Part of macOS
TextInputMenuAgentKeyboard and typing
○ Leave it
Handles keyboard layouts, spelling and input menus.
What it is
Supports typing: layouts, spell check, and input methods.
If you stop it
macOS starts it again straight away. Leave it.
The verdict
○ Leave it. Part of macOS, or something that starts again by itself. You never need to close these.
In Activity Monitor
TextInputMenuAgentTextInputSwitcherimklaunchagentkeyboardservicesdAppleSpell
From Procession’s guide, in the words the app shows.