About

FlexTree is a tree-structured data storage and management library based on the Left-Right Value (Nested Set Model) algorithm, targeting Node.js (and Bun) environments. It combines efficient tree-structure queries with a concise API, letting developers perform CRUD, traversal, move, and export operations on trees without hand-writing complex recursive SQL.

Feature Overview

• Efficient queries: Based on the Left-Right Value algorithm, relationship queries such as descendants, ancestors, children, and siblings can all be completed in a single SQL statement—no recursion required.
• Concise API: Semantic method naming with full TypeScript generics support—custom fields still get precise type hints.
• Complete operations: Covers the full lifecycle, including add (with nested batch add), delete, move, update, find, traverse, and export.
• Data safety: Transactional writes guarantee atomicity, a concurrency read guard prevents dirty reads, and tree-structure verify (verify) and repair (repair) are provided.
• Multi-database: Decouples database access via the adapter pattern—ships with three adapters (SQLite, Prisma, Bun SQLite) and can be extended to any database such as MySQL, PostgreSQL, Oracle, or SQL Server.
• Flexible customization: Supports custom key fields, multiple trees in a single table (treeId), singleton management, lazy loading, node events, and more.

Suitable Scenarios

FlexTree is a query-first storage structure, best suited for tree data that is read-heavy and write-light, for example:

• Organization and department hierarchies
• Product / content category catalogs
• Menus and permission trees
• Nested comments and replies
• Hierarchical data such as regions and tags

For scenarios with frequent structural changes (high-frequency writes), consider the trade-offs in Features, Strengths & Limitations before choosing.

Next

• Quick Start: Get up and running with FlexTree in minutes.
• How It Works: Learn about the Left-Right Value algorithm and how it compares to other tree-storage solutions.
• Features: A full overview of FlexTree's capabilities and limitations.
• Changelog: View version changes.

Project Information

• License: MIT
• Source repository: GitHub
• Runtime: Node.js / Bun