backend-manager

Imported from metacraft-labs/codetracer (src/backend-manager/AGENTS.md). Install upstream with npx skills add metacraft-labs/codetracer --skill backend-manager. Copyright stays with the author.

Backend Manager Development Guide

Building and Testing

Build:

cargo build

Run tests:

cargo nextest run

Run a single test:

cargo nextest run --profile single <test_name>

Lint:

cargo clippy

MCP Server Setup

The MCP server exposes CodeTracer trace querying as tools for LLM agents. It communicates via JSON-RPC 2.0 over stdin/stdout (Model Context Protocol).

Claude Code Configuration

Add to .claude/mcp.json in your project root:

{
  "mcpServers": {
    "codetracer": {
      "command": "backend-manager",
      "args": ["trace", "mcp"],
      "env": {
        "CODETRACER_PYTHON_API_PATH": "/path/to/codetracer/python-api"
      }
    }
  }
}

If backend-manager is not on your PATH, use the full path to the binary.

Other MCP Clients

Any MCP-compatible client can connect by spawning backend-manager trace mcp and communicating via stdin/stdout with newline-delimited JSON-RPC 2.0.

Environment Variables

• CODETRACER_PYTHON_API_PATH - Path to the Python API package (required for exec_script tool to import codetracer).
• CODETRACER_DAEMON_SOCK - Override the daemon socket path (used in tests).
• TMPDIR - Affects where the daemon socket and PID files are created.

Available MCP Tools

• exec_script - Execute a Python script against a trace.
• trace_info - Get metadata about a trace.
• list_source_files - List source files in a trace.
• read_source_file - Read a source file from a trace.

Available MCP Prompts

• trace_query_api - Returns the Python Trace Query API reference for LLM context.

Available MCP Resources

After loading a trace (via exec_script or trace_info), resources become available:

• trace:///<trace_path>/info - Trace metadata (JSON)
• trace:///<trace_path>/source/<file_path> - Source file content (text)