Rune-stone

Full Project Example: Online Bookstore Orders

This example demonstrates the complete RUNE pipeline from business requirements to tested code.

The Pipeline

REQUIREMENTS.md  ──▶  specs/*.rune  ──▶  src/*.py  ──▶  tests/*.py
   (Analyst)        (Analyst + AI)   (Developer + AI) (Developer + AI)

Step 1: Analyst writes requirements

The analyst produces REQUIREMENTS.md — a plain-language document describing what the system should do. No code, no technical spec. Just business rules and examples.

Step 2: Analyst + AI generates RUNE specs

The analyst feeds the requirements to an AI assistant (Claude, GPT, Cursor) with the RUNE skill loaded. The AI translates each requirement into a formal .rune specification:

• specs/calculate_order_total.rune — from requirement “Calculate Order Total”
• specs/validate_coupon.rune — from requirement “Validate Coupon”
• specs/check_free_shipping.rune — from requirement “Check Free Shipping”

Each spec contains the exact signature, behavior rules, constraints, edge cases, and test cases — all derived from the business rules.

Step 3: Developer + AI generates implementation

The developer gives the .rune specs to their AI coding tool. The AI generates implementations that follow the spec exactly:

• src/order_total.py — implements calculate_order_total.rune
• src/coupon.py — implements validate_coupon.rune
• src/shipping.py — implements check_free_shipping.rune

Step 4: Developer + AI generates tests

From the same specs, the AI generates a complete test suite:

• tests/test_order_total.py — 10 tests from spec
• tests/test_coupon.py — 9 tests from spec
• tests/test_shipping.py — 9 tests from spec

Directory Structure

full-project/
├── README.md                           # This file
├── REQUIREMENTS.md                     # Step 1: Business requirements
├── specs/
│   ├── calculate_order_total.rune      # Step 2: Formal specs
│   ├── validate_coupon.rune
│   └── check_free_shipping.rune
├── src/
│   ├── order_total.py                  # Step 3: Implementations
│   ├── coupon.py
│   └── shipping.py
└── tests/
    ├── test_order_total.py             # Step 4: Test suites
    ├── test_coupon.py
    └── test_shipping.py

Running the Tests

cd examples/full-project
pip install pytest
pytest tests/ -v

Why This Works

The .rune spec acts as a contract between analyst and developer:

• Analyst defines what the code should do (behavior, constraints, edge cases)
• Developer defines how the code does it (implementation, architecture, patterns)
• AI translates in both directions — requirements to spec, spec to code
• Tests are generated automatically from the spec, not invented after the fact

The spec is the single source of truth. If requirements change, update the spec, regenerate the code.

Try It Yourself

1. Read REQUIREMENTS.md
2. Give it to your AI assistant with: “Generate RUNE specs from these requirements”
3. Compare what you get with the specs in specs/
4. Then ask: “Generate Python code from calculate_order_total.rune”
5. Compare with src/order_total.py

For the complete setup guide (what to upload, what prompts to use, how to iterate), see the Workflow Guide.

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