Ralphthon @SF sponsored by OpenAI
Ralphthon @SF
✅ Hack Guide: https://ralphthon.team-attention.com/guide
If you want to touch your laptop, you put on a lobster costume first. 🦞
While your AI agent codes, you meet the builders who are shaping what comes next.
This isn't just a hackathon. It's your entry point into a top-tier network of agent-native engineers
While your agent works, you're in the room with speakers, builders, and conversations you won't find anywhere else.
Prizes
🥇 1st Place — $10,000 in API credits + 6 months of ChatGPT Pro
🥈 2nd Place — $5,000 in API credits + 6 months of ChatGPT Pro
🥉 3rd Place — $3,000 in API credits + 6 months of ChatGPT Pro
All accepted participants receive $100 in OpenAI API credits for the event.
⚠️ In-person only (San Francisco) · Application required · Teams of 1–4
⚠️ This event is being filmed by a professional video crew. If you prefer not to appear on camera, please let us know at check-in — we'll provide a sticker for your name badge so the crew knows to keep you out of frame.
🔌 Bring a power strip! Outlet access at the venue may be limited — bringing your own power strip helps you and your neighbors stay charged.
Speakers
Geoffrey Huntley: Creator of Ralph Loop
Romain Huet: Head of Developer Experience @OpenAI, working on Codex
Mo Tiwari : ex @OpenAI, Stanford CS PhD
Jaegyu Lee: Winner of 1st Ralphthon, Maintainer of ouroboros
Judges
Q — Maintainer of oh-my-opencode(40K ⭐)
Yeachan Heo (bellman) — Maintainer of oh-my-claude-code(11K ⭐) & oh-my-codex
Yujong Lee - Co Founder of char.com YC S25 (8K ⭐)
John Jeong - CEO of char.com YC S25 (8K ⭐)
Chanhee Lee - Co Founder of Aside, YC F25
CJ Na - Co Founder & CTO of Carvis, ex) Cruise
Jay Warida - Co Founder & CEO of Carvis
Mantra Patel - Engineer at Stack Auth (YC S24)
Justin Shin - Kakao Ventures
Sheshansh Agrawal - Research Lead @ Contextual AI
George Zhang - Maintainer of OpenClaw & Pi
Austin Wang - Founder & CEO, Manaflow (YC S24) & cmux.com (11k stars)
Shriank K. - Co-Founder @ Seed Labs
Schedule (Tentative): 28th March SF
8:30 AM – Doors open · Check-in · Team building
9:30 AM – Welcome & intro · How to run Codex + Ralph Loop like a pro
10:00 AM – Hacking begins · Spec writing & agent setup
12:30 PM – Ralph begins. Agents run autonomously.
If you want to touch your laptop, you put on a lobster costume first. 🦞12:30 – 3:30 PM – While your agent works, you connect
3:30 PM – Laptops open · Review what your agent built & prepare your demo
4:30 PM – Submission deadline · Science Fair begins — every team demos at their table, judges walk the floor
5:30 PM – Speaker session 🎤
6:30 PM – Finalist demos on stage
7:30 PM – Awards
~8:00 PM – Networking
Sponsored by
OpenAI
Naver D2SF
Hanriver Partners
Kakao Ventures
Bass Ventures
Weights & Biases is the AI developer platform powering the AI industry. AI labs and enterprises from multiple industries — including AstraZeneca, Canva, Cohere, OpenAI, Meta, Snowflake, Square, Toyota, and Wayve — rely on Weights & Biases as their system of record for training and fine-tuning AI models and developing agentic AI applications with confidence. Weights & Biases has been acquired by CoreWeave to deliver the leading AI Cloud Platform — purpose-built to develop, deploy, and iterate AI faster for the world’s leading AI labs and enterprises. The AI Developer Platform Weave is a developer-first toolkit for tracing, debugging and evaluating your AI apps. Try Weave for free today: https://wandb.com/weave.
OSS Partners
Accumulated stars of 60K from OSS partners
Previous in Seoul
Ralphthon originated in Seoul (Feb 28 – Mar 1, 2026) as a 24-hour overnight format where builders set up agents, went to sleep, and woke up to what shipped.
Notable open-source contributions from Seoul:
oh-my-claude-code 9K ⭐ — 2nd place winner's harness
Ouroboros 1k ⭐ — 1st place winner's harness
About
Organized by Team Attention. We run creative hackathons, clubs, and open-source projects at the intersection of community and AI-native workflows.
Previous events: Skillthon (Anthropic-sponsored) → Ralphthon Seoul (OpenAI + Kakao Ventures) → Ralphthon SF
All attendees must submit an application and be approved to attend.
Contact
GB Jeong gb-jeong