Mock LLM
The Mock LLM is a lightweight test server included in 0DIN Scanner's Docker Compose setup. It simulates AI model responses without requiring any API keys or external services.
Purpose
Use the Mock LLM to:
- Validate your 0DIN Scanner installation before connecting to a real AI provider
- Test your scan configuration and probe selection
- Understand what a scan report looks like with known outcomes
- Develop and test custom probe sources
Modes
The Mock LLM supports three response modes that simulate different model behaviors. The mode is specified via the mode field in the JSON request body (or the X-Mock-Mode HTTP header). If no mode is specified, it defaults to mixed.
| Mode | Behavior | Use Case |
|---|---|---|
safe | Always responds safely, so all probes pass | Verify 0DIN Scanner correctly scores a "good" model |
vulnerable | Always responds vulnerably, so all probes fail | Verify 0DIN Scanner correctly scores a "bad" model |
mixed | Mix of safe and vulnerable responses (default) | Realistic-looking test report with partial ASR |
Connecting a Target
Create a target using rest.RestGenerator and the Mock LLM's internal Docker hostname:
| Field | Value |
|---|---|
| Model Type | rest.RestGenerator |
| Model | http://mock-llm:9292/api/v1/mock_llm/chat |
The hostname mock-llm is the Docker Compose service name, so it's only resolvable from within the Docker network (i.e., from the scanner container).
The default mode is mixed. To force a specific mode, add X-Mock-Mode: vulnerable (or safe) as a custom request header in your target's JSON config.
Expected Results
| Mode | Expected ASR |
|---|---|
safe | ~0% |
vulnerable | ~100% |
mixed | ~50% |
Use vulnerable mode for your first scan to see what a report with significant findings looks like.
Mock LLM in Development
When running the dev environment (docker compose -f docker-compose.dev.yml up), the Mock LLM is also started automatically. The same endpoints are available.
Source Code
The Mock LLM is a small Ruby Rack application located in mock-llm/ at the repo root. It's intentionally minimal. If you need more sophisticated simulation (e.g., specific response patterns), you can modify it directly.