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Phase 5

Memory Retrieval

~2 min read

Concept & How It Works

    Why Does It Exist?

    Storing memory is useless if the agent can't find the right piece at the right moment. Retrieval quality directly impacts answer accuracy.

    Real-World Analogy

    Memory retrieval is a librarian fetching the right shelf — not dumping the entire library on your desk.
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    Visual Workflows

    What is Memory Retrieval?

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    Example

    Scenario

    User asks 'What did we decide about the database?' Retrieval fetches the semantic memory entry from last week's architecture discussion, not unrelated chat about lunch.

    Solution

    In Agent Memory, apply Memory Retrieval to this scenario: User asks 'What did we decide about the database?' Retrieval fetches the semantic memory entry from last week's architecture discussion, not unrelated chat about lunch. Identify the inputs, run the technique, validate the output, and note one thing you would monitor in production.

    Practice Task

    Do this before moving to the next module — reading alone is not enough.

    Open the Code Walkthrough below and run it locally. Change one parameter related to Memory Retrieval (e.g. model, temperature, top_k, or tool name), observe the difference in output, and write 2–3 sentences explaining what changed.

    Code Walkthrough

    Highlighted lines show where Memory Retrieval happens in the code.

    Memory Retrieval
    1def retrieve(query, store, user_id, k=5):  # define a reusable function2    return store.similarity_search(  # return the result3        query,4        k=k,5        filter={"user_id": user_id},6        score_threshold=0.7,7    )

    Commands to Remember

    Commands to Remember

    • pip install chromadb # vector store for long-term memory
    • pip install redis # fast session / working memory
    • pip install tiktoken # count tokens before injecting memory

    Common Mistakes

    • Treating Memory Retrieval as a black box without evaluation
    • Ignoring cost and latency in production
    • Skipping error handling for memory retrieval

    Cheat Sheet

    Quick recap — the most important points from this module.

    Cheat Sheet

    quick ref
    • Memory Retrieval
    • Top-K Retrieval
    • Reranking
    • Hybrid Search