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

# Introduction

> TypeScript SDK for cross-chain token transfers

The Omni Bridge SDK lets you build cross-chain token transfers into your application. It handles the complex parts — address validation, amount encoding, fee calculation — and gives you back unsigned transactions to sign and broadcast however you like.

## What It Does

You tell the SDK where tokens should go. It figures out the rest:

* Validates addresses across different chain formats
* Normalizes token amounts between different decimal precisions
* Encodes transactions for the bridge contracts
* Calculates fees for relayer-assisted finalization

The SDK is **library agnostic**. It returns plain transaction objects that work with viem, ethers, @solana/web3.js, near-kit, or whatever signing solution you prefer.

## Supported Chains

<CardGroup cols={3}>
  <Card title="EVM" icon="ethereum">
    Ethereum, Base, Arbitrum, Polygon, BNB Chain
  </Card>

  <Card title="NEAR" icon="circle-nodes">
    NEAR Protocol
  </Card>

  <Card title="Solana" icon="sun">
    Solana
  </Card>

  <Card title="Bitcoin" icon="bitcoin">
    Bitcoin, Zcash
  </Card>
</CardGroup>

## Packages

Install everything with the umbrella package, or just the chains you need:

```bash theme={null}
# Everything
npm install @omni-bridge/sdk

# Just EVM chains
npm install @omni-bridge/core @omni-bridge/evm

# Just NEAR
npm install @omni-bridge/core @omni-bridge/near
```

| Package               | What it's for                                 |
| --------------------- | --------------------------------------------- |
| `@omni-bridge/core`   | Validation, types, API client (always needed) |
| `@omni-bridge/evm`    | Ethereum, Base, Arbitrum, Polygon, BNB        |
| `@omni-bridge/near`   | NEAR Protocol                                 |
| `@omni-bridge/solana` | Solana                                        |
| `@omni-bridge/btc`    | Bitcoin, Zcash                                |
| `@omni-bridge/sdk`    | Re-exports everything                         |

## Next Step

<Card title="Getting Started" icon="rocket" href="/getting-started">
  Build your first cross-chain transfer in 5 minutes
</Card>