Large language model (LLM) agents are moving beyond reactive responses toward proactive assistance that anticipates user needs without explicit requests. However, existing proactive agents primarily address immediate needs, while many everyday situations involve delayed intentions that can only be acted on hours or days later. Humans handle such intentions through prospective memory, the ability to remember to act on an intention when the right moment arises. In this paper, we introduce ProMemAgent, the first proactive agent to incorporate prospective memory over everyday sensory contexts for long-horizon proactive assistance. ProMemAgent organizes past sensory perceptions (e.g., egocentric video and audio) into context-aware memory, generating prospective cues and linking earlier events with subsequent developments for future retrieval. Given the current context, it retrieves relevant past events and performs memory-augmented proactive reasoning to determine whether assistance is needed. We further introduce CPMBench, the first benchmark for evaluating long-horizon proactive assistance over sensory contexts, comprising 1,000 instances across eight everyday categories. Extensive experiments show that ProMemAgent achieves the best memory retrieval performance and consistently outperforms all baselines on long-horizon proactive assistance.
Figures & tables
Figure 1: Comparison of prior work (top) and ours (bottom). Reactive agents require explicit requests, and prior proactive agents address immediate needs. ProMemAgent incorporates context-aware prospective memory to connect current and historical contexts and assist with implicit delayed intentions at the right moment.
Figure 2: Distribution of timeline instances.
Figure 3: Overview of ProMemAgent. It extracts sensory contexts and constructs context-aware memory through prospective cue generation and cross-event linking. During inference, it retrieves past events via cue-triggered retrieval and performs memory-augmented reasoning to provide long-horizon proactive assistance when needed.
Method
Memory Retrieval
Proactive Decision
End-to-End Assistance
DIR ↑
SCR ↑
FD ↓
Acc-P ↑
Acc-PA ↑
Set-P ↑
Set-R ↑
Set-F1 ↑
Proactive Agents
Proactive Agent (8B)
-
-
7.0
77.8
74.7
63.8
30.1
40.9
ContextAgent (8B)
-
-
43.3
59.8
46.8
17.7
22.8
19.9
Full-Context LLMs (Open- and Closed-Source )
Qwen2.5-32B
-
-
15.7
73.2
68.3
43.4
29.3
35.0
Qwen3-4B
-
-
19.0
69.8
63.8
32.1
22.0
26.1
Qwen3-8B
-
-
27.0
69.8
63.4
37.7
39.8
38.7
Table 1: Main results on CPMBench. All metrics are in percentages (%). The best and second-best results are in bold and underlined , respectively. “-” denotes inapplicable retrieval metrics.
Method
DIR ↑
SCR ↑
Set-P ↑
Set-R ↑
Set-F1 ↑
Proactive Agent (8B)
-
-
63.6
21.5
32.2
ContextAgent (8B)
-
-
11.0
12.3
11.6
Qwen3-32B
-
-
35.2
49.2
41.0
GPT-5.4
-
-
50.0
61.5
55.2
text-embedding-3-small
20.0
10.7
55.6
15.4
24.1
T-Mem (Horizon-based)
26.2
14.3
44.8
20.0
27.7
Table 2: Main results on CPMBench-Omni.
Figure 4: Qualitative results of ProMemAgent in proactive and non-proactive cases.
Method
CPMBench
Direct QA
DIR ↑
SCR ↑
FD ↓
Set-R ↑
Set-F1 ↑
Recall@10 ↑
ProMemAgent
81.3
72.0
4.3
66.7
75.2
98.1
w/o Lf
81.3
38.0
14.7
66.7
65.9
98.1
w/o Kf
47.2
42.0
2.7
32.5
46.8
99.5
w/o Wf
66.7
61.0
3.0
54.5
67.3
98.1
w/o MCT
26.0
15.0
4.0
21.1
32.3
99.5
Table 3: Memory components ablation on CPMBench.
Figure 5: Impact of reasoner variants on CPMBench. K denotes training context sizes and “Qw” denotes Qwen.
Figure 6: Sensitivity to the content and cue-triggered retrieval budgets ( kC , kCT ) on CPMBench.
Appendix figures & tables10 assets
Supplementary material from the paper’s appendix.
Appendix
Figure 7: An example scenario from CPMBench and its four variants, showing representative events from the Positive timeline and its annotation, followed by the variant-specific events of the other three variants.
Figure 8: Summarized prompt for sensory context extraction in ProMemAgent.
Figure 9: Summarized prompt for prospective cue generation in ProMemAgent’s memory construction.
Figure 10: Summarized prompt for cross-event linking in ProMemAgent’s memory construction.
Figure 11: Summarized prompt for proactive reasoning in ProMemAgent.
Figure 12: Summarized prompt for data generation.
Figure 13: Summarized judge prompt in the evaluation.
Annotator 1
Annotator 2
GPT-5-mini
GPT-5.6 Luna
Annotator 1
-
93.9
95.7
89.6
Annotator 2
93.9
-
94.8
95.7
GPT-5-mini
95.7
94.8
-
92.2
GPT-5.6 Luna
89.6
95.7
92.2
-
Appendix
Table 4: Pairwise agreement (%) between two human annotators and two LLM judges.
