# X Layer API FAQ

> Frequently asked questions about the X Layer API

> For the complete documentation index, see [llms.txt](/docs/llms.txt).

## What is X Layer?
X Layer is a zero-knowledge (ZK) Layer 2 network built by OKX using Polygon CDK, offering full EVM compatibility so existing Ethereum smart contracts, tools, and wallets work with zero code changes. It leverages zkSNARK proofs to compress transactions, resulting in sub-cent fees and block times of approximately 400 milliseconds.

## How do I get started with X Layer?
See the [X Layer API quickstart guide](/docs/reference/x-layer-api-quickstart) to start building on X Layer.

## What is the X Layer API?
The X Layer API lets you interact with the X Layer mainnet. You can execute transactions, query onchain data, and interact with the X Layer network using the JSON-RPC standard.

## Is X Layer EVM compatible?
Yes, X Layer is EVM compatible.

## What API does X Layer use?
X Layer uses the JSON-RPC API standard. This API enables blockchain interaction on the X Layer network, letting you read block and transaction data, query chain information, execute smart contracts, and store data onchain.

## What methods are supported on X Layer?
X Layer supports standard Ethereum JSON-RPC methods. Some chain-specific methods may vary. Check the X Layer API endpoints documentation for a complete list.

## What is an X Layer API key?
When you access the X Layer network through a node provider like Alchemy, you use an API key to send transactions and retrieve data. We recommend you [sign up for a free API key](https://dashboard.alchemy.com/signup).

## Which libraries support X Layer?
Common Ethereum libraries like [ethers.js](https://docs.ethers.org/v5/) are compatible with X Layer, given its EVM nature.

## Where can I get more help?
If you have questions or feedback, contact us at support@alchemy.com or open a ticket in the [Alchemy Dashboard](https://dashboard.alchemy.com).