CopilotKit × Daytona — runCode showcase

The deployable demo behind the Daytona cookbook recipe. A minimal CopilotKit Built-in Agent app whose only added capability is a runCode server tool that executes Python / TypeScript / JavaScript inside an isolated Daytona sandbox and streams the result back to the chat — with a custom useRenderTool card (fixed-height streaming code pane with syntax highlighting and a fixed-height result pane).

What's inside

• app/api/copilotkit-single/route.ts — the recipe's runCode tool wired into a BuiltInAgent on createCopilotEndpointSingleRoute. Pure recipe code (Python/TS/JS via daytona.create({ language })).
• app/page.tsx — CopilotKitProvider + CopilotSidebar + a useRenderTool({ name: "runCode" }) renderer using react-syntax-highlighter (Prism + vscDarkPlus, mirroring @copilotkit/react-ui's own CodeBlock).
• A system prompt that tells the agent the tool result is rendered directly to the user, so it doesn't restate stdout in chat text.

Prerequisites

• Node 18+
• An OpenAI API key (OPENAI_API_KEY) — the recipe defaults to openai:gpt-5.4-mini, overridable via the MODEL env var.
• A Daytona API key (DAYTONA_API_KEY) — create one in the Daytona dashboard.

Run locally

npm install
echo "OPENAI_API_KEY=sk-…"      > .env.local
echo "DAYTONA_API_KEY=…"       >> .env.local
npm run dev   # http://localhost:3000

Open the page, click into the sidebar chat, and ask something like:

Run a Python snippet that prints the first 10 Fibonacci numbers.

Run JavaScript that logs Date.now().

Notes

• This is a standalone npm project — intentionally not in the monorepo's pnpm-workspace.yaml. npm install here installs against published @copilotkit/*@1.58.0, which is the same surface the recipe targets.
• new Daytona() throws at module load if DAYTONA_API_KEY is missing, so the app won't boot without it. That's by design — the key is required, not optional.
• For arbitrary languages beyond Python/TS/JS, swap sandbox.process.codeRun for sandbox.process.executeCommand(...) and optionally use a custom Daytona Image with the toolchain preinstalled. See the recipe's Going further section.