Prolog Debug Mcp — independently scanned and version-tracked by SaferSkills.
SaferSkills independently audited Prolog Debug Mcp (Agent Skill) and scored it 100/100 (green). The audit ran 55 deterministic rules across Security, Supply Chain, Maintenance, Transparency, and Community; it found 0 high-severity and 0 lower-severity findings. The full rule-by-rule trace and per-finding evidence are below. Free, methodology-open.
Findings & checks · 0 flagged
Every scanned point with the score it earned and what moved between them.
First recorded scan — no prior version to compare against.
The primary manifest — the file an agent reads to learn what this artifact does.
An MCP (Model Context Protocol) server that exposes SWI-Prolog as a debugging and diagnostic reasoning engine. Claude parses errors and symptoms, Prolog does logical deduction to find root causes.
┌─────────────┐ stdio/SSE ┌─────────────────┐
│ Claude │ ◄─────────────────► │ MCP Server │
│ (or LLM) │ (MCP) │ (Python) │
└─────────────┘ └────────┬────────┘
│
│ janus-swi
▼
┌─────────────────┐
│ SWI-Prolog │
│ (swipl engine) │
└─────────────────┘ # macOS
brew install swi-prolog
# Ubuntu/Debian
sudo apt install swi-prologcd prolog-debug-mcp
uv syncAdd to ~/.claude/settings.json:
{
"mcpServers": {
"prolog-debug": {
"command": "uv",
"args": ["run", "--directory", "/path/to/prolog-debug-mcp", "python", "-m", "prolog_debug_mcp.server"]
}
}
}| Tool | Description |
|---|---|
assert_dependency | Add a dependency: service depends on depends_on |
assert_error | Record an observed error/symptom for a service |
find_root_causes | Find all possible root causes for a service's errors |
suggest_checks | Get suggested services to check based on dependencies |
impact_analysis | Find all services affected if a given service fails |
check_cycles | Check for dependency cycles involving a service |
get_status | Get current session status (all services, dependencies, errors) |
clear_session | Clear all asserted facts, start fresh |
query | Run arbitrary Prolog query (advanced) |
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.pyThe server uses a knowledge base with these key predicates:
depends(Service, DependsOn) - Service depends on DependsOnerror(Service, Symptom) - Service has an observed error/symptomroot_cause(Service, Symptom, Path) - Traces errors through dependencies to find root causeshas_cycle(Service) - Detects dependency cyclesA root cause is found when:
This allows the system to answer "why is X failing?" by following the dependency chain to the actual source of the problem.
| Component | Choice | Rationale |
|---|---|---|
| MCP Framework | mcp (official SDK) | Official Python SDK for MCP |
| Prolog Bridge | janus-swi | 5x faster than pyswip, C API, actively maintained |
| Prolog Engine | SWI-Prolog 9.1.12+ | Required by janus, robust, good docs |
| Python | 3.10+ | Type hints, async support |
CC0 1.0 Universal - Public Domain
~30 seconds. Free. No account. Every finding cites a rule and a line of evidence.