Stretch features and what to ship next

You have a working app. Now what makes it stand out? This lesson is the menu of upgrades that turn a demo into a product worth building a brand around.

You have a working car. Stretch features are the radio, the AC, the leather seats. Pick the ones your audience cares about.

Top stretch features for a beginner AI chat app:

1. Model picker: let user choose GPT-4o-mini vs Gemini Flash vs Claude Haiku-class.
2. Token usage display: show running cost.
3. Export chat as Markdown.
4. Voice input (st.audio_input).
5. Image uploads (multimodal models).
6. Themed UI: tweak theme in .streamlit/config.toml.
7. Authentication: gate behind a simple password or Supabase auth.
8. Streaming + cancellation.
9. History persistence (Supabase, SQLite).
10. Per-conversation save and resume.

Pick 2 and ship. Do not chase them all on the first version.

Token counter:

total_tokens = sum(msg.get("tokens", 0) for msg in st.session_state.messages)
st.sidebar.metric("Tokens used", total_tokens)

Where msg["tokens"] is appended from response.usage per call.