Automatic chain routing for raw EVM transactions

Raw EVM transactions now automatically route to the correct blockchain based on the encoded transaction's chain ID. You no longer need to specify a blockchain parameter — the platform detects the target chain and routes accordingly.

Previously, raw signing on an EVM wallet required a blockchain parameter to override the wallet's native chain. Now the platform reads the chainId from the RLP-encoded transaction and resolves the target blockchain automatically:

• Known chain ID (Ethereum, Arbitrum, Polygon, Base, BNB Chain, Avalanche, 1Money) — the platform routes the transaction to that chain's connector and supports both signOnly=true and signOnly=false.
• Unknown chain ID — the platform treats the transaction as cross-chain raw signing: it signs only and requires a policy with a CHAIN_ID matcher.

The blockchain field on the raw transaction request is deprecated. Existing API integrations that send the field continue to work — the platform ignores the value for all raw transactions. EVM transactions route by the chain ID in the encoded transaction; non-EVM transactions always execute on the wallet's native blockchain.

An Ethereum wallet signing and broadcasting an Arbitrum transaction:

POST /v2/vaults/{vaultId}/wallets/{walletId}/transactions/raw
{
  "encodedTransaction": "<RLP-encoded transaction with Arbitrum chainId>",
  "signOnly": false
}

You don't need a blockchain parameter. The platform extracts the Arbitrum chain ID and routes the transaction to the Arbitrum connector.

• Automatic chain routing
• Cross-chain raw signing
• Cross-chain transactions