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

# 📚 Core Concepts

Welcome to the foundational layer of **QIE** — an EVM-compatible blockchain. This page explains the key ideas that power our network and help you build efficient, scalable, and secure dApps that benefit from both Ethereum and Cosmos ecosystems.

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### 🧱 1. EVM Compatibility

QIE is fully compatible with the **Ethereum Virtual Machine (EVM)**, meaning:

* You can write smart contracts in **Solidity** or **Vyper**.
* Ethereum tools like **MetaMask**, **Hardhat**, **Truffle**, and **Remix** work seamlessly.
* You can deploy contracts, use Ethereum libraries, and migrate dApps with minimal changes.

> ✅ If it works on Ethereum, it works on QIE — with cross-chain capabilities.

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### ⚡ 2. High Throughput via Cosmos Stack

QIE leverages the **Cosmos SDK** and **Tendermint Core (CometBFT)** consensus for high performance:

* Fast block times (\~2 seconds)
* Finality on each block (no probabilistic finality)
* Designed to support high-volume dApps like DeFi, games, and on-chain identity

> Achieving thousands of TPS through modular design and parallel transaction execution.

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### 💰 3. Low Transaction Fees

Thanks to our efficient architecture and Cosmos-based fee model:

* Fees are predictable and **much lower than Ethereum**.
* Ideal for microtransactions, NFTs, and other cost-sensitive operations.
* Developers can subsidize gas for users or use fee abstraction models.

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### 🔄 4. Tendermint-Based Consensus

QIE uses **Tendermint Core** (BFT-based consensus), offering:

* **Fast finality** (no waiting for confirmations)
* High throughput and network stability
* **Validator-based governance** for upgrades and economic changes

> Want to become a validator or delegator? Explore our Validator Setup Guide

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### 🧩 5. Modular Architecture

QIE offers a highly modular design:

* Add or modify modules without hard forks
* Customize features like staking, governance, and fee handling
* Future-proof architecture supporting upgrades and innovation

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### 🔗 6. Interoperability via IBC & Bridges

QIE is **interoperable by design**, thanks to:

* **IBC (Inter-Blockchain Communication)** for direct messaging between Cosmos chains
* Bridges to Ethereum and other major ecosystems
* Support for ERC-20, ERC-721, ERC-1155 standards

> Build multi-chain dApps and access liquidity across chains.

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### 🧠 7. Smart Contracts & Storage

On QIE, smart contracts:

* Run on the **EVM-compatible execution layer**
* Maintain state across blocks with native on-chain storage
* Can access external data via oracles and cross-chain interfaces

Smart contracts deployed on Ethereum can be migrated with minimal changes.

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### 📊 8. Native Coin

* **Coin Symbol:** QIE
* **Utility:** Paying gas fees, staking, validator rewards, governance
* Can be transferred across Cosmos chains via IBC and bridged to EVM chains

> Designed for real utility, governance, and ecosystem incentives.

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