 Courses from Noah Hein

Ethereum is a decentralized, open-source blockchain with smart contract functionality. 

ethereum

Welcome to Noah's course on Introduction to Smart Contracts with Ethereum and Solidity. 

Introduction to Introduction to Smart Contracts with Ethereum and Solidity

Solidity is an object-oriented, high-level language for implementing smart contracts.

solidity

We will start off with calling the `increment` and `decrement` functions on your `Number` smart contract that's deployed on the Ropsten testnet. After we've interacted with it successfully, we'll go to a website known as a "block explorer" that allows us to easily see our smart contract, and the individual transactions that we sent.

Interact With Your Smart Contract On Ropsten

Now that we've have our Ropsten ETH and added it our MetaMask wallet, we'll learn how to deploy our `Number` smart contract to the Ropsten testnet. We will be using the free version of [QuickNode Link](https://www.quicknode.com/) as our rcp-url. 

Deploy To Ropsten using Forge and QuickNode

Test Faucets are common tools in the web3/blockchain ecosystem. There are many different faucets for all of the different blockchains, and the many networks deployed on them. Faucets are a way to fund your wallet with fake/test cryptocurrency for you to play around in a low-risk environment.

Here, we'll find a Ropsten faucet and use it to add test ETH to our newly-created MetaMask wallet.

If developing with Anvil was your "dev" environment, you can think of "testnets" such as Ropsten as being a public, pseudo-staging environment.

Use Ropsten as a Test Faucet

We will [download MetaMask](https://metamask.io/), set up an account, and copy your private key for use in the next lessons. We'll also briefly learn about the structure of a browser-based non-custodial wallet. 

Non-custodial wallets are wallets where no other party holds any private information about it. This makes it very powerful — in that you have 100% control over what goes on in your wallet. But it also means you are ENTIRELY responsible. There is no do-over button, no password reset, and no support agent to help you out should you go down the wrong path. 

Install MetaMask to Use as a Test Network to Store Sensitive Information

We will start off by using cast to interact with our contract that's deployed locally on Anvil. This time instead of calling `increment` we will call `decrement`. This will teach us how to interact with our smart contract whenever it expects the user to supply some data.

Send a Transaction With Arguments To Your Smart Contract On Anvil using Cast

To send data, we'll use `cast send` to send a transaction that we signed with our private key to the network. We use Cast to call the `increment` function we built in a previous lesson. Then we will check Anvil to see the logs that our transaction generated.

Write Data To Your Smart Contract On Anvil using Cast

Cast is another tool that Foundry leverages to make smart contract development easier for you. Cast will allow you to read/write data from your contracts through the terminal with minimal inputs. We'll learn how to use [cast](https://book.getfoundry.sh/reference/cast/cast) and how to read our deployed smart contract numbers.

Read Data From Your Smart Contract On Anvil using Cast

You will learn how to inspect the Application Binary Interface — commonly referred to as ABI — of your smart contract. ABI's are generated whenever your contract is complied. It is the source of truth for how the contract expects information flowing into it to be shaped. You need the ABI to take a look at how to send transactions to and from a smart contract.

[forge book reference](https://book.getfoundry.sh/reference/forge/forge-inspect) 

Inspect Your Contract's ABI

We deploy our smart contract to the local Anvil server running in the background on our machine. After we deploy the contract, we will look over some of the logging that Anvil produced for us.

Deploy Your Smart Contract to Anvil

We will start up a local blockchain that behaves like Ethereum, allowing us to test and prototype our smart contracts' behavior rapidly. It provides useful features out of the box, such as logging so we can follow the executions as they happen and pre-funded accounts with their corresponding private keys.

**Please Be Warry!** Never use or send money to the addresses on mainnet Ethereum. These keys are the same every single time. There are sure to be bots waiting to drain these wallets when funds get sent to them.

Start a Local Blockchain With Anvil

Now that we tested a smart contract in solidity with fuzzed inputs, we'll move on to testing our smart contracts in an idiomatic fashion. We will delete the negative test case for the `decrement` function, and will replace it with a function that expects a specific error instead of any generic failure. The `vm` object is used to do this, and we'll pick up on the vocabulary word "cheatcode" which is a reference to the various utilities that forge provides you through the `vm` object.

[Here are more examples](https://book.getfoundry.sh/forge/cheatcodes.html) of how cheatcodes are used.

And [here is the reference sheet](https://book.getfoundry.sh/cheatcodes/) for an overview of all the available cheatcodes.

Identify Anti-patterns within Smart Contract Testing

Here in the same file, `Contract.t.sol`, we'll test your smart contract's `increment` and `decrement` functions. We will learn about how Forge will fuzz tests and how to properly constrain the `vm` object to ensure you are testing it under the right specific conditions.

Test a Smart Contract in Solidity with Constrained and Fuzzed Inputs

We will use the `Test.sol` smart contract that Forge provides to turn your smart contract into something that can be tested. We'll configure the file using the `setup` function and successfully run our test suite.

Set Up and Test a Smart Contract in Solidity

Now that Foundry is installed, we can build out the functionality of our smart contract written in Solidity. We'll create various functions that allow you to increment, decrement, and read a number whose state is kept in your smart contract. 

