--bg stops when it cannot be told apart from prompt text, and --exec joins the special launch flags
claude --bg now exits with an error instead of starting anything when the flag might be prompt text, and --exec is handled alongside other launch flags
You'll noticeTier: how much it should matter to you
2Useful: my rating, 1 to 5
3Signal: worth watching, 1 to 5
SessionsArea: what it touches
ImprovementsKind: in v2.1.299,
ImprovementsSection of the release
What
claude --bg starts a background session, which is a Claude Code session that keeps working without you watching it. Combined with --exec, it runs a shell command as a background job instead. This release changes how both flags are handled:
--bg now refuses to start when Claude Code cannot tell the flag apart from your prompt text. It exits with status 1 and prints a message ending: "so nothing was started. To start a background session put it first: claude --bg ".
After a --exec job is handed off to run in the background, Claude Code now waits for one more follow-up step to finish.
--exec was added to an internal list of command-line flags. Before this release the list held only --resume-session-at, --resume-drops-turn and --project-config-root.
Why
Before, an ambiguous command line could quietly start, or fail to start, a background session you did not mean to run. Now you get a clear error and nothing runs. Put --bg first, directly before your prompt.
How sure we are
One source agreesOne thing we can check says the same as this entry.
Anthropic's release notes agreeFixed a prompt or reply of --bg or --background to a background session being taken for the flag, which could start new sessions over and…
