Concept dictionary
System Prompt
A system prompt is a set of higher-priority instructions supplied by a model provider or application developer to shape an AI assistant's role, behavior, boundaries, and response style.
- Review state
- Reviewed in POC
- Freshness
- Current
- Version
- 2
Also called
- System Prompt
- System Message
Remember it this wayThe application sets the role before the user makes the request.
In plain language
The user usually writes the visible request, while the application may also send background instructions that establish how the assistant should respond. Exact instruction priority and visibility depend on the system.
Why it matters
System prompts can explain consistent product behavior, but they are only one control layer and can interact with tools, policies, retrieval, user input, and model limitations.
Example
A support assistant receives background instructions to answer only from approved documentation and to hand uncertain cases to a person.
Common misconception
A system prompt is not an absolute security boundary. It guides behavior but still requires testing, access controls, and application-level safeguards.
Related terms
Sources
- NIST AI 100-2 E2025, Adversarial Machine LearningNIST terminology for system prompts and prompt-based attacks.
Learn more
- Contrast intended instructions with [[prompt-injection|Prompt Injection]].