Can Vim Auto-Indent Be Configured Per Project Directory?

Yeah, you can totally customize indentation per project. My go-to is '.editorconfig' for shared projects because it's simple and other editors respect it too; install the EditorConfig plugin and you’re set. For solo hacks, I drop autocmds in my vimrc targeting the project path, e.g. an autocmd matching */myrepo/* that does setlocal shiftwidth=2 softtabstop=2 expandtab. If you need local .vimrc files in the repo, be careful: enabling 'exrc' can execute arbitrary code, so either use a plugin that prompts before sourcing or keep a whitelist. I also sometimes use modelines for single-file overrides (vim: set ts=4 sw=4 et:) but prefer project-level settings to avoid per-file noise. Try EditorConfig first — low friction and team-friendly, and then fall back to autocmds for edge cases.

I'll be blunt: yes, you absolutely can set up Vim to auto-indent differently per project directory, and I've done it a bunch of times across projects with different coding styles.

When I need a project-specific policy I usually pick one of three safe routes: use a repository-level '.editorconfig' with the EditorConfig Vim plugin (works across editors and is a huge life-saver), add per-project autocommands in my global vimrc that match the project path, or—if I must—use a controlled local vimrc mechanism (with security checks). For example, in your main vimrc you can add an autocmd that applies settings only when the buffer lives under a particular path:

augroup proj_indent
autocmd!
autocmd BufRead,BufNewFile /path/to/myproj/* setlocal shiftwidth=4 tabstop=4 expandtab
augroup END

That keeps the rules scoped to files under that directory. I avoid blindly enabling 'exrc' because executing arbitrary project .vimrc files can be risky; instead I either require a checked-in '.editorconfig' or use a trusted plugin like 'localvimrc' that prompts you before sourcing. Also remember to use setlocal so other projects aren’t affected. For Neovim, the same autocmds work, but I often detect the project root via an LSP/root_pattern helper and then apply settings dynamically. Overall, choose EditorConfig if you want a cross-editor approach, or autocommands if you prefer staying purely in Vim land.

Oh, for sure — I set different indent rules for different repos all the time. The cleanest cross-tool approach is to put a '.editorconfig' at the repo root and install the EditorConfig plugin for Vim; then your tab/space/indent settings are automatically honored by everyone who has that plugin. If you want a pure-Vim approach, add autocmd rules in your ~/.vimrc that match directory patterns and use setlocal: something like

autocmd BufRead,BufNewFile */projects/foo/* setlocal shiftwidth=2 softtabstop=2 expandtab

That applies only to files under that folder. A caution: enabling local project .vimrc files with 'set exrc' can be handy but risky — malicious projects could run arbitrary Vimscript. If you go that route, use a plugin that asks for confirmation or maintain a whitelist. For Neovim folks, you can use Lua in your init to detect project roots and apply options programmatically. I've used both EditorConfig and autocommands; EditorConfig wins for team consistency, autocommands win for quick personal hacks.

Different projects, different rules — I like having the editor adapt to the repo so I stop fighting indentation when switching branches. My usual pattern is to prefer a repository-controlled file like '.editorconfig' because it communicates style to everyone and tools like prettier or clang-format can mirror it. But when I need something local and quick, I add project-specific autocmds in my main vimrc that check the file path or project root and then set local options. For instance:

augroup local_indent
autocmd!
autocmd BufEnter /home/me/work/special_project/* setlocal tabstop=4 shiftwidth=4 noexpandtab
augroup END

That way, if I'm editing within that folder I get tabs, elsewhere I get spaces. I also sometimes use a local dotfile called '.vimrc.local' and a tiny bootstrapping snippet in my global config that sources it only after confirming a checksum or asking me once — avoids security holes from random projects. For Neovim users, hooking into root detection via lspconfig or using a tiny Lua script to read '.editorconfig' values works great. Ultimately, use setlocal so buffers don't leak settings, and prefer EditorConfig for collaboration.