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198 points alexmrv | 1 comments | | HN request time: 0s | source

Hey HN! I built a proof-of-concept for AI memory using Git instead of vector databases.

The insight: Git already solved versioned document management. Why are we building complex vector stores when we could just use markdown files with Git's built-in diff/blame/history?

How it works:

Memories stored as markdown files in a Git repo Each conversation = one commit git diff shows how understanding evolves over time BM25 for search (no embeddings needed) LLMs generate search queries from conversation context Example: Ask "how has my project evolved?" and it uses git diff to show actual changes in understanding, not just similarity scores.

This is very much a PoC - rough edges everywhere, not production ready. But it's been working surprisingly well for personal use. The entire index for a year of conversations fits in ~100MB RAM with sub-second retrieval.

The cool part: You can git checkout to any point in time and see exactly what the AI knew then. Perfect reproducibility, human-readable storage, and you can manually edit memories if needed.

GitHub: https://github.com/Growth-Kinetics/DiffMem

Stack: Python, GitPython, rank-bm25, OpenRouter for LLM orchestration. MIT licensed.

Would love feedback on the approach. Is this crazy or clever? What am I missing that will bite me later?

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jmtulloss ◴[] No.44969997[source]
Seems really interesting! It would be great to see some evals to understand how well this works when stacked up against different approaches and use cases.
replies(1): >>44970014 #
1. alexmrv ◴[] No.44970014[source]
Keen to do this as well! But couldn't find a good reliable eval for memory creation and retrieval, if you have one you could recommend i'd give it a go asap.