Overview

An overview of foundational concepts critical to understanding the AI SDK

The AI SDK standardizes integrating artificial intelligence (AI) models across supported providers. This enables developers to focus on building great AI applications, not waste time on technical details.

For example, here’s how you can generate text with various models using the AI SDK:

import { generateText } from 'ai';
import { openai } from '@ai-sdk/openai';

const result = await generateText({
  model: openai('gpt-4'),
  prompt: 'Explain the concept of machine learning.',
});

console.log(result.text);

To effectively leverage the AI SDK, it helps to familiarize yourself with the following concepts:

Generative artificial intelligence

Generative artificial intelligence refers to models that predict and generate various types of outputs (such as text, images, or audio) based on what’s statistically likely, pulling from patterns they’ve learned from their training data. For example:

• Given a photo, a generative model can generate a caption.
• Given an audio file, a generative model can generate a transcription.
• Given a text description, a generative model can generate an image.

Large language models

A large language model (LLM) is a subset of generative models focused primarily on text. An LLM takes a sequence of words as input and aims to predict the most likely sequence to follow. It assigns probabilities to potential next sequences and then selects one. The model continues to generate sequences until it meets a specified stopping criterion.

LLMs learn by training on massive collections of written text, which means they will be better suited to some use cases than others. For example, a model trained on GitHub data would understand the probabilities of sequences in source code particularly well.

However, it’s crucial to understand LLMs’ limitations. When asked about less known or absent information, like the birthday of a personal relative, LLMs might “hallucinate” or make up information. It’s essential to consider how well-represented the information you need is in the model.

Embedding models

An embedding model is used to convert complex data (like words or images) into a dense vector (a list of numbers) representation, known as an embedding. Unlike generative models, embedding models do not generate new text or data. Instead, they provide representations of semantic and syntactic relationships between entities that can be used as input for other models or other natural language processing tasks.

Core AI SDK functions

The AI SDK provides several core functions for working with language models:

Text generation

import { generateText } from 'ai';
import { openai } from '@ai-sdk/openai';

const result = await generateText({
  model: openai('gpt-4'),
  prompt: 'Invent a new holiday and describe its traditions.',
});

console.log(result.text);

Streaming text

import { streamText } from 'ai';
import { openai } from '@ai-sdk/openai';

const result = streamText({
  model: openai('gpt-4'),
  prompt: 'Write a poem about embedding models.',
});

for await (const textPart of result.textStream) {
  process.stdout.write(textPart);
}

Structured output

import { generateObject } from 'ai';
import { openai } from '@ai-sdk/openai';
import { z } from 'zod';

const result = await generateObject({
  model: openai('gpt-4'),
  schema: z.object({
    recipe: z.object({
      name: z.string(),
      ingredients: z.array(z.string()),
      steps: z.array(z.string()),
    }),
  }),
  prompt: 'Generate a lasagna recipe.',
});

console.log(result.object);

Tool calling

import { generateText, tool } from 'ai';
import { openai } from '@ai-sdk/openai';
import { z } from 'zod';

const result = await generateText({
  model: openai('gpt-4'),
  tools: {
    weather: tool({
      description: 'Get the weather in a location',
      inputSchema: z.object({
        location: z.string().describe('The location to get the weather for'),
      }),
      execute: async ({ location }) => ({
        location,
        temperature: 72 + Math.floor(Math.random() * 21) - 10,
      }),
    }),
  },
  prompt: 'What is the weather in San Francisco?',
});

console.log(result.text);

In the next section, you will learn about the difference between model providers and models, and which ones are available in the AI SDK.