All of the functions will have different visibility modifiers and types that constrain the behavior of your functions. We'll create our own custom error that is thrown whenever you step outside the bounds of your intended functionality.

Write a Smart Contract in Solidity

We will learn about how to install foundry, and initialize your project using the forge command line utility. 

After creating a new project, we'll learn about the high-level architecture of a forge application.

[Here is the documentation](https://book.getfoundry.sh/getting-started/installation) on how to install Foundry.

Install and Initialize a Foundry Application

Smart Contracts are programs stored on the blockchain that run when certain conditions are fulfilled. 

These Smart Contracts have many benefits to them such as speed, transparency, and security. The contract is immediately run as soon as the requirements are fulfilled. This creates a system where you place trust in a transparent system, instead of an opaque intermediary. 

Noah will show you how to write, test, and deploy smart contracts on Ethereum, using the popular smart contract language, Solidity. You'll also learn how to use Foundry, a popular dev-toolbelt, to streamline our whole development process. 

Throughout this course, you'll learn how to:
- safely and securely set up Smart Contracts
- write and read data on your Smart Contract
- send transactions with specific arguments to your Smart Contract
- deploy your Smart Contract using Forge and QuickNode

And more!

Introduction to Smart Contracts with Ethereum and Solidity

Stop waiting for a single AI agent! This lesson demonstrates a powerful workflow to massively parallelize your AI-driven development in Cursor. Learn how to use tools like `file-forge` to package your project context, prompt advanced AI models (like Gemini in AI Studio) to brainstorm features and generate setup scripts, and then leverage a custom `git worktree` CLI tool (`wt`) to automatically launch an "army" of isolated Cursor instances, each tackling a different task on its own branch.

**Workflow Demonstrated / Key Benefits:**

*   **Bundle Project Context:** Use `file-forge` to create an AI-friendly representation of your codebase.
*   **AI-Powered Brainstorming & Scripting:** Prompt a reasoning model (e.g., Gemini via AI Studio) to suggest features *and* generate a shell script (`zsh`/`bash`) to automate setup.
*   **Automated Worktree Creation:** Execute the generated script which uses a custom `git worktree` CLI (`wt`) to:
    *   Create new branches and worktrees for each suggested feature.
    *   Install dependencies automatically (e.g., `pnpm install`).
    *   Launch multiple, isolated Cursor instances.
*   **Parallel AI Development:** Assign different features or implementation approaches to each Cursor agent (Composer) simultaneously.
*   **Efficient Monitoring:** Easily switch between active Cursor projects/worktrees using `Ctrl+R` or OS spaces.
*   **Seamless Integration:** Merge completed features back into your main branch using `wt merge` or use agents to commit, push, and create Pull Requests via the GitHub CLI (`gh pr create`).
*   **Boost Productivity:** Dramatically speed up iteration and experimentation by running multiple AI agents concurrently without conflicts.

This approach transforms your workflow, allowing you to explore multiple development paths simultaneously and integrate the best results efficiently using standard Git practices.

**Resources** 

https://www.npmjs.com/package/@johnlindquist/worktree
https://www.npmjs.com/package/@johnlindquist/file-forge

**Want to Learn More? Sign-up for my Cursor Workshop!**

https://egghead.io/workshop/cursor

John Lindquist

Swarm Intelligence: Massively Parallelize Your AI Agents in Cursor

Creating powerful and context-aware tools for Cursor IDE becomes straightforward when leveraging information directly from your current project. In this lesson, you'll learn how to build a custom MCP (model context protocol) tool that intelligently requests essential details—such as the current project path and conversation summaries—from your Cursor project.

Workflow demonstrated in this lesson:

- Define MCP tool parameters to request specific project details.
- Pass project path and conversation summaries into your MCP tool.
- Automatically write or update files within your current project using these parameters.

Key benefits:

- Automate tasks with precision based on your active project's context.
- Simplify interactions by creating AI-driven CLI commands tailored to your needs.
- Open endless possibilities for integrating external APIs and advanced automation.

Through this practical demonstration, you'll gain a versatile technique for enhancing your development workflow in Cursor IDE.

[https://github.com/johnlindquist/mcp-cursor-tool-starter](https://github.com/johnlindquist/mcp-cursor-tool-starter)

Build MCP Tools Using Project Context for Custom Cursor IDE Automation

Setting up custom MCP (Machine Command Protocol) servers in Cursor can involve tedious steps, such as configuring node paths or referencing additional commands. This lesson shows how to streamline this process by bundling your MCP server directly into a standalone executable.

Workflow demonstrated in this lesson:

- Use a simple MCP server project starter.
- Run a single bundling command to create an executable.
- Right-click the generated executable, copy its full path, and add that directly to your Cursor settings.

Key benefits:

- Eliminates the need for complex node path configurations.
- Simplifies the setup and integration of custom MCP servers into Cursor.
- Makes the server executable instantly accessible within your Cursor environment.

By following this streamlined approach, you can quickly and easily integrate custom MCP servers into Cursor, making your development workflow cleaner and more efficient.

