Multimodal LLM agents operating in complex game environments must continually reuse past experience to solve new tasks efficiently. In this work, we propose Echo, a transfer-oriented memory framework that enables agents to derive actionable knowledge from prior interactions rather than treating memory as a passive repository of static records. To make transfer explicit, Echo decomposes reusable knowledge into five dimensions: structure, attribute, process, function, and interaction. This formulation allows the agent to identify recurring patterns shared across different tasks and infer what prior experience remains applicable in new situations. Building on this formulation, Echo leverages In-Context Analogy Learning (ICAL) to retrieve relevant experiences and adapt them to unseen tasks through contextual examples. Experiments in Minecraft show that, under a from-scratch learning setting, Echo achieves a 1.3x to 1.7x speed-up on object-unlocking tasks. Moreover, Echo exhibits a burst-like chain-unlocking phenomenon, rapidly unlocking multiple similar items within a short time interval after acquiring transferable experience. These results suggest that experience transfer is a promising direction for improving the efficiency and adaptability of multimodal LLM agents in complex interactive environments.
Figures & tables
Figure 2: Comparison of item unlocking progress across different agents. The x-axis represents the iteration steps, and the y-axis indicates the number of unique items unlocked. Our method shows a significantly faster progression, exhibiting a “rapid unlocking” phenomenon in the mid-stage, where similar items are unlocked in an explosive manner. Compared to previous methods (MP5 [ 38 ] , Voyager [ 42 ] , JARVIS-1 [ 45 ] , and MrSteve [ 36 ] ), our approach achieves equivalent milestones about 1.3 × –1.7 × faster.
Figure 3: Overview of motivation and Problem Framework. (a) Traditional MLLM-based agents struggle to generalize across complex real-world environments due to different state transitions and causal relations ( hard to transfer ) and may exhibit unstable control arising from hallucinations. (b) The proposed Structured In-Context Learning framework introduces a unified CSD that decomposes environmental knowledge into five explicit transfer dimensions.
Figure 4: Overview of the CSD schema.
Figure 5: ICL-based analogical learning workflow using the CSD memory bank.
Figure 6: Overview of our iterative framework. The system performs perception, memory retrieval, planning, verification, and execution in a loop. A three-layer architecture (perception, decision, execution) interacts with short- and long-term memory to support structured ICAL and case-based transfer.
Method
Recipe (Succ@0→10 / 30) ↑
Functional Eq. (Succ@0→10 / 30) ↑
Crafting Chain (Succ@0→10 / 30) ↑
Utility Blocks (Succ@0→10 / 30) ↑
Bed
Iron Pickaxe
Shield
BridgeEq
SmeltEq
WeaponEq
WeaponSet
ToolBench
ArmorSet
CraftGrid
CraftTable
Furnace
Memory-enhanced Models
Voyager [ 42 ]
35.0 / 62.5
30.0 / 57.5
25.0 / 50.0
17.5 / 40.0
15.0 / 35.0
15.0 / 32.5
22.5 / 45.0
27.5 / 55.0
17.5 / 40.0
45.0 / 77.5
35.0 / 65.0
25.0 / 47.5
Self Verification [ 42 ]
25.0 / 47.5
25.0 / 45.0
17.5 / 37.5
12.5 / 27.5
10.0 / 25.0
7.5 / 20.0
15.0 / 32.5
17.5 / 40.0
10.0 / 27.5
30.0 / 55.0
22.5 / 45.0
12.5 / 32.5
MrSteve [ 36 ]
22.5 / 40.0
20.0 / 37.5
17.5 / 35.0
47.5 / 77.5
45.0 / 77.5
42.5 / 72.5
15.0 / 32.5
17.5 / 35.0
12.5 / 27.5
25.0 / 45.0
17.5 / 35.0
10.0 / 22.5
MP5 [ 38 ]
40.0 / 67.5
37.5 / 65.0
35.0 / 60.0
45.0 / 75.0
42.5 / 70.0
37.5 / 65.0
35.0 / 65.0
35.0 / 62.5
30.0 / 57.5
42.5 / 72.5
35.0 / 65.0
27.5 / 52.5
Table 1: From-scratch learning in Minecraft (Success@0→10 / Success@0→30) . Higher is better. Results are averaged over worlds, map variants, and resource configurations. denotes full model; denotes component disabled.