Method
Memory Retrieval
Proactive Decision
End-to-End Assistance
DIR ↑
SCR ↑
FD ↓
Acc-P ↑
Acc-PA ↑
Set-P ↑
Set-R ↑
Set-F1 ↑
Proactive Agents
Proactive Agent (8B)
-
-
4.8
77.7
74.7
63.6
21.5
32.2
ContextAgent (8B)
-
-
38.7
59.8
47.6
11.0
12.3
11.6
Full-Context LLMs (Open- and Closed-Source )
Qwen2.5-32B
-
-
3.0
75.4
72.1
50.0
7.7
13.3
Qwen3-4B
-
-
19.6
67.9
62.2
23.3
15.4
18.5
Qwen3-8B
-
-
28.6
62.9
57.9
23.8
23.1
23.4
Appendix
Table 5: Main results on CPMBench-Omni. All metrics are in percentages (%). The best and second-best results are in bold and underlined , respectively. “-” denotes inapplicable retrieval metrics.
Method
Memory Retrieval
Proactive Decision
End-to-End Assistance
DIR ↑
SCR ↑
FD ↓
Acc-P ↑
Acc-PA ↑
Set-P ↑
Set-R ↑
Set-F1 ↑
Proactive Agents
Proactive Agent (8B)
-
-
6.9
77.9
74.4
65.6
30.5
41.7
ContextAgent (8B)
-
-
37.9
60.5
48.3
15.3
16.0
15.7
Full-Context LLMs (Open- and Closed-Source )
Qwen2.5-32B
-
-
12.4
73.0
67.5
41.5
20.6
27.6
Qwen3-4B
-
-
13.4
70.8
64.8
30.5
13.7
18.9
Qwen3-8B
-
-
24.5
70.1
64.1
39.5
37.4
38.4
Appendix
Table 6: Out-of-domain results on CPMBench, with three categories excluded from reasoner fine-tuning.
As assistants move from reactive answering toward proactive intervention, memory changes role: it no longer only supplies the answer to a query, it determines whether and when to speak at all. Prior work in this setting hands the system the relevant fact in context; we study the regime that makes the problem hard, where the evidence justifying an intervention must be mined from a long-horizon personal memory. We introduce MemoProBench, a benchmark for memory-driven proactive assistance (MPA), pairing egocentric video with year-long, distractor-rich user memories (~618K tokens on average), human-verified trigger windows, and a protocol that scores content and timing jointly. Every baseline we evaluate performs poorly (at most 15%), including frontier models given summarized or retrieval-augmented memory. A controlled study explains why: with oracle evidence delivered inside the trigger window GPT-5.3-Chat reaches 96%; letting it choose the timing drops it to 38%, and replacing oracle evidence with retrieval drops it to 15%. Content and timing are separately necessary, and missing either is catastrophic. Guided by this, we build MemoProAgent with a plug-and-play harness that surfaces memory from a graph-organized store and gates it down to what is worth interrupting for, plus a lightweight RL stage that curbs early and repeated firing. Without any training, MemoProAgent lifts strict accuracy from below 10% to 37.5% on Qwen3.8-27B and 38% on GPT-5.3-Chat; RL post-training reaches 42.4%.
Shenglai Zeng, Xiao Yang, Tiffany Ma +15
Michigan State University · Meta Reality Labs · Meta Superintelligence Labs +3
A significant challenge in agentic AI is prospective memory: the ability to execute an intention at a specific future cue or state while other activities are ongoing. We introduce PM-Bench, a text-based benchmark for measuring prospective memory capabilities in modern LLM agents. Inspired by the Virtual Week paradigm from cognitive science, PM-Bench evaluates how well LLM agents maintain user intentions, execute delayed intentions, and monitor latent environment changes. Over the course of a simulated seven-day week, agents must continue an ongoing activity while deciding whether any deferred task is due. We compare eight state-of-the-art LLMs on PM-Bench under eight different agent configurations. PM-Bench proves challenging across all settings: the best method, a GPT-5.4 agent, reaches only 65.1% F1 score under our evaluation. Furthermore, no single strategy for improving prospective memory dominates across models. We release PM-Bench as a controlled testbed for diagnosing these failures and developing training or inference-time interventions that support reliable prospective behavior.
Proactivity is a core expectation for AGI. Prior work remains largely confined to laboratory settings, leaving a clear gap in real-world proactive agent: depth, complexity, ambiguity, precision and real-time constraints. We study this setting, where useful intervention requires inferring latent needs from ongoing context and grounding actions in evolving user memory under latency and long-horizon constraints. We first propose DD-MM-PAS (Demand Detection, Memory Modeling, Proactive Agent System) as a general paradigm for streaming proactive AI agent. We instantiate this paradigm in Pask, with streaming IntentFlow model for DD, a hybrid memory (workspace, user, global) for long-term MM, PAS infra framework and introduce how these components form a closed loop. We also introduce LatentNeeds-Bench, a real-world benchmark built from user-consented data and refined through thousands of rounds of human editing. Experiments show that IntentFlow matches leading Gemini3-Flash models under latency constraints, while identifying deeper user intent.