Learn Auth0, Firebase and Leaflet

An easy to implement, adaptable authentication and authorization platform which basically makes your login box awesome.



auth0

After a user successfully logs in, Auth0 sends an ID token to your React application. Auth0, uses ID Tokens to cache user profile information and give it to a client application. The caching of ID tokens can improve the performance and responsiveness of your React application.

You can use the data from the ID token to personalize the user interface of your application. The Auth0 React SDK decodes the ID token and stores its data in the user object from the `useAuth0()` React hook. 

Customize UI With ID Token Data From The useAuth0 Hook's User Object

React is one of the web’s most popular frameworks for building JavaScript applications. 

If you know what you’re doing, React can drastically simplify how you build, use, and maintain code.

Whether you’re a React newbie or you’re ready for advanced techniques, you can level-up with egghead. Explore our in-depth courses, lessons, and community resources to build more powerful applications and crack open your career.

react

You can log out users from your React application by logging them out of their Auth0 sessions using the `logout()` method from the Auth0 React SDK.

Create a `logout-button.js` file in the src/components/buttons folder

Create a logout button component with the following code

```js
import { useAuth0 } from "@auth0/auth0-react";
import React from "react";

export const LogoutButton = () => {
  const { logout } = useAuth0();

  const handleLogout = () => {
    logout({
      logoutParams: {
        returnTo: window.location.origin,
      },
    });
  };

  return (
    <button className="button__logout" onClick={handleLogout}>
      Log Out
    </button>
  );
};
```

The `logout() method from Auth0 React SDK clears the application session and redirects to the Auth0 /v2/logout endpoint to clear the Auth0 session.

You can pass an object argument to `logout()` to customize the logout behavior of the React application. You can define a `logoutParams` property on that object to define parameters for the /v2/logout call. This process is invisible to the user. 

Pass the `logoutParams.returnTo` option to specify the URL where Auth0 should redirect your users after they log out. 

Setting `logoutParams.returnTo` to `window.location.origin` will ensure that Auth0 redirects your users to your production URL that you add to the "Allowed Logout URLs" list.




End Auth0 User Session with the logout Method from useAuth0 Hook

In this lesson, we create an AuthenticationGuard file that uses the Auth0React SDK to protect React routes by requiring login. 

You need to create the AuthenticationGuard component, pass in a component prop, and use it to protect any React route. 

```js
import { withAuthenticationRequired } from "@auth0/auth0-react";
import React from "react";
import { PageLoader } from "./page-loader";

export const AuthenticationGuard = ({ component }) => {
  const Component = withAuthenticationRequired(component);

  return <Component />;
};
```

Will also demonstrates how to use the AuthenticationGuard component to protect the profile, and admin routes in the application. 

```js
import { useAuth0 } from "@auth0/auth0-react";
import React from "react";
import { Route, Routes } from "react-router-dom";
import { PageLoader } from "./components/page-loader";
import { AuthenticationGuard } from "./components/authentication-guard";
import { AdminPage } from "./pages/admin-page";
import { CallbackPage } from "./pages/callback-page";
import { HomePage } from "./pages/home-page";
import { NotFoundPage } from "./pages/not-found-page";
import { ProfilePage } from "./pages/profile-page";
import { ProtectedPage } from "./pages/protected-page";
import { PublicPage } from "./pages/public-page";

export const App = () => {

  return (
    <Routes>
      <Route path="/" element={<HomePage />} />
      <Route
        path="/profile"
        element={<AuthenticationGuard component={ProfilePage} />}
      />
      <Route path="/public" element={<PublicPage />} />
      <Route
        path="/protected"
        element={<AuthenticationGuard component={ProtectedPage} />}
      />
      <Route
        path="/admin"
        element={<AuthenticationGuard component={AdminPage} />}
      />
      <Route path="/callback" element={<CallbackPage />} />
      <Route path="*" element={<NotFoundPage />} />
    </Routes>
  );
};

```

Use Auth0 component withAuthenticationRequired To Protect React Router 6 Routes

The `isAuthenticated` value represents the authentication state of your users it's tracked by the Auth0 React SDK. This value returns `true` when the user has been authenticated and `false` they're when not. Use `isAuthenticated` to render UI elements conditionally depending on the authentication state of your users.

```js
import { useAuth0 } from "@auth0/auth0-react";
import React from "react";
import { LoginButton } from "../../buttons/login-button";
import { LogoutButton } from "../../buttons/logout-button";
import { SignupButton } from "../../buttons/signup-button";

export const NavBarButtons = () => {
  const { isAuthenticated } = useAuth0();

  return (
    <div className="nav-bar__buttons">
      {!isAuthenticated && (
        <>
          <SignupButton />
          <LoginButton />
        </>
      )}
      {isAuthenticated && (
        <>
          <LogoutButton />
        </>
      )}
    </div>
  );
};
```
Authentication process doesn’t happen in your React application when using Auth0. Your React application will redirect your users to the Auth0 Universal Login page. Auth0 asks for credentials and redirects the user back to your application with the result of the authentication.


