# Welcome to Across

**Across is the fastest, cheapest, most secure and decentralized way to bridge tokens and execute crosschain swaps** :tent:

Across is an interoperability protocol powered by intents. It enables the fastest and cheapest way to bridge funds with better security tradeoffs than traditional bridges. Developers can use Across to build production-ready crosschain apps in less than a day! 

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### Bridge to Hyperliquid for free!

Using the Swap API, you can now bridge USDC from major chains to USDH on Hyperliquid for free. 

No fees, no slippage, and 1 USDC = 1 USDH on arrival.

<a href="../developer-quickstart/crosschain-swap" class="button primary" data-icon="badge-check">Integrate the Swap API Today!</a>    <a href="https://t.me/acrosstg" class="button secondary" data-icon="comments-question-check">Need Help?</a>
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***

## Quickstart

Pick your learning path and learn how Across allows you to ship crosschain apps in the fastest and easiest way possible.

### Integrate Across

Across can be easily integrated via our easy to use REST API into any application requiring instant, low cost crosschain value transfer. Let users easily onboard assets without leaving your app.&#x20;

Start with the Bridge Integration Guide and progress to learn how you can make multichain and single chain experiences

<table data-view="cards"><thead><tr><th></th><th></th><th data-hidden data-card-cover data-type="files"></th><th data-hidden data-card-target data-type="content-ref"></th></tr></thead><tbody><tr><td><strong>Swap Integration Guide</strong></td><td>Use the Swap API to get executable calldata and swap tokens instantly</td><td><a href="https://462745353-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FaWQyh5Xkad3O9yHZEqaK%2Fuploads%2FSbWyCmLxiBFQjUpiKl5S%2FBridge%20Integration%20Guide.png?alt=media&#x26;token=55ec23f5-aefd-4bb9-a8df-15f9865f42f9">Bridge Integration Guide.png</a></td><td><a href="../developer-quickstart/crosschain-swap">crosschain-swap</a></td></tr><tr><td><strong>Across SDK</strong></td><td>Integrate crosschain swaps into your app quickly</td><td><a href="https://462745353-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FaWQyh5Xkad3O9yHZEqaK%2Fuploads%2FltHB707D889lWfc9Rz1p%2FAcross%20SDK.png?alt=media&#x26;token=f43c6b3b-59c9-4af6-b36d-df0633e836d7">Across SDK.png</a></td><td><a href="../reference/app-sdk-reference">app-sdk-reference</a></td></tr><tr><td><strong>Across APIs</strong></td><td>Explore all Across APIs to securely interface with the protocol</td><td><a href="https://462745353-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FaWQyh5Xkad3O9yHZEqaK%2Fuploads%2Fz0hQDvq9novzuN2QDR80%2FAcross%20API.png?alt=media&#x26;token=ccc94c6d-d62d-4e87-8c83-7ad2220a4900">Across API.png</a></td><td><a href="../reference/api-reference">api-reference</a></td></tr></tbody></table>

### Embedded Crosschain Actions

Build seamless staking, minting and more functionalities where bridging is abstracted away with Across

<table data-view="cards"><thead><tr><th></th><th></th><th data-hidden data-card-target data-type="content-ref"></th><th data-hidden data-card-cover data-type="files"></th></tr></thead><tbody><tr><td><strong>Concepts</strong></td><td>Learn how embedded cross-chain actions work</td><td><a href="../developer-quickstart/embedded-crosschain-swap-actions">embedded-crosschain-swap-actions</a></td><td><a href="https://462745353-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FaWQyh5Xkad3O9yHZEqaK%2Fuploads%2FhqyQ4oalhyEC4bmAGk7M%2FAcross%20Concepts.png?alt=media&#x26;token=d16e2f25-3212-47b2-a1ef-07e4db863d27">Across Concepts.png</a></td></tr><tr><td><strong>Generic Multicaller Handler</strong></td><td>Use our already-deployed and audited contract</td><td><a href="../developer-quickstart/embedded-crosschain-swap-actions/transfer-erc20-tokens-after-swap">transfer-erc20-tokens-after-swap</a></td><td><a href="https://462745353-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FaWQyh5Xkad3O9yHZEqaK%2Fuploads%2FFg653Zrj88wn4A4qrPUo%2FAcross%20Multicaller.png?alt=media&#x26;token=96d69db2-8dad-4025-a8c3-26a1e634f8b8">Across Multicaller.png</a></td></tr></tbody></table>

### Learn How Across Works

Deep-dive into Across and learn about the various actors that help build the fastest, most secure, low-cost and decentralized intent-based interoperable protocol.

