Semantic Memory
~3 min read
Concept & How It Works
Why Does It Exist?
Agents need a fact layer separate from conversation logs. Semantic memory answers 'what do I know about X?' without replaying entire chat histories.
Real-World Analogy
Semantic memory is an encyclopedia entry about you — facts without the story of when you mentioned them.
Visual Workflows
What is Semantic Memory?
Example
Scenario
Semantic memory holds: {user: 'Alice', stack: 'TypeScript', team_size: 8, preferred_linter: 'eslint'} — retrieved when Alice asks about CI setup.
Solution
In Agent Memory, apply Semantic Memory to this scenario: Semantic memory holds: {user: 'Alice', stack: 'TypeScript', team_size: 8, preferred_linter: 'eslint'} — retrieved when Alice asks about CI setup. 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 Semantic Memory (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 Semantic Memory happens in the code.
1# Semantic Memory — 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 Semantic Memory8 model="gpt-4o-mini",9 messages=[10 {"role": "system", "content": "You explain semantic memory clearly."},11 {"role": "user", "content": f"What is semantic memory?"},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 Semantic Memory as a black box without evaluation
- Ignoring cost and latency in production
- Skipping error handling for semantic memory
Cheat Sheet
Quick recap — the most important points from this module.
Cheat Sheet
quick ref- •Semantic Memory
- •Fact Extraction
- •Knowledge Base
- •Entity Memory