> ## Documentation Index
> Fetch the complete documentation index at: https://docs.functionlab.app/llms.txt
> Use this file to discover all available pages before exploring further.

# Overview

# Function Lab Documentation

**Function Lab** is a powerful Shopify app that enables advanced configuration of Shopify Functions through a flexible rule-based engine. Build sophisticated discount logic, customize checkout behavior, and create dynamic cart transformations—all through JSON configuration, no code required.

## What is Function Lab?

Function Lab leverages Shopify's Functions API to provide fine-grained control over your store's pricing, checkout, and cart behavior. Instead of writing and deploying custom functions, you configure rules using a declarative JSON format powered by the `shopify-rules-engine`.

### Key Capabilities

* **Product Discounts**: Percentage or fixed amount discounts with advanced targeting
* **Shipping Discounts**: Free shipping, rate adjustments, and method-specific rules
* **Order Discounts**: Cart-level discounts with flexible targeting
* **Delivery Customization**: Hide, reorder, or filter shipping methods
* **Payment Customization**: Control available payment methods
* **Cart Transforms**: Merge line items into bundles or update cart properties

## Why Use Function Lab?

### No Code Required

Configure complex business logic through JSON rules instead of writing and maintaining custom functions.

### Powerful Expression System

Use JMESPath or custom filter syntax to query cart data, customer attributes, product metadata, and more.

### Dynamic Pricing

Implement tiered pricing, customer-specific rates, geographic pricing, and conditional discounts.

### Real-Time Testing

Test your configurations directly in the Shopify admin with instant preview feedback.

### Professional-Grade Features

* Multi-rule strategies with precedence control
* Facts system for complex calculations
* Conditional logic with boolean operations
* Metafield and customer attribute integration
* Performance-optimized evaluation engine

## Quick Navigation

### New to Function Lab?

Start with the [Quick Start Guide](getting-started/quick-start.md) to create your first function in 5 minutes.

### Understanding the Basics

Read [Core Concepts](getting-started/core-concepts.md) to learn the fundamental building blocks: rules, conditions, events, and facts.

### Building Specific Functions

Jump to [Function Types](function-types/product-discounts/overview.md) to explore detailed documentation for each function type with examples.

### Advanced Use Cases

Explore [Advanced Features](advanced/facts/README.md) for complex conditions, dynamic values, and performance optimization.

### Looking for Examples?

Browse the [Cookbook](reference/cookbook/README.md) for 30+ ready-to-use recipes covering common business scenarios.

### Need Help?

Check the [Troubleshooting Guide](reference/troubleshooting/README.md) for common errors and debugging strategies.

## Version & Compatibility

This documentation covers Function Lab for Shopify Functions API. All examples are tested and validated against the current Shopify Functions API specification.

**Requirements:**

* Shopify Plus plan (required for Functions API access)
* Function Lab app installed from Shopify App Store
* Admin API access for function configuration

## What's in This Documentation

| Section               | What You'll Find                                                       |
| --------------------- | ---------------------------------------------------------------------- |
| **Getting Started**   | Quick start tutorial, core concepts, testing guide, common patterns    |
| **Function Types**    | Detailed reference for each function type with parameters and examples |
| **Advanced Features** | Facts system, complex conditions, dynamic values, optimization         |
| **Reference**         | Complete API reference, cookbook recipes, troubleshooting guide        |

## Community & Support

* **GitHub Issues**: Report bugs or request features
* **Documentation Feedback**: Help us improve these docs
* **App Support**: Contact Function Lab support team

***

**Ready to get started?** → [Quick Start Guide](getting-started/quick-start.md)

**Want to understand the concepts first?** → [Core Concepts](getting-started/core-concepts.md)

**Looking for specific examples?** → [Cookbook](reference/cookbook/README.md)