System Prompt

Overview

system_prompt is a route-local plugin for inserting or modifying the system prompt on matched traffic.

It aligns to config/plugin/system-prompt/expert.yaml.

Key Advantages

• Keeps instruction shaping local to the route.
• Makes prompt mode explicit instead of hiding it in application code.
• Works well for expert, persona, or workflow-specific routes.

What Problem Does It Solve?

Some routes need a different instruction layer than the router default. system_prompt lets those routes attach the extra prompt context without affecting unrelated traffic.

When to Use

• one route needs an expert or persona-specific instruction layer
• prompt insertion should happen after the decision matches
• prompt policy should stay visible in the route config

Configuration

Use this fragment under routing.decisions[].plugins:

plugin:
  type: system_prompt
  configuration:
    enabled: true
    mode: insert
    system_prompt: You are a domain expert. Answer precisely, state tradeoffs, and keep the response actionable.