assistant-ui/runtime
Guide for assistant-ui runtime system and state management. Use when working with runtimes, accessing state, or managing thread/message data.
Guide for assistant-ui runtime system and state management. Use when working with runtimes, accessing state, or managing thread/message data.
npx skills add https://github.com/assistant-ui/skills/tree/main/skills/runtimeGuide for assistant-ui runtime system and state management. Use when working with runtimes, accessing state, or managing thread/message data.
This repo contains 7 individual skills — each has its own dedicated page.
Overview and router for assistant-ui, the React library for building AI chat interfaces from composable primitives. Use for high-level, cross-cutting, or architecture-overview questions: choosing packages, picking a runtime, or understanding the layered model (RuntimeCore, Runtime, context hooks, primitives) and message model. Covers the `@assistant-ui/react` core plus `@assistant-ui/react-ai-sdk`, `@assistant-ui/react-langgraph`, `assistant-stream`, and `assistant-cloud`; `AssistantRuntimeProvider`; the primitives `ThreadPrimitive`, `MessagePrimitive`, `ComposerPrimitive`; the hooks `useAui`, `useAuiState`, `useAuiEvent`; and runtime selection across `useChatRuntime`, `useExternalStoreRuntime`, `useLangGraphRuntime`, `useLocalRuntime`. For a specific area route to a focused sibling instead: setup, runtime, primitives, tools, streaming, cloud, thread-list, or update. Not for hands-on tasks already owned by those siblings.
Builds and customizes assistant-ui chat UI from composable, unstyled @assistant-ui/react primitives that follow Radix-style part composition. Use when assembling or styling a custom Thread, Composer, message rendering, action bar, or branch picker from building blocks: ThreadPrimitive (.Root, .Viewport, .Messages, .Empty, .ScrollToBottom), ComposerPrimitive (.Input, .Send, .Cancel, .Attachments), MessagePrimitive (.Parts/.Content, .Error), ActionBarPrimitive (.Copy, .Edit, .Reload, .Speak, feedback, .ExportMarkdown), BranchPickerPrimitive, AttachmentPrimitive, ThreadListPrimitive, ThreadListItemPrimitive. Covers MessagePrimitive.Parts children render functions for text, image, reasoning, and tool-call parts; conditional rendering with AuiIf (deprecated .If); and gotchas like wrapping in AssistantRuntimeProvider and adding className since primitives ship unstyled. For prebuilt drop-in UI and scaffolding use setup; for multi-thread sidebar behavior use thread-list.
Installs and configures assistant-ui in a project via the CLI, and picks the right runtime for a backend. Use for first-time install, scaffold, or config: `npx assistant-ui@latest create my-app` (templates default, minimal, cloud, cloud-clerk, langgraph, mcp), `npx assistant-ui@latest init [--yes] [--overwrite]` in an existing Next.js app, or `npx assistant-ui@latest add` registry components (markdown-text, thread-list). Also use to choose a runtime hook for a backend: useChatRuntime (AI SDK), useLangGraphRuntime, useAgUiRuntime, useA2ARuntime, useLocalRuntime (custom streaming API), or useExternalStoreRuntime (Redux/Zustand). Covers Vite/TanStack Start setup, shadcn styling, the playground --preset flag, and avoiding the deprecated @assistant-ui/styles and @assistant-ui/react-ui packages. For upgrading an existing install or post-upgrade breakage use update; for building UI from raw parts use primitives.
Streaming backends and wire protocols for assistant-ui via the assistant-stream package. Use when building a custom (non-AI-SDK) streaming endpoint with createAssistantStreamResponse or createAssistantStreamController, emitting parts through appendText/appendReasoning/appendSource/appendFile/addToolCallPart and setResponse; choosing between the AI SDK Data Stream format (toUIMessageStreamResponse) and the native Assistant Transport format; encoding or decoding streams with DataStreamEncoder/DataStreamDecoder, AssistantTransportEncoder/AssistantTransportDecoder, PlainTextEncoder, or UIMessageStreamDecoder; or wiring streamed chunks into useLocalRuntime or useChatRuntime. Use specifically for debugging stream wire issues: text-delta, part-start, result events, text/event-stream content-type, SSE format, tool calls not rendering, or partial text not showing. For general non-stream debugging route to the relevant focused skill, not the parent overview.
Implements multi-thread (conversation history) management in assistant-ui apps: rendering the prebuilt `ThreadList` next to `Thread`, or building a custom sidebar with `ThreadListPrimitive` and `ThreadListItemPrimitive` (Root, New, Items, Trigger, Title, Archive, Unarchive, Delete). Covers thread CRUD through the `useAui()`/`useAuiState()` API: `switchToThread`, `switchToNewThread`, and per item `rename`, `archive`, `unarchive`, `delete`, `generateTitle`, `initialize`, plus reading `s.threads.threadIds`/`archivedThreadIds`/`mainThreadId`. Includes cloud-backed persistence via `useChatRuntime` + `AssistantCloud` and a local `useRemoteThreadListRuntime` + `InMemoryThreadListAdapter` path. Use when a user wants a thread list/sidebar, switching, searching, sorting, drag-and-drop, or renaming/archiving/deleting conversations. For single-thread state, messages, or composer use runtime; for cloud auth/persistence setup use cloud.
Registers LLM tools and renders custom tool-call UI in assistant-ui (@assistant-ui/react). Use when adding frontend-only tools with makeAssistantTool / useAssistantTool (browser actions like clipboard, navigation, localStorage, async-generator streaming, AbortSignal), rendering backend AI SDK tool() calls with makeAssistantToolUI / useAssistantToolUI (status.type running/complete/incomplete/requires-action, args, result, artifact via ToolCallMessagePartProps), building generative UI from tool results, or implementing human-in-the-loop and approval flows (addResult, resume with context.human(), respondToApproval for server-side needsApproval gates). Covers registering tool components inside AssistantRuntimeProvider and the case-sensitive toolName matching that connects a tool to its UI. Reach for this when tool UI is not rendering, a tool is not being called, or a result is not showing.
Upgrades an existing assistant-ui project to current releases and executes the resulting migrations. Use when the user wants to update, upgrade, bump, or migrate @assistant-ui/react, @assistant-ui/react-ai-sdk, ai, or @ai-sdk/react, hits peer-dependency conflicts or post-upgrade type errors, or must apply renamed APIs after a version jump. Detects installed versus latest versions via npm ls / npm view, then routes through breaking-change references for each jump (AI SDK v4/v5 to v6; assistant-ui 0.8.x to 0.14.x): useAssistantApi to useAui, runtime.threadList to runtime.threads, ThreadPrimitive.ViewportSlack removal, the primitives components prop to children render functions, toDataStreamResponse to toUIMessageStreamResponse, maxSteps to stopWhen: stepCountIs(n). Runs npx assistant-ui@latest upgrade, pnpm/npm add @latest, and npx tsc --noEmit to verify. For a first-time install or fresh scaffold (not an upgrade) use setup instead.
AI Agent skill routing pattern for choosing the right skills before complex work starts.
Exercise: Build applications with GitHub Copilot agent mode
Generates custom design system rules for the user's codebase. Use when user says "create design system rules", "generate rules for my project", "set up design rules", "customize design system guidelines", or wants to establish project-specific conventions for Figma-to-code workflows. Requires Figma MCP server connection.
Codex skill for converting slide images, PDFs, and image-based PPTX files into editable PowerPoint decks.
GitHub repository for sotoia/framer-design-skill updated in the agent skills ecosystem.
Set bounded, verifiable coding loops for Codex, Claude Code, Cursor, and SKILL.md-compatible agents.