System Prompt
soul.md - who am I today? Personality, role and rules as the very first message: how an agent gets its identity.
Basics
Free for everyone: the concept, the analogy, the why.
Before the conversation starts, the harness gives the agent an identity: the system prompt. It sets tone, role and boundaries - and like everything else, it gets read aloud on every single call.
This tier is currently being written. Here is the outline it will follow:
- The system role - Where identity sits in the messages array, and why it travels with every call.
- What belongs in a soul.md - Tone, role, limits - and what has no business being there.
- Rules that hold - How to tell whether an instruction is actually being followed.
Try it interactively
With a free account: hands-on experiments and the quiz for this phase.
Going deeper
With a free account: experiments, quizzes and the deeper material.
Deep dive
For pro members: the depth for everyone who wants to actually build it.