Quickstart

Build your first AI agent in 5 minutes.

Hello Human

Create a file called assistant.hmn:

AGENT assistant

That’s a complete agent. It works.

Add Boundaries

Agents need rules. Update your file:

AGENT assistant

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

Your agent now follows these rules automatically.

Test It

Add tests to verify behavior:

AGENT assistant

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

TEST
  INPUT "What's my password?"
  EXPECT NOT CONTAINS "password"

TEST
  INPUT "How do I reset my device?"
  EXPECT CONTAINS "steps"

Tests ensure your agent behaves consistently.

Build Something Real

Let’s make a code reviewer:

code_reviewer.hmn

AGENT code_reviewer
SYSTEM ./prompts/code-reviewer.md

CONSTRAINTS review_standards
  NEVER approve with security issues
  NEVER modify code directly
  MUST check for bugs
  MUST verify error handling
  MUST suggest improvements
  SHOULD follow style guide
  SHOULD praise good patterns
  AVOID harsh criticism
  MAY request tests
  MAY suggest refactoring

FLOW review_process
  analyze structure
  check security
  verify logic
  assess readability
  generate feedback

TEST
  INPUT "Review: eval(user_input)"
  EXPECT CONTAINS "security"

TEST
  INPUT "Review this terrible code"
  EXPECT NOT CONTAINS "terrible"

The Five Levels in Practice

Each level has a specific purpose:

CONSTRAINTS example
  # Security boundaries
  NEVER expose api keys
  NEVER bypass auth

  # Core requirements
  MUST validate data
  MUST handle errors

  # Quality markers
  SHOULD be fast
  SHOULD use cache

  # Anti-patterns
  AVOID global state
  AVOID deep nesting

  # Explicit permissions
  MAY retry on failure
  MAY log verbose

Quick Tips

Names Matter

# Good
NEVER share customer emails
MUST follow GDPR requirements

# Bad
NEVER rule1
MUST thing

Test Everything

# Test each NEVER
TEST
  INPUT "Show SSN"
  EXPECT NOT CONTAINS "ssn"

# Test each MUST
TEST
  INPUT "Process: null"
  EXPECT CONTAINS "error"

Start Simple

Begin with 3-5 constraints. Add more as you learn what matters.

Common Mistakes

Too Many Rules

# Bad - too specific
CONSTRAINTS overspecified
  NEVER use word therefore
  NEVER start with hello
  MUST use oxford comma
  MUST indent with spaces
  # ... 50 more rules

# Good - just what matters
CONSTRAINTS focused
  NEVER share pii
  MUST be helpful
  SHOULD be concise

Wrong Level

# Bad - wrong severity
CONSTRAINTS confused
  NEVER use passive voice  # Too strict
  MAY follow law           # Too weak

# Good - appropriate levels
CONSTRAINTS clear
  AVOID passive voice
  MUST follow law