Key Features
What makes Across the fastest, cheapest, and most secure crosschain interoperability protocol.
Three Settlement Mechanisms
Across is unique in offering three independent settlement pathways. The Swap API automatically selects the optimal mechanism for each transfer.
Intents — Relayer Network
Sub-2-second fills via a competitive relayer network that fronts capital on the destination chain. The default pathway for most transfers.
CCTP V2 / CCTPFast — Native USDC
Circle's Crosschain Transfer Protocol for native USDC mint-and-burn. Supports transfers up to $10M per transaction with no relayer capital required.
OFT — Native USDT0
LayerZero's Omnichain Fungible Token standard for native USDT0 settlement. More OFT tokens coming soon.
Feature Highlights
| Feature | Details |
|---|---|
| Sub-2-second fills | Competitive relayer network delivers funds on the destination chain in ~2 seconds on mainnet |
| 23+ mainnet chains | Solana, MegaETH, Plasma, Monad, Hyperliquid, and all major L2s |
| CCTP V2 / CCTPFast | Native USDC settlement up to $10M per transaction. CCTPFast offers faster attestation where available |
| Sponsored routes | Zero-fee transfers on select routes (e.g., USDC to USDH on Hyperliquid) |
| Embedded crosschain actions | Compose DeFi operations — swap, bridge, and execute destination-chain calls in a single transaction |
| OFT for USDT0 | Native USDT0 mint-and-burn settlement via LayerZero. More tokens coming soon |
| ERC-7683 standard | Implements the crosschain intent standard for interoperability with other intent-based systems |
| V4 ZK proofs | Succinct/SP1 zero-knowledge proofs enable permissionless chain expansion without governance votes |
Speed
Across's relayer network fills most transfers in ~2 seconds on mainnet. Relayers compete on speed, fronting their own capital on the destination chain and getting repaid later through the settlement process.
Testnet fills take ~1 minute due to lower relayer competition.
Chain Coverage
Across supports 23+ mainnet chains including:
- EVM L2s — Arbitrum, Optimism, Base, Polygon, zkSync, Linea, Scroll, Blast, Mode, Redstone, Zora, and more
- Alt-L1s and new chains — Solana, MegaETH, Plasma, Monad
- App-specific chains — Hyperliquid (HyperCore + HyperEVM)
- Testnet support — 8 testnet chains for development
See the full list via the /swap/chains endpoint.
Sponsored Routes
Certain routes are zero-fee — the protocol or partners subsidize the transfer cost. For example, USDC to USDH on Hyperliquid is a sponsored route with no bridge fee.
Check the /swap/approval response for fee breakdowns. Sponsored routes show 0 total fees.
Embedded Crosschain Actions
Bridge and execute in one transaction. Attach arbitrary contract calls to your crosschain transfer — the MulticallHandler executes them atomically on the destination chain.
Use cases:
- Swap + deposit into Aave
- Bridge + add liquidity to a DEX
- Transfer + stake on the destination chain
ERC-7683
Across implements the ERC-7683 crosschain intent standard, enabling interoperability with other intent-based protocols and standardized order formats.
V4 — ZK-Powered Expansion
Across V4 introduces zero-knowledge proofs via Succinct's SP1 prover for settlement verification. This enables:
- Permissionless chain expansion — new chains can be added without governance votes
- Faster settlement — ZK proofs replace the optimistic challenge period
- Reduced trust assumptions — cryptographic verification instead of economic security
V4 is rolling out progressively. See Across V4 for technical details.