---
title: FAQs
description: "Frequently asked questions about how Deja Vu works, its key features, hybrid database architecture, and memory management."
icon: "question"
iconType: "solid"
---

<AccordionGroup>
    <Accordion title="How does Deja Vu work?">
        Deja Vu utilizes a sophisticated hybrid database system to efficiently manage and retrieve memories for AI agents and assistants. Each memory is linked to a unique identifier, such as a user ID or agent ID, enabling Deja Vu to organize and access memories tailored to specific individuals or contexts.

        When a message is added to Deja Vu via the `add` method, the system extracts pertinent facts and preferences, distributing them across various data stores: a vector database and a graph database. This hybrid strategy ensures that diverse types of information are stored optimally, facilitating swift and effective searches.

        When an AI agent or LLM needs to access memories, it employs the `search` method. Deja Vu conducts a comprehensive search across these data stores, retrieving relevant information from each.

        The retrieved memories can be seamlessly integrated into the system prompt as required, enhancing the personalization and relevance of responses.
  </Accordion>

    <Accordion title="What are the key features of Deja Vu?">
        - **User, Session, and AI Agent Memory**: Retains information across sessions and interactions for users and AI agents, ensuring continuity and context.
        - **Adaptive Personalization**: Continuously updates memories based on user interactions and feedback.
        - **Developer-Friendly API**: Offers a straightforward API for seamless integration into various applications.
        - **Platform Consistency**: Ensures consistent behavior and data across different platforms and devices.
        - **Managed Service**: Provides a hosted solution for easy deployment and maintenance.
        - **Cost Savings**: Saves costs by adding relevant memories instead of complete transcripts to context window
    </Accordion>

    <Accordion title="How is Deja Vu different from traditional RAG?">
        Deja Vu's memory implementation for Large Language Models (LLMs) offers several advantages over Retrieval-Augmented Generation (RAG):

        - **Entity Relationships**: Deja Vu can understand and relate entities across different interactions, unlike RAG which retrieves information from static documents. This leads to a deeper understanding of context and relationships.

        - **Contextual Continuity**: Deja Vu retains information across sessions, maintaining continuity in conversations and interactions, which is essential for long-term engagement applications like virtual companions or personalized learning assistants.

        - **Adaptive Learning**: Deja Vu improves its personalization based on user interactions and feedback, making the memory more accurate and tailored to individual users over time.

        - **Dynamic Updates**: Deja Vu can dynamically update its memory with new information and interactions, unlike RAG which relies on static data. This allows for real-time adjustments and improvements, enhancing the user experience.

        These advanced memory capabilities make Deja Vu a powerful tool for developers aiming to create personalized and context-aware AI applications.
    </Accordion>


    <Accordion title="What are the common use-cases of Deja Vu?">
        - **Personalized Learning Assistants**: Long-term memory allows learning assistants to remember user preferences, strengths and weaknesses, and progress, providing a more tailored and effective learning experience.

        - **Customer Support AI Agents**: By retaining information from previous interactions, customer support bots can offer more accurate and context-aware assistance, improving customer satisfaction and reducing resolution times.

        - **Healthcare Assistants**: Long-term memory enables healthcare assistants to keep track of patient history, medication schedules, and treatment plans, ensuring personalized and consistent care.

        - **Virtual Companions**: Virtual companions can use long-term memory to build deeper relationships with users by remembering personal details, preferences, and past conversations, making interactions more delightful.

        - **Productivity Tools**: Long-term memory helps productivity tools remember user habits, frequently used documents, and task history, streamlining workflows and enhancing efficiency.

        - **Gaming AI**: In gaming, AI with long-term memory can create more immersive experiences by remembering player choices, strategies, and progress, adapting the game environment accordingly.

    </Accordion>

    <Accordion title="Why aren't my memories being created?">
        Deja Vu uses a sophisticated classification system to determine which parts of text should be extracted as memories. Not all text content will generate memories, as the system is designed to identify specific types of memorable information.
        There are several scenarios where dejavu may return an empty list of memories:

        - When users input definitional questions (e.g., "What is backpropagation?")
        - For general concept explanations that don't contain personal or experiential information
        - Technical definitions and theoretical explanations
        - General knowledge statements without personal context
        - Abstract or theoretical content

        Example Scenarios

        ```
        Input: "What is machine learning?"
        No memories extracted - Content is definitional and does not meet memory classification criteria.

