Pretrained vision-language-action models (VLAs) often fail midway through unseen long-horizon tasks. Recursive self-improvement (RSI) offers a remedy, but embodied RSI methods either refine the harness around a frozen executor and so cannot add a missing motion, or train the executor on persistent failures without asking whether a failure lies in how the executor is called or in what it can do. We ask when a self-improving embodied system should change the weights of its executor, and propose AdaRSI, an on-demand RSI framework for embodied agents. A coding agent first improves its skills and harness, then attributes persistent failures by retrying failing sub-steps from saved states, and fine-tunes only the sub-steps that remain unreliable, with demonstrations it collects itself and experience carried over from earlier tasks. On all 50 target tasks of RoboCasa365, with GR00T N1.5 as the executor and no human demonstrations, AdaRSI improves the VLA on all three suites and raises its success on unseen composite tasks from 4.6% to 13.8%. Compared with fine-tuning every sub-step, it reaches slightly higher success while using only 28% of the GPU time and 22% of the self-collected demonstrations, and fine-tuning without a harness trains more yet gains far less.
Figures & tables
Figure 1: Comparison of self-improvement strategies. Harness-only improvement is bounded by what the executor can do, while fine-tuning every sub-step is costly and can make sub-steps that already worked worse. AdaRSI refines the harness first, which also sets the states from which policies are trained and called, and fine-tunes only the sub-steps that remain unreliable.
Figure 2: Pipeline of AdaRSI. The agent first refines its harness, then attributes persistent failures and fine-tunes only the sub-steps that remain unreliable, using demonstrations it collects itself. Trained policies join a library, from which the deployed agent calls the recommended policy for each sub-step.
Self-improvement
Success rate on RoboCasa365 (%)
Method
Agent
Harness
Weights
Atomic-Seen 18 tasks
Composite-Seen 16 tasks
Composite-Unseen 16 tasks
All 50 tasks
GR00T N1.5 [ 21 ]
✗
✗
✗
75.4
43.0
4.6
42.4
Agent + VLA
✓
✗
✗
72.2
43.6
5.9
41.8
Agent + harness
✓
✓
✗
78.3
48.0
9.9
46.7
AdaRSI (ours)
✓
✓
✓
79.7
49.0
13.8
48.8
Gain over VLA
+4.3
+6.0
+9.2
+6.4
Table 1: Success rates (%) on the 50 target tasks of RoboCasa365. Each task is tested on 50 scenes, All averages over the 50 tasks, and no system uses human demonstrations.
No self-improvement
No agent
Self-improving agents
Task
VLA
Agent + VLA
Fixed procedure
Agent + weights
Agent + harness
Always train
AdaRSI
Δ vs. harness
ArrangeBreadBasket
0.0
0.0
0.0
2.0
2.0
0.0
2.0
0.0
ArrangeTea
0.0
0.0
0.0
0.0
2.0
2.0
0.0
-2.0
BreadSelection
22.0
22.0
36.0
26.0
42.0
56.0
52.0
+10.0
CategorizeCondiments
0.0
0.0
0.0
0.0
0.0
6.0
2.0
+2.0
CuttingToolSelection
20.0
30.0
40.0
42.0
50.0
32.0
36.0
-14.0
Table 2: Per-task success rates (%) on Composite-Unseen. All systems, including the ablations of Sec. 5.3 , run on the same 50 scenes per task. The last column is the gain of AdaRSI over Agent + harness in points.
Policies
Training
Execution
Suite / variant
Used / trained
GPU min.
Used share
FT steps
Atomic-Seen
12/72
1,175
17%
21.7%
Composite-Seen
8/34
901
25%
2.3%
Composite-Unseen
Agent + weights
5/45
1,204
12%
3.9%
Always train
104/118
3,411
89%
71.2%
Table 3: Policies trained and used at test time. A policy counts as used if the deployed agent calls it, used share is the share of training time spent on used policies, and FT steps is the share of manipulation steps at test time that fine-tuned policies execute. The counts of Always train include the policies of AdaRSI, which it reuses.
