Cursive is a universal and intuitive framework for interacting with LLMs.

It works in any JavaScript runtime and has a heavy focus on extensibility and developer experience.

■ Highlights

✦ Compatible - Cursive works in any runtime, including the browser, Node.js, Deno, Bun and Cloudflare Workers. Through WindowAI, users can securely bring their own credentials, provider, and model to completions.

✦ Extensible - You can easily hook into any part of a completion life cycle. Be it to log, cache, or modify the results.

✦ Functions - Easily describe functions that the LLM can use along with its definition, with any model (currently supporting GPT-4, GPT-3.5, Claude 2, and Claude Instant)

✦ Universal - Cursive's goal is to bridge as many capabilities between different models as possible. Ultimately, this means that with a single interface, you can allow your users to choose any model.

✦ Informative - Cursive comes with built-in token usage and costs calculations, as accurate as possible.

✦ Reliable - Cursive comes with automatic retry and model expanding upon exceeding context length. Which you can always configure.

■ Quickstart

1. Install.

   npm i cursive

2. Start using.

   import { useCursive } from 'cursive'
   
   const cursive = useCursive({
       openAI: {
           apiKey: 'sk-xxxx'
       }
   })
   
   const { answer } = await cursive.ask({
       prompt: 'What is the meaning of life?',
   })

■ Usage

Conversation

Chaining a conversation is easy with cursive. You can pass any of the options you're used to with OpenAI's API.

const resA = await cursive.ask({
    prompt: 'Give me a good name for a gecko.',
    model: 'gpt-4',
    maxTokens: 16,
})

console.log(resA.answer) // Zephyr

const resB = await resA.conversation.ask({
    prompt: 'How would you say it in Portuguese?'
})

console.log(resB.answer) // Zéfiro

Streaming

Streaming is also supported, and we also keep track of the tokens for you!

const result = await cursive.ask({
    prompt: 'Count to 10',
    stream: true,
    onToken(partial) {
        console.log(partial.content)
    }
})

console.log(result.usage.totalTokens) // 40

Functions

You can use Type to define and describe functions, along side with their execution code. This is powered by the typebox library.

import { Type, createFunction, useCursive } from 'cursive'

const cursive = useCursive({
    openAI: {
        apiKey: 'sk-xxxx'
    }
})

const sum = createFunction({
    name: 'sum',
    description: 'Sums two numbers',
    parameters: {
        a: Type.Number({ description: 'Number A' }),
        b: Type.Number({ description: 'Number B' }),
    },
    async execute({ a, b }) {
        return a + b
    },
})

const { answer } = await cursive.ask({
    prompt: 'What is the sum of 232 and 243?',
    functions: [sum],
})

console.log(answer) // The sum of 232 and 243 is 475.

The functions' result will automatically be fed into the conversation and another completion will be made. If you want to prevent this, you can add pause to your function definition.

const createCharacter = createFunction({
    name: 'createCharacter',
    description: 'Creates a character',
    parameters: {
        name: Type.String({ description: 'The name of the character' }),
        age: Type.Number({ description: 'The age of the character' }),
        hairColor: Type.StringEnum(['black', 'brown', 'blonde', 'red', 'white'], { description: 'The hair color of the character' }),
    },
    pause: true,
    async execute({ name, age, hairColor }) {
        return { name, age, hairColor }
    },
})

const { functionResult } = await cursive.ask({
    prompt: 'Create a character named John who is 23 years old.',
    functions: [createCharacter],
})

console.log(functionResult) // { name: 'John', age: 23 }

If you're on a 0.x.x version, you can check here for the old documentation.

Hooks

You can hook into any part of the completion life cycle.

cursive.on('completion:after', (result) => {
    console.log(result.cost.total)
    console.log(result.usage.total_tokens)
})

cursive.on('completion:error', (error) => {
    console.log(error)
})

cursive.ask({
    prompt: 'Can androids dream of electric sheep?',
})

// 0.0002185
// 113

Embedding

You can create embeddings pretty easily with cursive.

const embedding = await cursive.embed('This should be a document.')

This will support different types of documents and integrations pretty soon.

Reliability

Cursive comes with automatic retry with backoff upon failing completions, and model expanding upon exceeding context length -- which means that it tries again with a model with a bigger context length when it fails by running out of it.

You can configure this behavior by passing the retry and expand options to useCursive.

const cursive = useCursive({
    maxRetries: 5, // 0 disables it completely
    expand: {
        enable: true,
        defaultsTo: 'gpt-3.5-turbo-16k',
        modelMapping: {
            'gpt-3.5-turbo': 'gpt-3.5-turbo-16k',
            'gpt-4': 'claude-2',
        },
    },
    allowWindowAI: true,
    countUsage: false, // When disabled doesn't load and execute token counting and price estimates
})

■ Examples

• Nuxt ⇢ Simple Application
• Cloudflare Workers ⇢ Simple Edge API

■ Roadmap

Vendor support

• [x] Anthropic
• [ ] Cohere (works on browser through WindowAI)
• [ ] Azure OpenAI models
• [ ] Huggingface (works on browser through WindowAI)
• [ ] Replicate (works on browser through WindowAI)

■ Credits

Thanks to @disjukr for transferring the cursive npm package name to us!