Launch an isolated, disposable Neovim instance owned by this server and attach to it as a UI client. Returns a session id for the other tools. Use nvim_close when finished.

Attach as an additional UI to an already-running Neovim instance. The instance belongs to the user: nvim_close will refuse to terminate it. Note that Neovim sizes the screen to the smallest attached UI, so the requested size can shrink what the user sees.

Return the rendered Neovim screen as plain text rows, plus cursor, mode, size, current buffer/window and floating-window geometry. The screen is the source of truth; the metadata explains it. Rows are plain text with no cursor markers or line numbers, so substring matching is reliable. Resets the nvim_observe_diff baseline.

Return only what changed since the last observation: changed screen rows with their before/after text, plus cursor, mode and size deltas. Much smaller than a full nvim_observe for verifying a single action. Resets the baseline.

Send a key sequence to Neovim. Returns as soon as the keys are queued, not when the screen has updated: follow with nvim_wait before observing, otherwise the observation races the redraw.

Execute an Ex command. A command that Neovim rejects comes back as an error result with Neovim's own message. Like nvim_input, this does not wait for the screen to settle.

Block until a screen condition holds, so an observation is not raced against the redraw it is meant to see. On timeout the error includes the screen as it was, so a failed wait is diagnosable.

Terminate a Neovim instance this server launched and release its session. Refuses attach-mode sessions: that instance belongs to the user, and attach sessions are released when the server shuts down.