pre-check](#pre-check).
2. **Install SDK**: Follow language guide:
   - [Java](./references/install/java.md)
   - [Node.js](./references/install/nodejs.md)
   - [Python](./references/install/python.md)
3. **Verify install**: Re-read dependency file to confirm SDK added
4. **Restart service**: Prefer starting new instance on different port over killing process
5. **Search for existing traces**: Before reproducing the bug, first try `search_debug_traces(projectId, query="<symptom>")` to check if relevant trace data already exists.
   - **If traces found** → Skip reproduction, proceed directly to [Phase 2: Analyze & Fix](#phase-2-analyze--fix) using the found `traceId`.
   - **If no traces found** → Continue to Step 6...