jcode-ui-core

The framework-agnostic core of jcode-ui — types, the ChatRuntime abstraction, and headless React primitives for AI chat interfaces.

Use this directly when you want the behavior (streaming, virtualization, tool dispatch, auto-follow) with your own styling layer. For the full styled experience, use jcode-ui.

What's inside

• types — Message, ToolCall, Approval, ThreadItem (discriminated union), TokenSnapshot, Goal, TodoItem, AskUserQuestion/Answer.
• runtime — the ChatRuntime contract (getState / subscribe / actions), createExternalStoreRuntime (adapts any Redux-shaped store), createMockRuntime (scriptable, for demos/tests), <RuntimeProvider> + useRuntimeState/useRuntimeSelector/useRuntimeActions hooks.
• adapters — ToolRendererRegistry, the plugin seam for tool-call visualization.
• primitives — headless components: Thread (virtualized + auto-follow), MessageView, Composer, ToolCallView, ApprovalBlock, AskUserBlock.
• hooks — useAutoScroll, useStreamFollow, useFocusOnIdle.

Install

pnpm add jcode-ui-core

React is an optional peer dependency — the non-React entries (types, runtime core, adapters) work in any TS project.

Quick start (headless)

import { RuntimeProvider, createExternalStoreRuntime } from 'jcode-ui-core/runtime'
import { Thread, MessageView, Composer } from 'jcode-ui-core/primitives'

const runtime = createExternalStoreRuntime({ store, select, actions })

;<RuntimeProvider runtime={runtime}>
  <Thread
    renderItem={(item) => {
      if (item.kind === 'message') return <MessageView message={item.data} />
      // …your tool/approval renderers
    }}
  />
  <Composer />
</RuntimeProvider>

Runtime contract

interface ChatRuntime {
  getState: () => RuntimeState
  subscribe: (listener: () => void) => () => void
  readonly actions: RuntimeActions
}

RuntimeState carries items / isRunning / tokenSnapshot / goal / todos / queued. RuntimeActions exposes sendMessage, enqueueMessage, stop, resolveApproval, submitAskUser, editMessage, removeQueuedMessage. See the runtime docs.

License

MIT