—embed

Use stdin/stdout as a msgpack-RPC channel, so applications can embed and control Nvim via the RPC API. If the channel is closed (except by :detach), Nvim exits. Waits for the client (“embedder”) to call nvim_ui_attach() before sourcing startup files and reading buffers, so that UIs can deterministically handle (display) early messages, dialogs, etc. The client can do other requests before nvim_ui_attach (e.g. nvim_get_api_info for feature-detection). During this pre-startup phase the user config is of course not available (similar to —cmd). Non-UI embedders must pass —headless, then startup will continue without waiting for nvim_ui_attach:

nvim --embed --headless

which is equivalent to:

vim --headless --cmd "call stdioopen({'rpc': v:true})"

UI embedders that want the UI protocol on a socket (instead of stdio) must pass —listen as well as —embed:

nvim --embed --listen addr