Across

# Across Protocol Documentation > Across Protocol is a crosschain interoperability protocol powering fast, low-cost token transfers across 23+ chains. > Three settlement mechanisms: Intents (relayer network), CCTP (USDC), and OFT (USDT). > API base URL: https://app.across.to/api ## Introduction - [Actors in the System](https://docs.across.to/introduction/actors): The key participants that make crosschain transfers work — users, relayers, LPs, dataworkers, and the UMA oracle. - [API Keys & Integrator ID](https://docs.across.to/introduction/api-keys): How to get an API key and integrator ID for production use of the Across APIs. - [Audits](https://docs.across.to/introduction/audits): Security audits of the Across Protocol and UMA smart contracts. - [The Bridge Across](https://docs.across.to/introduction/bridge-across): A quick overview of what is happening with $ACX, and where to follow updates. - [Bug Bounty](https://docs.across.to/introduction/bug-bounty): Report vulnerabilities and earn rewards through the Across Protocol bug bounty program. - [Direct Route Linking](https://docs.across.to/introduction/direct-route-linking): Link users directly to a pre-filled bridge route on the Across UI. - [Technical FAQ](https://docs.across.to/introduction/faq): Frequently asked questions about integrating Across Protocol. - [Key Features](https://docs.across.to/introduction/features): What makes Across the fastest, cheapest, and most secure crosschain interoperability protocol. - [Fee […gekürzt]