I mostly work in neovim, but I'll open cursor to write boilerplate code. I'd love to use something cli based like Claude Code or Codex, but neither of them implement semantic indexing (vector embeddings) the way Cursor does. It should be possible to implement an MCP server which does this, but I haven't found a good one.
I use a small plugin I’ve written my self to interact with Claude, Gemini 2.5 pro or GPT. I’ve not really seen the need for semantic searching yet. Instead I’ve given the LLM access to LSP symbol search, grep and the ability to add files to the conversation. It’s been working well for my use cases but I’ve never tried Cursor so I can’t comment on how it compares. I’m sure it’s not as smooth though. I’ve tried some of the more common Neovim plugins and for me it works better, but the preference here is very personal. If you want to try it out it’s here: https://github.com/isaksamsten/sia.nvim
Tool-calling agents with search tools do very well at information retrieval tasks in codebases. They are slower and more expensive than good RAG (if you amortize the RAG index over many operations), but they're incredibly versatile and excel in many cases where RAG would fall down. Why do you think you need semantic indexing?
Unfortunately I can only give an anecdotal answer here, but I get better results from Cursor than the alternatives. The semantic index is the main difference, so I assume that's what's giving it the edge.
Is it a very large codebase? Anything else distinctive about it? Are you often asking high-level/conceptual questions? Those are the questions that would help me understand why you might be seeing better results with RAG.
