Metamask: Getting error “contract is missing references for the following libraries” even after adding as libraries when retrieving contract factory using ethers.js

Metamask Contract Factory Error: “Missing Links”

When deploying smart contracts, especially when integrating third-party libraries, you often encounter problems during the installation. One common issue is when hardhat detects errors that require additional library dependencies in the contract linker configuration.

In this article, we will delve into the specifics of Metamask and ethers.js integration using Hardhat, examine why the “Missing links from contract” error appears, and take steps to resolve the issue.

Understanding the contract linker configuration

When deploying a smart contract with external libraries, the linker configuration plays a crucial role in ensuring that all required dependencies are included. The contract linker configuration determines which dependencies are linked to the contract binary.

In Metamask, you can specify a network using the --network flag and then require specific library dependencies. For example:

npx hardhat network metamask --network solana dev --proxy 

The “Contract is missing links” error

When Metamask encounters the following error message:

The contract is missing links for the following libraries: [library1], [library2]...

this means that hardhat cannot determine which dependencies the contract requires. This can happen for various reasons, such as:

• The contract linker configuration is incomplete or incorrect.

• The library dependency is not properly specified with the–networkflag.

• An external library requires additional build steps (such as a Webpack configuration file).

Troubleshooting

To resolve this issue, follow these steps:

• Check your contract linker configuration: Verify that your contract linker configuration accurately defines all required library dependencies using the–network’ flag.

• Use the --proxy flag correctly

  : Ensure that you are using the correct proxy URL for each network.

Example Configuration

Here is an example of the complete configuration:

const hardhatConfig = {
// Your MetaMask account and network (e.g. Solana)
networks: {
solana: {
name: 'solana',
host: '
// Specify the proxy URL with the --proxy flag
proxy: {
// Example proxy configuration with a custom Webpack configuration file
https: (addr) => ${addr}.unpkg.com,
},
},
},
};

• Check library dependencies: Make sure all required libraries are properly specified with the --network' flag and are included in the contract linker configuration.

Additional Tips

• Usewebpack.config.js` file to configure Webpack for your project.

• Check if any custom proxy configurations or build steps are implemented correctly.

By following these guidelines, you can resolve the “Missing references in contract” error and successfully deploy smart contracts with external libraries using Metamask and ethers.js.