Use the Value of isAuthenticated to Render Components Conditionality

Create a `signup-button.js` file under the src/components/buttons folder

Add the following code:

```js
import { useAuth0 } from "@auth0/auth0-react";
import React from "react";

export const SignupButton = () => {
  const { loginWithRedirect } = useAuth0();

  const handleSignUp = async () => {
    await loginWithRedirect({
      appState: {
        returnTo: "/profile",
      },
      authorizationParams: {
        screen_hint: "signup",
      },
    });
  };

  return (
    <button className="button__sign-up" onClick={handleSignUp}>
      Sign Up
    </button>
  );
};
```
Adding `authorizationParams` to the `loginWithRedirect()` configuration object with the `screen_hint ` property and a value of `signup` will take users from your React application to the sign-up page.

Pass authorizationParams to loginWithRedirect to Direct Users to Auth0 Sign Up

Create a buttons folder the src/components folder

Create a `login-button.js` file and add the following code:

```js
import { useAuth0 } from "@auth0/auth0-react";
import React from "react";

export const LoginButton = () => {
  const { loginWithRedirect } = useAuth0();

  const handleLogin = async () => {
    await loginWithRedirect({
      appState: {
        returnTo: "/profile",
      },
    });
  };

  return (
    <button className="button__login" onClick={handleLogin}>
      Log In
    </button>
  );
};
```

`loginWithRedirect()` redirects to the Auth0 /authorize endpoint to start the authentication process. You can pass a configuration object to this method to customize the login experience.

Setting up the value of `appState.returnTo` to "/profile", you are telling the Auth0 React SDK to: When my users log in with Auth0 and return to my React application, take them to the "Profile" page.

If you don't set up this `appState.returnTo` option, your users will be redirected by default to the / path after they log in.

Apply useAuth0 hook and loginWithReditect to Add User Login to React Application

Install the Auth React SDK on the terminal 

```bash
npm install @auth0/auth0-react
```

Create an `auth0-provider-with-navigate.js` file in the src folder.

Add the following code.

```js
import { Auth0Provider } from "@auth0/auth0-react";
import React from "react";
import { useNavigate } from "react-router-dom";

export const Auth0ProviderWithNavigate = ({ children }) => {
  const navigate = useNavigate();

  const domain = process.env.REACT_APP_AUTH0_DOMAIN;
  const clientId = process.env.REACT_APP_AUTH0_CLIENT_ID;
  const redirectUri = process.env.REACT_APP_AUTH0_CALLBACK_URL;

  const onRedirectCallback = (appState) => {
    navigate(appState?.returnTo || window.location.pathname);
  };

  if (!(domain && clientId && redirectUri)) {
    return null;
  }

  return (
    <Auth0Provider
      domain={domain}
      clientId={clientId}
      authorizationParams={{
        redirect_uri: redirectUri,
      }}
      onRedirectCallback={onRedirectCallback}
    >
      {children}
    </Auth0Provider>
  );
};
```

Wrap the `Auth0ProviderWithNavigate` component around the `App` component inside of `index.js` to give it access to the `Auth0Context`.

`Auth0ProviderWithNavigate` needs the `BrowserRouter` component from React Router to be its parent, grandparent, or great-great-great-grandparent.


Install Auth0 React SDK and Create Auth0Provider with Access to Session History

Click the **Create Application** button.

Sign up for a [free Auth0 account](https://a0.to/egghead-react) here. 

Add the name "React Code Sample" and select "Single Page Applications" and the application type then click **Create**

Click on the **Settings** tab of your Auth0 Application page, scroll down to "Application URIs" section, and fill in these values:

**Allowed Callback URLs**
http://localhost:4040/

**Allowed Logout URLs**
http://localhost:4040

**Allowed Web Origins**
http://localhost:4040

Scroll down and click the **Save Changes** button.

On the "Basic Information" section get the Auth0 Domain and Auth0 Client ID values and paste them a `.env` file in the root of the project.

```env
REACT_APP_AUTH0_DOMAIN=AUTH0-DOMAIN
REACT_APP_AUTH0_CLIENT_ID=AUTH0-CLIENT-ID
REACT_APP_AUTH0_CALLBACK_URL=http://localhost:4040/
```





Link Auth0 Application to React Application

Start by cloning the `spa_react_javascript_hello-world_react-router-6` repository on its starter branch:

```bash
git clone -b starter git@github.com:auth0-developer-hub/spa_react_javascript_hello-world.git
```

Change your current directory to `spa_react_javascript_hello-world_react-router-6`

```bash
cd spa_react_javascript_hello-world
```

Install the project dependencies

```bash
npm install
```

Run the React application on `http://localhost:4040`

```bash
npm start
```


Download Starter Application from Auth0 Developer Center

Get started building web applications with Angular and Firebase.

In this course, you'll learn how to set up and use Firebase in your Angular applications using the AngularFire library.

