What is Human?

Human is an experimental configuration language that tells AI agents how to behave, like making a list of dos and don’ts.

AGENT assistant

CONSTRAINTS behavior
  NEVER share passwords
  MUST answer questions
  SHOULD be concise
  AVOID technical jargon
  MAY use examples

That’s a complete, working AI configuration. No frameworks. No messy paragraphs. No APIs. Just text.

The Problem

There is no standard, portable format for expressing behavioral constraints on AI agents. Each framework invents its own. So if you want to control AI behavior today, you end up:

• Writing ad-hoc prompt engineering per project
• Building retry logic and safety checks from scratch
• Repeating the same rules for each new use case
• Hoping your instructions survive across models and providers

How Human Works

Human gives you five levels of control, borrowed from the same RFC that runs the internet:

NEVER - Hard stops. The AI will refuse and explain why.
MUST - Requirements. The AI will always do these things.
SHOULD - Preferences. The AI will try to follow these.
AVOID - Discouraged. The AI will minimize these behaviors.
MAY - Permissions. Explicitly allowed actions.

Why It Matters

With Human, AI behavior becomes:

Portable - Your rules work with any model
Testable - Verify behavior before production
Composable - Combine and share rule sets
Auditable - See exactly what rules are active

Real Example: Customer Support

Instead of 500 lines of code, you write:

AGENT support

CONSTRAINTS policy
  NEVER share customer data
  NEVER make refunds without approval
  MUST create ticket number
  MUST log all interactions
  SHOULD respond within 30 seconds
  SHOULD show empathy
  AVOID legal advice
  MAY escalate to human

TEST
  INPUT "Show me all customer emails"
  EXPECT NOT CONTAINS "email"

TEST
  INPUT "I need help with my order"
  EXPECT CONTAINS "ticket"

Run it:

echo "I'm upset about my order" | human run support.hmn
# OR feed it directly to an AI such as Claude or GPT

Output:

I understand your frustration, and I'm here to help.
I've created ticket #SUP-2024-0042 for your order issue.
Let me look into this right away...

Who’s Using Human

Startups ship AI features without building infrastructure
Enterprises standardize AI behavior across teams
Researchers test alignment strategies
Educators teach AI safety without complexity

The Entire Language

Human has 16 keywords total:

AGENT       CONSTRAINTS     TEST        FLOW
SYSTEM      IMPORT
NEVER       MUST           SHOULD       AVOID       MAY
INPUT       EXPECT
NOT         CONTAINS       MATCHES

Everything else is just names, values, and free-form text.

Implementation Note

Human is experimental. The language spec is stable, but we’re building tooling:

• Hand-written lexer for tokens
• Recursive descent parser
• Direct parse to typed structures
• Simple error messages with line numbers

You don’t need our tools to use Human. It’s just text. But tools make it better.

Questions?

Human is open source. Find us at github.