Introducing the Model Spec

Update on February 12, 2025: We’ve released an updated version of the Model Spec. This update reinforces our commitments to customizability, transparency, and intellectual freedom to explore, debate, and create with AI without arbitrary restrictions—while ensuring that guardrails remain in place to reduce the risk of real harm. It builds on the foundations we introduced last May, drawing from our experience applying it in varied contexts from alignment research to serving users across the world. You can read more about the update in this blog post.

May 8, 2024: We are sharing a first draft of the Model Spec, a new document that specifies how we want our models to behave in the OpenAI API and ChatGPT. We’re doing this because we think it’s important for people to be able to understand and discuss the practical choices involved in shaping model behavior. The Model Spec reflects existing documentation that we’ve used at OpenAI, our research and experience in designing model behavior, and work in progress to inform the development of future models. This is a continuation of our ongoing commitment⁠ to improve model behavior using human input, and complements our collective alignment work⁠ and broader systematic approach to model safety.

Shaping Desired Model Behavior

Model behavior, or the way that models respond to input from users—encompassing tone, personality, response length, and more—is critical to the way humans interact with AI capabilities. Shaping this behavior is a still nascent science, as models are not explicitly programmed but instead learn from a broad range of data⁠. 

Introducing the Model Spec

1. Objectives: Broad, general principles that provide a directional sense of the desired behavior

2. Rules: Instructions that address complexity and help ensure safety and legality

3. Default behaviors: Guidelines that are consistent with objectives and rules, providing a template for handling conflicts and demonstrating how to prioritize and balance objectives