Grok Generative UI

Ask what X thinks about anything. grok-4.6 runs xAI's X Search server-side, then composes the answer out of real React components through CopilotKit frontend tools — it picks which components appear and what goes in them. There is no fixed dashboard being filled in.

Every post on screen is a real post the model found. Nothing is authored by hand.

Stack: Next.js 16 + CopilotKit v2 (@copilotkit/react-core/v2) + BuiltInAgent pointed at xai.responses("grok-4.6")

Highlights:

• 5 frontend tools registered via useFrontendTool — one search, four renderers
• x_search runs on xAI's infrastructure; no X/Twitter API credentials involved
• Headless CopilotChatView composed into the page layout, so the composer is the page's own input when centered and the rail's input once a run starts
• Paint-in reveal: each panel walks skeleton → wireframe → rendered as its tool lands
• Disk cache for search results so the demo replays in ~1s instead of 45–90s

Prerequisites

• Node.js 20+
• An xAI API key with access to grok-4.6 and the x_search server-side tool

Run locally

git clone https://github.com/CopilotKit/CopilotKit.git
cd CopilotKit/examples/showcases/grok-generative-ui
cp .env.example .env.local   # then put your XAI_API_KEY in .env.local
npm install
npm run warm                 # optional; pre-fetches the starter prompts
npm run dev

Open http://localhost:3000 and ask what is X saying about grok 4.6?

The cache

A cold x_search costs 45–90s, which makes iterating painful. npm run warm runs the three starter prompts once and writes the results to .cache/x-search/; after that they return in about a second.

Entries come from real searches, so a cache hit renders exactly what a live run would — it buys latency, not fidelity. npm run warm -- --fresh re-searches, and any topic outside the warmed set still hits the live API.

The cache keys on the topic the agent extracts, not on what you type: "what is X saying about grok 4.6?" reaches searchX as "grok 4.6". Lookup folds case and punctuation and falls back to substring containment.

How it works

you ──▶ CopilotKit runtime ──▶ BuiltInAgent(model: xai.responses("grok-4.6"))
                                     │
                                     │   all five are FRONTEND tools
                                     ├─ searchX ──▶ POST /api/x-search
                                     │                └─ x_search  ← runs on xAI
                                     ├─ renderSummary          ┐
                                     ├─ renderSentimentSplit   │
                                     ├─ renderArgumentMap      ├─▶ your components
                                     └─ renderReceipts         ┘

Every tool is a frontend tool — deliberately

An earlier version registered searchX as a backend ToolDefinition on BuiltInAgent while the renderers came from useFrontendTool. Mixing the two stopped the frontend tools from reaching the model at all: it reported them as "not available in my current setup" and narrated fabricated results instead of rendering.

All five are frontend tools now, so they reach the model through one path. searchX is a thin client that POSTs to /api/x-search, which is where x_search actually executes.

Runs must go through copilotkit.runAgent

// wrong — runs without the tools registered by useFrontendTool
await agent.runAgent();

// right — attaches them
await copilotkit.runAgent({ agent });

The raw AG-UI method hands the model an empty toolset, producing the same "tools unavailable" symptom.

Why searchX wraps x_search instead of exposing it directly

xAI's Responses API runs server-side tools on their infrastructure and will not accept client-side function tools in the same request. CopilotKit frontend tools are client-side function tools, so the two can never appear together. x_search therefore runs inside lib/x-search.ts, isolated, as the only tool in its request.

Why a model instance, not a model string

BuiltInAgent accepts BuiltInAgentModel | LanguageModel. The string "xai:grok-4.6" routes through the built-in provider list; xai.responses("grok-4.6") points at xAI's Responses API directly, which is what makes the server-side tools available at all.

maxSteps defaults to 1. It is set to 10 here — at the default the agent calls searchX and stops before rendering anything.

Composing the chat instead of embedding it

The UI uses the headless CopilotChatView and places its scrollView and input slots into the page layout. Two non-obvious props make that work:

• welcomeScreen={false} — with zero messages CopilotChatView returns its own welcome layout before it reads the children render prop, silently discarding your layout until the first message.
• input={{ showDisclaimer: false }} — an object slot merges over the bound props. Passing disclaimer="" does not work; the input falls back to the default label on an empty string.

Versions

@ai-sdk/[email protected] emits LanguageModelV4, which [email protected] does not accept — it wants V2/V3. 3.0.120 pins the same @ai-sdk/[email protected] as [email protected]. Don't bump it without checking that pairing.

Notes

• lib/discourse.ts holds a fixture captured from a real X search on 2026-08-12, used for offline UI iteration. The live path does not read it.
• Post avatars resolve per handle through unavatar.io and fall back to a tinted initial. They are derived from the handle, never from model output, so the demo cannot invent a face for a real account.