ollama-model-safety-guardrails

Ollama Model Selection for Sensitive Content Processing

Problem

When using Ollama to process legal but sensitive content (e.g., sex work information in jurisdictions where it's legal, adult content analysis, harm reduction data), many popular models refuse to engage with the content due to built-in safety guardrails, even with explicit system prompts establishing legal context.

Context / Trigger Conditions

• LLM returns responses like "I cannot assist with this request" or generic safety disclaimers
• The content is legal in context (e.g., sex work in Uruguay under Ley 17.515)
• System prompts establishing legal/professional context are ignored
• You need structured data extraction, summarization, or analysis of sensitive text
• Using Ollama locally (privacy-first, no API key needed)

Solution

Model Selection

Recommendation: Use mistral (or mixtral for better quality) when processing legal-but-sensitive content that other models refuse.

API Selection: Chat vs Generate

Use /api/chat instead of /api/generate for system prompt support:

// WRONG: /api/generate doesn't properly support system prompts
const response = await fetch('http://localhost:11434/api/generate', {
  method: 'POST',
  body: JSON.stringify({ model: 'mistral', prompt: userPrompt, system: systemPrompt }),
});

// RIGHT: /api/chat with messages array
const response = await fetch('http://localhost:11434/api/chat', {
  method: 'POST',
  body: JSON.stringify({
    model: 'mistral',
    messages: [
      { role: 'system', content: systemPrompt },
      { role: 'user', content: userPrompt },
    ],
    stream: false,
  }),
});
const data = await response.json();
const result = data.message?.content || '';