Learn Discord, Egghead and Jwt

Mock Service Worker is an API mocking library that allows you to write client-agnostic mocks and reuse them across any frameworks, tools, and environments.



Mocking WebSocket APIs with Mock Service Worker

**Note:** This course is being actively developed and more lessons will be added in the future.

Cursor is an AI-enhnaced code editor that allows you to call upon the robots to refactor or stub out functions for you with natural language. 

In this course, John will show you workflows that will save you time and effort by utilizing the features such as its mult-line editing and context.

In particular, by giving Cursor's AI the proper context, whether that's lines of code or multiple files, you'll get better output when trying to extend or refactor logic that's present.


Bite-size video tutorials for badass web developers.

egghead

Productive Developer Workflows with AI Enhanced Cursor IDE

We can use the Discord API to build bots, integrations, and extensions for the platform.

discord

The final step we need to take is to deploy our Discord bot to production. We'll be using using GitHub and Railway.app. 

[Railway.app](https://railway.app/) is a deployment platform that allows us to deploy our bot to the cloud. They give you $5 or 500 hours of free usage per month, which probably won't last you the full month, but it's a great way to get started.

Deploy a Discord.js Bot for Production

Disabling buttons can be useful in Discord servers to prevent users from clicking on buttons that are no longer relevant. By disabling a button, you can inform users why the button is no longer clickable and avoid confusion or frustration.

By the end of this lesson, you will be able to create a button that will disable itself when a submissions for a book-club have closed.

Conditionally Disable a Custom Discord Button

Now, let's learn how to add roles to users in a Discord server using a Discord.js collector.

By the end of this lesson, you will be able to create a collector to gather users who click on a specific button, filter out users who do not have a certain role, and add a specific role to the users who meet the filter criteria.

Add Roles to Users using a Discord.js Collector

Let's now learn how to create dynamic channels and roles with our Discord bot.

We want to be able to create new roles and channels for the book clubs and their attendants that we create in our server.

We'll be using methods from the `interaction` object to create the role and channel. And, we'll make sure to create both the role and channel each with the correct permissions.

Create Dynamic Channels and Roles with a Discord Bot

In this lesson, you will learn how to create custom buttons in Discord.js using `ActionRowBuilder` and `ButtonBuilder`. You will also learn how to style and add text to the button using `ButtonStyle` and the `setEmoji` method.

We'll need to make these buttons for our book-club message to give users the ability to let us know that they want to be a part of the club. 

`ActionRowBuilder` and `ButtonBuilder` are important, here's what they do:

`ActionRowBuilder` is used to create a row of buttons or other action components in a Discord message. This class provides methods for adding buttons, text, and other components to the row, as well as methods for formatting the row.

`ButtonBuilder` is used to create individual buttons within the `ActionRowBuilder`. This class provides methods for setting the text, emoji, style, and other properties of the button.

By using them both, we are able to create a row of buttons exactly how we want them to look!

Create Custom Discord Buttons with ActionRowBuilder and ButtonBuilder

In this lesson, you will be learning how to display relative time in a Discord embedded message using the Unix timestamp. 

We'll be adding a countdown timer to an embedded message to show the time remaining until submissions to a book-club close.

By the end of this lesson, you will have the ability to convert hours into seconds, add it to the current time in the Unix timestamp, and create a variable to store the wait time in seconds to display the short date time and relative time in Discord.

Display Relative Time in a Discord Embedded Message

Let's convert our Discord bot to respond with embedded messages.

Embedded messages in Discord are a great way to make your bot's responses look a lot more visually appealing!

We'll create a new command called `/bookclub` that will take in a book title, an author, and the number of hours until the submission deadline from the user. Then, it will `reply` with an object that Discord will automatically convert into an embedded message.

Have a Discord Bot Respond with Embedded Messages

In this lesson, you will learn how to build custom commands that can receive user input.

As a Discord user, you may have noticed that many servers use custom commands to provide information, moderate the chat, or enhance the overall user experience. By learning how to build these custom commands, you'll be able to create a more interactive and dynamic Discord server for your community!

We'll start by introducing the basics of slash commands and how they can be used in a Discord app. You'll then learn how to create a simple command that sends a response back to the user who triggered the command. 

We'll also cover how to make your commands more dynamic by adding arguments.

