> ## Documentation Index
> Fetch the complete documentation index at: https://docs.layerzero.network/llms.txt
> Use this file to discover all available pages before exploring further.

# LayerZero V2 Solidity Contract Standards

> Overview of Solidity Contract Standards on LayerZero V2. Learn the architecture, features, and how to get started building. LayerZero enables secure...

LayerZero enables seamless crosschain messaging, configurations for security, and other quality of life improvements to simplify crosschain development.

## LayerZero Solidity Contract Standards

<Columns cols={3}>
  <Card title="OApp Standard" icon="wrench" href="/v2/developers/evm/oapp/overview">
    The push-based message passing standard, enabling crosschain data transfer and external function calls.
  </Card>

  <Card title="OFT Standard" icon="wrench" href="/v2/developers/evm/oft/quickstart">
    Extension of OApp, combining the ERC20 token standard with core bridge logic to make Omnichain Fungible Tokens.
  </Card>

  <Card title="ONFT Standard" icon="wrench" href="/v2/developers/evm/onft/quickstart">
    Combines the ERC721 token standard with core bridge logic to make Omnichain Non-Fungible Tokens.
  </Card>
</Columns>

<Columns cols={3}>
  <Card title="lzRead Standard" icon="wrench" href="/v2/developers/evm/lzread/overview">
    Pull contract state information from other networks to a source blockchain using Omnichain Queries.
  </Card>

  <Card title="Composer Standard" icon="wrench" href="/v2/developers/evm/composer/overview">
    Trigger additional contract calls and logic after push or pull based messages finish executing.
  </Card>

  <Card title="OVault Standard" icon="wrench" href="/v2/developers/evm/ovault/overview">
    Enable crosschain deposits and withdrawals with unified vault interfaces for omnichain liquidity management.
  </Card>
</Columns>

<br />

<Info>
  To find all of LayerZero's contract standards visit the [**LayerZero Devtools**](https://github.com/LayerZero-Labs/devtools).

  To see the core protocol contracts, visit the [**LayerZero V2**](https://github.com/LayerZero-Labs/layerzero-v2) repository.
</Info>

You can also ask for help or follow development in the [Discord](https://discord.com/invite/ktbvm8Nkcr).