fix(sdk): support standard ethers wallets for direct EIP-7594 submission

packages/sdk/src/blob-submitter.ts

@@ -21,6 +21,7 @@ import {
   commitmentToVersionedHash
 } from './kzg.js';
 import { SerializeEIP7495 } from './serialize.js';
+import { signBlobTransaction } from './sign-blob-transaction.js';
 
 export interface BlobSubmitterConfig {
   rpcUrl: string;
@@ -113,7 +114,7 @@ export class BlobSubmitter {
           }
         ]
         const unsignedSerializedTX = SerializeEIP7495(tx, null, blobs);
-        const signature = await signer.signRawTransaction(unsignedSerializedTX)
+        const signature = await signBlobTransaction(signer, unsignedSerializedTX);
         const serializedTX = SerializeEIP7495(tx, signature, blobs);
         const txHash = await this.provider._perform({
             method: "broadcastTransaction",

packages/sdk/src/sign-blob-transaction.ts

@@ -0,0 +1,17 @@
+import { ethers, type Signature } from 'ethers';
+import type { Signer } from './types.js';
+
+/** Sign the digest of an unsigned EIP-7594 blob transaction. */
+export async function signBlobTransaction(signer: Signer, unsignedTx: string): Promise<Signature> {
+  if (typeof signer.signRawTransaction === 'function') {
+    return signer.signRawTransaction(unsignedTx);
+  }
+
+  if (signer instanceof ethers.BaseWallet) {
+    return signer.signingKey.sign(ethers.keccak256(unsignedTx));
+  }
+
+  throw new Error(
+    'EIP-7594 direct submission requires an ethers BaseWallet or a signer with signRawTransaction(rawTx)'
+  );
+}

packages/sdk/src/types.ts

@@ -18,7 +18,7 @@ import type {
 } from 'ethers';
 
 // Re-export ethers types
-export type Signer = EthersSigner & { signRawTransaction(rawTx: BytesLike): Promise<Signature> };
+export type Signer = EthersSigner & { signRawTransaction?: (rawTx: BytesLike) => Promise<Signature> };
 export type Provider = EthersProvider;
 export type FeeData = EthersFeeData;
 export type TransactionResponse = EthersTransactionResponse;

packages/sdk/test/__unit__/sign-blob-transaction.test.ts

@@ -0,0 +1,31 @@
+import { ethers } from 'ethers';
+import { signBlobTransaction } from '../../src/sign-blob-transaction.js';
+import type { Signer } from '../../src/types.js';
+
+const unsignedTx = '0x03c0';
+
+describe('EIP-7594 blob transaction signing', () => {
+  test('a standard ethers Wallet signs the raw transaction digest', async () => {
+    const wallet = new ethers.Wallet(`0x${'11'.repeat(32)}`);
+    const signature = await signBlobTransaction(wallet, unsignedTx);
+
+    expect(ethers.recoverAddress(ethers.keccak256(unsignedTx), signature)).toBe(wallet.address);
+  });
+
+  test('a custom raw transaction signer is still supported', async () => {
+    const wallet = new ethers.Wallet(`0x${'22'.repeat(32)}`);
+    const signature = wallet.signingKey.sign(ethers.keccak256(unsignedTx));
+    const customSigner = {
+      signRawTransaction: jest.fn(async () => signature),
+    } as unknown as Signer;
+
+    expect(await signBlobTransaction(customSigner, unsignedTx)).toBe(signature);
+    expect(customSigner.signRawTransaction).toHaveBeenCalledWith(unsignedTx);
+  });
+
+  test('unsupported signers fail with an actionable error', async () => {
+    await expect(signBlobTransaction({} as Signer, unsignedTx)).rejects.toThrow(
+      'requires an ethers BaseWallet or a signer with signRawTransaction'
+    );
+  });
+});