We choose the AngularFire library because it is an official library created by the Firebase and Angular teams to work better with Angular.

It helps you by wrapping everything into observables and helps update zones. 

By the end of this course, you'll be able to build web applications using Cloud Firestore as your database, Firebase Authentication as your Auth system, Cloud Storage to save files, and Firebase Hosting to deploy your applications to the web.

TypeScript is a typed superset of JavaScript that compiles to plain JavaScript.

typescript

Build Full Stack Web Applications with Angular and Firebase

firebase

The last step we'll take is to make our application public.

We'll use the Angular CLI to generate a production build of our application, and then we'll use the Firebase CLI to deploy our application to Firebase hosting servers.

Firebase hosting is a great choice for us because Firebase Hosting will incorporate the services that we use in the app by default.


Deploy an Angular Web Application Powered by Firebase to Firebase Hosting

Angular is a development platform for creating applications using modern web standards. Angular includes a wealth of essential features such as mobile gestures, animations, filtering, routing, data binding, security, internationalization, and beautiful UI components. It's extremely modular, lightweight, and easy to learn.

angular

We want to secure our file storage so not just anyone can upload files to our Cloud Firestore.

We'll go through Cloud Storage Security rules to add rules and restrictions to our bucket server-side. You'll notice that the default rules for storage are the same as the database in that they are open to anyone for 30 days.

There are a few restrictions that we will implement:
    - Only allowing authenticated users to upload files.
    - Restrict the size of the files we want to upload.
    - Restrict the type of files we want to upload. (__i.e: only accept images or pdfs__)


Restrict File Uploading to Firebase Cloud Firestore with Cloud Storage Security Rules

Users can now see that files are attached to tasks but they can't do much with that. We need to let users be able to download the files so we'll do that in this lesson. 

We'll create a button for users to download the files they have in their tasks. We take a JavaScript first approach here by creating an anchor tag and adding all of the properties we need to allow for a download.


Download Files from Firebase Cloud Storage in Angular

Ionic is the beautiful, free and open source mobile SDK for developing native and progressive web apps with ease.

ionic

Now that file uploading works, we want to actually show that a task has files associated with it. To do this we will need to update the task object with a file property that we'll push files too.

In this lesson, we'll use Cloud Storage methods like getDownloadUrl() to get the file's download URL from our bucket.

Then we'll add that file's information to our task and persist it in the database to show the list of files in a task to the user.

While we do this, you'll see how we can easily add a spinner when files are being uploaded using Ionic loadingController.


Save and Display Tasks Files Utilizing Firebase Cloud Storage getDownloadUrl

We want our users to have more power by uploading and downloading files to the tasks they create.

In this lesson, we'll start creating the functionality that will allow our users to upload files. I went ahead and created the UI and click handler for this feature so we can focus on the actual file uploading.

We'll use the browser's `<input type="file">` to select files from our device and then we'll use Cloud Storage methods to upload the file to our storage bucket.


Upload Files to Firebase Cloud Storage with AngularFire storage uploadBytes

Our Security Rules are getting repetitive with all the logic that we've copy and pasted for the several actions we currently have.

In this lesson, we'll go through our security rules and extract the duplicated rules into functions that we can call.

With this approach, we can eliminate the copy/pasting and make our functions a bit more readable.


Refactor Firebase Security Rules to Use Functions for Easier Reading

Currently our Firebase Security Rules aren't as secure as they could be. When it comes to tasks, we are comparing the request's user on the task to the requests auth id. If someone intercepted this request and changed the ids here they could get away with it.

In this lesson, we'll go through our security rules and create a different set of security rules depending on the action the user is performing. For tasks specifically we will check the documents user id against the request user id.

We'll take things a step further as well and write different rules if a user is trying to create, delete, or update a task document.


Break Up Firebase Security Rules Into Different Actions Depending on Operation Performed

All the security we've added to our application has been client side. In a production app this isn't enough, we want to add security to our database directly.

We'll start securing our application's database with Firestore Security Rules.

We'll write security rules to prevent unauthenticated users from accessing our database, and then we'll add extra rules so that only a document's owner can access that document.


Secure your Firestore Data with Security Rules

Now that tasks are actually associated with a user in our database, we want to only show a user their own tasks.

To do this we'll revisit our task list and make some changes to use the `query()` and `where()` methods to filter our list before we get it from the database.

We'll learn how to pass our user's ID to a query and fetch only the tasks that belong to that user. Because Firebase uses Observables, you'll also see how we handle and change observables in Angular.


Query and Filter Documents from Firestore by userId with query()

Now that we have users in our application, we need to start associating them with tasks that are created. We'll revisit our task object and add our currently logged-in user's ID to our task object so that we can show users only their tasks. This is done through the Firebase Auth module.

Store the User's ID in the Task Documents That are Saved in Firestore

User authentication has been implemented but you'll notice if you navigate to any route in the app you are free to do so whether you're logged in or not. Let's fix this.

`@angular/fire` gives us a feature that is prepared to handle protected routes: the authentication guard.

