Can a Frontier VLM Serve as a Robot Policy for Memory-Dependent Manipulation?

Jack B. JedlickiAmish SethiHeng Yang

Harvard University

92.1%success on RoboMME's 800 test episodes
13 / 16tasks at or above the human score
+31.3points over the best leaderboard entry
0RoboMME-specific training: a frozen model
Bar chart of success on the 800 RoboMME test episodes: GPT-6-Astra full context 92.1, human players 90.5, GPT-6-Astra planner with a RoboMME-trained VLA 79.1, PonderPounce-9B 60.8, Gemini-2.5-Pro as planner 47.9.

Success on the 800 RoboMME test episodes, as reported by each source. Light grey bars use RoboMME's oracle skill interface, in which a privileged planner executes chosen skills. Our result is a single run.

Abstract

We use a frozen frontier vision-language model, GPT-6-Astra, directly as the robot policy on RoboMME, a benchmark of 16 memory-dependent manipulation tasks spanning temporal, spatial, object, and procedural memory. The model keeps the whole episode in context and outputs every end-effector waypoint and gripper command, with no RoboMME-specific training. On the 800 test episodes it succeeds in 92.1%, above the previously reported human score of 90.5%, which was obtained with an oracle skill interface, and far ahead of the best leaderboard entry (60.8%) and of a hierarchical system that pairs the same model with a RoboMME-trained policy (79.1%). It matches or exceeds the human score on 13 of the 16 tasks. Its 63 failures concentrate in two tasks and are mostly premature completions and mistimed or unintended button presses. These results blur the usual division between long-horizon planning, memory and end-effector control, and raise the question of how much of this stack a single general-purpose model can take over in embodied systems.

One model, the whole episode, every waypoint

  • Full context. All sampled camera frames (one every 0.15 s), the task video and the model's own previous answers stay in one conversation. Nothing is summarized or dropped.
  • Direct control. At every step the model outputs the next end-effector pose and gripper command. RoboMME's motion planner only executes it: no skills, no object snapping, no privileged state.
  • No benchmark training. One system prompt for all 16 tasks. The model sees RGB images, its own pose and the camera calibration, never depth, object poses or the benchmark's oracle subgoals.
System diagram: the RoboMME task sends the goal, task video, subsampled frames and robot state to GPT-6-Astra, whose context is the episode history; it outputs a waypoint executed by the motion planner, and new frames return after each action.
In the waypoint setting (leaderboard) the model commands every end-effector pose. The oracle-planner setting is used in the paper only as a diagnostic.

One success for each of the 16 tasks

Each clip is one test episode, chosen as the success closest to the task's median length.

Left: front camera · right: wrist cameraRed border: task video shown before the robot actsPlayed at 1.5× real time

Counting

temporal memory

Remember how many times something happened or must be done.

BinFill

49/50 solved

“put three green cubes into the bin, then press the button to stop”

PickXtimes

50/50 solved

“pick up the red cube and place it on the target, repeating this action two times, then press the button to stop”

SwingXtimes

49/50 solved

“pick up the green cube, move it to the top of the right-side target, then move it to the top of the left-side target, repeating this back-and-forth motion three times, finally press the button to stop”

StopCube

27/50 solved

“press the button to stop the cube just as it reaches the target for the third time”

Permanence

spatial memory

Track objects that are hidden, covered or swapped while out of view.

VideoUnmask

47/50 solved

“watch the video carefully, then pick up the container hiding the blue cube”

VideoUnmaskSwap

48/50 solved

“watch the video carefully, then pick up the container hiding the green cube”

ButtonUnmask

50/50 solved

“first press the button, then pick up the container hiding the green cube”

ButtonUnmaskSwap

49/50 solved

“first press both buttons on the table, then pick up the container hiding the green cube”

Reference

object memory

Act on the object that was highlighted, picked or placed earlier.

