File Auto-complete in Vim and Neovim

I wanted file auto-completion in Markdown notes, especially for wiki-links like [[another-note]], paths, headings, and ambiguous filenames such as multiple README.md files in one vault.

The first thing I learned is that installing an LSP server is not the same thing as getting a good completion experience. I started with marksman, and while it can attach to Neovim and provide Markdown intelligence, installing the binary alone was not enough. Neovim still needed an actual completion UI.

I eventually switched to markdown-oxide, which is a better fit for note-taking workflows. The setup that made the most sense was:

markdown-oxide as the Markdown LSP
nvim-cmp as the completion UI
cmp-nvim-lsp as the bridge between nvim-cmp and the LSP

The important Neovim detail was keeping the configuration narrow. I only enabled nvim-cmp for Markdown buffers, and I used the documented markdown_oxide keyword pattern so completion can match spaces, /, and # inside wiki-links and heading references.

That matters because the built-in Neovim completion popup is fairly limited for this kind of Markdown navigation. Once I moved to nvim-cmp, the setup was much closer to what I actually wanted: note-oriented completion, not a general coding environment.

Tips for others:

Decide what you want first: a coding LSP setup or a note-linking setup. They are not the same.
Do not assume brew install ... is the full job. You still need Neovim-side completion configured.
If your goal is Markdown links and wiki-links, markdown-oxide plus nvim-cmp is a better fit than a bare LSP plus Neovim's default completion.
If you have lots of duplicate filenames, a richer completion UI helps much more than the default popup.
Check :LspInfo to confirm the server is actually attached in the Markdown buffer you are editing.

The shortest version of the setup is: install markdown-oxide, install nvim-cmp and cmp-nvim-lsp, wire them together only for Markdown, and treat this as a note-writing workflow rather than a code-completion workflow.