We'll add that guard to our routing module to protect our tasks page, and redirect unauthenticated users to the login page.


Show Protected Pages only to Authenticated Users with AngularFire Authentication Guard

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

Juri Strumpflohner

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.

Ákos Kőműves

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.

Hey Everyone 👋,

John Lindquist here with the **sixth issue of AI Dev Essentials!** The AI coding landscape continues its rapid evolution, and this week is packed with significant updates. Cursor has rolled out its major 0.50 release, overhauling pricing, supercharging its AI features, and refining the developer experience. We're also seeing exciting new open-source entrants like the Zed code editor and the Cloudflare Agent Framework, plus fresh practical tips for your AI-assisted workflows. There's a lot to unpack, so let's dive in!

---

### New egghead.io Lessons This Week

* **[Clean up Legacy Functions for Testability in Cursor (0.50+) with cmd+k](https://egghead.io/clean-up-legacy-functions-for-testability-in-cursor-0-50-with-cmd-k~x1wb0)**

  Learn to refactor legacy code by extracting logic into new, top-level functions using Cursor's "Edit Full File" mode (Cmd+K then Cmd+Shift+Enter). This lesson shows how to break down monolithic functions into smaller, testable units and use "Fix in Chat" for quick error resolution, making your codebase more modular and maintainable.

* **[Automatically Improve Cursor Rules Using Custom Prompts](https://egghead.io/automatically-improve-cursor-rules-using-custom-prompts~5010d)**

  Refine unclear AI prompts or Cursor rules (.mdc files) by referencing a dedicated "best practices" rule file directly within Cmd+K. This lesson demonstrates how to instantly improve instruction clarity and leverage your own standards for better AI outcomes, with an option to have the AI Agent explain the improvements.


---

## 🚀 Cursor 0.50 Update: Key Enhancements
_Cursor's significant 0.50+ update simplifies pricing, boosts AI capabilities, and refines the developer experience. Highlights from their [changelog](https://www.cursor.com/changelog):_

### Simplified Pricing & Enhanced Model Access
Cursor introduces a unified, request-based pricing model. Max Mode, for demanding tasks, now offers token-based access to all top models. (*Note: Older Cursor versions will have access to previous MAX versions and long context mode for a few more weeks before they are sunset. [Read more about Max Mode](https://docs.cursor.com/max-mode).*)

### Advanced AI, Agentic Features & Broader Context
AI capabilities are enhanced with a new Tab Model for multi-file changes, a Background Agent (preview) for parallel tasks ([read more](https://docs.cursor.com/background-agent)), the ability to include the entire codebase in context using `@folders`, and fast agent-assisted edits in long files.

### Streamlined Workflow & Developer Experience
Developer workflow is streamlined with a refreshed Inline Edit (Cmd/Ctrl+K) integrated with agent options, support for multi-codebase projects via Workspaces, and improved chat features like markdown export and duplication.

---

## 🛠️ Dev Tooling, Frameworks & Ecosystem

_The developer ecosystem keeps expanding with new frameworks, SDKs, and practical agentic workflows._

* **Zed: The World's Fastest AI Code Editor**
  
  Zed is a new, open source, Rust-based code editor designed for agentic, collaborative editing. Features include automatic context discovery, real-time agent streaming, and extensibility via MCPs and tools. ([Zed](https://x.com/zeddotdev/status/1920102691365138826), [Blog](https://zed.dev/blog/fastest-ai-code-editor?x=60))

* **Cloudflare Agent Framework Video & Demo**
  
  Craig Dennis shows off the Cloudflare Agent Framework: synchronized agent state, client-side SQL storage, durable execution of third-party APIs (like YouTube), and human-in-the-loop RPC. [Watch the video](https://www.youtube.com/watch?v=ULu8hjFe_S0) | [GitHub](https://github.com/craigsdennis/kudos-agent) ([Craig Dennis](https://x.com/craigsdennis/status/1920643394872762487))

* **Mermaid Diagrams Coming to Cursor**
  
  The Cursor team announced that they will support Mermaid diagrams—great for visualizing complex code and data pipelines. ([ian](https://x.com/shaoruu/status/1922183290896744816))

* **AI SDK 5 Preview: UI Message Persistence**
  
  Store UI messages (not model messages) for better state restoration and backend integration (e.g., Langchain). ([Lars Grammel](https://x.com/lgrammel/status/1921542049821610068))

* **Gemini 2.5 Pro Turns YouTube Videos into Interactive Learning Apps**
  
  See it in action and check out [50+ free AI agent and RAG tutorials](https://github.com/Shubhamsaboo/awesome-llm-apps) ([Shubham Saboo](https://x.com/Saboo_Shubham_/status/1921210422742626449)).