By the end of the lesson, you'll understand how to receive and respond to input from users and be able to build more sophisticated bots that can interact with your users in meaningful ways.

Receive and Respond to Input From Users with Discord.js Slash Commands

Now that our files are set up, we can now write our first Discord.js slash command.

By create custom commands, we extend the functionality of our Discord bot and can make it much more fun and interesting. 

We'll start by creating a new file in the commands folder, importing the slash command builder, and defining the data and execute sections of the command. We'll then register the command and test it in the Discord application.

By the end of this lesson, you'll have a solid understanding of how to create custom slash commands in Discord.js. So get ready to dive in and start building!

Create Your First Discord.js Slash Command

Node.js is a platform built on Chrome's JavaScript runtime for easily building fast, scalable network applications. Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices.

node

In this lesson, you will be setting up the necessary files for your first Discord.js slash command. The goal of this lesson is to give you a solid foundation to build upon as you create your own custom commands for Discord.

We will be importing and using `fs` and `path` to read from the command and events directories, using `Collection` from Discord to store and retrieve your commands, and creating the `Client` using the `GatewayIntentBits. 

Also, we are going to deploy your commands and set up events to execute them properly once they're written.

Setup for Discord.js Slash Commands

Using the Discord.js library, we're going to send our first message command! 

Let's create a classic "hello world" message command and learn how to create a new client instance, enable the necessary gateway intents, listen for specific events, and respond to those events by accessing a "message object" and then sending a message back.

Create your first Discord.js Bot Message Command

Now that we've set up a bot on our Discord server, let's write some code to get it do some fun stuff.

We're going to set up a new project and use the `Discord.js` library. While setting up this project you'll learn how to properly configure the client and log in to your bot by passing a Discord API token to `client.login`.

Once the project is set up we'll send our first event using the `client.once` and event, and set up some scripts so that we can start the bot using yarn.

Throughout the lesson, you will be introduced to important concepts and best practices for building Discord bots. By the end of the lesson, you will have a basic understanding of how to create a simple bot and be ready to continue building

Send your first Discord.js Bot Event 

In this lesson, you'll learn how to create and configure a Discord bot.

You will see how to create the bot, select the options you will need, give it the correct amount of permissions, and add it to your server.

Here is the link to the Discord Developer Portal: [https://discord.com/developers/applications](https://discord.com/developers/applications)

Create and Configure a Bot using the Discord Developer Portal

You'll be learning about collectors, sending custom messages, creating channels and roles, all dynamically. All of the different topics I cover in this course will be a guide for you to use each of these concepts individually so I highly encourage you to take what you learn to build something new and tell me what you build! 

I'll cover how to setup your bot in the discord developer portal then we'll set it up locally. I'll go over how to create a simple chat bot then go into much more detail on how to create slash commands. There is a break on lesson 5 where I'll go over some files that I've copy over from the Discord.js guide. There will be a template you can clone if you don't want to copy the files over yourself but I'll be running through each of them individually so you can understand what's going on.

The Discord.js guide is a super helpful resource when you need more information on specific topics you're struggling with. Discord.js also has a massive Discord channel that's a great place to ask questions that you just can't figure out yourself. The last resource is the Discord status page to check for things like api outages and other issues on Discord's side. All three of these resources will be linked down in the description. 

With that said, thank you for taking my course and let's get to it. 

Resources: 
- Discord.js Guide
    - [https://discordjs.guide/](https://discordjs.guide/)
- Discord Channel
    - [https://discord.com/invite/djs](https://discord.com/invite/djs)
- Discord Status Page
    - [https://discordstatus.com/](https://discordstatus.com/)

Introduction to Build a Book Club Bot with Discord.js

Build a Book Club Bot with Discord.js

JavaScript® (often shortened to JS) is a lightweight, interpreted, object-oriented language with first-class functions, most known as the scripting language for Web pages, but used in many non-browser environments as well such as node.js or Apache CouchDB. It is a prototype-based, multi-paradigm scripting language that is dynamic, and supports object-oriented, imperative, and functional programming styles.

javascript

Do you want to allow users of your app to create an account and sign in with their Google profile? If so, this 10-minute video will show you how to set up within your Auth0 tenant! 

The Google social connection allows users to log in to your application using their Google profile. By simply adding the connection within your Auth0 dashboard, enabling it for your application, and creating a project within your Google developer console, you can be up and running within no time!

