Under every agent memory launch, the same comment appears: "so it's RAG with extra steps." Instead of arguing, we opened the shipping source of mem0, LangGraph, Graphiti and Generative Agents at pinned commits and read the actual read and write paths. The answer is more interesting than either side of the flame war.
Disclosure up front: I work on Mnemoverse, a memory layer for AI agents, so this is a vendor reading competitors' code, and you should weigh it accordingly. Two rules held throughout: in the full version every code claim cites file, lines and a pinned commit, and this short tour names file and commit wherever it quotes code; and there is not a single performance number, ours or anyone's. The full version with all 40 numbered claims and sources lives in our library; this is the short tour.
At read time, the skeptic is right
When a memory layer answers a query, here is mem0's shipping search path (mem0/memory/main.py, commit 001c235): embed the query, over-fetch from a vector store, run a keyword search alongside, fuse the scores, optionally rerank.
# Step 2: Embed query