---

## 💡 Prompting, Workflows & Best Practices

* **Prompting Techniques for Gemini Thinking Models**
  
  - Provide step-by-step instructions and refine as needed
  - Use multishot prompting for deeper understanding
  - Define output and behavior with clear system instructions
  - Debug and steer by checking reasoning for inconsistencies
  - For long outputs, be specific in your prompt
  [Full thread](https://x.com/googleaidevs/status/1922033670224806082) ([Google AI Developers](https://x.com/googleaidevs/status/1922033670224806082))

* **10 Brutal Lessons from 6 Months of Vibe Coding**
  
  [Reddit post](https://www.reddit.com/r/PromptEngineering/comments/1kk1i8z/10_brutal_lessons_from_6_months_of_vibe_coding/) ([Ian Nuttall](https://x.com/iannuttall/status/1921901239526109543))

* **Org Charts as Agent Architectures**
  
  Manu Cornet's classic comic is a surprisingly apt metaphor for AI agent architectures—even the Microsoft one. ([sunil pai](https://x.com/threepointone/status/1921105337907548350))

* **Pro Tip: Add Cursor's Docs to Cursor**
  
  Get Cursor tips inside Cursor by adding its own documentation. ([Fili](https://x.com/filiksyos/status/1920887960729170203))

* **Plan & Act Modes in Cline: Context-First Agentic Coding**
  
  Cline's Plan Mode helps you and the agent gather context and co-create a strategy before any code is written. Act Mode then executes with full context for robust, maintainable code. ([Cline](https://x.com/cline/status/1920009558971580648), [Blog](https://cline.bot/blog/plan-smarter-code-faster-clines-plan-act-is-the-paradigm-for-agentic-coding))

---

## 👨‍💻 Community Buzz & Quick Links

* **Anthropic is Thinking About a Meta Registry**
  
  [Discussion](https://github.com/modelcontextprotocol/registry/discussions/11) ([Sam Bhagwat](https://x.com/calcsam/status/1920250600412811314))

* **OpenAI Deep Research for GitHub Repos in ChatGPT**
  
  Connect GitHub repos to ChatGPT's deep research agent for detailed, cited reports. [Example](https://chatgpt.com/s/dr_681bf67f214c81918c0e9f934cd17171) ([OpenAI Developers](https://x.com/OpenAIDevs/status/1920556386083102844))

---

## ✨ Workshop Spotlight: Conquer the Complexity of Cursor ✨

Master practical AI development workflows in Cursor. This hands-on workshop covers Agents, multi-file analysis, effective prompting, Cursor rules, and strategies for handling AI failures.

* **When:** Thursday, May 22, 2025, 9:00 AM to 2:00 PM (PDT)
* **Where:** Zoom (Live Q&A included)
* **Investment:** ~~$249~~ $200 (Early Bird - 20% off until May 14th at midnight!)

[Read More](https://egghead.io/workshop/cursor) | [Register Now](https://buy.stripe.com/3csdSh2GTdhucTedQW)

_(Team training also available)_

---

That's the scoop for this issue! The pace of change is only accelerating—new models, smarter agents, and better tools are landing every week. If you have feedback or questions, hit reply! Always happy to chat about the latest in AI dev tools.

John Lindquist

[egghead.io](https://egghead.io)

AI Dev Essentials #6: Cursor 0.50, Zed, Cloudflare & AI Workflows

Cursor 0.50 drops with streamlined pricing and smarter agents. Zed and Cloudflare launch new dev tools. Plus, NotebookLM and Gemini push mobile AI forward.

Hey Everyone 👋,  
  
John Lindquist here with the **fifth issue of AI Dev Essentials!** This week, I've been relying more on GPT-4.1 in Cursor (which seems vastly improved since I last tried it) when building CLI and node tools. GPT 4.1 seems more aggressive in using tools as a pseudo reasoning step, while Gemini 2.5 Pro often jumps straight to code changes based on its "real" reasoning. I'm finding that GPT 4.1 in Cursor is becoming legit, especially with a "please explain that back to me" workflow. The speed allows for almost instant alignment. This "time to alignment" is so critical. It's that moment you \*know\* the AI is on the same page after a brain dump. On another note, programming is getting weird! I had a moment working on an MCP process manager where all the code was correct, but my \*English descriptions\* of what it was doing were too technical and thus misleading. Wild times!  
  
Big news: **Gemini 2.5 Pro upgrade** launched a couple hours ago. I'm super excited for this to land in Cursor, hopefully even later today! For now, you can try it out in AI Studio. I can't wait to see the improvements in Cursor's agent mode, especially since the tool calling is reportedly vastly improved. Beyond that, the major themes this week include impressive new **generative AI capabilities** for voice, a continued surge in **developer tooling and frameworks** (especially open source), and ongoing discussions around **prompting best practices and AI model quirks.**  
  
Let's dive in!

* * *

🎓 New egghead.io Lessons This Week
-----------------------------------

*   [When to Use Cursor Rules Instead of MCPs](https://egghead.io/when-to-use-cursor-rules-instead-of-mcps~zazdq)
    
    This lesson demonstrates creating a Cursor Rule for a CLI tool (\`ghx\` for scraping GitHub examples) to make it available to the agent. It highlights how agent requested rules can be a simpler alternative to MCPs for tool integration, offering more control over context.
    