How To Add Google Authentication with Auth0

JSON Web Tokens are an open, industry standard RFC 7519 method for representing claims securely between two parties.

Now that we have both the user and the token we can encode a JWT. This is made easy by the `jsonwebtoken` library that we will be using. 

To create a function that encodes a jwt, the function will need the user and token. Inside the function, definition create a `jwtPayload` object that just contains the essential data for encoding. Then, pass the payload to the `jsonwebtoken` library `sign` method and return the signed token.

Finally we store the jwt in the user's localStorage.

Encode User Data with JSON Web Token (JWT)

Now that we have our encoded JWT we need to be able to decode it!

The `jsonwebtoken` library makes this very easy. All we have to do is pass the `jwt` and our `token` to a decoder function. In that function definition we pass the arguments into the `verify` method and return the result.

Identify Users with JWT

We are going to use our JWT to make a protected request. 

All we have to do is create a button with a click event that calls our `fetchRepos` function. In the fetchRepos function make a fetch request to the `/repos` endpoint. In the fetch, pass an Authorization header with your JWT as a Bearer token. Then just await the response!

Use JWT to Make a Protected Request

This lesson demonstrates how to give Cursor direct access to your terminal output using the [Nx MCP extension](https://nx.dev/getting-started/ai-integration?utm_source=youtube&utm_medium=videos&utm_campaign=Nx-AI&utm_id=Nx-AI), enabling automatic error detection and fixing in monorepo projects.

**Workflow demonstrated in this lesson:**

- Encounter a runtime error when serving a Vite application in an Nx monorepo
- Install and configure the Nx Console extension with MCP integration
- Ask Cursor to check your terminal for errors and fix the underlying issues
- Watch as the AI accesses running task details and terminal output through Nx MCP tools
- Observe how it analyzes workspace relationships to identify incorrect imports and missing dependencies

**Key benefits:**

- Seamless Error Handling: AI gains direct access to terminal output and running task information
- Automatic Diagnosis: Accurately identify the root cause of errors without manual copying
- Context-Aware Fixes: Leverage workspace knowledge to implement proper solutions
- Reduced Context Switching: Eliminate the need to manually relay information between terminal and AI



Juri Strumpflohner

Enable Cursor to directly access the terminal to read the output and fix issues

See how Nx MCP gives AI coding assistants direct access to terminal output and running tasks, enabling automatic error detection and fixing.

This lesson demonstrates how to solve the predictability problem when using AI to generate code in monorepos by combining Cursor with Nx generators.

**Workflow demonstrated in this lesson:**

- Explore how Nx generators provide predictable scaffolding for new libraries
- Set up [Nx Console with MCP](https://nx.dev/features/enhance-AI?utm_source=egghead&utm_medium=videos&utm_campaign=Nx-AI&utm_id=Nx-AI) integration to expose generator capabilities to Cursor
- Use the AI assistant to brainstorm a new feature with the help of the Nx MCP tools
- Have Cursor leverage the Nx MCP tools to trigger the appropriate Nx generator for creating a React-based feature library
- Observe how the AI assistant takes the generated library and further integrates it into the codebase

**Key benefits:**

- **Predictable Code Structure**: Ensure generated libraries follow your project's and organization's conventions
- **Consistent Setup**: Maintain uniform configuration across TypeScript projects and package.json files
- **Guided Implementation**: Combine AI instructions with structured, predictable code generation

Enable Cursor to generate predictable project setups

Learn how to combine Cursor AI with Nx generators for predictable library creation in monorepos, ensuring consistent structure across your codebase.

This lesson demonstrates how AI assistants struggle with complex monorepo structures and how to dramatically improve their understanding using the [Nx MCP extension](https://nx.dev/features/enhance-AI?utm_source=egghead&utm_medium=videos&utm_campaign=Nx-AI&utm_id=Nx-AI) in Cursor.

**Workflow demonstrated in this lesson:**

- Observe how AI initially attempts to understand monorepo structure by scanning package.json files and analyzing folder hierarchies
- Install the Nx Console extension and configure the Nx MCP server in your project
- Enable the Nx MCP integration in Cursor's settings to access 15 powerful workspace tools
- Ask the AI assistant questions about your workspace structure and dependencies
- Watch as the AI leverages Nx's knowledge to accurately identify project relationships
- Visualize dependencies through an interactive graph generated by the Nx tools

**Key benefits:**

- Enhanced Workspace Understanding: AI assistants gain direct access to Nx's comprehensive workspace knowledge
- Accurate Dependency Mapping: Precisely identify connections between libraries and applications
- More efficient parsing of your workspace structure for your AI assistant

Give Cursor monorepo awareness with the Nx MCP

Learn how to enhance AI capabilities in monorepo setups using Nx MCP integration with Cursor, providing better project insights and dependency visualization.

