Research

ReasoningBank: Scaling Agent Self-Evolving with Reasoning Memory

ReasoningBank turns agent successes and failures into reusable reasoning strategies that improve future tasks without updating model weights.

Siru Ouyang, Jun Yan, I-Hung Hsu, Yanfei Chen, Ke Jiang, Zifeng Wang, Rujun Han, Long T. Le, Samira Daruki, Xiangru Tang, Vishy Tirumalashetty, George Lee, Mahsan Rofouei, Hangfei Lin, Jiawei Han, Chen-Yu Lee, Tomas PfisterMar 16, 2026ICLR 202612 min readGoogle Cloud AI Research; Yale University; University of Illinois Urbana-Champaign
EMERGINGAI AgentsAdvanced

Key takeaway

The system retrieves relevant memory, judges outcomes, extracts strategy or failure lessons, and consolidates them into an evolving memory bank; MaTTS makes additional test-time exploration feed higher-quality memories back into the loop.

Updated on Oct 2, 2026

01

Abstract

ReasoningBank turns agent experience into reusable reasoning memory. Instead of retaining raw trajectories, it distills successful strategies and failure lessons, retrieves relevant memories before future tasks, and consolidates new experience into an evolving memory bank.

02

Introduction

Persistent agents repeatedly encounter related tasks but normally do not convert experience into reusable reasoning knowledge. ReasoningBank adds a learning layer between past trajectories and future decisions.

03

Problem

Raw trajectories are long and noisy, while success-only memory discards lessons contained in failures. The system needs compact, transferable reasoning knowledge that can be retrieved when a future task resembles a previous one.

04

Background

The approach connects test-time learning, memory-augmented agents, embedding retrieval, LLM-based trajectory evaluation, and self-improvement. MaTTS extends this idea by making additional test-time trajectories contribute to memory quality.

05

Methodology

For each task, relevant memory items are retrieved with embedding similarity and injected into the agent context. After execution, an LLM judge labels the trajectory, useful strategies and pitfalls are extracted, and the memory bank is consolidated.

Figure 1

ReasoningBank cumulative improvement

Original arXiv figure showing ReasoningBank cumulative successful tasks compared with no memory.

arXiv HTML v2

Figure 2

ReasoningBank closed loop

Original arXiv figure showing memory retrieval, extraction, LLM judging, and consolidation.

arXiv HTML v2

Figure 3

MaTTS

Original arXiv figure comparing vanilla test-time scaling with parallel and sequential memory-aware scaling.

arXiv HTML v2

Formula notes

Mathematical details

Agent policy with memory

Equation
πL(⋅∣M,A)\pi_{\mathcal L}(\cdot|\mathcal M,\mathcal A)

The agent policy is parameterized by the backbone LLM and conditioned on the memory module and available actions.

A
-action space
L
-backbone language model
M
-ReasoningBank memory

Environment transition

Equation
T(st+1∣st,at)\mathcal T(s_{t+1}|s_t,a_t)

The environment transition maps the current state and chosen action to the next state.

T
-environment transition function
a_t
-action selected at time t
s_t
-state at time t

MaTTS scaling factor

Equation
k=number of trajectories for parallel scaling or refinement steps for sequential scalingk=\text{number of trajectories for parallel scaling or refinement steps for sequential scaling}

k controls how much additional test-time experience is generated for memory-aware scaling.

k
-parallel trajectory count or sequential refinement count

06

Architecture

ReasoningBank has three core stages: memory retrieval, memory extraction, and memory consolidation. Stored items contain a title, description, and reasoning content. MaTTS adds parallel self-contrast or sequential self-refinement.

07

Dataset

Experiments cover WebArena, Mind2Web, and SWE-Bench-Verified using Gemini-2.5 and Claude-3.7. WebArena includes Shopping, Admin, GitLab, Reddit, and Multi subsets.

08

Training

The system is primarily an inference-time learning mechanism rather than foundation-model retraining. Experience is converted into reusable memory during task execution and later retrieved for related tasks.

09

Experiments

The reported experiments evaluate memory-augmented agents across WebArena, Mind2Web, and SWE-Bench-Verified, with gains reported across the evaluated backbone models and datasets.

10

Baselines

Baselines include the underlying agents without ReasoningBank memory and alternative test-time scaling approaches.

11

Results

The central result is that abstracted strategies and failure lessons transfer across tasks, while MaTTS makes additional test-time computation more useful by converting it into durable memory.

12

Ablation

Memory retrieval, judging, extraction, consolidation, and MaTTS scaling are the key components whose removal changes memory quality or reuse.

13

Limitations

Memory quality depends on judging and extraction, retrieval can surface irrelevant memories, and contradictory or stale memories can accumulate.

14

Conclusion

ReasoningBank turns agent experience into a reusable reasoning asset and provides continual test-time improvement without changing model weights.

15

References

ReasoningBank primary paper and related work on memory-augmented agents, test-time scaling, self-improvement, WebArena, Mind2Web, SWE-Bench-Verified, and MaTTS.

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