Build AI Memory Systems with MongoDB Atlas, AWS and Claude

When working with conversational AI, most developers fall into a familiar trap: They treat memory as simple storage—write data in, read data out. But human memory doesn't work this way. Our brains actively evaluate information importance, strengthen connections through repetition, and let irrelevant details fade over time. This disconnect creates AI systems that either remember too much (overwhelming users with irrelevant details) or too little (forgetting critical context). The stakes are significant: Without sophisticated memory management, AI assistants can't provide truly personalized experiences, maintain consistent personalities, or build meaningful relationships with users.

The application we're exploring represents a paradigm shift—treating AI memory not as a database problem but as a cognitive architecture challenge. This transforms AI memory from passive storage into an active, evolving knowledge network.

A truly intelligent cognitive memory isn't one that never forgets, but one that forgets with intention and remembers with purpose.

Imagine an AI assistant that doesn't just store information but builds a living, adaptive memory system that carefully evaluates, reinforces, and connects knowledge just like a human brain. This isn't science fiction—it's achievable today by combining MongoDB Atlas Vector Search with AWS Bedrock and Anthropic's Claude. You'll move from struggling with fragmented AI memory systems to building sophisticated knowledge networks that evolve organically, prioritize important information, and recall relevant context exactly when needed.

The cognitive architecture of AI memory

At its simplest, our memory system mimics three core aspects of human memory:

• Importance-weighted storage: Not all memories are equally valuable.

• Reinforcement through repetition: Important concepts strengthen over time.

• Contextual retrieval: Memories are recalled based on relevance to current context.

This approach differs fundamentally from traditional conversation storage:

Traditional conversation storage	Cognitive memory architecture
Flat history retention	Hierarchical knowledge graph
Equal weighting of all information	Importance-based prioritization
Keyword or vector-only search	Hybrid semantic & keyword retrieval
Fixed memory lifetime	Dynamic reinforcement & decay
Isolated conversation fragments	Connected knowledge network

The practical implication is an AI that "thinks" before remembering—evaluating what information to prioritize, how to connect it with existing knowledge, and when to let less important details fade.

Let's build a minimum viable implementation of this cognitive memory architecture using MongoDB Atlas, AWS Bedrock, and Anthropic's Claude. Our focus will be on creating the fundamental components that make this system work.

Service architecture

The following service architecture defines the foundational components and their interactions that power the cognitive memory system.

Figure 1. AI memory service architecture.

Built on AWS infrastructure, this comprehensive architecture connects user interactions with sophisticated memory management processes. The User Interface (Client application) serves as the entry point where humans interact with the system, sending messages and receiving AI responses enriched with conversation summaries and relevant contextual memories.

At the centre sits the AI Memory Service, the critical processing hub that coordinates information flow, processes messages, and manages memory operations across the entire system. MongoDB Atlas provides a scalable, secure, multi-cloud database foundation.

The system processes data through the following key functions:

• Bedrock Titan Embeddings for converting text to vector representations.

• Memory Reinforcement for strengthening important information.

• Relevance-based Retrieval for finding contextually appropriate memories.

• Anthropic’s Claude LLM handles the importance assessment to evaluate long-term storage value, memory merging for efficient information organization, and conversation summary generation.

This architecture ultimately enables AI systems to maintain contextual awareness across conversations, providing more natural, consistent, and personalized interactions over time.

Database structure

The database structure organizes information storage with specialized collections and indexes that enable efficient semantic retrieval and importance-based memory management.

Figure 2. Example of a database structure.

The database design strategically separates raw conversation data from processed memory nodes to optimize performance and functionality. The Conversations Collection maintains chronological records of all interactions, preserving the complete historical context, while the Memory Nodes Collection stores higher-level semantic information with importance ratings that facilitate cognitive prioritization. Vector Search Indexes enable efficient semantic similarity searches with O(log n) performance, allowing the system to rapidly identify contextually relevant information regardless of database size. To manage storage growth automatically, TTL(Time-To-Live) Indexes expire older conversations based on configurable retention policies. Finally, Importance and User ID indexes optimize retrieval patterns critical to the system's function, ensuring that high-priority information and user-specific context can be accessed with minimal latency.

Memory node structure

The Memory node structure defines the data schemas that combine content with cognitive metadata to enable human-like memory operations.

Figure 3. The memory node structure.