TypeScript can sometimes feel like bunch of nonsense. But once you internalize a few key patterns, the type system starts to feel like a powerful tool instead of an obstacle.

Here are a few tricks that I’ve personally found valuable, especially if you’re working on a large codebase or building libraries.

---

## 1. Optional Keys vs Optional Values

There’s a big difference between marking a property as optional and allowing `undefined` as a value. These look similar:

```ts
type OptionalKey = {
  foo?: string;
}

type OptionalValue = {
  foo: string | undefined;
}
```

But they behave differently:

* `foo?: string` means the key `foo` might not be present at all.
* `foo: string | undefined` means `foo` is always present, but its value might be `undefined`.

Why this matters? The difference between them affects the way you use it:

* How you check if a property exists
* Function argument inference
* Serializing/deserializing data from external sources

### Example

```ts
function logFoo(obj: OptionalKey) {
  if ('foo' in obj) {
    console.log(obj.foo?.toUpperCase());
  }
}

function logBar(obj: OptionalValue) {
  console.log(obj.foo?.toUpperCase()); // May log undefined
}
```

As a rule of thumb, use `foo?: Type` (Optional Key) when the property might not be present, and `foo: Type | undefined` (Optional Value) when the key is always expected.

---

## 2. Pick and Omit for Object Key Manipulation

When you need to reshape object types by including or excluding specific keys, `Pick` and `Omit` are your go-to tools.

This type utilities are part of the language and are always available for your use, they are particulary useful when you need to derive types.

> Don't forget, Pick and Omit works over Object shapes

### Pick

```ts
type User = {
  id: number;
  name: string;
  email: string;
};

type PublicUser = Pick<User, 'id' | 'name'>;
// { id: number; name: string }
```

`Pick` is useful when exposing a public-facing API without leaking sensitive fields, it lets you choose what properties will be included

### Omit

```ts
type PrivateUser = Omit<User, 'email'>;
// { id: number; name: string }
```

Use `Omit` when you want to reuse a base type but remove some fields for specific scenarios, like forms or UI display logic.

These utilities keep your types DRY and consistent. Instead of redefining structures, you can derive them from existing ones, reducing duplication and potential errors.

---

## 3. Extract and Exclude for Union Filtering

Unlike `Pick` and `Omit`, which work on object keys, `Extract` and `Exclude` operate on union types, they are pretty similar in how the work.

### Extract

```ts
type Status = 'draft' | 'published' | 'archived';

type ArchivedOnly = Extract<Status, 'archived'>;
// 'archived'
```

Use `Extract` when you want to narrow down a union to only include specific members.

### Exclude

```ts
type VisibleStatus = Exclude<Status, 'archived'>;
// 'draft' | 'published'
```

Use `Exclude` when you want to remove one or more members from a union.


These are essential tools when refining API responses, filtering variants, or creating conditional logic that needs to type-check specific string literal options.

---

## 4. Loose Autocomplete

This is a different kind of trick, this one affects how your editor understand your types.

Sometimes you want to offer a set of suggestions to the user without forcing them to pick from a fixed list.

### The trick

```ts
type Variant = 'success' | 'warning' | 'info'

function setVariant(variant: Variant | (string & {})) {
  // ...
}
```

Now TypeScript will offer autocompletion for the variants defined in the `Variant` union, but will also allow  allow any other string.


`string & {}` is essentially still a string, but TypeScript treats it as a branded version, preserving autocomplete while keeping it assignable to `string`.

> [Here](https://egghead.io/blog/using-branded-types-in-typescript) you can found another article related to [Branded Types](https://egghead.io/blog/using-branded-types-in-typescript)

### Use cases

* Props with suggested values
* Config objects
* Third-party data with flexible inputs

---

## 5. Mapped Types for Smart Rewrites

Mapped types let you create new types from existing ones by transforming each property. This concept is a cornerstone of TypeScript’s type system and is covered more deeply in my article: [Learn the Key Concepts of TypeScript’s Powerful Generic and Mapped Types](https://egghead.io/blog/learn-the-key-concepts-of-typescript-s-powerful-generic-and-mapped-types).