[https://github.com/johnlindquist/mcp-cursor-tool-starter]()

Easy MCP Server Setup in Cursor IDE with Bundled Executables

TanStack Router is the foundation for TanStack Start, which is gaining significant attention due to its innovative approach to application development.

This course focuses on getting effective TanStack Router, a modern and scalable routing solution for React applications. You will learn how to:
- set up and scaffold new applications,
- use file-based routing
- create nested routes
- manage dynamic route parameters and more.

The course covers advanced features like route loaders, caching strategies, and lifecycle hooks, which are crucial for enhancing application performance and user experience.

By understanding TanStack Router, you can build more efficient, type-safe, and maintainable applications, leveraging its integration with data fetching libraries like TanStack Query.

This knowledge is essential for developers looking to improve their routing skills and stay ahead in the field.

Tomasz Ducin

Up and Running with Tanstack Router and React

Learn TanStack Router for React: set up apps, use file-based routing, manage routes, and boost app performance.


In this lesson, we explore how TanStack Router integrates with the [native browser history API](https://developer.mozilla.org/en-US/docs/Web/API/History) to manage navigation.

As we navigate through different routes, the URL changes are stored in the browser's history, allowing users to use the forward and backward buttons to traverse their navigation history.

This functionality also **enables permalinks**, meaning users can copy and paste URLs to access specific routes directly.

Additionally, we learn how to programmatically interact with the history object to move forward or backward through the navigation stack, enhancing the user experience by providing full control over navigation actions.

This compatibility with the native history API ensures that TanStack Router applications behave similarly to traditional websites, offering a seamless and intuitive user experience.

Browse History in Tanstack Router

Browse history in TanStack React Router using the native history API for seamless navigation

In this lesson, we explore how to hook into TanStack Router's lifecycle hooks to execute custom logic during route changes.

The hooks we'll look into are: `onEnter`, `onStay`, and `onLeave`, which are triggered when entering, staying within, or leaving a route, respectively.

All hooks receive a detailed match parameter, providing information about the route's path, ID, and tons of other details.

This allows for the implementation of features like animations or logging when navigating between routes.

We also learn how to use these hooks to track and manage state changes as users interact with the application, making it easier to implement complex behaviors based on route transitions.

Hook into Route Lifecycle Hooks in Tanstack Router

Hook into TanStack React Router's lifecycle hooks for custom route logic and animations.

In this lesson, we learn how to handle not found errors in TanStack Router by using the `notFoundComponent` at both nested and global levels.

To trigger the display of a `notFoundComponent`, we must throw a specific error using the `notFound` function within a loader or other lifecycle method of a route. This approach allows us to provide custom error messages for specific routes or globally across the application.

We explore how to define a notFoundComponent within a specific route's configuration and how to set a `defaultNotFoundComponent` at the router global level, which applies to all routes unless overridden locally. This flexibility ensures that users receive meaningful feedback when encountering non-existent routes.

Provide NotFoundComponent at Nested Route or Global Level in Tanstack Router

Handle notFound errors in TanStack Router with notFoundComponent at nested or global levels.



In this lesson, we learn how to access dynamic route parameters using the `useParams` hook in TanStack Router.

When used with a specific `Route` object, `useParams` provides type-safe access to route parameters, ensuring that TypeScript knows the exact types of these parameters.

This approach eliminates the possibility of undefined/optional values, making it safer for accessing parameters like `employeeId`.

However, when using `useParams` globally without specifying a route, it requires an options object with `{ strict: false }`, which reduces type safety.

In this case, the hook can access parameters from any route in the application, but it does not guarantee their existence or type. This flexibility allows components to be reused across different routes, but it requires careful handling of potential errors.



Access Dynamic Route Parameters with useParams in Tanstack Router

Access dynamic route parameters with useParams in TanStack React Router for type-safe routing.

In this lesson, we learn how to reorganize file-based routes in TanStack Router to accommodate nested routing structures.

We explore how to create additional nested routes by converting files into directories, allowing for further nesting.

For example, to create a nested route like `/employees/$employeeId/edit`, we can create a **directory** (!) named `$employeeId` and place an `index.tsx` file inside it to define the route component for this nested route.

This approach provides flexibility in organizing files while maintaining the convention that file names and locations align with route paths. We also see how to adapt existing components and loaders to work with these reorganized routes, enabling features like edit forms or delete actions (or whatever) within nested routes.


Reorganize File-Based Routes in Tanstack Router

Reorganize file-based routes in TanStack Router for flexible nested routing.



In this lesson, we learn how to parametrize the loader for a nested route in TanStack Router.

We focus on a nested route like `/employees/$employeeId`, where the `$employeeId` is a **dynamic parameter**.

To fetch data for this route, we use a `loader` function that accesses the `$employeeId` parameter. This is achieved by using the params object available in the `loader` function, which contains the dynamic segments of the URL. We then use this parameter to call a function like `getEmployeeById`, which fetches specific employee details from an API.

We highlights that TanStack Router **automatically infers types** for these parameters, ensuring type safety for nested routes.

Parametrize Route Loader for Nested Route in Tanstack Router

Parametrize nested route loaders in TanStack Router using path parameters

Noah Hein

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