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6363If Claude starts a [background Bash task](/docs/en/tools-reference#bash-tool-behavior) during a `claude -p` run, for example a dev server or a watch build, that shell is terminated about five seconds after Claude has returned its final result and stdin has closed. The grace period lets a task that finishes right after the result still deliver its output. Before v2.1.163, a never-exiting background process would hold the `claude -p` invocation open indefinitely.
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65Background [subagents](/docs/en/sub-agents) and workflows are exempt from the five-second grace because their result is part of the final output, so `claude -p` waits for them to complete. From v2.1.182, that wait is capped at ten minutes by default so a stuck background agent cannot hold the process open indefinitely. Adjust the cap with [`CLAUDE_CODE_PRINT_BG_WAIT_CEILING_MS`](/docs/en/env-vars), or set it to `0` to wait without a limit.
65Background [subagents](/docs/en/sub-agents) and workflows are exempt from the five-second grace because their result is part of the final output, so `claude -p` waits for them to complete. From v2.1.182, that wait is capped at ten minutes of continuous idle waiting by default, so a stuck background agent can't hold the process open indefinitely. Adjust the cap with [`CLAUDE_CODE_PRINT_BG_WAIT_CEILING_MS`](/docs/en/env-vars), or set it to `0` to wait without a limit.
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6767### Stop a run with SIGTERM
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