
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.
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)orCurate(r, k, i, m, v). Several actions can run in parallel within one step. A run lasts at most T_max steps. Retrievedoes semantic-similarity search over M.Curateretrieves 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
- MemPilot
- Vision language model
Techniques named here
- Objective-wise advantage decoupling
- Prefix-based marginal utility estimation
- On-demand multimodal memory curation
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