Importance of Fixing the Issue

Oct 13, 2025 by wbrum.org 44 views

Introduction

The Alchemy SDK provides a set of core RPC methods that allow developers to interact with the Ethereum network. However, when using these methods, it has been observed that passing a lower case from address can result in an error. This article will delve into the issue, provide a detailed explanation, and offer a solution to ensure seamless interoperability with libraries like ethers.

Problem Description

When using the eth_sign, personal_sign, and eth_signTypedData_v4 RPC methods, passing a lower case from address can lead to an error. This is because these methods expect the from address to be in upper case, also known as checksummed. The error message indicates that the address is not the current account, which can be misleading.

Importance of Fixing the Issue

Fixing this issue is crucial for interoperability with libraries like ethers, which send requests with lower case addresses. The ethers library is a popular JavaScript library for interacting with the Ethereum network, and it is used by many developers. By ensuring that the Alchemy SDK supports lower case from addresses, we can provide a seamless experience for developers who use both libraries.

How to Reproduce the Issue

To reproduce the issue, you can run the following script with the appropriate environment variables set:

import { LocalAccountSigner } from "@aa-sdk/core";
import { createLightAccountAlchemyClient } from "@account-kit/smart-contracts";
import { alchemy, arbitrumSepolia } from "@account-kit/infra";

const { PRIVATE_KEY, ALCHEMY_API_KEY, ALCHEMY_POLICY_ID } = process.env;

const client = await createLightAccountAlchemyClient({
  transport: alchemy({ apiKey: ALCHEMY_API_KEY }),
  chain: arbitrumSepolia,
  signer: LocalAccountSigner.privateKeyToAccountSigner(PRIVATE_KEY),
  policyId: ALCHEMY_POLICY_ID,
});

// transform the checksummed signer address to lower case address
const lowerCaseFrom = client.account.address.toLowerCase();

// this will throw
const sign = await client.request({
  method: "personal_sign",
  params: ["0x" + Buffer.from("foo").toString(), lowerCaseFrom], 
});

console.log("sign", sign);

Relevant Code or Sample Reproduction

The relevant code or sample reproduction is the script above, which demonstrates how to reproduce the issue.

Solution

To solve this issue, we need to ensure that the from address is in upper case when using the eth_sign, personal_sign, and eth_signTypedData_v4 RPC methods. We can achieve this by transforming the lower case from address to upper case using the toUpperCase() method.

Here is an updated version of the script that fixes the issue:

import { LocalAccountSigner } from "@aa-sdk/core";
import { createLightAccountAlchemyClient } from "@account-kit/smart-contracts";
import { alchemy, arbitrumSepolia } from "@account-kit/infra";

const { PRIVATE_KEY, ALCHEMY_API_KEY, ALCHEMY_POLICY_ID } = process.env;

const client = await createLightAccountAlchemyClient({
  transport: alchemy({ apiKey: ALCHEMY_API_KEY }),
  chain: arbitrumSepolia,
  signer: LocalAccountSigner.privateKeyToAccountSigner(PRIVATE_KEY),
  policyId: ALCHEMY_POLICY_ID,
});

// transform the lower case signer address to upper case address
const upperCaseFrom = client.account.address.toUpperCase();

// this will not throw
const sign = await client.request({
  method: "personal_sign",
  params: ["0x" + Buffer.from("foo").toString(), upperCaseFrom], 
});

console.log("sign", sign);

By transforming the lower case from address to upper case, we can ensure that the eth_sign, personal_sign, and eth_signTypedData_v4 RPC methods work seamlessly with libraries like ethers.

Conclusion

Introduction

In our previous article, we discussed the issue with the eth_sign, personal_sign, and eth_signTypedData_v4 RPC methods not supporting lower case from addresses. We also provided a solution to fix the issue by transforming the lower case address to upper case. In this article, we will answer some frequently asked questions (FAQs) related to this issue.

Q: What is the issue with the `eth_sign`, `personal_sign`, and `eth_signTypedData_v4` RPC methods?

A: The issue is that these methods expect the from address to be in upper case, also known as checksummed. However, when a lower case from address is passed, the methods throw an error.

Q: Why is this issue important?

A: This issue is important because it can cause problems when using libraries like ethers, which send requests with lower case addresses. By fixing this issue, we can ensure seamless interoperability between the Alchemy SDK and libraries like ethers.

Q: How can I reproduce the issue?

A: You can reproduce the issue by running the following script with the appropriate environment variables set:

import { LocalAccountSigner } from "@aa-sdk/core";
import { createLightAccountAlchemyClient } from "@account-kit/smart-contracts";
import { alchemy, arbitrumSepolia } from "@account-kit/infra";

const { PRIVATE_KEY, ALCHEMY_API_KEY, ALCHEMY_POLICY_ID } = process.env;

const client = await createLightAccountAlchemyClient({
  transport: alchemy({ apiKey: ALCHEMY_API_KEY }),
  chain: arbitrumSepolia,
  signer: LocalAccountSigner.privateKeyToAccountSigner(PRIVATE_KEY),
  policyId: ALCHEMY_POLICY_ID,
});

// transform the checksummed signer address to lower case address
const lowerCaseFrom = client.account.address.toLowerCase();

// this will throw
const sign = await client.request({
  method: "personal_sign",
  params: ["0x" + Buffer.from("foo").toString(), lowerCaseFrom], 
});

console.log("sign", sign);

Q: How can I fix the issue?

A: You can fix the issue by transforming the lower case from address to upper case using the toUpperCase() method. Here is an updated version of the script that fixes the issue:

import { LocalAccountSigner } from "@aa-sdk/core";
import { createLightAccountAlchemyClient } from "@account-kit/smart-contracts";
import { alchemy, arbitrumSepolia } from "@account-kit/infra";

const { PRIVATE_KEY, ALCHEMY_API_KEY, ALCHEMY_POLICY_ID } = process.env;

const client = await createLightAccountAlchemyClient({
  transport: alchemy({ apiKey: ALCHEMY_API_KEY }),
  chain: arbitrumSepolia,
  signer: LocalAccountSigner.privateKeyToAccountSigner(PRIVATE_KEY),
  policyId: ALCHEMY_POLICY_ID,
});

// transform the lower case signer address to upper case address
const upperCaseFrom = client.account.address.toUpperCase();

// this will not throw
const sign = await client.request({
  method: "personal_sign",
  params: ["0x" + Buffer.from("foo").toString(), upperCaseFrom], 
});

console.log("sign", sign);

Q: What are the implications of this issue?

A: The implications of this issue are that developers who use the eth_sign, personal_sign, and eth_signTypedData_v4 RPC methods with lower case from addresses may experience errors. By fixing this issue, we can ensure that these methods work seamlessly with libraries like ethers.

Q: How can I prevent this issue in the future?

A: To prevent this issue in the future, you can ensure that the from address is in upper case when using the eth_sign, personal_sign, and eth_signTypedData_v4 RPC methods. You can do this by transforming the lower case address to upper case using the toUpperCase() method.

Conclusion

In conclusion, the issue with the eth_sign, personal_sign, and eth_signTypedData_v4 RPC methods not supporting lower case from addresses is a significant problem that can be solved by transforming the lower case address to upper case. By doing so, we can ensure interoperability with libraries like ethers and provide a seamless experience for developers who use both libraries. We hope that this article has provided a detailed explanation of the issue and a solution to fix it.