Figure 7: Comparison of task performance when keeping or removing individual design axes. Left: bar charts for each task showing median performance change under “Keep Only” and “Remove” scenarios. Right: correlation heatmap between task outcomes and design axes (thicker borders indicate stronger correlations).
Figure 8: Continuous learning performance comparison. The figure shows the success rate (%) over 31 training episodes (0–30) across five agents: Ours , JARVIS-1 , MP5 , MrSteve , and Voyager . The shaded region (episodes 5–15) highlights the fast learning phase of our method. Compared to all baselines, our method demonstrates a faster learning rate in the mid-phase .
Figure 9: Transferring from a wooden pickaxe to a stone pickaxe.
Large language model (LLM) agents can reuse experience from prior task executions to improve performance on subsequent tasks. Although existing methods enable cross-agent experience sharing, differences in agents' execution histories and task requirements make shared experiences difficult to reuse effectively. We propose XferAgent, a framework for cross-agent experience transfer that organizes reusable experience in local and shared experience graphs. XferAgent reconciles compatible contributions from heterogeneous agents while avoiding unreliable merges. For each new task, it selects shared experiences and integrates them with the target agent's local experience to support task execution. Experiments across diverse task domains show improvements over representative memory-based methods and effective experience transfer between heterogeneous agent frameworks. Cumulative task success also increases over successive task passes as agents update and reuse their experiences.
Weihao Li, Jun Bai, Shijie Chen +3
McCormick School of Engineering, Northwestern University · School of Computer Science, McGill University · Mila – Quebec AI Institute +1
Large language model agents are expected to continuously adapt to new tasks and environments over their lifetime by reusing past experience. However, existing memory-based agents struggle to transfer reusable experience across environments and suffer from catastrophic forgetting as experience accumulated. To address these challenges, we propose LifeMem, a lifelong learning framework that enables agents to transfer knowledge across multiple environments. During learning, LifeMem clusters accumulated interaction trajectories based on underlying workflows to extract reusable skills. When solving a new task at inference time, the agent recalls relevant skills and trajectories to guide actions. To validate our method, we conduct experiments across 10 environments and over 13k tasks with 2k newly annotated interaction trajectories. Results show that LifeMem enables effective experience reuse in lifelong learning, achieving both reduced forgetting on learned tasks and superior cross-task transfer. Further analysis reveals that task streaming impacts learning, while consolidating structurally similar trajectories within memory boosts performance.
Yuli Qiu, Yutong Li, Wei Su +5
School of Computer Science and Technology, Beijing Institute of Technology · School of Computer Science and Engineering, Beihang University · Research Center for Social Computing and Interactive Robotics, Harbin Institute of Technology +1
We present PEAM, a Parametric Embodied Agent Memory framework in Minecraft that transforms agent memory from inference-time retrieval into parameter-resident skills internalized through experience. PEAM pairs a slow deliberative LLM for open-ended reasoning with a fast parametric module for reflexive execution of consolidated skills. The fast module is a multimodal Mixture-of-Experts LoRA architecture with per-category physically isolated adapters, enabling parameter-level continual learning without catastrophic forgetting. We treat failure as a first-class training signal: failure--correction trajectory pairs are internalized through a joint behavioral-cloning and contrastive objective, so the agent learns not only what succeeds but also how corrected actions differ from failed ones. To govern consolidation, PEAM introduces a parameterization-worthiness score for deciding which experience should be internalized, and a scale-free self-triggered consolidation mechanism for deciding when to internalize without task-specific hand-tuned thresholds, making the agent self-evolving as the trigger transfers across task distributions without re-tuning. Experiments in Minecraft show that PEAM improves long-horizon task performance, mitigates forgetting on previously consolidated skills, and improves parametric-versus-retrieval efficiency over retrieval-based embodied agents and parametric memory variants.
Yuchen Guo, Junli Gong, Weicheng Wang +3
Northwestern University · Northeastern University · South China University of Technology +2