Sidekick.nvim is nice, you get a "real" terminal window on the side with many different agents to choose from.
Either opencode, claude, gemini, copilot, basically most that are relevant :D
Its a pretty light connection-layer, so it helps with sending context.
FWIW, it's also made by Folke, the same developer who made lazy.nvim and snacks.nvim, as well as some other high-quality plugins.