# Overview

{% hint style="info" %}

### 📜 **TL;DR:**

* The Hemi Bitcoin Kit (hBK) enables direct interaction with Bitcoin blockchain data within Ethereum’s environment.
* hBK utilizes Hemi Virtual Machine (hVM) to embed a fully indexed Bitcoin node inside the Ethereum Virtual Machine (EVM).
* hBK allows Ethereum smart contracts to query Bitcoin data using precompiled calls, ensuring efficient, trustless data access.
  {% endhint %}

***

## ⚙️ How It Works

#### Hemi Virtual Machine (hVM)

The hVM is the backbone of the hBK’s interoperability features, embedding a Bitcoin node within the EVM. This setup allows Ethereum smart contracts to directly query Bitcoin data without relying on external bridges or third-party oracles, ensuring trustless, efficient, and secure access to Bitcoin data.

* Direct Access: Smart contracts can communicate with Bitcoin data embedded in the EVM, enabling them to make queries and receive data via precompiled calls.
* Indexed Data: The fully indexed Bitcoin node maintains transaction history, UTXOs, and meta-protocols like Ordinals and BRC-20 tokens.

#### Developer Interface: Simplified Interaction with Bitcoin

The hBK abstracts technical complexities, offering developers straightforward methods for accessing Bitcoin data, allowing them to:

1. Directly Pass Data to Precompiled Calls: Simple data serialization/deserialization processes provide a transparent gateway to precompiled Bitcoin calls.
2. Enhanced Query Functions (Upcoming): hBK is set to introduce enhanced functions, combining multiple precompile calls and additional processing steps for advanced operations.

This dual approach ensures developers can create Bitcoin-aware applications without managing low-level integration details, focusing instead on innovation and functionality.

***

## 🔑 Key Features

* **Embedded Node Access:** hBK integrates a fully indexed Bitcoin node within Hemi’s EVM environment, exposing robust Bitcoin data for smart contract use.
* **Precompiled Calls for Direct Data Retrieval:** Passthrough functions facilitate Bitcoin data queries with direct calls, automatically handling the data structures.
* **Enhanced Functions for Advanced Queries:** Future upgrades will introduce enhanced functions, combining multiple calls and added processing to support more complex queries and data requirements.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.hemi.xyz/building-bitcoin-apps/hemi-bitcoin-kit-hbk/overview.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.