<table data-view="cards"><thead><tr><th></th><th></th><th data-hidden data-card-target data-type="content-ref"></th><th data-hidden data-card-cover data-type="files"></th></tr></thead><tbody><tr><td><strong>Crosschain Intents</strong></td><td>An intent is a type of order where a user specifies an <em>outcome</em> instead of an <em>execution path</em></td><td><a href="../concepts/what-are-crosschain-intents">what-are-crosschain-intents</a></td><td><a href="https://462745353-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FaWQyh5Xkad3O9yHZEqaK%2Fuploads%2F289nPcoETiN3qHtY5T4R%2Fhow%20across%20works.png?alt=media&#x26;token=1ddda08d-8780-4007-b50f-78b939d998cb">how across works.png</a></td></tr><tr><td><strong>Intent Lifecycle</strong></td><td>These steps are intended to fit into almost any system that requires crosschain transfers</td><td><a href="../concepts/intent-lifecycle-in-across">intent-lifecycle-in-across</a></td><td><a href="https://462745353-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FaWQyh5Xkad3O9yHZEqaK%2Fuploads%2FkNgKGE9m3IBubicUbcaQ%2FIntents%20Lifecycle.png?alt=media&#x26;token=3c5c7758-517d-40fa-9e27-349892500cf7">Intents Lifecycle.png</a></td></tr><tr><td><strong>ERC-7683 in Production</strong></td><td>Explore how Across implements ERC-7683 by using AcrossOriginSettler contract </td><td><a href="../developer-quickstart/erc-7683-in-production">erc-7683-in-production</a></td><td><a href="https://462745353-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FaWQyh5Xkad3O9yHZEqaK%2Fuploads%2FgrvnjRUFWPFOpK2VkkcF%2FERC7683.png?alt=media&#x26;token=a53038b9-a6fa-4093-9c2f-74a65783a824">ERC7683.png</a></td></tr></tbody></table>

### Relayers

Join the growing network of independent relayers. Earn up to 100% APY.

<table data-view="cards"><thead><tr><th></th><th></th><th data-hidden data-card-target data-type="content-ref"></th><th data-hidden data-card-cover data-type="files"></th></tr></thead><tbody><tr><td><strong>Running a Relayer</strong></td><td>Technical instructions to follow and run your own Across V3 relayer</td><td><a href="../relayers/running-a-relayer">running-a-relayer</a></td><td><a href="https://462745353-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FaWQyh5Xkad3O9yHZEqaK%2Fuploads%2FBEKVZnp2iJqdvemfSaPC%2FRelayer%201.png?alt=media&#x26;token=bf2110fe-f57c-4e82-b19e-66d2a9b50dab">Relayer 1.png</a></td></tr><tr><td><strong>Relayer Nomination</strong></td><td>A time-limited period of exclusivity to fill a given deposit for a relayer</td><td><a href="../relayers/relayer-nomination">relayer-nomination</a></td><td><a href="https://462745353-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FaWQyh5Xkad3O9yHZEqaK%2Fuploads%2FzTN5aystpr0RagjzJtoI%2FRelayer%202.png?alt=media&#x26;token=f1de4365-3504-440c-b663-29a5c060d54f">Relayer 2.png</a></td></tr></tbody></table>

***

## Contracts and Chains

Across supports a large number of chains and the list is evergrowing as expand support and onboard ecosystems. You can learn all about the mainnet and testnet [supported chains here](https://legacy-docs.across.to/reference/supported-chains)

You can also find all the contract addresses for all the chains (mainnet and testnet) that [Across supports here](https://github.com/across-protocol/contracts/blob/master/deployments/deployments.json).

***

## Developer and Community Support

We request all developers building on Across to [join our discord server](https://discord.across.to) and gain instant help on any issues they face while integrating Across to their apps.&#x20;

You can find more [developer support resources here](https://legacy-docs.across.to/resources/support-links)

The security of our protocol is extremely crucial. If you notice any bugs in the protocol, please [report them here](https://legacy-docs.across.to/resources/bug-bounty). You can also find details of our [audits here](https://legacy-docs.across.to/resources/audits).