# Across Docs

## V3 Developer Docs

- [Welcome to Across](https://docs.across.to/introduction/welcome-to-across)
- [What is Across?](https://docs.across.to/introduction/what-is-across)
- [Technical FAQ](https://docs.across.to/introduction/technical-faq): Find quick solutions to some of the most frequently asked questions about Across Protocol.
- [Migration Guides](https://docs.across.to/introduction/migration-guides)
- [Migration from V2 to V3](https://docs.across.to/introduction/migration-guides/migration-from-v2-to-v3)
- [Migration to CCTP](https://docs.across.to/introduction/migration-guides/migration-to-cctp): Across is migrating to Native USDC via CCTP for faster, cheaper bridging with no extra trust. Expect lower fees and better capital efficiency.
- [Migration Guide for Relayers](https://docs.across.to/introduction/migration-guides/migration-to-cctp/migration-guide-for-relayers)
- [Migration Guide for API Users](https://docs.across.to/introduction/migration-guides/migration-to-cctp/migration-guide-for-api-users)
- [Migration Guide for Non-EVM and Prefills](https://docs.across.to/introduction/migration-guides/migration-guide-for-non-evm-and-prefills)
- [Breaking Changes for Indexers](https://docs.across.to/introduction/migration-guides/migration-guide-for-non-evm-and-prefills/breaking-changes-for-indexers)
- [Breaking Changes for API Users](https://docs.across.to/introduction/migration-guides/migration-guide-for-non-evm-and-prefills/breaking-changes-for-api-users)
- [Breaking Changes for Relayers](https://docs.across.to/introduction/migration-guides/migration-guide-for-non-evm-and-prefills/breaking-changes-for-relayers)
- [Testnet Environment for Migration](https://docs.across.to/introduction/migration-guides/migration-guide-for-non-evm-and-prefills/testnet-environment-for-migration)
- [Instant Bridging in your Application](https://docs.across.to/use-cases/instant-bridging-in-your-application)
- [Bridge Integration Guide](https://docs.across.to/use-cases/instant-bridging-in-your-application/bridge-integration-guide)
- [Multichain Bridge UI Guide](https://docs.across.to/use-cases/instant-bridging-in-your-application/multichain-bridge-ui-guide)
- [Single Chain Bridge UI Guide](https://docs.across.to/use-cases/instant-bridging-in-your-application/single-chain-bridge-ui-guide)
- [Embedded Crosschain Actions](https://docs.across.to/use-cases/embedded-crosschain-actions)
- [Crosschain Actions Integration Guide](https://docs.across.to/use-cases/embedded-crosschain-actions/crosschain-actions-integration-guide)
- [Using the Generic Multicaller Handler Contract](https://docs.across.to/use-cases/embedded-crosschain-actions/crosschain-actions-integration-guide/using-the-generic-multicaller-handler-contract)
- [Using a Custom Handler Contract](https://docs.across.to/use-cases/embedded-crosschain-actions/crosschain-actions-integration-guide/using-a-custom-handler-contract)
- [Crosschain Actions UI Guide](https://docs.across.to/use-cases/embedded-crosschain-actions/crosschain-actions-ui-guide)
- [Settle Crosschain Intents](https://docs.across.to/use-cases/settle-crosschain-intents): Across Settlement is the only production-ready modular layer for fast, low-cost crosschain Intents and seamless interoperability.
- [ERC-7683 in Production](https://docs.across.to/use-cases/erc-7683-in-production)
- [What are Crosschain Intents?](https://docs.across.to/concepts/what-are-crosschain-intents)
- [Intents Architecture in Across](https://docs.across.to/concepts/intents-architecture-in-across)
- [Intent Lifecycle in Across](https://docs.across.to/concepts/intent-lifecycle-in-across)
- [Canonical Asset Maximalism](https://docs.across.to/concepts/canonical-asset-maximalism)
- [API Reference](https://docs.across.to/reference/api-reference)
- [App SDK Reference](https://docs.across.to/reference/app-sdk-reference)
- [Contracts](https://docs.across.to/reference/contract-addresses)
- [Aleph Zero](https://docs.across.to/reference/contract-addresses/arbitrum-chain-id-42161)
- [Arbitrum](https://docs.across.to/reference/contract-addresses/arbitrum-chain-id-42161-1)
- [Base](https://docs.across.to/reference/contract-addresses/base-chain-id-8453)
- [Blast](https://docs.across.to/reference/contract-addresses/blast)
- [Ethereum](https://docs.across.to/reference/contract-addresses/mainnet-chain-id-1)
- [Linea](https://docs.across.to/reference/contract-addresses/linea-chain-id-59144)
- [Ink](https://docs.across.to/reference/contract-addresses/ink-chain-id-57073)
- [Lisk](https://docs.across.to/reference/contract-addresses/lisk)
- [Mode](https://docs.across.to/reference/contract-addresses/mode-chain-id-34443)
- [Optimism](https://docs.across.to/reference/contract-addresses/optimism-chain-id-10)
- [Polygon](https://docs.across.to/reference/contract-addresses/polygon-chain-id-137)
- [Redstone](https://docs.across.to/reference/contract-addresses/redstone-chain-id-690)
- [Scroll](https://docs.across.to/reference/contract-addresses/scroll-chain-id-534352)
- [Soneium](https://docs.across.to/reference/contract-addresses/soneium-chain-id-1868)
- [Unichain](https://docs.across.to/reference/contract-addresses/unichain)
- [World Chain](https://docs.across.to/reference/contract-addresses/scroll-chain-id-534352-1)
- [zkSync](https://docs.across.to/reference/contract-addresses/zksync-chain-id-324)
- [Zora](https://docs.across.to/reference/contract-addresses/zora-chain-id-7777777)
- [Selected Contract Functions](https://docs.across.to/reference/selected-contract-functions): Detailed contract interfaces for depositors.
- [Supported Chains](https://docs.across.to/reference/supported-chains): Across supports 18 mainnets and 9 testnets, including Ethereum, Arbitrum, Base, Optimism, and more for seamless crosschain development.
- [Fees in the System](https://docs.across.to/reference/fees-in-the-system)
- [Actors in the System](https://docs.across.to/reference/actors-in-the-system)
- [Security Model and Verification](https://docs.across.to/reference/security-model-and-verification)
- [Disputing Root Bundles](https://docs.across.to/reference/security-model-and-verification/disputing-root-bundles)
- [Validating Root Bundles](https://docs.across.to/reference/security-model-and-verification/validating-root-bundles)
- [Tracking Events](https://docs.across.to/reference/tracking-events)
- [Running a Relayer](https://docs.across.to/relayers/running-a-relayer)
- [Relayer Nomination](https://docs.across.to/relayers/relayer-nomination)
- [Release Notes](https://docs.across.to/resources/release-notes)
- [Developer Support](https://docs.across.to/resources/support-links): Get developer support for Across via Discord and explore helpful resources on Twitter, Medium, and GitHub.
- [Bug Bounty](https://docs.across.to/resources/bug-bounty)
- [Audits](https://docs.across.to/resources/audits)

