AUGUSTUS: An LLM-Driven Multimodal Agent System with Contextualized User Memory
Jitesh Jain, Shubham Maheshwari, Ning Yu, Wen-mei Hwu, Humphrey Shi
TL;DR
AUGUSTUS addresses the limited multimodal external memory in LLM-driven agents by modeling memory after human cognition, introducing a hierarchical contextual memory of semantic tags and a two-stage CoPe search for concept-driven retrieval. The system operates in an encode–store–retrieve–act loop, leveraging open-source encoders, a Mixtral-based planner, and function calling to autonomously manage memory and tools. Empirical results show CoPe search achieves competitive multimodal retrieval performance on ImageNet while being approximately 3.5× faster than vector-based RAG, and AUGUSTUS outperforms MemGPT on the MSC conversational benchmark, highlighting benefits in personalization and efficiency. This work advances cognition-aligned multimodal agents, enabling robust memory-based reasoning and personalized interactions across image, audio, and video modalities.
Abstract
Riding on the success of LLMs with retrieval-augmented generation (RAG), there has been a growing interest in augmenting agent systems with external memory databases. However, the existing systems focus on storing text information in their memory, ignoring the importance of multimodal signals. Motivated by the multimodal nature of human memory, we present AUGUSTUS, a multimodal agent system aligned with the ideas of human memory in cognitive science. Technically, our system consists of 4 stages connected in a loop: (i) encode: understanding the inputs; (ii) store in memory: saving important information; (iii) retrieve: searching for relevant context from memory; and (iv) act: perform the task. Unlike existing systems that use vector databases, we propose conceptualizing information into semantic tags and associating the tags with their context to store them in a graph-structured multimodal contextual memory for efficient concept-driven retrieval. Our system outperforms the traditional multimodal RAG approach while being 3.5 times faster for ImageNet classification and outperforming MemGPT on the MSC benchmark.
