Shows: streamChat → textStream → await usage, and that the API key is read from the environment by the app and passed explicitly into createAnthropic (core never reads process.env).
Run: from the repo root, npm install && npm run build, then ANTHROPIC_API_KEY=sk-ant-… npm run dev -w @deuz-examples/01-basic-stream -- "your question" (Node ≥ 22.6 — the script uses native TypeScript stripping).
Look at: index.ts — streamChat is called without await and without a try; failures come back as an error part and rejected promises, never a synchronous throw.