*   [Brainstorming and Planning with Mermaid Diagrams in Cursor](https://egghead.io/brainstorm-and-planning-with-mermaid-diagrams-in-cursor~9iu69)
    
    Learn to use Cursor Rules to enable Mermaid diagram generation. The lesson shows how to create and iterate on diagrams (like basic to do app flows and sequence diagrams for optimistic updates) visually within Cursor, providing a way to plan before coding.
    
*   [Create Complex Cursor Shortcuts to Run Commands and Generate AI Commits](https://egghead.io/create-complex-cursor-shortcuts-to-run-commands-and-generate-ai-commits~7arof)
    
    This lesson walks through setting up a custom keyboard shortcut (Command+Shift+S) in Cursor's JSON settings to run a sequence of commands: stage all git changes, use Cursor to generate a commit message, commit, and then push/pull.
    

* * *

💰 AI Coding Assistant Valuations & Acquisitions Skyrocket
----------------------------------------------------------

_The AI coding assistant space is on fire with some massive financial moves happening._

*   **Anysphere (Cursor IDE) Hits $9 Billion Valuation**
    
    Cursor's parent company, Anysphere, reportedly secured a new $900 million funding round, pushing its valuation to an estimated $9 billion. Key investors include Thrive Capital, Andreessen Horowitz (a16z), and Accel. This is a huge jump from their $2.5 billion valuation in January 2025, showing incredible investor confidence. (Source details from PitchBook: "Maker of AI-coding software Cursor is doubling its valuation every 8 weeks", citing The Financial Times; and Crunchbase News: "AI-Powered Coding Tool Anysphere Lands $900M At $9B — Report".)
    
*   **OpenAI Reportedly Acquires Windsurf (formerly Codeium) for ~$3 Billion**
    
    In what would be its largest acquisition, OpenAI is said to be acquiring Windsurf. Windsurf, an AI-assisted coding tool, was previously valued around $1.25 billion. This move clearly signals OpenAI's intent to bolster its position in the AI developer tools market. (Source details from Mashable citing Bloomberg: "OpenAI is buying Windsurf for $3 billion. What does that mean for ChatGPT?"; and Investing.com citing Reuters/Bloomberg: "OpenAI agrees to buy Windsurf for about $3 billion, Bloomberg News reports".)
    
    My take: It seems like OpenAI, above all, needed the team behind Windsurf. The value of people talented in code generation is through the roof right now. But they also needed a product ASAP, so it's essentially like they're paying for same day shipping, even with this incredible amount of money. And it boggles my mind that Cursor's valuation is estimated at $9 billion. I know a lot of us developers look at both Windsurf and Cursor and kind of think to ourselves that we could have forked VS Code and built these things. So, seeing an incomprehensible amount of value being assigned to what looks like something that we could build if we just would have dedicated our time to it is always pretty shocking.
    

* * *

Here are the highlights that caught my eye this past week:

🚀 Model & Platform Updates
---------------------------

_This week saw some impressive new releases and updates in the model space, particularly around generative capabilities for voice, alongside ongoing platform refinements._

*   **Gemini 2.5 Pro Upgrade: Now with Better Coding and Function Calling.**
    
    Google announced a significant upgrade to Gemini 2.5 Pro. It boasts improved performance in coding (especially frontend web dev, editing, and transformation) and more reliable function calling. The new model (\`gemini-2.5-pro-preview-05-06\`) automatically replaces the previous version with the same pricing and rate limits. [Details](https://developers.googleblog.com/en/gemini-2-5-pro-io-improved-coding-performance)
    
    This is the update I've been waiting for! Reliable tool/function calling is a massive unlock for agentic workflows. Eager to put this through its paces in Cursor.
    
*   **Minimax's High Ranking Text to Speech Models on Replicate.**
    
    Minimax's speech-02 models (speech-02-hd and speech-02-turbo) and voice cloning capabilities are now available on Replicate. They are touted as top ranking TTS models. [Replicate Blog](https://replicate.com/blog/minimax-text-to-speech)
    
*   **Gemini 2.0 Flash Photo Editing.**
    
    Google's Gemini 2.0 Flash is showcased for its ability to edit photos using natural language, without needing traditional tools like layers or brushes. (Mentioned by Rishabh, [Source](https://x.com/Rixhabh__/status/1919641187696418896))
    
*   **Grok 3.5 Beta Coming Soon.**
    
    Elon Musk announced that Grok 3.5 will have an early beta release next week for SuperGrok subscribers. He claims it can accurately answer technical questions by reasoning from first principles. ([Source](https://x.com/elonmusk/status/1917099777327829386))
    

🛠️ Developer Tooling, Frameworks & Ecosystem
---------------------------------------------

_The developer ecosystem continues to expand with new open source tools for data extraction, updates to agent frameworks, and interesting discussions on platform choices and best practices._