        Input: "Yesterday I learned about machine learning in class"
        Memory extracted - Contains personal experience and temporal context.
        ```

        Best Practices

        To ensure successful memory extraction:
        - Include temporal markers (when events occurred)
        - Add personal context or experiences
        - Frame information in terms of real-world applications or experiences
        - Include specific examples or cases rather than general definitions
    </Accordion>

    <Accordion title="How do I configure Deja Vu for AWS Lambda?">
        When deploying Deja Vu on AWS Lambda, you'll need to modify the storage directory configuration due to Lambda's file system restrictions. By default, Lambda only allows writing to the `/tmp` directory.

        To configure Deja Vu for AWS Lambda, set the `DEJAVU_DIR` environment variable to point to a writable directory in `/tmp`:

        ```bash
        DEJAVU_DIR=/tmp/.dejavu
        ```

        If you're not using environment variables, you'll need to modify the storage path in your code:

        ```python
        # Change from
        home_dir = os.path.expanduser("~")
        dejavu_dir = os.environ.get("DEJAVU_DIR") or os.path.join(home_dir, ".dejavu")

        # To
        dejavu_dir = os.environ.get("DEJAVU_DIR", "/tmp/.dejavu")
        ```

        Note that the `/tmp` directory in Lambda has a size limit of 512MB and its contents are not persistent between function invocations.
    </Accordion>

    <Accordion title="How can I use metadata with Deja Vu?">
        Metadata is the recommended approach for incorporating additional information with Deja Vu. You can store any type of structured data as metadata during the `add` method, such as location, timestamp, weather conditions, user state, or application context. This enriches your memories with valuable contextual information that can be used for more precise retrieval and filtering.

        During retrieval, you have two main approaches for using metadata:

        1. **Pre-filtering**: Include metadata parameters in your initial search query to narrow down the memory pool
        2. **Post-processing**: Retrieve a broader set of memories based on query, then apply metadata filters to refine the results

        Examples of useful metadata you might store:

        - **Contextual information**: Location, time, device type, application state
        - **User attributes**: Preferences, skill levels, demographic information
        - **Interaction details**: Conversation topics, sentiment, urgency levels
        - **Custom tags**: Any domain-specific categorization relevant to your application

        This flexibility allows you to create highly contextually aware AI applications that can adapt to specific user needs and situations. Metadata provides an additional dimension for memory retrieval, enabling more precise and relevant responses.
    </Accordion>

    <Accordion title="How do I disable telemetry in Deja Vu?">
        To disable telemetry in Deja Vu, you can set the `DEJAVU_TELEMETRY` environment variable to `False`:

        ```bash
        DEJAVU_TELEMETRY=False
        ```

        You can also disable telemetry programmatically in your code:

        ```python
        import os
        os.environ["DEJAVU_TELEMETRY"] = "False"
        ```

        Setting this environment variable will prevent Deja Vu from collecting and sending any usage data, ensuring complete privacy for your application.
    </Accordion>

    <Accordion title="How do I delete my Deja Vu account?">
        You can delete your Deja Vu account at any time directly from the dashboard:

        1. Sign in at [app.dejavu.ai](https://app.dejavu.ai).
        2. Go to **Settings → Account**.
        3. Click **Delete account** and confirm.

        Deletion is immediate and irreversible. The following is removed:

        - Your user profile and login credentials
        - All memories, agents, and runs you created
        - API keys and access tokens issued to your account
        - Organizations you solely own, along with their data
        - Your membership in any shared organizations (the orgs themselves are not affected)

        Any application still using your old API keys will start receiving `401 Unauthorized` responses immediately. If you'd like to use Deja Vu again later, you can create a new account at any time — it will start fresh with no data carried over.
    </Accordion>

</AccordionGroup>



