Transaction Formatters / EIP2718 TX Types

[aaronmgdr]

Looking through the code i see there is some support for chains having custom transaction formatters. Im wondering what the intended use of these are: Could for example the be used to extend support for other EIP2718 transaction types?

On a related note am i correct that transaction Serializers are only used with local Accounts?

[jxom]

That could indeed be an example! viem is designed to adapt to different Chain block/transaction/etc schemas (eg. Celo).

serializeTransaction can be used with any Account that can sign a transaction. A Local Account can sign a serialized transaction locally via account.signTransaction(...), and a JSON-RPC Account can sign a serialized transaction via eth_signTransaction (not exposed yet).

[aaronmgdr]

oh ok so for for wallets a Custom Account with unique serialization abilitity can be created like https://github.com/wagmi-dev/viem/blob/main/site/docs/accounts/custom.md

right?

[jxom]

Yep! You can also use our sign utility in there if you are constructing the serialized transaction yourself.

[jxom]

Actually, I think we need to export sign. Can do that if you need it.

[aaronmgdr]

oh yeah that would be awesome

[aaronmgdr]

In creating a custom transactionSerializer ive come across a few functions / types that are not exported that would be beneficial to have. (such as the sign method you mentioned). I plan to make a PR (or series of PRs? -- let me know if there is a preference).

functions i hope to export

• sign
• serializeAccessList

Types

• SignTransactionArgs
• SignTransactionReturnType

new functions extracted from existing functions

right now viem has function to go from publicKeyToAddress or privateKeyToAccount but to get from a privateKey to just an address is not possible. given there is already publicKeyToAddress all that is needed is something like

export function privateKeyToPublicKey(privateKey: string) {
  return toHex(secp256k1.getPublicKey(privateKey.slice(2), false))
}

similarly if you are open to exposing functions to go from mneumonic to private key or hd to private key then all a custom account would need is one customAccountFromPrivateKey function.

[aaronmgdr]

#665