Glossary

What Is the Universal Manipulation Interface (UMI)?

UMI is an open-source handheld-gripper framework for collecting robot demonstrations without a robot. Firsthand is not part of it and does not use it.

Last reviewed: October 2026

Short answer

The Universal Manipulation Interface (UMI) is an open-source data collection and policy learning framework from a 2024 paper. A person demonstrates tasks with a handheld parallel-jaw gripper carrying a GoPro camera, and the recording is processed into end-effector actions for training robot policies. It is a gripper method, not egocentric human video, and Firsthand is not part of it.

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What is the Universal Manipulation Interface?

UMI stands for Universal Manipulation Interface. It is described in the paper Universal Manipulation Interface: In-The-Wild Robot Teaching Without In-The-Wild Robots and on its project site, and the authors open-source it. The paper frames a choice between teleoperated robot data, which needs costly hardware and expert operators, and in-the-wild human video, which has a large embodiment gap to robots. UMI sits between them: a sensorized handheld gripper that people carry into any environment, so no robot is needed during collection.

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How does UMI data differ from egocentric human video?

In UMI the demonstrator holds a gripper, so every recorded motion is a gripper motion. In egocentric human video the contributor uses their own hands, with pose and action layers delivered beside the video. Firsthand is not part of UMI, endorsed by it or related to its authors or their institutions. The site states no default compatibility and does not state that Firsthand builds or collects with a handheld gripper. It states egocentric human capture: head and wrist cameras worn by paid, consented contributors, collected fast, on demand and to a written skill spec, under a perpetual, buyer-owned commercial license. Gripper width and robot-frame end-effector actions are not stated as delivered fields.

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Who released UMI and why?

The paper is by Cheng Chi, Zhenjia Xu and co-authors, with affiliations at Stanford University, Columbia University and Toyota Research Institute. The project page lists it at Robotics: Science and Systems (RSS) 2024.

The stated motivation is that earlier handheld devices struggled to balance action diversity with transferability, because of limited visual context, imprecise actions, latency differences and weak policy representations.

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How does the UMI handheld gripper collect data?

The hardware is a trigger-activated, handheld, 3D-printed parallel-jaw gripper with soft fingers. A GoPro is mounted on it as the only sensor and recording device, with a 155-degree fisheye lens and two physical side mirrors that give an implicit stereo view. A second gripper can be added for bimanual tasks.

The paper describes a four-step protocol: optional clock synchronisation, optional gripper calibration, a mapping scan of each new scene (usually around one minute), then demonstrations recorded as one video each.

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What does a UMI demonstration record?

Each demonstration is one mp4 from the gripper-mounted camera, with the camera’s built-in IMU data stored in the file. Actions are recovered afterwards: an inertial-monocular SLAM system built on ORB-SLAM3 estimates a 6-DoF end-effector pose at metric scale, and fiducial markers track finger width. A script matches left and right grippers by camera serial number and converts the videos into a training dataset.

The GitHub repository shows that pipeline writing a dataset.zarr.zip file. Against a motion-capture benchmark, the paper reports a mean absolute trajectory error of 6.1 mm and 3.5 degrees, and lists the need for enough scene texture as a limitation.

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How is UMI data turned into robot policies?

The policy takes a sequence of synchronised observations (RGB image, relative end-effector pose and gripper width) and outputs relative end-effector poses and gripper width. The paper uses Diffusion Policy for all experiments, with inference-time latency matching and a relative-trajectory action representation, and describes the resulting policies as hardware-agnostic.

Because the camera is fixed to the fingers, the paper says mounting the setup on a robot needs no camera-robot-world calibration.

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What did the paper find?

The authors evaluated four tasks: cup arrangement, dynamic tossing, bimanual cloth folding and dish washing. In an in-the-wild experiment, 3 demonstrators collected 1,400 cup-arrangement demonstrations in 12 person-hours across 30 locations. The policy reached 71.7% success (43 of 60 trials) in two unseen environments, while a policy trained only on narrow-domain data scored 0%.

On cup arrangement, the gripper was more than 3 times faster than space-mouse teleoperation and ran at 48% of bare-hand speed. These are the authors’ results on their own setup; Firsthand makes no performance claim against them.

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How do you request custom pretraining data?

Write the target skills, environments and signals into a skill spec and confirm them on a Spec Pilot, a small fast first batch. This is on-demand custom collection of egocentric human data, not a gripper program and not a catalog download.

Where coverage is deep, the median from signed spec to first validated batch is 48 hours; where it is thin, three to four weeks. Billing is per validated hour.

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UMI at a glance, as stated in the paper, project site and GitHub repository

UMI at a glance, as stated in the paper, project site and GitHub repository
ItemWhat the official source states
Full nameUniversal Manipulation Interface
Released byPaper by Chi, Xu and co-authors; Stanford University, Columbia University, Toyota Research Institute
Collection hardwareHandheld 3D-printed parallel-jaw gripper with soft fingers; one GoPro; 155-degree fisheye lens; two side mirrors
Per-demonstration dataOne mp4 per demonstration with embedded IMU data; a mapping video per scene
Action recoveryInertial-monocular SLAM (ORB-SLAM3 based) for 6-DoF pose; fiducial markers for gripper width
Training datasetZarr (dataset.zarr.zip) from the repository pipeline; RLDS and LeRobot Not stated
Policy learningDiffusion Policy; relative end-effector trajectories; inference-time latency matching
LicenceRepository: MIT. Hardware design licence: Not stated in the sources read
Firsthand relationshipNone. Firsthand is not part of UMI

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Handheld-gripper data vs egocentric human video

Handheld-gripper data vs egocentric human video
DimensionUMI (per the paper and project site)Firsthand egocentric capture (per the site)
What the demonstrator holdsA handheld parallel-jaw gripperNothing; contributors use their own hands
Capture deviceOne gripper-mounted camera with IMUHead camera and two wrist cameras; 6-DoF IMUs at 200 Hz
Action signal6-DoF end-effector pose from SLAMHand pose (21 joints per hand), contact events, action segments
Gripper widthTracked with fiducial markersNot stated as delivered
Delivery formatZarr training dataset; RLDS Not statedRLDS, LeRobot, WebDataset, HDF5 / zarr
How it is obtainedAdopting team builds grippers and collectsCustom collection to a skill spec, fast and on demand
LicenceRepository MIT; hardware licence Not statedPerpetual, buyer-owned commercial license
Robot resultsPolicy results reported in the paperNot stated

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Frequently asked questions

What is the Universal Manipulation Interface?
An open-source framework that collects robot demonstrations with a handheld parallel-jaw gripper carrying a GoPro, then trains robot policies from them, per its paper.
How does UMI collect handheld gripper data?
A person records each demonstration as one mp4. SLAM and fiducial markers then recover end-effector pose and finger width.
Is UMI egocentric human video?
No. The camera is mounted on a gripper, so the recorded motion is a gripper motion rather than a human hand.
Does Firsthand use UMI or a handheld gripper?
The site does not state that it does. Firsthand is not part of UMI or endorsed by it, and the site states no default compatibility.
What licence does UMI use?
The GitHub repository is released under the MIT licence. The hardware design licence is Not stated in the sources read.
How fast can custom pretraining data be collected?
Where coverage is deep, the median from signed spec to first validated batch is 48 hours; where it is thin, three to four weeks.