New CLI flag --resume-session-at=<message-uuid> for resuming a session starting at a specific point in the transcript.
Details
- Must be combined with
--resume; without it Claude Code exits immediately withError: --resume-session-at requires --resume. - The value is the
uuidfield of a specific message in the saved transcript — not a timestamp, ordinal index, or boundary marker. - When the UUID is found, the loaded transcript is sliced to include only messages up to and including that message (
messages.slice(0, index + 1)), so the resumed session behaves as if the conversation ended exactly at that point. - When the UUID is not found in the transcript, Claude Code exits with
No message found with message.uuid of: <value>and a non-zero exit code. - Available in the TypeScript SDK as the
resumeSessionAtoption on the session options object; the SDK translates it to--resume-session-at=<value>in the subprocess argument list. - The flag is hidden from
--helpoutput (.hideHelp()); the internal help string reads: "When resuming, only messages up to and including the assistant message with <message.id>".
Evidence
--resume-session-at <message id> CLI option definition and the c.messages.findIndex((d) => d.uuid === t.resumeSessionAt) slicing inside loadInitialMessages / dqf (search for "resume-session-at")
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
One source agreesOne thing we can check says the same as this entry.
Anthropic's release notes agree
Fixed ExitWorktree failing with "no active EnterWorktree session" after resuming a session with --continue/--resume in print/SDK mode