Claude runs parallel tasks in nested sessions that report back to the main thread

Anthropic says that when a user asks Claude to run tasks in parallel, Claude starts a separate nested session for each task.

Each nested session reports its result back to the main session when it finishes, which Anthropic says keeps the main thread readable. The report, posted by the @ClaudeDevs account on X, does not describe limits on the number of parallel sessions or how they are priced.