Metamask: Getting “contract is missing links for the following libraries” error even after adding as libraries while getting contract factory using ethers.js

Metamask Contract Factory Error: “Missing Links”

When deploying your smart contracts, particularly when integrating third-party libraries, you often encounter issues during deployment. One common problem arises when hardhat encounters errors that require additional library dependencies to be included in the contract’s linker configuration.

In this article, we’ll delve into the specifics of Metamask and ethers.js integrations using Hardhat, explore why the “Contract is missing links” error occurs, and provide steps to resolve this issue.

Understanding 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’s linker configuration determines which dependencies are linked into the contract’s binary code.

In Metamask, you can use the --network flag to specify a network and, subsequently, 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:

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

it means that hardhat is unable to determine which dependencies are required by the contract. This can happen due to various reasons, such as:

• The contract’s linker configuration is incomplete or incorrect.

• A library dependency is not properly specified using the --network flag.

• An external library requires additional build steps (e.g., a Webpack configuration file).

Resolving the Error

To resolve this issue, follow these steps:

• Check your contract’s linker configuration: Verify that your contract’s linker configuration accurately specifies 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 a complete configuration:

const hardhatConfig = {

  // Your MetaMask account and network (e.g., solana)

  networks: {

    solana: {

      name: 'solana',

      host: '


      // Specify the proxy URL using the --proxy flag

      proxy: {

        // Example proxy configuration with a custom Webpack config file

        https: (addr) => ${addr}.unpkg.com,

      },

    },

  },

};

• Verify your library dependencies: Ensure that all required libraries are properly specified using the --network flag and included in your contract’s linker configuration.

Additional Tips

• Use a webpack.config.js file to configure Webpack for your project.

• Verify that any custom proxy configurations or build steps are correctly implemented.

By following these guidelines, you should be able to resolve the “Contract is missing links” error and successfully deploy your smart contracts with external libraries using Metamask and ethers.js.

SOLANA ERROR INVALID