A persona is a named block of instructions you can hand to an agent instead of retyping the same brief every time. Give it a name and the instructions you want the agent to follow, and it's available the next time you start or configure an agent.
Knot ships with a set of built-in personas. You can also create your own. Either kind can be enabled or disabled; a disabled persona stays in your list but isn't offered when launching an agent. Deleting a built-in persona hides it rather than removing it outright, so it won't come back the next time Knot starts.
Personas are managed from the Personas pane in Settings, where you can add a new persona, edit an existing one's name and instructions, enable or disable it, or delete it.
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