Across Developer DocumentationSolana Migration Guide
Prepare for USDC bridging on Solana — API changes, deposit flow, and relayer requirements.
Across supports USDC bridging on Solana, connecting Ethereum Mainnet and other chains to Solana's ecosystem. This guide covers the API changes, deposit flow, and relayer updates required.
No testnet support for Solana. Across does not support Solana devnet or testnet. You must test on Solana mainnet with small token amounts. The Across App-SDK does not yet support Solana.
API Changes
recipient Parameter Required
The /suggested-fees endpoint now requires the recipient parameter in Solana Pubkey format (base-58 encoded string) when the destination is Solana. Missing or invalid Solana public keys return a 400 error.
const params = new URLSearchParams({
inputToken: "0xaf88d065e77c8cC2239327C5EDb3A432268e5831", // USDC on Arbitrum
outputToken: "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v", // USDC on Solana
originChainId: "42161",
destinationChainId: "34268394551451", // Solana chain ID
amount: "10000000", // 10 USDC
recipient: "YourSolanaPublicKeyBase58", // Required — Solana Pubkey format
});
const res = await fetch(
`https://app.across.to/api/suggested-fees?${params}`
);Response Changes
Response fields display Solana addresses where applicable (base-58 format instead of hex).
Transaction Size Limit
Solana transactions have a maximum size limit of 1,232 bytes. This affects deposits with attached messages (embedded actions) from EVM to Solana. If you need large payloads, contact the Across team.
Deposit Flow
Fetch Quote
Call /suggested-fees with the Solana chain ID (34268394551451) as destinationChainId and include the recipient in Solana Pubkey format. Add your integratorId.
Call deposit() on SVM SpokePool
Use the deposit function on the SVM SpokePool contract. A reference script demonstrates proper invocation with integratorId.
Track the Deposit
Use the /deposit/status endpoint to monitor the fill status.
Relayer Updates
Relayers must update to the latest versions of:
@across-protocol/sdk@across-protocol/contracts@solana/kit(replaces@solana/web3.js@^2.0.0)
For Solana transactions, relayers transition from fillV3Relay to fillRelay. Solana-specific fill functions are required, and relayers must monitor events via the emit_cpi!() method in Anchor.
When filling to or from Solana, relayers must always specify a valid address on the chain where they request repayment. Failing to do so may result in loss of funds.
Key Details
| Property | Value |
|---|---|
| Solana Chain ID | 34268394551451 |
| SVM SpokePool | DLv3NggMiSaef97YCkew5xKUHDh13tVGZ7tydt3ZeAru |
| Supported tokens | USDC |
| Testnet | Not available — test on mainnet with small amounts |
| App-SDK | Not yet supported for Solana |
Early Solana support positively affects relayer nomination percentages. If you're running a relayer, supporting Solana fills early can improve your standing.