@varlabs/ai.ui-core

Framework-agnostic chat/stream/tool-call/HITL state machine for the AI SDK, consumed by framework bindings like @varlabs/ai.ui-react.

Installation

npm install @varlabs/ai.ui-core
# or
yarn add @varlabs/ai.ui-core
# or
pnpm add @varlabs/ai.ui-core

Usage

createChatCore owns message state and turns your provider's stream into UI-ready state updates. You supply streamFn - your own provider call, normalized to the SDK's StreamEvent stream - and subscribe to state changes:

import { createChatCore } from '@varlabs/ai.ui-core';

const chat = createChatCore({
  streamFn: (messages) => myProviderStream(messages),
  clientTools: {
    getWeather: async (args) => fetchWeather(args),
  },
});

const unsubscribe = chat.subscribe((state) => {
  console.log(state.status, state.messages);
});

await chat.sendMessage('What is the weather in Paris?');

Tool calls that require human approval surface as state.pendingApproval; call chat.approve() or chat.deny(reason) to resolve them. Durability across reloads comes from an optional jobStore (see @varlabs/ai.state) - if omitted, an in-memory store is used.

This package has no framework dependency. If you're using React, use @varlabs/ai.ui-react's useChat hook instead of calling createChatCore directly.

License

MIT