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

# App Kits

> Build payment and liquidity workflows across blockchains with App Kits

App Kits is a suite of SDKs for composing multichain payment and liquidity flows
without orchestrating separate, low-level protocol integrations for each
blockchain or use case.

The App Kit SDK is the all-in-one core package. Install it to access every
capability — Send, Bridge, Swap, and Unified Balance — behind one type-safe
interface. Or, you can install Bridge Kit, Swap Kit, or Unified Balance Kit
separately.

## Quick install

To get started quickly, install the App Kit SDK and the Viem adapter:

<CodeGroup>
  ```bash npm theme={null}
  npm install @circle-fin/app-kit @circle-fin/adapter-viem-v2 viem
  ```

  ```bash yarn theme={null}
  yarn add @circle-fin/app-kit @circle-fin/adapter-viem-v2 viem
  ```
</CodeGroup>

Need a different adapter or individual kits? See the full
[installation](/app-kit/tutorials/installation) guide.

## Core capabilities

Combine and use any of the App Kit SDK's built-in core capabilities in your app.
Bridge, Swap, and Unified Balance are also available as individual kits.

<CardGroup cols={3}>
  <Card title="Bridge" icon="bridge" href="/app-kit/bridge">
    Transfer USDC across blockchains.
  </Card>

  <Card title="Swap" icon="arrows-rotate" href="/app-kit/swap">
    Exchange one token for another on the same blockchain.
  </Card>

  <Card title="Send" icon="paper-plane" href="/app-kit/send">
    Transfer tokens between wallets on the same blockchain.
  </Card>

  <Card title="Unified Balance" icon="layer-group" href="/app-kit/unified-balance">
    Create a chain-abstracted balance and spend it instantly.
  </Card>
</CardGroup>

## Key benefits

* **Simple setup**: Get up and running with minimal configuration and a few
  lines of code.
* **Application monetization**: Collect a custom fee from end users without
  writing new code.
* **Flexible configurations**: Specify custom RPC endpoints and wallet clients.
* **Broad compatibility**: Works with Viem, Ethers, Solana, and Circle Wallets,
  integrating smoothly with existing developer workflows.
* **Protocol abstraction**: Build against a single interface over underlying
  protocols such as [Gateway](https://developers.circle.com/gateway) and
  [CCTP](https://developers.circle.com/cctp).
* **Composable workflows**: Combine multiple capabilities in one product flow
  without stitching together separate protocol integrations.