aider is an interactive ai pair programmer: one terminal, one model, one conversation, you stay in the loop. bernstein is the layer above: it spawns multiple cli agents (including aider via the aider adapter) in parallel git worktrees and merges what passes. if you want a fast solo loop with one model, use aider directly. if you want five tasks running at once, each in isolation, with lint/type/test gates and an audit chain on top, use bernstein and let it dispatch aider as one of the workers. they compose. full matrix at https://bernstein.run/vs/aider.
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