GHOST HACK
powered by
July 18 – August 18, 2026 · $3,000 in cash
A monthly challenge for ghosts — build across the Physical AI stack and compete for a $3,000 prize. Top teams get invited to the in-person Ghost Trials and drafted as permanent teams for Season 2.
League robots: Unitree G1, Booster K1, Agibot X2, LeRobot SO-101.
Three tracks, one prize each
$1,000 per track. Enter one, or all three.
Locomotion
The SuperSONIC Challenge
Teach a humanoid a move it can't do yet. NVIDIA SONIC is the whole-body control model behind Ultimate Bots' fighting and dancing humanoids — the model and its fine-tuning recipe are open. Find a motion the Unitree G1 is physically capable of but the stock model can't perform — strikes, kicks, throws, flips, dance, character movement — build the motion dataset that teaches it, and fine-tune until it lands. Easy moves score low; the harder and more original the move, the higher you score.
Manipulation
Give the machines hands
Post-train NVIDIA GR00T N1.7 — NVIDIA's vision-language-action model — on demonstrations of a task of your choosing. Target any embodiment GR00T supports; if we can run it, we can judge it. Pick-and-place is table stakes — tool use, multi-step tasks, and dexterity under variation are where the prize lives. Collect or generate the demonstrations, post-train with the provided recipe, and show your policy completing the task in simulation, reliably, across trials.
Experimental
Bring your own stack
World and action models, JEPA-style predictive models, novel data engines, teleoperation rigs, sim tooling — anything that makes robots more capable. If you can demo it and a robotics team would want it, it belongs here. The one track where the rules are: there are no rules.
From signup to stage
Register
Apply as a ghost using the form below. Pick a team name and have every teammate register with the same one — that's how we track your team and its resubmissions. A team of one still picks a name. Registering unlocks your $50 of Nebius compute and the Discord invite.
Pick your track and target skill
One move, one task, or one idea — depth beats breadth. Enter one track or all three.
Build your data
This is the real work. Generate synthetic motion (NVIDIA Kimodo text-to-motion is built into Ultimate Bots Studio), augment open datasets, lift motion from video, teleoperate demonstrations, or capture your own — source anywhere you're licensed to.
Train in simulation
The fastest path is the Nebius Physical AI Workbench — a web workbench with chat-driven setup, ready-made training recipes, and built-in Rerun visualization, so you spend your month on data and iteration, not environment setup. Every model and recipe is open — run it locally or on any cloud.
Submit from July 31
The submission page opens two weeks in — spend those weeks building. Update your entry as often as you like until the close on August 16, 11:59pm PT, under the same team name you registered with. Your model, dataset, config, a demo video, and a short writeup — checklist below.
Winners announced live, August 18
One winner per track, picked by the Ultimate Bots team and our advisors.
Ghost Trials
Winning online is step one. Here's exactly what happens next.
We deploy your work
Strong submissions get ported to the league robots as they arrive — Ultimate Bots engineers handle sim-to-real, so you don't need a robot and you don't need to travel. By announcement day, the winning skills are already running on real hardware.
Your skill performs live
Winning moves and tasks run on stage at an Ultimate Bots show, credited to you, in front of the crowd and the stream.
Standouts get called up
The strongest builders — winners and honorable mentions — are invited to Ghost Trials: in-person sessions in San Francisco where you run your work on real hardware, side by side with the Ultimate Bots team.
The Trials feed the league
Perform at the Trials and you enter the draft pool for a ghost spot — the league's official builder track, where teams of pilots and ghosts compete through the season.
- Model checkpoints + recipes — SONIC (whole-body control) and GR00T VLA (manipulation), with ready-to-run fine-tuning and post-training recipes.
- Nebius Physical AI Workbench — chat-driven setup, per-track recipes, Rerun visualization built in.
- $50 Nebius compute — sized for a focused fine-tune from a released checkpoint. You're adapting a model, not training one from scratch.
- Ultimate Bots Studio — NVIDIA Kimodo text-to-motion for synthetic motion generation and video-to-robot retargeting.
- Support — the Ghost Hack Discord: announcements, per-track channels, help desk, and office hours through the window.
- Your trained model or policy — in the format specified in the docs, ready to deploy.
- The dataset you built, and how you made it.
- Your training config — the run must be reproducible.
- A short demo video in simulation.
- A before/after against the stock model.
- A one-page writeup: what you taught it, why it's hard, how you did it.
Four criteria per track
Ambition
How hard and original is the skill you chose.
Execution
Does it land: clean, physically real, and reliable across runs.
Data craft
The quality and ingenuity of your dataset and pipeline.
Reproducibility
We can run what you shipped.
We run finalists through our own evaluation — in simulation and deployed on the league robots — but the numbers assist the judges; they don't replace them. These are physical skills, judged by people who put robots on stage.
Register as a ghost
Apply as a ghost to enter GHOST HACK. Pick a team name and have every teammate register with the same one. Registering unlocks your $50 of Nebius compute and the Ghost Hack Discord invite — our team follows up with next steps.
- Open worldwide. Solo or teams up to 4. Free to enter.
- You keep ownership of everything you create — dataset, code, model. Open-sourcing is encouraged, never required.
- Winners grant Ultimate Bots the right to run the winning skill on real robots and across our channels — that's how your work gets on stage.
- You're responsible for your licenses. Build only on models and data whose terms permit it; some datasets are free only for non-commercial or small-company use.
- The fine print: entries and prizes are subject to standard eligibility verification, official rules, and applicable law.
Questions
Do I need a robot?
No. Everything runs in simulation — we handle real-robot deployment for winners.
Do I need to travel?
No. The hackathon is fully online. Ghost Trials invitations are in person (San Francisco), but winning and deployment don't require travel.
Can I enter multiple tracks?
Yes — submit to each separately, judged independently.
When do submissions open?
July 31, two weeks in — the first stretch is for building. The link lands here and in Discord, and you can update your entry until August 16.
Does $50 of compute actually cover it?
Yes for the intended scope: you're fine-tuning from released checkpoints, not pretraining. Spend your effort on data.
Who owns my work?
You do. See Rules & ownership.
Everything you need
Registration is open now. Show us what you've got.
