Memory Ranking
~2 min read
Concept & How It Works
Why Does It Exist?
Top-k vector search returns plausible but not always best results. Ranking ensures the most useful memories win the limited token budget.
Real-World Analogy
Memory ranking is a search engine's second page — vector search is the crawl; ranking is the algorithm that puts the best answer first.
Visual Workflows
What is Memory Ranking?
Example
Scenario
Five memories match 'deployment.' Ranking boosts the one from yesterday about the staging deploy over a six-month-old note about deployment theory.
Solution
In Agent Memory, apply Memory Ranking to this scenario: Five memories match 'deployment. 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 Ranking (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 Ranking happens in the code.
1# Memory Ranking — minimal example2from openai import OpenAI3
4client = OpenAI() # create API client5
6# Ask the model to explain this topic7response = client.chat.completions.create( # core API call for Memory Ranking8 model="gpt-4o-mini",9 messages=[10 {"role": "system", "content": "You explain memory ranking clearly."},11 {"role": "user", "content": f"What is memory ranking?"},12 ],13 temperature=0,14)15print(response.choices[0].message.content) # show output for debuggingCommands to Remember
Commands to Remember
pip install chromadb # vector store for long-term memorypip install redis # fast session / working memorypip install tiktoken # count tokens before injecting memory
Common Mistakes
- Treating Memory Ranking as a black box without evaluation
- Ignoring cost and latency in production
- Skipping error handling for memory ranking
Cheat Sheet
Quick recap — the most important points from this module.
Cheat Sheet
quick ref- •Memory Ranking
- •Cross-Encoder
- •MMR
- •Recency Decay