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How concepts work

CodeCrafters

Introduction

Learn more about content access with a CodeCrafters membership.

Unlimited content access

Turbo test runs

Learn more about accessing code examples with a CodeCrafters membership

Code examples

Learn more about dark mode access with a CodeCrafters membership

Dark mode

Learn more about anonymous mode access with a CodeCrafters membership

Anonymous mode

Learn more about perks offered to CodeCrafters members.

Perks

Learn more about the Publish to GitHub feature

Publish to GitHub

Learn more about how the CodeCrafters program interface works

Program Interface

Running into test failures that are hard to debug? Try these steps.

How do I debug test failures?

Can I install additional dependencies?

Can I re-attempt a challenge in a different language?

How do I debug test failures in the Redis Challenge?

In CodeCrafters challenges, you'll write code to pass each stage and we'll verify your code submissions. Read more below to understand how exactly this works.

How do challenges work?

Instructions on resolving error related to large files

Large files found

Git clone errors

Instructions on resolving error related to no changes found

No changes found

How do I install the CLI?

How do I use the CLI?

How do I update the CLI?

How do I get an invoice?

Instructions on requesting an invoice in your local currency

How do I get a local currency invoice?

How do I get access the Forum?

If you've completed one or more challenges, you'll find your profile page at https://app.codecrafters.io/users/&lt;your_github_username&gt;kj.

Where is my profile page?

Can I list multiple languages on my profile page?

Instructions on deleting your CodeCrafters account

How do I delete my account?

Learn about how you can help us build CodeCrafters

Learn about how you can help us add language support

Learn about how to create starter code for a language

Starter Code

Learn about how to structure a test runner image for the CodeCrafters test runner

Test Runner Image Interface

Learn about what Concepts are, and how to create them.

The following tips should help you choose what concepts to build.

Choosing concepts

Creating concepts

Testing concepts

Publishing concepts

The following tips should help you build a great CodeCrafters challenge.

Planning your challenge

Pre-launching your challenge

Details on building the stage instructions and test cases for your challenge.

Building your challenge

The following tips should help you write great stage instructions for your challenge.

Writing stage instructions

Schema for the course-definition.yml file.

Course Definition Reference

Forum

Demo

Contributor Guides

Try Now

Login

Learn how to solve CodeCrafters challenges in C++

Learn how to solve CodeCrafters challenges in C#

Learn how to solve CodeCrafters challenges in Go

Learn how to solve CodeCrafters challenges in Java

Java

Learn how to solve CodeCrafters challenges in JavaScript

JavaScript

Learn how to solve CodeCrafters challenges in Kotlin

Kotlin

Learn how to solve CodeCrafters challenges in OCaml

OCaml

Learn how to solve CodeCrafters challenges in Python

Python

Learn how to solve CodeCrafters challenges in Ruby

Ruby

Learn how to solve CodeCrafters challenges in Rust

Rust

Learn how to solve CodeCrafters challenges in TypeScript

TypeScript

Learn how to solve CodeCrafters challenges in Zig

Contributors

Adding Language Support

Authoring Concepts

Authoring Challenges

How concepts work