Each node includes an importance score that enables memory prioritization similar to human memory processes, allowing the system to focus on what matters most. The structure tracks access count, which facilitates reinforcement learning by recording how frequently memories are retrieved. A critical feature is the summary field, providing quick semantic access without processing the full content, significantly improving efficiency. Vector embeddings within each node enable powerful semantic search capabilities that mirror human associative thought, connecting related concepts across the knowledge base. Complementing this, the ConversationMessage structure preserves raw conversational context without interpretation, maintaining the original exchange integrity. Both structures incorporate vector embeddings as a unifying feature, enabling sophisticated semantic operations that allow the system to navigate information based on meaning rather than just keywords, creating a more human-like cognitive architecture.

Memory creation process

The memory creation process transforms conversational exchanges into structured memory nodes through a cognitive pipeline mimicking human memory formation by thoughtfully evaluating new information against existing knowledge, rather than indiscriminately storing everything.

Figure 3. The memory creation process.

Through repetition, memories are strengthened via reinforcement, similar to human cognitive processes. At its core, the LLM functions as an "importance evaluator" that assigns each memory a value on a 1-10 scale, reflecting how humans naturally prioritize information based on relevance, uniqueness, and utility. This importance rating directly affects a memory's persistence, recall probability, and survival during pruning operations. As the system evolves, memory merging simulates the human brain's ability to consolidate related concepts over time, while importance updating reflects how new discoveries change our perception of existing knowledge. The framework's pruning mechanism mirrors our natural forgetting of less significant information. Rather than simply accumulating data, this dynamic system creates an evolving memory architecture that continuously refines itself through processes remarkably similar to human cognition.

Memory retrieval process

The memory retrieval process leverages multiple search methodologies that optimize both recall and precision to find and contextualize relevant information across conversations and memory nodes.

Figure 4. The memory retrieval process.

When initiated, the system converts user queries into vector embeddings while simultaneously executing parallel operations to enhance performance. The core of this system is its hybrid search methodology that combines vector-based semantic understanding with traditional text-based keyword search, allowing it to capture both conceptual similarities and exact term matches. The process directly searches memory nodes and applies different weighting algorithms to combine scores from various search methods, producing a comprehensive relevance ranking.

After identifying relevant memories, the system fetches surrounding conversation context to ensure retrieved information maintains appropriate background, followed by generating concise summaries that distill essential insights. A key innovation is the effective importance calculation that dynamically adjusts memory significance based on access patterns and other usage metrics. The final step involves building a comprehensive response package that integrates the original memories, their summaries, relevance scores, and contextual information, providing users with a complete understanding of retrieved information without requiring exhaustive reading of all content. This multi-faceted approach ensures that memory retrieval is both comprehensive and precisely tailored to user needs.

Code execution flowchart

The code execution flowchart provides a comprehensive mapping of how API requests navigate through the system architecture, illuminating the runtime path from initial client interaction to final response delivery.

Figure 5. The code execution flowchart.

When a request enters the system, it first encounters the FastAPI endpoint, which serves as the primary entry point for all client communications. From there, specialized API route handlers direct the request to appropriate processing functions based on its type and intent.

During processing, the system creates and stores message objects in the database, ensuring a permanent record of all conversation interactions. For human-generated messages meeting specific significance criteria, a parallel memory creation branch activates, analyzing the content for long-term storage. This selective approach preserves only meaningful information while reducing storage overhead.

The system then processes queries through embedding generation, transforming natural language into vector representations that enable semantic understanding. One of the most sophisticated aspects is the implementation of parallel search functions that simultaneously execute different retrieval strategies, dramatically improving response times while maintaining comprehensive result quality. These searches connect to MongoDB Atlas to perform complex database operations against the stored knowledge base.

Retrieved information undergoes context enrichment and summary generation, where the AWS Bedrock (Anthropic’s Claude) LLM augments raw data with contextual understanding and concise overviews of relevant conversation history. Finally, the response combination module assembles diverse data components—semantic matches, text-based results, contextual information, and generated summaries—into a coherent, tailored response that addresses the original request.

The system's behavior can be fine-tuned through configurable parameters that govern memory processing, AI model selection, database structure, and service operations, allowing for optimization without code modifications.

Memory updating process

The memory updating process dynamically adjusts memory importance through sophisticated reinforcement and decay mechanisms that mimic human cognitive functions.

Figure 6. The memory updating process.

When new information arrives, the system first retrieves all existing user memories from the database, then methodically calculates similarity scores between this new content and each stored memory. Memories exceeding a predetermined similarity threshold are identified as conceptually related and undergo importance reinforcement and access count incrementation, strengthening their position in the memory hierarchy. Simultaneously, unrelated memories experience gradual decay as their importance values diminish over time, creating a naturally evolving memory landscape. This balanced approach prevents memory saturation by ensuring that frequently accessed topics remain prominent while less relevant information gracefully fades. The system maintains a comprehensive usage history through access counts, which informs more effective importance calculations and provides valuable metadata for memory management. All these adjustments are persistently stored in MongoDB Atlas, ensuring continuity across user sessions and maintaining a dynamic memory ecosystem that evolves with each interaction.