## V2 Developer Docs

- [Overview](https://docs.across.to/developer-docs/how-across-works/readme): Below is an overview of how a bridge transfer on Across works from start to finish.
- [Roles within Across](https://docs.across.to/developer-docs/how-across-works/readme/roles-within-across): Describing key roles within the Across system.
- [Fee Model](https://docs.across.to/developer-docs/how-across-works/readme/fee-model)
- [Validating Root Bundles](https://docs.across.to/developer-docs/how-across-works/readme/validating-root-bundles): Root bundles instruct the Across system on how to transfer funds between smart contracts on different chains to refund relayers and fulfill user deposits.
- [Disputing Root Bundles](https://docs.across.to/developer-docs/how-across-works/readme/disputing-root-bundles)
- [Across API](https://docs.across.to/developer-docs/developers/across-api)
- [Across SDK](https://docs.across.to/developer-docs/developers/across-sdk)
- [Contract Addresses](https://docs.across.to/developer-docs/developers/contract-addresses)
- [Mainnet (Chain ID: 1)](https://docs.across.to/developer-docs/developers/contract-addresses/mainnet-chain-id-1)
- [Arbitrum (Chain ID: 42161)](https://docs.across.to/developer-docs/developers/contract-addresses/arbitrum-chain-id-42161)
- [Optimism (Chain ID: 10)](https://docs.across.to/developer-docs/developers/contract-addresses/optimism-chain-id-10)
- [Base (Chain ID: 8453)](https://docs.across.to/developer-docs/developers/contract-addresses/base-chain-id-8453)
- [zkSync (Chain ID: 324)](https://docs.across.to/developer-docs/developers/contract-addresses/zksync-chain-id-324)
- [Polygon (Chain ID: 137)](https://docs.across.to/developer-docs/developers/contract-addresses/polygon-chain-id-137)
- [Selected Contract Functions](https://docs.across.to/developer-docs/developers/selected-contract-functions): Explanation of most commonly used smart contract functions
- [Running a Relayer](https://docs.across.to/developer-docs/developers/running-a-relayer): Technical instructions that someone comfortable with command line can easily follow to run their own Across V2 relayer
- [Integrating Across into your application](https://docs.across.to/developer-docs/developers/integrating-across-into-your-application): Instructions and examples for calling the smart contract functions that would allow third party projects to transfer assets across EVM networks.
- [Composable Bridging](https://docs.across.to/developer-docs/developers/composable-bridging): Use Across to bridge + execute a transaction
- [Developer notes](https://docs.across.to/developer-docs/developers/developer-notes)
- [Migration from V2 to V3](https://docs.across.to/developer-docs/developers/migration-from-v2-to-v3): Information for users of the Across API and the smart contracts (e.g. those who call the Across SpokePools directly to deposit or fill bridge transfers and those who track SpokePool events).
- [Support Links](https://docs.across.to/developer-docs/additional-info/support-links)
- [Bug Bounty](https://docs.across.to/developer-docs/additional-info/bug-bounty)
- [Audits](https://docs.across.to/developer-docs/additional-info/audits)

