Originally published on mihaibuilds.com . Cross-posting here because dev.to is where I find a lot of this kind of work myself. For the past year I kept hitting the same wall. I'd have a real conversation with Claude — work through a database design, debug something gnarly, agree on a convention I wanted to keep — and the next morning it was gone. Not summarized. Not searchable. Just gone. ChatGPT was the same. Every assistant I used had the long-term memory of a goldfish, and the workaround the industry settled on was "paste the relevant context back in every time." That's not memory. That's me being the memory. So I built one. Memory Vault is an open-source, self-hosted AI memory system you run yourself: Postgres with pgvector underneath, hybrid search on top, an MCP server so Claude can read and write to it directly, a knowledge graph that extracts entities without an LLM bill, a local LLM chat with retrieved-source citations, and a one-command Docker setup.…