You can consider Mapped types as some kind of function that transform a type in another by using all of the utilities and features of Typescript, like the above utilities and tricks, but also string literals, and more.

### Example: feature flags

```ts
type Config = {
  debug: string;
  logging: string;
};

type FeatureFlags = {
  [K in keyof Config]: boolean;
};
// This will create the following type
// { debug: boolean; logging: boolean }
```

### General Utility Type

```ts
type Booleanize<T> = {
  [K in keyof T]: boolean;
};
```

Mapped types are perfect for:

* Adapting backend responses
* Creating flexible utility types
* Rewriting shapes while preserving keys
* Enforcing contracts between layers

They’re also essential in combination with generics to create reusable type logic across your app or library.

> Found more about Generics in the following article [An Introduction to Typescript Generics](https://egghead.io/blog/an-introduction-to-typescript-generics)

---

## 6. The IIMT Pattern (Infer Inside Mapped Type)

This pattern unlocks the power of `infer` within mapped types, allowing you to extract and reuse internal type information from complex structures.

It dynamically inspects each property of a type (by using `infer`), and if that property matches a specific shape (e.g., a function), it extracts part of it.

This means you can build new types that are entirely based on the structure of other types without manually copying anything.

### The pattern

```ts
type API = {
  getUser: () => Promise<{ name: string }>;
  logout: () => void;
};

type ReturnTypes<T> = {
  [K in keyof T]: T[K] extends (...args: any) => infer R ? R : never;
};

// Result:
// {
//   getUser: Promise<{ name: string }>;
//   logout: void;
// }
```

Here, ReturnTypes iterates over each key in the API object and uses conditional types to check if the value is a function. If it is, it uses infer R to grab the return type of that function.

### How it works
- `keyof T` iterates over each key of the input type.
- `T[K]` accesses the value type at each key.
- `T[K] extends (...args: any) => infer R` checks if that value is a function. (consider this as a conditional block)
-  `infer R` captures the return type of the function.
- If the value is not a function, the fallback is never.

This pattern is composable—you can use it to build return type maps, argument type maps, or anything else you need.

```ts
type ArgumentTypes<T> = {
  [K in keyof T]: T[K] extends (...args: infer A) => any ? A : never;
};
```

This will give you a type with the argument list of each function in a mapped type.

You can use this in different situations like:

- Generating automatic schemas
- Building strongly-typed service clients
- Rewriting function maps
- Validating types without duplicating logic

If you’re building libraries or dynamic APIs, this pattern is a must-have in your TypeScript toolbox.

Once it clicks, it opens the door to expressive, scalable, and maintainable type logic.




Matías Hernández

Advanced TypeScript Tricks for Cleaner, Safer Code

Improve your TypeScript skills with advanced patterns like Pick, Exclude, mapped types, and the infer-inside-mapped-type trick.

John Lindquist

AI Dev Essentials #8: Claude's Costly Lessons, Google's AI Flood & Workshop Alert 🚀

Claude Max Mode in Cursor is powerful but pricey—one vague task can rack up costs fast. Learn how to control it and explore the latest AI dev tools.

Debugging complex web forms can be a grind. You manually input data, check console logs, and painstakingly try to reproduce bugs. This lesson unveils a powerful, largely automated workflow using Cursor's AI agent in conjunction with the Playwright MCP to thoroughly test a web form, identify issues, and even fix the underlying code.

First, you'll see how to instruct the AI to instrument your form's code with exhaustive console logging. Then, by providing only the URL of the live form, you'll delegate the testing process to the AI, which uses Playwright to interact with the form in multiple ways, attempting to break it and discover edge cases. The AI then analyzes the generated console logs to produce a detailed report of its findings. Finally, armed with this report and the original code, the AI can attempt to fix the identified bugs and re-verify its changes, all while you "go get a sandwich."

