> For the complete documentation index, see [llms.txt](https://0x-docs.gitbook.io/0x-cross-chain-api-beta/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://0x-docs.gitbook.io/0x-cross-chain-api-beta/introduction.md).

# Introduction

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This version of docs is deprecated. Please access up-to-date docs [here](https://docs.0x.org/docs/cross-chain-api/introduction).
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## **What is the 0x Cross Chain API?**

The 0x Cross Chain API is a fast, flexible API that lets developers programatically access tokens across various blockchains, enabling cross-chain swap functionality in any app or wallet. It's designed to provide the same powerful aggregation and transaction-building features that 0x offers for same-chain swaps - now available across EVM, Solana, and Tron chains.

Whether you're building a new application, or expanding the offering of your existing product, this API helps you integrate cross-chain token swaps with minimal overhead and maximum efficiency.

### How It Works 

<figure><img src="/files/lkTPeG7P62ZgIP0zZIFA" alt=""><figcaption></figcaption></figure>

1. **Get a quote** -  your app calls `/quotes` or `/quotes/stream`. The API queries multiple bridge providers and liquidity sources, then returns the best routes with ready-to-sign transactions.
2. **Submit** - the user signs and submits the origin transaction. On EVM chains, a token allowance may be required first (see `issues.allowance` in the response).
3. **Bridge** - the bridge provider picks up the order and delivers tokens to the destination chain. This takes seconds to minutes depending on the bridge.
4. **Track** -  poll `/status` with the origin tx hash and `quoteId`. The status service monitors the bridge and reports progress through to completion or failure recovery.

### Supported Chains and Providers

[Supported Chains and Providers](/0x-cross-chain-api-beta/reference/supported-chains-and-providers.md) for the full list with chain IDs, address formats, and bridge coverage.


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