Customizing your AI agent's personality and behavior with SOUL.md

Every Klow agent has a SOUL.md file in its workspace. This file is loaded at the start of every session — it's the first thing your agent reads before doing anything else. It shapes personality, expertise, tone, boundaries, and behavior. If you want your agent to act a specific way, SOUL.md is where you define it.

What goes in SOUL.md

Think of SOUL.md as a job description combined with a personality brief. It answers: Who are you? What do you do? How do you communicate? What are your rules?

Formal vs. casual: two approaches

The same agent framework can feel completely different based on SOUL.md. Here's the difference:

Formal business agent

Casual personal assistant

Giving your agent domain expertise

SOUL.md is also where you inject domain knowledge. If your agent handles crypto, tell it the protocols you use, the chains you care about, your risk tolerance. If it handles marketing, give it your brand guidelines, target audience, and tone of voice. The more specific you are, the less you'll need to repeat yourself in every conversation.

The full workspace file system

SOUL.md isn't the only file that shapes behavior. Your agent's workspace has several key files:

• →SOUL.md — personality, expertise, communication rules (loaded every session)
• →MEMORY.md — curated long-term memory: key facts, preferences, project context
• →HEARTBEAT.md — checklist for periodic proactive check-ins
• →TOOLS.md — notes about the agent's specific tool configuration and environment
• →memory/ folder — daily log files the agent writes automatically

MEMORY.md: the long-term brain

While SOUL.md defines who the agent is, MEMORY.md defines what it knows. Add key context here: your company's mission, important contacts, ongoing projects, decisions that were made. The agent reads this every session, so it always has the big picture without you needing to repeat it.

Editing workspace files

You can edit all workspace files from the Klow dashboard under the Workspace tab. Changes take effect on the agent's next session — no redeploy, no restart. You can also ask your agent to edit its own files: "Update your SOUL.md to be more concise" works perfectly. For more agent optimization, see 10 power-user tips and agent streaks and daily digests.

“A well-written SOUL.md is the difference between an agent that feels like a generic chatbot and one that feels like it was built specifically for you. Spend 10 minutes on it. You'll save hours.”