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MemPilot: Orchestrating On-Demand Multimodal Memory Curation for LLM Agents
arxiv.orgpaper

MemPilot: Orchestrating On-Demand Multimodal Memory Curation for LLM Agents

MemPilot is a framework that lets LLM agents curate memory on demand rather than query-agnostically, using a multi-step policy trained via reinforcement learning to choose between retrieving from pre-built memory or delegating query-specific curation of raw multimodal history to heterogeneous LLMs and VLMs. The policy controls evidence amount, curation instructions, model choice, and visual access, and is optimized with objective-wise advantage decoupling and prefix-based marginal utility estimation to balance performance, cost, and latency. Tested across five multimodal agent-memory benchmarks, it achieves broader performance-cost-latency trade-off frontiers than existing trade-off-aware baselines.

TL;DR An RL-trained policy orchestrates on-demand, query-specific multimodal memory curation for LLM agents, trading off performance, cost, and latency better than prior baselines.
Document

What it claims

MemPilot keeps two views of an agent's history. One is a query-agnostic memory bank that any off-the-shelf memory system can build. The other is the raw multimodal history, kept for curation at query time. A text-only orchestrator LLM, trained with GRPO under a preference vector λ = (λ_Q, λ_C, λ_L), decides step by step how to spend runtime compute across quality, monetary cost and latency. λ_Q is fixed at 1 throughout. The fetched text stops before the results section, so no benchmark numbers are available here.

How it works

  • Dual-view memory. The bank M is replaceable, so memory construction stays separate from orchestration. The raw history H is split into fixed-length token chunks, and each chunk keeps its original multimodal context.
  • Action space. At each step the policy emits either Retrieve(r, k) or Curate(r, k, i, m, v). Several actions can run in parallel within one step. A run lasts at most T_max steps.
  • Retrieve does semantic-similarity search over M.
  • Curate retrieves raw chunks and sends them to a selected model m from a pool of LLMs and VLMs.
  • Curate arguments. The retrieval query r ("what") is kept separate from the curation instruction i ("how"). For example, r is "Lena's dress options" and i is "extract the two dress types she considered". The evidence count k replaces a fixed top-k. The flag v decides whether raw images go to a vision-capable model.
  • Model routing. The orchestrator never sees pixels. For routing it gets anonymized model IDs plus short profiles giving parameter scale and supported modalities.
  • Rewards.
  • Quality Q is a task metric such as F1.
  • Cost C is the token cost of the orchestrator plus the token cost of delegated calls.
  • Latency L is a proxy estimator, not wall-clock time, because wall-clock is too noisy for stable training. Details are in Appendix A.1.
  • Advantage.
  • Each objective's advantage is normalized separately, then combined: A^λ = λ_Q·A^Q + λ_C·A^C + λ_L·A^L.
  • Per-step credit adds η·Δu. Δu comes from answer "probes" run on the evidence prefix before and after step t, and their difference estimates that step's marginal utility.
flowchart TD
  Q[User query + evidence so far] --> P{Orchestrator policy}
  P -->|Retrieve r,k| M[Memory bank M]
  P -->|Curate r,k,i,m,v| H[Raw history H]
  H --> S{Select model m}
  S --> L[Text LLM]
  S -->|v: include images| V[VLM]
  M --> O[Append observation]
  L --> O
  V --> O
  O -->|until stop or T_max| P
  P -->|stop| A[Final answer]

Evidence

The page says that experiments on five multimodal agent-memory benchmarks give broader performance–cost–latency frontiers than trade-off-aware baselines. It also reports behavioral shifts in model choice, visual access and compute allocation as λ changes. The truncated text names neither the benchmarks nor any scores.

How to use it

The page links a project website, a GitHub repository and a "MemPilot Collection", but the extracted text does not give their URLs. It gives no install commands, orchestrator model size, licence or training compute.

Limits

  • No results here. The text ends partway through Section 3.3, so this document cannot report any number, baseline or benchmark name.
  • Latency is modelled, not measured. Reported latency gains may not match your serving stack.
  • Cost depends on the model pool. Cost and latency trade-offs are tied to the pool's pricing and profiles, which the page shows only as anonymized IDs.
  • Fixed quality weight. λ_Q is always 1, so preferences only move the cost and latency weights.
  • Raw history must be kept. Curate works over H, so you need to retain the full multimodal history, images included, alongside your memory bank.

Technologies named here

Techniques named here

  • Objective-wise advantage decoupling
  • Prefix-based marginal utility estimation
  • On-demand multimodal memory curation