Sub-step
π0
Fine-tuned
Δ
Motions beyond π0
Open microwave door WaffleReheat
0/18
7/18
+7
Pick up glass bottle RecycleBottlesByType
2/44
17/44
+15
Motions π0 already performs
Place croissant on board BreadSelection
16/40
11/40
-5
Place jam on board BreadSelection
14/39
9/39
-5
Table 4: Paired sub-step test. π0 and the fine-tuned policy run from the same states with the same instruction and number of steps, and entries give successful over tested starts.
Self-improvement
Training cost (16 tasks)
Method
Online agent
Harness
Weights
On-demand
Success (%)
Policies
Demos
GPU min.
GR00T N1.5 [ 21 ]
✗
✗
✗
–
4.6
0
0
0
Fixed procedure
✗
✓
✓
✓
6.9
reused from AdaRSI
Agent + VLA
✓
✗
✗
–
5.9
0
0
0
Agent + weights
✓
✗
✓
✓
7.2
45
556
1,204
Agent + harness
✓
✓
✗
–
9.9
0
0
0
Table 5: Ablations on the 16 Composite-Unseen tasks. Online agent means that the agent runs at deployment, and on-demand that it fine-tunes only selected sub-steps. Training cost counts every policy trained, and that of Always train includes the training of AdaRSI.
Figure 3: Success against training cost on Composite-Unseen. Arrows trace AdaRSI, which improves the harness first and then fine-tunes on demand. Systems in the shaded region cost at least as much as AdaRSI and succeed less.
Task
Agent + harness
AdaRSI w/ π0 + procedure
AdaRSI + weights
WaffleReheat
0
5 ( +5 )
19 ( +14 )
RecycleBottlesByType
0
5 ( +5 )
9 ( +4 )
BreadSelection
21
27 ( +6 )
26 ( −1 )
WashFruitColander
24
27 ( +3 )
29 ( +2 )
CuttingToolSelection
25
20 ( −5 )
18 ( −2 )
Total (of 250)
70
84 ( +14 )
101 ( +17 )
Table 6: Weights against procedure. From left to right, each column adds the revised procedure and then the fine-tuned weights, with the change in parentheses. Entries count successes out of 50 on the five tasks whose success changes in the weight round.
Successes (of 50)
Policies
Tokens (M)
Demonstrations
GPU minutes
Task
Always
Ours
Always
Ours
Always
Ours
Always
Ours
Always
Ours
ArrangeBreadBasket
0
1
5
3
184.9
159.8
57
17
123
57
ArrangeTea
1
0
6
3
186.2
161.4
72
22
164
70
BreadSelection
28
26
9
2
163.1
125.2
116
17
212
56
CategorizeCondiments
3
1
5
2
172.6
135.7
79
26
179
81
CuttingToolSelection
16
18
6
3
127.0
108.4
89
33
163
65
Table 7: AdaRSI (Ours) against Always train (Always). Costs count every policy trained, and those of Always include the training of AdaRSI. Tokens are input tokens of the improvement phase, and the last row gives Always/Ours ratios.
Variant
Success (%)
Demos
GPU min.
Agent + harness
12.0
0
0
Lowest first
11.8
312
636
AdaRSI
16.6
316
796
Table 8: Choosing what to train on the non-pilot Composite-Unseen tasks. Lowest first trains the sub-steps on which π0 succeeds least, under the same budget.
Case
Sub-step (task)
π0
Fine-tuned
Lesson
Training needed
Worked
Open French-door fridge GarnishPancake
0/6
6/6
A few demonstrations suffice, but the task still fails .
Partly worked
Pick up the skewer HeatKebabSandwich
0/16
3/16
The motion is learned in only some kitchens .
Did not work
Close toaster-oven door HeatKebabSandwich
1/9
0/9
Training does not yet produce the motion, and π0 stays the default.
Training not needed
Helped
Set up the mug CoffeeSetupMug
13/20
31/40
Training can raise the reliability of a sub-step π0 already performs.
Table 9: Outcomes of training a sub-step. Cases from the pilot tasks, comparing π0 and the fine-tuned policy from the same held-out starts. The last three rows come from Atomic-Seen pilots.