**Workflow demonstrated in this lesson:**

*   Instruct Cursor's AI agent to add comprehensive `console.log` statements to your form's TypeScript (.tsx) file.
*   Provide the live URL of the web form (running on `localhost`) to the AI, without giving it direct access to the updated code file.
*   Direct the AI to use the Playwright MCP to open the URL in a browser.
*   Task the AI with devising and executing multiple test scenarios (e.g., empty submission, invalid inputs, mismatched passwords) to fill out and submit the form.
*   Have the AI retrieve and analyze the browser's console logs after each test attempt.
*   Generate a consolidated report detailing the form's behavior, observed errors, and potential bugs based on the logs.
*   Instruct the AI to use this report and the original form code (now brought back into context) to fix the identified issues.
*   Optionally, have the AI re-run the tests to verify the fixes.

**Key benefits:**

*   **Automated Test Execution:** Leverage Playwright through Cursor to automatically interact with your live form.
*   **AI-Driven Test Case Generation:** The AI devises different input strategies to uncover bugs.
*   **Log-Based Bug Reporting:** Automatically capture and analyze console output to pinpoint issues.
*   **Hands-Off Debugging:** Delegate the testing and initial bug reporting to the AI.
*   **Efficient Bug Fixing Cycle:** Use AI-generated reports to quickly guide AI-assisted code corrections.
*   **Focus on High-Level Direction:** Instead of manual testing, you guide the AI's testing strategy and bug-fixing process.

By the end of this lesson, you'll have a robust method for delegating the tedious aspects of form testing and debugging to Cursor's AI, allowing for more efficient development and a more reliable end product.

---

**Phase 1: Instrumenting Code with Exhaustive Logging**

**Context:**
*   `{@filePath}` (e.g., `App.tsx`) is in Cursor's context.

**Prompt:**
"In `{@filePath}`, add exhaustive console logging for all form events, state changes, and validation logic. Focus on capturing input values, current errors, and the outcome of validation checks. The goal is to have detailed logs for later analysis. Do *not* fix any existing code errors; only add logging. Stop after modifying the file."

---

**Phase 2: AI-Driven Form Testing with Playwright and Log Analysis**

**Context:**
*   `{@formURL}` (e.g., `http://localhost:5173`) is in Cursor's context.
*   The live form at `{@formURL}` should be running the version of the code that *includes the exhaustive logging* added in Phase 1.
*   Playwright MCP is available.

**Prompt:**
"Using the Playwright MCP and the live form at `{@formURL}`:
1.  Devise [N, e.g., 3-5] distinct test scenarios to fill out and submit the form. Include scenarios designed to trigger validation errors and edge cases (e.g., empty submission, invalid data types, boundary values, mismatched passwords).
2.  For each scenario:
    *   Execute the form interaction using Playwright.
    *   Retrieve all browser console logs generated during that interaction.
3.  Compile a consolidated 'Form Behavior Report' detailing:
    *   Each test scenario and the inputs used.
    *   Observed behavior/UI state (e.g., error messages displayed).
    *   Key console log outputs relevant to errors or unexpected behavior.
    *   Any discrepancies or potential bugs identified.

---

**Phase 3: Fixing Bugs Based on AI Report and Re-Verification**

**Context:**
*   The 'Form Behavior Report' from Phase 2 is in the chat history.
*   `{@filePath}` (e.g., `App.tsx` – the original file, *not* the one Playwright interacted with, unless it's the same deploy) is in Cursor's context.
*   The live form at `{@formURL}` can be updated/re-deployed with fixes.
*   Playwright MCP is available.

**Prompt:**
"Based on the 'Form Behavior Report' (from our previous conversation) and the code in `{@filePath}`:
1.  Analyze the reported issues and implement the necessary code changes in `{@filePath}` to fix them.
2.  After applying the fixes and assuming the live form at `{@formURL}` is updated with these changes:
    *   Re-run *all previously defined test scenarios* using the Playwright MCP.
    *   Retrieve and analyze the console logs for each.
3.  Provide a verification summary: confirm if the original bugs are fixed and if any new regressions were introduced."

Capture Browser Logs with Playwright MCP in Cursor to Generate Reports

Fixing runtime errors in web applications, especially those that require browser interaction or appear in stages, can be a tedious back-and-forth. This lesson demonstrates how to create a powerful, automated debugging loop using Playwright MCP integrated into Cursor IDE via custom Rules, allowing the AI to interact with your live application, identify errors, and iteratively fix them.