## User Docs

- [About](https://docs.across.to/user-docs/how-to-use-across/about): Interoperability Powered by Intents
- [Bridging](https://docs.across.to/user-docs/how-to-use-across/bridging): Please scroll to the bottom of this page for our official bridging tutorial video or follow the written steps provided below.
- [Providing Bridge Liquidity](https://docs.across.to/user-docs/how-to-use-across/providing-bridge-liquidity): Please scroll to the bottom of this page for our official tutorial video on adding, staking or removing liquidity or follow the written steps provided below. You may add/remove liquidity at any time.
- [Protocol Rewards](https://docs.across.to/user-docs/how-to-use-across/protocol-rewards): $ACX is Across Protocol's native token. Protocol rewards are paid in $ACX to liquidity providers who stake in Across protocol. Click the subtab in the menu bar to see program details.
- [Reward Locking](https://docs.across.to/user-docs/how-to-use-across/protocol-rewards/reward-locking): Across Reward Locking Program is a novel DeFi mechanism to further incentivize bridge LPs. Scroll down to the bottom for instructions on how to get started.
- [Transaction History](https://docs.across.to/user-docs/how-to-use-across/transaction-history): On the Transactions tab, you can view the details of bridge transfers you've made on Across or via Across on aggregators.
- [Overview](https://docs.across.to/user-docs/how-across-works/overview)
- [Security](https://docs.across.to/user-docs/how-across-works/security): Across Protocol's primary focus is its users' security.
- [Fees](https://docs.across.to/user-docs/how-across-works/fees)
- [Speed](https://docs.across.to/user-docs/how-across-works/speed): How a user's bridge request gets fulfilled and how quickly users can expect to receive funds
- [Supported Chains and Tokens](https://docs.across.to/user-docs/how-across-works/supported-chains-and-tokens)
- [Token Overview](https://docs.across.to/user-docs/usdacx-token/token-overview)
- [Initial Allocations](https://docs.across.to/user-docs/usdacx-token/initial-allocations): The Across Protocol token, $ACX, was launched in November 2022. This section outlines the allocations that were carried out at token launch.
- [ACX Emissions Committee](https://docs.across.to/user-docs/usdacx-token/acx-emissions-committee): The AEC determines emissions of bridge liquidity incentives
- [Governance Model](https://docs.across.to/user-docs/governance/governance-model)
- [Proposals and Voting](https://docs.across.to/user-docs/governance/proposals-and-voting)
- [FAQ](https://docs.across.to/user-docs/additional-info/faq): Read through some of our most common FAQs.
- [Support Links](https://docs.across.to/user-docs/additional-info/support-links): Across ONLY uses links from the across.to domain. Please do not click on any Across links that do not use the across.to domain. Stay safe and always double check the link before opening.
- [Migrating from V1](https://docs.across.to/user-docs/additional-info/migrating-from-v1)
- [Across Brand Assets](https://docs.across.to/user-docs/additional-info/across-brand-assets): View and download different versions of the Across logo. The full Across Logotype and the Across Symbol are available in both SVG and PNG formats.