Using Server-Side Rendering (SSR) in a Multi-Chain Decentralized Application (DApp)

Building a decentralized application (DApp) that operates on multiple blockchain networks can be a challenging task, especially when it comes to server-side rendering (SSR). One of the key aspects of building a DApp is to ensure that the frontend and the backend are communicating with each other seamlessly. This communication is especially crucial when it comes to the active blockchain network that the DApp is operating on.

In this context, the problem of identifying the active blockchain network is similar to internationalization or localization, where the app needs to know the user's location to display content in the appropriate language or currency.

The Solution: Including the Chain ID in the URL

One of the simplest solutions to this problem is to include the chain ID of the active network in the URL. For example, example.com/<chain-id>/ and https://gmp.daolens.com/1/workspaces/0x00. This way, the server can use this information to determine the active network and return the appropriate content to the user.

I came across this issue while working on the Grant Management Protocol (GMP) product at DaoLens. The frontend of the GMP is open source, and you can check it out on GitHub. The frontend is deployed at https://gmp.daolens.com/.

Handling Different Cases

There are two cases that need to be handled when implementing this solution:

Chain ID Missing in the URL
- If the chain ID is missing in the URL, we need to decide on a default chain ID and redirect the user to that network.
- In the GMP, I used Next.js's middleware to achieve this.
Chain ID in the URL and the one active in the Wallet are not the same
- This mismatch is important to solve because a user signing a transaction might fail if the app is not aligned with the same network as the user's wallet.
- The easy fix is to show a modal highlighting the mismatch and giving the user options to either switch their wallet's network or the DApp's network.
- In the GMP, I use a network switcher component to handle this.

In conclusion, including the chain ID in the URL is a simple and effective solution to the problem of determining the active blockchain network in a multi-chain DApp. With the code available on GitHub, it's easier for developers to implement this solution in their projects.