Dev.to
7/27/2026
Building Nexus: a local Markdown-based memory layer for cross-LLM context persistence
Original: I kept losing context between LLMs, so I built a Markdown-based memory layer (and here is what I learned)
Short summary
A developer built Nexus, a local MCP server that stores project knowledge in plain Markdown, working with any LLM via Claude Desktop, Cursor, or Cline. It uses hybrid search (local embeddings plus BM25 keyword matching) and preserves decision history by archiving rather than deleting superseded notes. The article shares engineering lessons from real usage, including a subtle MCP initialization bug where the model ignored manifest instructions despite passing all tests.
- •Nexus is a local, LLM-agnostic memory layer using Markdown as the single source of truth with hybrid embedding+BM25 search
- •Archived and superseded notes preserve decision history, preventing repeated failed approaches
- •Real-world MCP integration revealed that passing tests doesn't guarantee correct model behavior in production
Generated with AI, which can make mistakes.
Is this a good recommendation for you?
