> For the complete documentation index, see [llms.txt](https://xylem.gitbook.io/xylem-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://xylem.gitbook.io/xylem-docs/readme.md).

# Introduction

Xylem is a revolutionary **multi-model embedded database** engine built from the ground up in modern C++17. It is designed to combine several core engineering concepts that traditionally require separate libraries:

* **Transactional MVCC Row Store with Predicate Locks** (Alternative to SQLite with advanced query-level locking)
* **Hierarchical Graph Database** (Alternative to Neo4j/custom graph stores)
* **Vector Search Similarity Index** (Alternative to FAISS/Pinecone)
* **Content-Addressable Blob Storage & physical shredding (BURN)** (Alternative to custom file containers with high-security erasing)
* **Query Interception & Overlays** (Flexible callback hook system for mocking, redirection, and custom operators)
* **Raw Flash Wear-Leveling Layer** (Alternative to littlefs/SPIFFS)

By packing all these components into a single format, Xylem provides a unified and highly robust data container.

## Why Xylem?

When developing software for edge devices, embedded systems (like ESP32/ARM), or local desktop tools, you often need to store different types of data:

1. **System Logs and Configuration:** Best stored in relational tables.
2. **Files, Images, Assets:** Best stored in a blob store with deduplication.
3. **AI Embeddings:** Best stored in a vector index for fast similarity search.
4. **Complex Directories or Networks:** Best stored in a graph.

Normally, developers are forced to layer multiple database libraries and virtual file systems on top of each other. This increases firmware size, duplicates memory budgets, and complicates crash consistency.

**Xylem solves this by merging all storage backends into a single raw block manager.**

## Core Links

* **GitHub Repository:** [xipid/xylem](https://github.com/xipid/xylem)
* **Discord Server:** [Join our Discord](https://discord.gg/s7Rg4DHuej)
* **PlatformIO Registry:** `xipid/Xylem`
* **License:** Apache 2.0