PolicyEngine

A small domain-specific language for business rules, parsed and evaluated at runtime.

📖 Overview

PolicyEngine lets rules be written in a readable DSL, parses them into an AST, and evaluates them against runtime context — so business logic lives in editable rules, not scattered conditionals.

Built on the "Antigravity" model.

🚀 Quick Start

# 1. Clone
git clone https://github.com/Kimosabey/policy-engine.git
cd policy-engine

# 2. Install
# (see docs/GETTING_STARTED.md for the full setup)

# 3. Run
docker compose up

✨ Key Features

• Readable rule DSL
• Parser → AST → evaluator pipeline
• Runtime rule updates without redeploy
• Explainable rule outcomes

🏗️ Architecture

%%{init: {'theme':'base','themeVariables':{'primaryColor':'#ffffff','lineColor':'#2563eb','mainBkg':'#ffffff'}}}%%
graph LR
    A([Rule DSL])
    B([Parser])
    C([AST])
    D([Evaluator])
    A --> B
    B --> C
    C --> D
    style A fill:#eff6ff,stroke:#2563eb,stroke-width:2px,color:#1e40af
    style B fill:#eff6ff,stroke:#2563eb,stroke-width:2px,color:#1e40af
    style C fill:#eff6ff,stroke:#2563eb,stroke-width:2px,color:#1e40af
    style D fill:#eff6ff,stroke:#2563eb,stroke-width:2px,color:#1e40af

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Designing a language — grammar, parsing, and safe evaluation — that non-authors can still read.

See docs/ARCHITECTURE.md for the full HLD/LLD and design decisions.

🧰 Tech Stack

Layer	Technology	Role
TypeScript	TypeScript	Type-safe application code
Node.js	Node.js	Application runtime / service layer

📚 Documentation

• Architecture — high- and low-level design, decision log
• Getting Started — prerequisites, setup, environment
• Failure Scenarios — fault analysis and recovery
• Interview Q&A — deep-dive walkthrough

🔭 Future Enhancements

• Rule versioning
• Dry-run / simulation
• Rule conflict detection

📄 License

Released under the MIT License.

👤 Author

Harshan Aiyappa Senior Full-Stack Hybrid AI Engineer Voice AI • Distributed Systems • Infrastructure