PickHighlight

49/50 solved

“first press the button, then pick up all cubes that have been highlighteted with white areas on the table”

VideoRepick

50/50 solved

“watch the video carefully, then pick up the same block that was previously picked up again, finally put it down and press the button to stop”

VideoPlaceButton

50/50 solved

“watch the video carefully, then place the green cube on the target right after the button was pressed”

VideoPlaceOrder

49/50 solved

“watch the video carefully, then place the green cube on the first target it was previously placed on”

Imitation

procedural memory

Reproduce a demonstrated manner, grasp, pattern or route.

MoveCube

27/50 solved

“watch the video carefully, then move the cube to the target in the same manner as before”

InsertPeg

46/50 solved

“watch the video carefully, then grasp the same end of the same peg you've picked before and insert it into the same side of the box”

PatternLock

50/50 solved

“watch the video carefully, then use the stick attached to the robot to retrace the same pattern”

RouteStick

47/50 solved

“watch the video carefully, then use the stick attached to the robot to navigate around the sticks on the table, following the same path”

Results by memory type and by task

Radar charts of success rate by suite and by task for GPT-6-Astra, human players and PonderPounce-9B.
Left: mean success of each suite's four tasks, with the memory type it targets. Right: all 16 tasks.

Success rate (%) on the 50 test episodes of each task. Human players used RoboMME's oracle skill interface; PonderPounce-9B is the best leaderboard entry (joint-angle control, mean of 3 runs). Crimson marks our scores at or above the human score.

SuiteTaskHumanPonderPounce-9BGPT-6-Astra (ours)
CountingBinFill9650.798
PickXtimes10093.3100
SwingXtimes8072.098
StopCube7882.754
PermanenceVideoUnmask9094.794
VideoUnmaskSwap9225.396
ButtonUnmask9297.3100
ButtonUnmaskSwap9034.098
ReferencePickHighlight9285.398
VideoRepick9240.7100
VideoPlaceButton9883.3100
VideoPlaceOrder9079.398
ImitationMoveCube9081.354
InsertPeg986.092
PatternLock8412.7100
RouteStick8634.794
Average90.560.892.1

Where it still fails

We audited all 63 failed episodes. Most are in two tasks: MoveCube, where the model ends with the gripper closed, and StopCube, where it presses the button too early or too late. Classes describe observable behaviour from the logs, not internal causes.

Sankey diagram of the 63 failures by class: premature completion 25, unintended button contact 12, late button press 11, motion planning failure 5, out-of-reach waypoint 4, unusable answer 3, other manipulation error 3.

Premature completion

MoveCube

“watch the video carefully, then move the cube to the target in the same manner as before”

The model picks up the bar and pushes the cube onto the target, as demonstrated, but declares the task done while still holding the bar. The pushing variants of MoveCube require an open gripper at the end. This is the largest failure group (23 MoveCube episodes).

Unintended button contact

StopCube

“press the button to stop the cube just as it reaches the target for the second time”

Waiting for the cube's second arrival, the model moves closer to the button “without pressing yet” (commanded TCP height 3.8 cm), but the fingertips depress it too early and the episode ends (12 StopCube episodes).

Late press

StopCube

“press the button to stop the cube just as it reaches the target for the fourth time”

The model counts the cube's crossings and presses on what it describes as the fourth arrival, but the press registers after the cube has passed the target (11 StopCube episodes).

Out-of-reach waypoint

VideoUnmask

“watch the video carefully, then pick up the container hiding the green cube, finally pick up another container hiding the blue cube”

After uncovering the green cube, the model sets the container aside at the edge of the arm's reach. The executor runs the motion until the 1300-step limit without reaching the pose (4 episodes).

Peg grasped by the wrong end

InsertPeg

“watch the video carefully, then grasp the same end of the same peg you've picked before and insert it into the same side of the box”

The model describes grasping the demonstrated end of the peg, but the environment judges that it lifted the other end and ends the episode.

BibTeX

@article{jedlicki2026frontier,
  title   = {Can a Frontier {VLM} Serve as a Robot Policy for Memory-Dependent Manipulation?},
  author  = {Jedlicki, Jack B. and Sethi, Amish and Yang, Heng},
  journal = {arXiv preprint},
  year    = {2026}
}