*   **ContextGem for Structured Data Extraction.**
    
    A new open source LLM framework, ContextGem, aims to simplify extracting structured data and insights from documents with minimal Python code. ([GitHub ContextGem](https://github.com/shcherbak-ai/contextgem) via Sumanth)
    
*   **Cloudflare Agents SDK Update: Upcoming Auth and State Handling.**
    
    An upcoming PR for the Cloudflare Agents SDK will enhance Agent classes to handle OAuth, redirect URLs, and reconnections out of the box. This makes every Agent an MCP client with state management. (Mentioned by Sunil Pai, [PR Link](https://github.com/cloudflare/agents/pull/254))
    
    Authorization has been one of the biggest challenges for MCPs, specifically because the MCP sits behind the AI agent. Most things are just configured in a simple JSON file defining your MCP servers. Triggering OAuth workflows inside UIs, which are essentially streaming text and working on other tasks, has been weird. Any sort of standardization and convenience they can add to authentication is very welcome, in my personal opinion.
    
*   **Persistent File Storage for Cloudflare Durable Objects Demo.**
    
    A demonstration of a real filesystem and terminal for Cloudflare Durable Objects using a Rust based chunked SQLite FUSE strategy ported to \`ctx.storage.sql\` and an xterm.js frontend. ([Demo](https://dofs.verifried.workers.dev/), [Tweet](https://x.com/benallfree/status/1919224851409379786))
    
    I love that as more new developers come on board, we can give them paradigms they're familiar with, like file systems and basic terminals to manipulate files. I think one of the biggest holdups for developers with things like images on their websites is they're just so unfamiliar with the various concepts around routing and where things are hosted. Any effort that brings existing paradigms that beginners understand to complex subjects is welcome, in my opinion.
    
*   **Stripe MCP Monetization.**
    
    Stripe now allows MCP developers to monetize their MCPs with subscriptions or usage based billing. It's compatible with various clients including Cloudflare's Agents SDK. ([Stripe MCP Payments](http://stri.pe/go/mcp-payments) via Jeff Weinstein)
    
    Stripe is obviously the biggest player in allowing people to spend money on things, so it's no surprise they're introducing ways to make money with MCPs. I'm definitely curious to see what sort of services will pop into existence now that you could request them from AIs. I'm in no hurry to pay for any MCP service myself, and I don't have any to recommend yet, but I'll definitely keep my eyes out for what may manifest from this.
    
*   **Cloudflare Workers Monorepo Template.**
    
    Jacob Hands shared a template for creating Workers monorepos. It's inspired by the \`mcp-server-cloudflare\` repo which deploys multiple Workers from one repo with shared packages. ([GitHub Template](http://github.com/jahands/workers-monorepo-template) via Jacob Hands)
    
*   **A Story of Migrating from Vercel to Cloudflare.**
    
    A developer shared their experience migrating their entire infrastructure to Cloudflare. They cited reasons related to control, security, performance, and pricing. ([Source](https://x.com/Osintly/status/1917964184198823951))
    
    I've seen a lot of people try to do this, especially with the perception that Next.js kind of locks you into Vercel. So I just think it's valuable for people to realize that options are out there and that a lot of your projects are more portable than you think they are.
    
*   **New MCP Authorization Spec.**
    
    A new MCP authorization spec has been introduced. It defines the MCP server as an OAuth "resource server" and outlines the authentication flow. Den Delimarsky provided a blog post with more details. ([Den Delimarsky's Blog](https://den.dev/blog/new-mcp-authorization-spec) via Yenkel)
    
    It'll be interesting to watch any of the MCP specs evolve over time. I know there's been a lot of work done with streaming. Authorization is obviously going to play a huge part. It'll be interesting to see all these pieces of MCPs fitting together and how all their auth will sync up, where the walls are built, and what they can and cannot do to communicate with each other. I can't imagine a system of roles and identifications for the various MCPs and how they allow each other to speak to one another is going to be critical for MCP moving forward.
    

💡 Prompting, Workflows & Best Practices
----------------------------------------

_This week brought fresh perspectives on interacting with LLMs, managing context, and structuring UI generation prompts._

*   **"AI Rivalry" Prompting Technique.**
    
    Greg Isenberg shared a technique of pitting different AI models (ChatGPT, Claude, Grok) against each other. You feed one's output to another with critical feedback to elicit better results. ([Source](https://x.com/gregisenberg/status/1918661279641723158))
    
    There's so much potential left to unlock when multiple models work with and against each other. It's still a little cost prohibitive to use this for a lot of the tools you're probably building by yourself. But I love any sort of back and forth or ping pong or even parallel agents coming to conclusions and fighting over what the best answers will be. I can only imagine what these techniques unlock. Hopefully someone will send me a credit card to run a bunch of experiments.
    
*   **Theo's Take on Major AI Models' Quirks.**
    
    Theo (t3.gg) shared a list of issues and frustrations with various AI models and providers including Gemini, Claude, ChatGPT, and Mistral. He covers setup, cost, and availability. ([Source](https://x.com/theo/status/1918810601968513249))
    
    I really agree with Theo's breakdown here. I've had a very similar experience trying out each of the models. So, definitely worth checking out his list. It's just a well written, very concise list.
    
