---
title: Small Talk
emoji: 🎙️
colorFrom: indigo
colorTo: green
sdk: gradio
sdk_version: 6.17.3
app_file: app.py
pinned: true
short_description: An AI-to-AI robot podcast hosted by Reachy Minis
tags:
  - reachy_mini
  - livekit
  - webrtc
  - three.js
  - track:wood
  - sponsor:nvidia
  - sponsor:modal
  - achievement:offbrand
  - achievement:llama
  - achievement:fieldnotes
  - achievement:offgrid
  - badge-tiny-titan
---

# Small Talk

An AI-to-AI podcast hosted by Reachy Mini robots. They join a live WebRTC call,
each with its own personality and voice, and talk it out while you watch a
Meet-style grid of their 3D digital twins moving in sync with the conversation.
Give them a topic and they write the script, design their own voices, dress
themselves, and go live. Own a Reachy Mini? It can join a show as a real cast
member and speak its lines through the actual robot.

**Team:** [GauravGosain](https://huggingface.co/GauravGosain) and [nkapila6](https://huggingface.co/nkapila6).

- **Demo video:** https://youtu.be/obP4C1eH77I
- **Build write-ups:** [Small Talk on the Hugging Face blog](https://huggingface.co/blog/build-small-hackathon/small-talk) · [nkapila.me](https://nkapila.me/posts/small-talk)
- **Launch posts:** [@_GauravGosain on X](https://x.com/_GauravGosain/status/2066013749304344915) · [Nikhil Kapila on LinkedIn](https://www.linkedin.com/posts/nikhilkapila_buildsmall-huggingface-modal-ugcPost-7471791298199408640-OBzS/)

## What you can do

- **Watch a live generated show.** Pick a topic. One structured Nemotron call
  writes the cast and the full speaker-to-dialogue script, Qwen3-TTS voices each
  line, and the next line renders while the current one plays. Subtitles, a
  pre-show "writers' room", and rolling continuations keep it going.
- **Set the cast.** A slider picks 2 to 5 hosts, or how many simulated co-hosts
  fill in around your physical robots.
- **Design a robot.** Choose a name, personality, voice, shell colour, and props.
  The same Nemotron brain styles its wardrobe from your description.
- **Tune into Reachy FM.** A radio station of AI-written songs with synced
  karaoke lyrics, a spinning vinyl deck, an audio-reactive visualizer, and a DJ
  robot in headphones that does mic breaks and bops to the beat.
- **Bring your own Reachy.** A single Go binary turns a physical Reachy Mini into
  a cast member that speaks its own lines, head and antennas moving with the
  speech.

## How it is built

The whole app is served by `gradio.Server`, a FastAPI host with Gradio's backend
where custom routes take priority, so the visitor only ever sees a hand-built
three.js frontend. There is no default Gradio component anywhere in the product.

```mermaid
flowchart LR
    topic([Topic]) --> llm["NVIDIA Nemotron 4B<br/>llama.cpp on Modal"]
    llm -->|one structured call| script[["Cast plus script<br/>(JSON)"]]
    script --> tts["Qwen3-TTS<br/>on Modal"]
    tts -->|"line N+1 renders<br/>while line N plays"| pub[ReachyPublisher]
    pub --> sfu{{"LiveKit SFU<br/>(WebRTC)"}}
    sfu --> web["Browser:<br/>3D twins + subtitles"]
    sfu --> robot["Physical Reachy<br/>(Go companion)"]
```

- **Brain.** NVIDIA Nemotron Nano (4B) served through llama.cpp on Modal. A single
  constrained, structured call returns the full cast and script as JSON. We found
  constrained structured output far more reliable than chaining calls.
- **Voice.** Qwen3-TTS VoiceDesign on Modal, one consistent character voice per
  host, generated as a cascade so there is no dead air between lines.
- **Realtime.** A self-hosted LiveKit SFU carries the audio over WebRTC. Subtitles
  and show status ride LiveKit data messages.
- **Twins.** The official Reachy Mini URDF and meshes in three.js, with head and
  antenna motion blending a speech-reactive envelope and the real recorded Reachy
  emotions and dances.

The Space itself runs CPU-only. All inference is delegated to Modal serverless GPUs.
The Modal serving code for the Nemotron (llama.cpp) and Qwen3-TTS endpoints lives in
[nkapila6/llama-modal-serve](https://github.com/nkapila6/llama-modal-serve).

## Built for the Build Small Hackathon

Everything runs on models well under the 32B cap, and most of the work is done by
a single 4B model. Small Talk is in the running for:

| Category | Why it qualifies |
|---|---|
| **Thousand Token Wood** | A whimsical, AI-native entertainment platform. |
| **NVIDIA** | The brain is NVIDIA Nemotron. |
| **Modal** | The LLM and the TTS both run on Modal at runtime. |
| **Off Brand** | A fully custom three.js UI built on `gradio.Server`. |
| **Tiny Titan** | The reasoning brain is a 4B model. |
| **Llama Champion** | Nemotron is served through the llama.cpp runtime. |
| **Off the Grid** | No proprietary or closed model APIs. Every model (Nemotron, Qwen3-TTS) is open-weight and self-hosted via llama.cpp; Modal provides the compute, not the model. |
| **Field Notes** | A full build write-up is published on the HF blog. |
| **Bonus Quest Champion** | The most bonus criteria met across the board. |

If you enjoy it, an upvote helps with Community Choice.

Source: [github.com/Gaurav-Gosain/small-talk](https://github.com/Gaurav-Gosain/small-talk)