Client integration flow

The following diagram illustrates the complete interaction sequence between client applications and the memory system, from message processing to memory retrieval. This flow encompasses two primary pathways:

Message sending flow: When a client sends a message, it triggers a sophisticated processing chain where the API routes it to the Conversation Service, which generates embeddings via AWS Bedrock. After storing the message in MongoDB Atlas, the Memory Service evaluates it for potential memory creation, performing importance assessment and summary generation before creating or updating a memory node in the database. The flow culminates with a confirmation response returning to the client. Check out the code reference on Github.

Memory retrieval flow: During retrieval, the client's request initiates parallel search operations where query embeddings are generated simultaneously across conversation history and memory nodes. These dual search paths—conversation search and memory node search—produce results that are intelligently combined and summarized to provide contextual understanding. The client ultimately receives a comprehensive memory package containing all relevant information. Check out the code reference on Github.

Figure 7. The client integration flow.

The architecture deliberately separates conversation storage from memory processing, with MongoDB Atlas serving as the central persistence layer. Each component maintains clear responsibilities and interfaces, ensuring that despite complex internal processing, clients receive unified, coherent responses.

Action plan: Bringing your AI memory system to life

To implement your own AI memory system:

1. Start with the core components: MongoDB Atlas, AWS Bedrock, and Anthropic’s Claude.

2. Focus on cognitive functions: Importance assessment, memory reinforcement, relevance-based retrieval, and memory merging

3. Tune parameters iteratively: Start with the defaults provided, then adjust based on your application's needs.

4. Measure the right metrics: Track uniqueness of memories, retrieval precision, and user satisfaction—not just storage efficiency.

To evaluate your implementation, ask these questions:

1. Does your system effectively prioritize truly important information?

2. Can it recall relevant context without excessive prompting?

3. Does it naturally form connections between related concepts?

4. Can users perceive the system's improving memory over time?

Real-world applications and insights

Case Study: From repetitive Q&A to evolving knowledge

A customer service AI using traditional approaches typically needs to relearn user preferences repeatedly. With our cognitive memory architecture:

1. First interaction: User mentions they prefer email communication. The system stores this with moderate importance.

2. Second interaction: User confirms email preference. The system reinforces this memory, increasing its importance.

3. Future interactions: The system consistently recalls email preference without asking again, but might still verify after long periods due to natural decay.

The result? A major reduction in repetitive questions, leading to a significantly better user experience.

Benefits

Applications implementing this approach achieved unexpected benefits:

1. Emergent knowledge graphs: Over time, the system naturally forms conceptual clusters of related information.

2. Insight mining: Analysis of high-importance memories across users reveals shared concerns and interests not obvious from raw conversation data.

3. Reduced compute costs: Despite the sophisticated architecture, the selective nature of memory storage reduces overall embedding and storage costs compared to retaining full conversation histories.

Limitations

When implementing this system, teams typically face three key challenges:

1. Configuration tuning: Finding the right balance of importance thresholds, decay rates, and reinforcement factors requires experimentation.

2. Prompt engineering: Getting consistent, numeric importance ratings from LLMs requires careful prompt design. Our implementation uses clear constraints and numeric-only output requirements.

3. Memory sizing: Determining the optimal memory depth per user depends on the application context. Too shallow and the AI seems forgetful; too deep and it becomes sluggish.

Future directions

The landscape for AI memory systems is evolving rapidly. Here are key developments on the horizon:

Short-term developments

1. Emotion-aware memory: Extending importance evaluation to include emotional salience, remembering experiences that evoke strong reactions.

2. Temporal awareness: Adding time-based decay that varies by information type (factual vs. preferential).

3. Multi-modal memory: Incorporating image and voice embeddings alongside text for unified memory systems.

Long-term possibilities

1. Self-supervised memory optimization: Systems that learn optimal importance ratings, decay rates, and memory structures based on user satisfaction.

2. Causal memory networks: Moving beyond associative memory to create causal models of user intent and preferences.

3. Privacy-preserving memory: Implementing differential privacy and selective forgetting capabilities to respect user privacy boundaries.

This approach to AI memory is still evolving. The future of AI isn't just about more parameters or faster inference—it's about creating systems that learn and remember more like humans do. With the cognitive memory architecture we've explored, you're well on your way to building AI that remembers what matters.