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Wordle App on Optimint


This tutorial guide will go over building a cosmos-sdk app for Optimint, the Optimistic Rollup implementation of Tendermint, for the popular game Wordle.

This tutorial will go over how to setup Optimint in the Ignite CLI and use it to build the game. The tutorial will go over the simple design, as well as conclude with future implementations and ideas to extend this codebase.

NOTE: This tutorial will explore developing with Optimint, which is still in Alpha stage. If you run into bugs, please write a Github Issue ticket or let us know in our Discord. Furthermore, while Optimint allows you to build sovereign rollups on Celestia, it currently does not support fraud proofs yet and is therefore running in "pessimistic" mode, where nodes would need to re-execute the transactions to check the validity of the chain (i.e. a full node). Furthermore, Optimint currently only supports a single sequencer.


Given this tutorial is targeted for developers who are experienced in Cosmos-SDK, we recommend you go over the following tutorials in Ignite to understand all the different components in Cosmos-SDK before proceeding with this tutorial.

You do not have to do those guides in order to follow this Wordle tutorial, but doing so helps you understand the architecture of Cosmos-SDK better.

Design Implementation

The rules of Wordle are simple: You have to guess the word of the day.

Key Points to Consider:

  • The word is a five-letter word.
  • You have 6 guesses.
  • Every 24 hours, there’s a new word.

The GUI for Wordle shows you a few indicators: a green highlight on a letter in a certain position means that’s the correct letter for the Wordle in the right position. A yellow highlight means it’s a correct letter for the Wordle included in the wrong position. A grey highlight means the letter isn’t part of the Wordle.

For simplicity of the design, we will avoid those hints, although there are ways to extend this codebase to implement that, which we will show at the end.

In this current design, we implement the following rules:

  • 1 Wordle can be submitted per day
  • Every address will have 6 tries to guess the word
  • It must be a five-letter word.
  • Whoever guesses the word correctly before their 6 tries are over gets an award of 100 WORDLE tokens.

We will go over the architecture to achieve this further in the guide. But for now, we will get started setting up our development environment.

Table of Contents For This Tutorial

The following tutorial is broken down into the following sections:

  1. Ignite and Chain Scaffolding
  2. Installing Optimint
  3. Modules
  4. Messages
  5. Types
  6. Keepers
  7. Running Wordle