# Ketchup

- **Event:** [Meta Global AI Developer Hackathon](https://cerebralvalley.ai/e/meta-ai-developer-hackathon)
- **When:** Oct 26, 12:00 PM – Nov 4, 9:00 PM (EST)
- **Where:** Online
- **Team:** [Ireen Jeang](https://cerebralvalley.ai/u/ireenj)
- **GitHub:** https://github.com/reenj01/Ketchup
- **Demo video:** https://youtu.be/4XgOuk1qBzY
- **Gallery:** https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery
- **Page:** https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/3434

Ketchup is a pair of small pocket devices, called Dots, that turn "let's catch up sometime" into a real plan on both people's calendars.

The problem: when two friends run into each other, they almost always say "we should catch up," and it almost never happens. Someone has to text, compare calendars, go back and forth, and pick a time, and that small chore is enough to make the plan die. It hits hardest for the people who need connection most: busy friends, people who just moved, and anyone who already feels awkward reaching out.

With Ketchup, the two friends just tap their Dots together. From there, each person's own AI agent reads only its owner's calendar, and the two agents negotiate with each other to find a time that works for both. While they talk, the Dot's light breathes white. When they agree, the owner taps the Dot and it says the time out loud. If it doesn't fit, the owner holds the Dot and just says what they want, like "no, pick a time at night." The light turns yellow while they talk, and the agents go back and find a new time. Once both people are happy, the plan is booked on both calendars and the light turns green.

There's no app to open, no texting and no scheduling links. It's built around the moment people actually make plans, which is face to face.

Privacy is part of the design. The Dots never listen all the time; the mic is on only while the owner holds the pressure sensor. The agents share only free time windows, never event titles. If one person asks for a change, the other person only hears that their friend would prefer a different time, never their words or reason.

What I built this week:
- Two real hardware Dots: a Raspberry Pi 5 (Mayo's) and an Arduino UNO Q (Frankie's). Each has a Hall sensor and magnet for the tap, an RGB LED, a pressure sensor for hold-to-talk, a mic and a speaker.
- A server that pairs two taps that arrive within 2 seconds and runs the two agents.
- Agent negotiation with hard rules enforced in code, not just in the prompt: at least 30 minutes free around other events, a time already offered is never offered again, and change requests add up as constraints across rounds.
- A live web simulator, so judges can try the whole flow in a browser with no login. It shows both Dots, the agents' conversation, each person's sample calendar, and a live list of every Meta model call: https://ireenjeang0726--ketchup-sim-web.us-east.modal.run

## More from Meta Global AI Developer Hackathon

- [Qai](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/3431)
- [StreetSense](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/3432)
- [TraceMend](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/3433)
- [personavision - Swarm of AI agents that test UX before real users](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/3435)
- [API Shift](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/3436)
- [Ghost AI Systems](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/3437)

---

Markdown version of https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/3434. Site index for agents: https://cerebralvalley.ai/llms.txt · full text: https://cerebralvalley.ai/llms-full.txt