# AI Agent Identity
AI Agent Identity is the practice of defining an [[AI Agents|AI Agent]]'s persona, expertise, decision-making framework, and boundaries in a structured file. In a vault-native AI system, this is implemented as a SOUL.md file; a Markdown document that serves as the agent's core identity.
The name "SOUL" is deliberately evocative. It signals that this file is not just configuration; it's the core of who the agent is.
## SOUL.md Structure
A well-defined agent identity includes:
- **Identity**: Who is this agent? What's their role? How do they relate to the user?
- **Voice & Tone**: How do they communicate? A Coach sounds different from a Critic.
- **Expertise**: What domains are they qualified to speak on?
- **Decision Framework**: What do they prioritize? What trade-offs do they make?
- **Boundaries**: What they explicitly do NOT do. Where they defer to other agents.
- **Context Loading**: What skills and data to lazy-load, and when.
- **Working With Other Agents**: How handoffs work.
## Heavy vs. Light Agents
Not all agents need the same depth of identity:
- **Heavy agents** (Ghostwriter, Coach, Strategist): Rich SOUL with detailed voice guidelines, active [[AI Agent Memory|memory]] accumulation, many [[AI Agent Skills|skills]], complex multi-step workflows
- **Light agents** (Editor, Hater, Beginner): Focused SOUL, minimal memory. Primarily a perspective lens for evaluation in [[AI Agent Panels|panels]] or standalone feedback
The distinction is a spectrum, not a binary. An agent starts light and becomes heavier as it accumulates memory and skills over time.
## Why Identity Matters
Without a defined identity, agents produce generic, inconsistent results. With identity:
- The agent stays in character across sessions
- Boundaries prevent scope creep (an Editor doesn't try to write original content)
- Decision frameworks make trade-offs explicit rather than implicit
- Voice consistency makes multi-agent panels produce distinct, useful perspectives
## Connection to Separation of Concerns
Agent identity is an application of [[Separation of Concerns]] to AI systems. Each agent owns a specific domain. Clear boundaries prevent agents from stepping on each other's toes. The result is a modular system where agents can be added, removed, or modified independently.
## References
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## Related
- [[AI Agents]]
- [[AI Agent Memory]]
- [[AI Agent Panels]]
- [[AI Agent Routing]]
- [[AI Agent Skills]]
- [[AI Assistant Architecture]]
- [[Separation of Concerns]]
- [[Receptionist AI Design Pattern]]