┌─────────────┐     stdio/SSE      ┌─────────────────┐
│   Claude    │ ◄─────────────────► │   MCP Server    │
│  (or LLM)   │      (MCP)         │   (Python)      │
└─────────────┘                    └────────┬────────┘
                                            │
                                            │ janus-swi
                                            ▼
                                   ┌─────────────────┐
                                   │   SWI-Prolog    │
                                   │  (swipl engine) │
                                   └─────────────────┘

cd prolog-debug-mcp
uv sync

{
  "mcpServers": {
    "prolog-debug": {
      "command": "uv",
      "args": ["run", "--directory", "/path/to/prolog-debug-mcp", "python", "-m", "prolog_debug_mcp.server"]
    }
  }
}

User: "My web app is returning 500 errors. It talks to a postgres
       database and a redis cache. The redis pod is in CrashLoopBackOff."

Claude: Let me set up the dependency model and record the errors.

[Calls assert_dependency("webapp", "postgres")]
[Calls assert_dependency("webapp", "redis")]
[Calls assert_error("webapp", "500_error")]
[Calls assert_error("redis", "crashloopbackoff")]
[Calls find_root_causes("webapp")]

Result:
{
  "service": "webapp",
  "root_causes": [
    {"symptom": "crashloopbackoff", "path": ["webapp", "redis"]}
  ]
}

Claude: The root cause traces to Redis being in CrashLoopBackOff.
        The webapp depends on Redis, so when Redis crashes, the
        webapp returns 500s. Check the Redis pod logs for why
        it's crash-looping.

# Run all tests
uv run pytest

# Run with verbose output
uv run pytest -v

# Run specific test file
uv run pytest tests/test_prolog.py