Coinbase Smart Wallet: Ability to set ownerIndex

[stephancill]

When interacting with Coinbase Smart Wallet accounts, the sign method does not provide an ownerIndex to the wrapSignature method, which defaults to 0.

I propose adding signatureOwnerIndex to the toCoinbaseSmartAccount function parameters like below:

diff --git a/src/account-abstraction/accounts/implementations/toCoinbaseSmartAccount.ts b/src/account-abstraction/accounts/implementations/toCoinbaseSmartAccount.ts
index b65ff68..d81565e 100644
--- a/src/account-abstraction/accounts/implementations/toCoinbaseSmartAccount.ts
+++ b/src/account-abstraction/accounts/implementations/toCoinbaseSmartAccount.ts
@@ -35,6 +35,7 @@ import type {
 export type ToCoinbaseSmartAccountParameters = {
   address?: Address | undefined
   client: Client
+  signatureOwnerIndex?: number | undefined
   owners: readonly OneOf<LocalAccount | WebAuthnAccount>[]
   nonce?: bigint | undefined
 }
@@ -74,7 +75,7 @@ export type CoinbaseSmartAccountImplementation = Assign<
 export async function toCoinbaseSmartAccount(
   parameters: ToCoinbaseSmartAccountParameters,
 ): Promise<ToCoinbaseSmartAccountReturnType> {
-  const { client, owners, nonce = 0n } = parameters
+  const { client, owners, nonce = 0n, signatureOwnerIndex = 0 } = parameters
 
   let address = parameters.address
 
@@ -179,6 +180,7 @@ export async function toCoinbaseSmartAccount(
 
       return wrapSignature({
         signature,
+        ownerIndex: signatureOwnerIndex
       })
     },
 
@@ -196,6 +198,7 @@ export async function toCoinbaseSmartAccount(
 
       return wrapSignature({
         signature,
+        ownerIndex: signatureOwnerIndex,
       })
     },
 
@@ -219,6 +222,7 @@ export async function toCoinbaseSmartAccount(
 
       return wrapSignature({
         signature,
+        ownerIndex: signatureOwnerIndex,
       })
     },
 
@@ -240,6 +244,7 @@ export async function toCoinbaseSmartAccount(
 
       return wrapSignature({
         signature,
+        ownerIndex: signatureOwnerIndex,
       })
     },
 

Alternatively you could add an index property to the owner accounts passed via the parameters i.e.

diff --git a/src/account-abstraction/accounts/implementations/toCoinbaseSmartAccount.ts b/src/account-abstraction/accounts/implementations/toCoinbaseSmartAccount.ts
index b65ff68..934ca9f 100644
--- a/src/account-abstraction/accounts/implementations/toCoinbaseSmartAccount.ts
+++ b/src/account-abstraction/accounts/implementations/toCoinbaseSmartAccount.ts
@@ -35,7 +35,7 @@ import type {
 export type ToCoinbaseSmartAccountParameters = {
   address?: Address | undefined
   client: Client
-  owners: readonly OneOf<LocalAccount | WebAuthnAccount>[]
+  owners: readonly (OneOf<LocalAccount | WebAuthnAccount> & { index?: number | undefined })[]
   nonce?: bigint | undefined
 }
 
@@ -179,6 +179,7 @@ export async function toCoinbaseSmartAccount(
 
       return wrapSignature({
         signature,
+        ownerIndex: owner.index
       })
     },
 
@@ -196,6 +197,7 @@ export async function toCoinbaseSmartAccount(
 
       return wrapSignature({
         signature,
+        ownerIndex: owner.index
       })
     },
 
@@ -219,6 +221,7 @@ export async function toCoinbaseSmartAccount(
 
       return wrapSignature({
         signature,
+        ownerIndex: owner.index,
       })
     },
 
@@ -240,6 +243,7 @@ export async function toCoinbaseSmartAccount(
 
       return wrapSignature({
         signature,
+        ownerIndex: owner.index,
       })
     },
 

The second method may require the introduction of a toOwner helper function which allows you to specify the index.

If you provide an incomplete set of owner accounts, the automatically generated initCode will be incorrect, so you would have to manually override that to be 0x if this method is used, which may not be ideal.

Please let me know what you think.

[jxom]

Think the first snippet should be fine – maybe just an ownerIndex parameter on toCoinbaseSmartAccount. Open to a PR!

[stephancill]

#2896