Figure 4: Case studies. (a) WashFruitColander is solved by the harness alone, which fixes the sub-step order and repositions the base. (b) In GetToastedBread, only the bread pickup is trained. Rows share the kitchen and initial state.
Adapting robot manipulation policies to new tasks and environments remains highly data-intensive, while the data needed for further improvement depends on the policy's current capabilities and failure modes. We introduce EmbodiRSI, an agentic system for recursive self-improvement (RSI) in a real-to-sim-to-real setting, where task-specific simulations are constructed from target deployment scenarios and used as low-cost environments for iterative policy improvement before transfer back to the physical world. EmbodiRSI uses policy execution feedback to guide subsequent experience acquisition and policy updates. Two complementary mechanisms close this loop: Collaborative Error Correction generates agent-assisted corrective trajectories from policy-reached states, while Adaptive Data Collection directs expert demonstration generation toward the current policy's weaknesses. The task-specific simulation serves as a reusable workspace for policy warm-up, repeatable evaluation, failure diagnosis, and targeted data generation across successive RSI rounds. Across three tabletop environments and 14 subtasks, EmbodiRSI increases scene-balanced autonomous simulation success from 50.4% to 83.5% over two RSI updates. With 400 adaptive simulated trajectories and only ten real-world refinement trajectories per subtask, EmbodiRSI achieves 83.1% scene-balanced autonomous real-world success, compared with 75.0% for adaptation using 200 real-world demonstrations per subtask. These results demonstrate that feedback-driven recursive improvement in deployment-specific simulations can enable data-efficient adaptation of embodied policies to physical environments.
Robot foundation models provide strong visuomotor control, yet their performance can degrade when object positions or task instructions change. Further improvements often require post-training on substantial robot data, which can be costly to collect through methods such as teleoperation. Agentic harnesses can adapt around the model, but current self-evolving harnesses use robot trials inefficiently when deciding which code and skill changes to pursue. We introduce EmbodiedRSI, a self-evolving agentic harness that autonomously decides where to explore next and turns the resulting physical interaction into improved code and skills. EmbodiedRSI realizes this through a Fast-Slow Dual-System Architecture, in which competing code and skill hypotheses are maintained in a Hypothesis Graph. Value-of-Information Experiment Selection chooses physical experiments that can distinguish these hypotheses. Their outcomes guide Code-Skill Co-Evolution. The Slow System builds Hierarchical Memory, and Reward-Grounded Memory Learning selects effective memory according to their value for later Fast-System improvement. On RoboCasa365, EmbodiedRSI reaches 77.0% overall success and 71.3% on Composite-Unseen, compared with 40.1% for the best baseline. EmbodiedRSI also reaches 86.8% overall success on LIBERO-Pro. Beyond benchmark performance, EmbodiedRSI transfers zero-shot to real-world robot, achieving 71.3% overall success across multiple challenging tasks.
Vision-language-action (VLA) policies generate executable robot actions, but plausible proposals can have different consequences for the task. We present EmbodiedSkills, a skill-based agent framework that augments frozen VLA policies with world action models for consequence-aware action selection. The framework defines reusable skills for scene observation, context encoding, candidate generation, consequence prediction, outcome evaluation, candidate comparison, and action execution. Five stages organize their input-output dependencies in a shared feedback loop, accommodating both continuous action chunks and pick-and-place primitives. At each decision point, independently trained world action models predict the latent consequences of a common set of policy proposals. Selection combines their outcome scores and prediction disagreement with a lightweight comparator that estimates the benefit of an alternative from agreement in its predicted effects. The predictive and comparison modules learn from matched-state candidate branches, while the action policy and pretrained observation encoders remain frozen. On MetaWorld MT50 and CLIPort, EmbodiedSkills improves success rates from 76.28% to 78.64% and from 33.94% to 36.83%, respectively. An additional CALVIN evaluation with the frozen FLOWER policy increases five-task-chain success from 77.10% to 77.90%. These results demonstrate the applicability of consequence-aware selection across different policy backends and action representations.
Wei Wang, Wenqiao Zhang, Yutong Lin +14
College of Computer Science and Technology, Zhejiang University · Nanjing University of Aeronautics and Astronautics · Cornell University +3