Full stack BAML with React/Next.js

BAML provides first-class support for React and Next.js applications through automatically generated type-safe hooks and server actions. Let's look at how easy it is to use BAML React hooks to handle the streaming automatically, giving your users real-time generation experience with zero extra code.

Every generated hook in your React code will have a code lens that shows the underlying prompt! This gives you full transparency from your frontend components all the way to the AI prompt, making debugging a breeze.

Example Usage

Here's a simple example of using BAML with React/Next.js. Once you define your BAML function, BAML will automatically generate a type-safe React hook for you.

// baml_src/story.baml
class Story {
  title string @stream.not_null
  content string @stream.not_null
}

function TellStory(input: string) -> Story {
  client "openai/gpt-4"
  prompt #"
    Tell me a story.

    {{ ctx.output_format() }}

    {{ _.role("user") }}

    Topic: {{input}}
  "#
}

Generate react hooks from the BAML function.

$ npx baml-cli generate

Use the generated hook in your React component.

// src/app/StoryComponent.tsx
'use client';

import { useTellStory } from '@/baml_client/react/client';

export function StoryComponent() {
  // Auto generated hook from BAML function
  const tellStory = useTellStory();

  return (
    <div>
      <button
        onClick={() => tellStory.mutate("a cat in the hat")}
        disabled={tellStory.isLoading}
      >
        Generate Story
      </button>

      {tellStory.data && <div>{tellStory.data.title}</div>}
      {tellStory.data && <div>{tellStory.data.content}</div>}
    </div>
  );
}

Reference Documentation

For complete API documentation of the React/Next.js integration, see:

Core Concepts

• Generated Hooks - Auto-generated hooks for each BAML function

Hook Configuration

• HookInput - Configuration options for hooks
• HookOutput - Return value types and states
• Error Types - Error handling and types

Next Steps

• Check out the BAML Examples for more use cases