Ethereum (EVM) support on Turnkey

Address derivation

Turnkey supports EVM address derivation with ADDRESS_TYPE_ETHEREUM. This address format is valid across all EVM chains and L2s.

Transaction construction and signing

To construct and sign an EVM transaction with Turnkey, we offer:

• @turnkey/viem: contains a createAccount method to create a Turnkey-powered custom account which Viem can use seamlessly.
• @turnkey/ethers: contains a TurnkeySigner which implements Ethers’ AbstractSigner interface. See Ethers docs.

Transaction parsing, policies, and signing

Turnkey has built an EVM parser which runs in a secure enclave, to parse unsigned EVM transactions and extract useful metadata: transaction source, destination, amount, chain ID, and more. See the EthereumTransaction struct in our policy language page for a full list.

As a bonus, Turnkey also takes care of combining the signature with the original payload if you use the SIGN_TRANSACTION activity types: the input is the unsigned payload (RLP encoded), and the output is the signed RLP encoded transaction, ready to be broadcast!

What transaction types does Turnkey support?

Turnkey supports the following transaction types: legacy, EIP-2930 (Type 1), EIP-1559 (Type 2), EIP-4844 (Type 3), EIP-7702 (Type 4). These transactions will get parsed by our transaction parser, and are compatible with our policy engine.

EIP-4844 (Type 3) support

You can use Turnkey’s SignTransaction endpoint to parse and sign Type 3 transactions, which conform to the EIP-4844 standard.

We’ve also added Type 3 support to our policy engine by including the parameter max_fee_per_blob_gas. More details about our policy engine language can be found here, and an example demonstrating how to use @turnkey/viem to sign Type 3 transactions can be found here.

Note: for Type 3 transactions, we are specifically handling parsing for payloads containing only the transaction payload body, without any wrappers around blobs, commitments, or proofs.

Accepted: tx_payload_body, defined as: rlp([chain_id, nonce, max_priority_fee_per_gas, max_fee_per_gas, gas_limit, to, value, data, access_list, max_fee_per_blob_gas, blob_versioned_hashes, y_parity, r, s])

Rejected: rlp([tx_payload_body, blobs, commitments, proofs])

• See that this is effectively wrapping the same tx_payload_body shape (defined above) alongside other blob-specific data
• We do not sign payloads that conform to this format. Payloads that consists of rlp([tx_payload_body, blobs, commitments, proofs]) are not transactions, they’re messages which are part of the gossip protocol to persist blobs on the beacon chain. In other words, they’re not meant to be signed: the signatures / integrity is taken care of with the signed commitments & proofs inside of these messages.

See https://github.com/ethereum/EIPs/blob/master/EIPS/eip-4844.md#blob-transaction and https://github.com/ethereum/EIPs/blob/master/EIPS/eip-4844.md#networking, respectively, for more.

EIP-7702 (Type 4) support

In addition to adding support for Type 3 transactions, Turnkey now also supports Type 4 transactions, which conform to the EIP-7702 standard. From https://eip7702.io/:

EIP-7702 gives superpowers to EOAs.

Specifically, it allows any EOA to set its code based on any existing smart contract. To do so, an EOA owner would sign an authorization that could then be submitted by anyone as part of the new transaction type. The code will be valid until replaced by another authorization. The authorization could be given for a single chain, or all chains at once.

This setup allows an EOA to mimic a smart contract account, particularly allowing transaction bundling, gas sponsorships, and custom permissioning schemes.

You can take advantage of Type 4 transaction support on Turnkey to:

1. Enable gasless transaction experiences: Design applications where transactions can be sponsored by third parties, removing the ETH requirement barrier for new users and simplifying onboarding.

2. Create seamless applications with transaction batching: Bundle multiple operations into single transactions, significantly reducing gas costs and improving UX for complex DeFi or high-frequency trading.

3. Implement flexible authentication systems: Build applications that can leverage passkeys and biometrics while maintaining compatibility with existing EOA infrastructure and reputation systems.

Type 4 transaction support is also live for our policy engine. Details about our engine language can be found here, and an example demonstrating how to use @turnkey/viem to sign Type 4 transactions can be found here.

Account abstraction

Turnkey is built to be flexible: a lot of our customers use Turnkey as a smart contract signer, alongside other types of signers.

This is so common that AA wallet providers have integrated Turnkey as a default solution in their documentation. Refer to our AA Wallet documentation for further information.

EIP-1193 provider

We’ve published an experimental package, which adheres to the EIP-1193 standard. It’s built to integrate seamlessly with a broad spectrum of EVM-compatible chains, offering capabilities like account management, transaction signing, and blockchain interaction.

Wallet signer

Did you know? Turnkey activities can be signed with an API key, a passkey…or any Ethereum wallet if you use our package!

Examples and demos

A lot of our demos use EVM chains and capabilities. The most complete demo is our Demo Embedded wallet, a fully-functional, hosted wallet which showcases (among other things) send and receive functionality on Sepolia.

Try it out at wallet.tx.xyz!

The code behind this demo is open-source, available at https://github.com/tkhq/demo-embedded-wallet/

If you’re looking for shorter, more focused examples, here are a few worth checking out:

• with-ethers: demonstrates how to use Turnkey with Ethers
• with-viem: demonstrates how to use Turnkey with Viem
• with-zerodev-aa: demonstrates how to use Turnkey with Zerodev + Viem to create sponsored transactions, and also EIP-7702 (Type 4) transactions
• with-biconomy-aa: demonstrates how to use Turnkey with Biconomy + Ethers / Viem to create sponsored transactions, including an example using Biconomy’s Nexus Client
• with-eth-passkeys-signer: demonstrates both Ethers and Viem integrations, with an optional Biconomy account abstraction integration.
• with-gnosis: shows how to use Turnkey with Gnosis (Safe).
• with-uniswap: shows how to use Turnkey with Uniswap, using Ethers.
• with-eip-1193-provider: short example focused on EIP-1193 provider usage.

Which EVM chains does Turnkey support?

Turnkey supports the EVM chains below for address derivation and signing arbitrary transactions:

• Arbitrum
• Aurora
• Avalanche C chain
• Avalanche Fuji
• Base
• Berachain
• BNB Smart Chain
• Celo
• Chiliz
• Cronos
• EON
• Ethereum
• Fantom
• Flare
• Gnosis
• Holesky Redstone
• Holesky Garnet
• Lukso
• Linea
• Monad
• Moonbeam
• Optimism
• Palm
• Polygon
• Redstone
• Scroll
• zkSync
• Zora

If you are using an EVM chain we do not support, feel free to contact us at [e-mail], on X, or on Slack.

Assistant

Responses are generated using AI and may contain mistakes.