**Workflow demonstrated in this lesson:**

*   Install and configure the Playwright MCP server in Cursor settings.
*   Create a custom Cursor Rule (e.g., "autofix") instructing the AI to:
    *   Use Playwright MCP to open a specified URL in a browser.
    *   Check for any errors displayed on the page.
    *   Automatically attempt to fix those errors in your codebase.
    *   Iterate this process until all errors are resolved.
*   Invoke the custom rule within Cursor's AI Agent, providing the application's URL.
*   Observe the AI agent launch Playwright, navigate the browser, identify errors, and apply code changes.
*   For errors hidden behind UI elements (like an error button), provide a screenshot to the AI, instructing it to interact with the UI to reveal and then fix subsequent errors.

**Key benefits:**

*   **Automated Debugging Cycle:** Let the AI handle the repetitive task of launching, testing, and fixing common web application errors.
*   **Iterative Problem Solving:** The AI can tackle multiple errors sequentially, making changes and re-testing.
*   **Browser Interaction:** Leverages Playwright to understand the application's state directly from the browser.
*   **Visual AI Assistance:** Use screenshots to guide the AI in interacting with UI elements to uncover and fix deeper issues.
*   **Reduced Manual Effort:** Spend less time manually debugging and more time on feature development.

By combining Playwright MCP with Cursor's AI Agent and custom Rules, you can significantly streamline your web development workflow, turning a frustrating debugging process into an automated one.

---

```json
    "playwright": {
      "command": "pnpm",
      "args": ["dlx", "@playwright/mcp@latest"]
    }
```

```
Please use the Playwright MCP to open a browser to the URL I provide, check for any errors, and then automatically fix those errors in my codebase, then continue to iterate until all the errors are gone.
```

Autofix Browser Errors with the Playwright MCP in Cursor

Automate browser-based debugging in web apps using Playwright MCP and Cursor IDE Rules—AI detects and fixes errors in real-time with minimal dev effort.

AI Dev Essentials #7: Microsoft's AI Blitz, Google's NotebookLM Shines & New Coding Agents

AI agents are reshaping coding in GitHub and VS Code, while NotebookLM’s mobile app quietly revolutionizes how developers collect and recall research on the go.

After a long AI-driven coding session in Cursor, getting a "second pair of eyes" on the generated code is crucial. Manually reviewing everything can be time-consuming. This lesson demonstrates how to use the CodeRabbit VS Code extension for an initial AI-powered code review, and then leverage Cursor's Agent to intelligently address the identified issues, even integrating test runs into the AI conversation.

**Workflow demonstrated in this lesson:**

*   Install and use the CodeRabbit extension to initiate an AI code review on your recent changes.
*   Examine potential issues and suggestions surfaced by CodeRabbit within the VS Code sidebar.
*   Apply CodeRabbit's direct code suggestions or use its "Fix with AI" feature.
*   Copy CodeRabbit's "Fix with AI" instructions into Cursor's Agent for more interactive and context-aware fixes.
*   Provide additional context to Agent, such as specific test commands (e.g., from Atuin command history), to guide the AI in fixing code and ensuring tests pass.
*   Iteratively work with Agent and CodeRabbit to refine code, apply fixes, and verify changes.
*   Stage changes with Git to easily revert or compare AI-suggested modifications.

**Key benefits:**

*   **Automated First-Pass Review:** Quickly get AI-driven feedback on your code changes.
*   **Integrated AI Fixing:** Seamlessly transition from CodeRabbit's suggestions to Cursor's Agent for more nuanced problem-solving.
*   **Contextual Debugging with AI:** Provide specific test commands and error messages to Agent for targeted fixes.
*   **Iterative Refinement:** Use the AI tools in a loop to address issues, test, and improve code quality.
*   **Improved Confidence:** Validate AI-generated and AI-assisted changes by running tests as part of the workflow.

By combining CodeRabbit's review capabilities with Cursor's Agent, you can create a more efficient and reliable workflow for reviewing, fixing, and testing code generated or modified with AI assistance.

Local AI Code Reviews with the CodeRabbit Extension in Cursor

Learn how to create a simple MCP Server to search GitHub Issues.

I'll show you how to set up an MCP server tool, receive parameters, add the server to Cursor, and run it. We'll see how we can return a simple text response from the MCP server, as well as a markdown-formatted text containing clickable links.

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Create a Simple GitHub Issue Search MCP Server using Cursor

Learn to build a simple MCP server to search GitHub issues and use it from Cursor.

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