*   **Tips for LLM Tools Editing Files with Diffs.**
    
    Matt Pocock initiated a discussion seeking examples and best practices for implementing LLM tools that edit files using diffs in TypeScript. ([Source](https://x.com/mattpocockuk/status/1918758488777408528))
    
    I hopped in on this discussion with Matt about my personal experience working with diffs. It's just so challenging to get LLMs to produce precise diff worthy code based on line numbers and white space, and then trying to match that up with the original file. It was a fascinating thread to read about how some people are solving the problem by using a second LLM trained specifically on diffing two files and essentially rewriting the entire file. It's a problem space I spent a lot of time in last year, but I'm just going to leave it up to all of these IDEs and tooling who are so far beyond where I got to now that it's not worth spending time on for myself.
    
*   **Prompting Guide for Lovable.dev for UI Generation.**
    
    Felix Haas shared a step by step guide on how to prompt Lovable.dev for better UI generation. It covers high level descriptions, look and feel, brand guidelines, UI library specification, and component details. ([Source](https://x.com/felixhhaas/status/1918316680108736775))
    
    I have some non developer friends using Lovable, and they seem to be really enjoying this, so I'm sending this over to them. This newsletter is more focused on a bit more experienced developers and what they would expect to read about, but this is definitely something I'm going to shoot over to a few people I know.
    
*   **Survey of AI Agent Protocols.**
    
    Elvis (omarsar0) highlighted key takeaways from a survey paper on AI Agent Protocols. He discussed the agent internet ecosystem, timelines, protocol overviews (MCP, A2A), evaluation considerations, and use case analyses. ([Source](https://x.com/omarsar0/status/1918723145923453022))
    
    I know that MCP gets so much attention, and it's interesting how it's taken over so quickly, but there are many other concepts to pay attention to, such as the A2A protocol. So it's definitely worth reading through how some of these things, when and why you would use different protocols.
    
*   **Vercel AI SDK \`useAssistant\` Hook.**
    
    Sam Denty pointed to the \`useAssistant\` hook in the Vercel AI SDK for building AI assistants. ([AI SDK Docs](https://ai-sdk.dev/docs/reference/ai-sdk-ui/use-assistant))
    
    The \`useAssistant\` hook was something I wasn't aware of, and Sam shared it with me. For an awesome hook for building out web based AI tools, I didn't know it existed, and I thought I'd pass it along because it covers a lot of scenarios that I would be building for web cases.
    

👨‍💻 X Posts from the Cursor Team
----------------------------------

_Folks from the Cursor team continue to share valuable insights and tips for getting the most out of the AI-first IDE._

*   **Effective Context Management in Cursor.**
    
    Eric Zakariasson (from the Cursor team) provided tips on managing context in Cursor. He emphasized the combination of intent and existing codebase state, using surgical @ mentions, rules for patterns, and MCP for external systems. ([Cursor Docs](https://docs.cursor.com/guides/working-with-context) via Eric Zakariasson)
    
*   **New Cursor Guide for Web Development.**
    
    Eric Zakariasson (from the Cursor team) also published a new guide for web development workflows in Cursor. ([Cursor Docs](https://docs.cursor.com/guides/tutorials/web-development))
    
*   **Cursor Rules for Better Results.**
    
    Ian (shaoruu) (from the Cursor team) shared examples of Cursor rules they use. These include specifying libraries, listing UI components, defining commands, and using "Auto Attach" for specific file contexts. ([Cursor Docs](https://docs.cursor.com/context/rules) via Ian)
    

✨ Workshop Spotlight: Conquer the Complexity of Cursor
------------------------------------------------------

Master practical AI development workflows in Cursor. This hands on workshop covers Agents, multi file analysis, effective prompting, Cursor rules, and strategies for handling AI failures.

**When:** Thursday, May 8, 2025, 9:00 AM to 2:00 PM (PDT)

**Where:** Zoom (Live Q&A included)

**Investment:** $249

[Read More](https://egghead.io/workshop/cursor) | [Register Now](https://buy.stripe.com/3csdSh2GTdhucTedQW)

_(Team training also available)_

That’s the scoop for this issue! As a final note, I'm excited for Google I/O in a couple of weeks. Since they're already releasing a huge update to my favorite model, and there are rumors around other models that are even better, I just can't wait to see what they have in store for us.  
  
If you have any feedback or questions, hit reply! Always happy to chat about the latest in AI dev tools.  
  
John Lindquist  
[egghead.io](https://egghead.io/)

AI Dev Essentials #5: 🤯 Cursor Valued at $9B, Gemini 2.5 Pro & More AI Updates

GPT-4.1 and Gemini 2.5 Pro are changing how devs build tools in Cursor. Plus: massive funding for Cursor, OpenAI acquires Windsurf, and new agentic dev tools.

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