Simple API for the App (Node or Python)

Why this matters

Browsers expose everything to the user. Keys, rate limits and logging belong on the server. A stub API first proves the plumbing without spending API credits.

What you will learn

You will add POST /api/ask (Next.js route handler or a small Express/FastAPI service), validate input length, return { answer: "…" } as plain JSON, and handle errors with clear messages.

How to do it

Pick one: Next.js Route Handler (fastest with our starter) or a separate FastAPI service. Document the choice.

Steps (do these in order)

1. Step 1 — Define the contract. Request JSON: { "question": "string" }. Response JSON: { "answer": "string" }. Errors: { "error": "string" }.
2. Step 2 — Validate. Reject empty questions and questions longer than 500 characters. Return HTTP 400 with a clear message.
3. Step 3 — Stub answer. For now return: "Stub: we received your question about <trimmed text>. AI comes in chapter 6."
4. Step 4 — Wire the form. On Submit, fetch('/api/ask', { method:'POST', headers:{'Content-Type':'application/json'}, body: JSON.stringify({question}) }). Show answer or error in the UI.
5. Step 5 — Log safely. Log only length and a request id — not full customer text in production logs if it may hold PII.

Practice

• Test with curl or Thunder Client: good question, empty question, too-long question.
• Write the three HTTP status codes you return (200 / 400 / 500) in the README.