[DOCS] `/branch` session docs omit the branched session ID usable with `/resume`

Documentation Type

Incorrect/outdated documentation

Documentation Location

https://code.claude.com/docs/en/sessions

Section/Topic

Branch a session

Current Documentation

The sessions guide currently says:

The original session is unchanged and remains available in the session picker. The /branch confirmation prints the original session's ID; to return to it, use that ID, the session picker, or /resume <original-name>. Permissions you approved with "allow for this session" do not carry over to the new branch. If you resume the same session in two terminals without forking, messages from both interleave into one transcript.

Related session guidance also says:

Resuming a session with claude --continue or claude --resume reopens it under the same session ID and appends new messages to the existing conversation. Forking with --fork-session or /branch copies the history into a new session ID, leaving the original unchanged.

What's Wrong or Missing?

For the v2.1.129 /branch fix about the success message including the new branch's session ID for /resume, the current docs still only describe the original session's ID.

That leaves the /branch docs incomplete in two ways:

A. The new branched session ID is not documented in the /branch workflow

The page explains how to get back to the original session, but not that the branched conversation has its own new session ID that can be used later with /resume.

B. The /branch confirmation behavior is described from the old perspective

The current wording says the confirmation prints the original session's ID, which does not explain the newer success-message behavior added for the branched session's /resume path.

Suggested Improvement

Update the Branch a session section to explicitly document the new branch session ID and how it relates to /resume.

For example, after the /branch example, add guidance like:

/branch creates a new session ID for the forked conversation. The success message includes that new session ID so you can later reopen the branched conversation with /resume or claude --resume <session-id>. The original session remains unchanged and can still be reopened separately.

If the success message now shows both the original and new session identifiers, call out which one resumes the original thread versus the branched thread.

Impact

Medium - Makes feature difficult to understand

Additional Context

Affected Pages:

| Page | Line(s) | Context |
|------|---------|---------|
| https://code.claude.com/docs/en/sessions | 80-96 | /branch section says the confirmation prints the original session's ID |
| https://code.claude.com/docs/en/how-claude-code-works | 109-111 | Session overview says /branch creates a new session ID, but does not connect that new ID to /resume |

Total scope: 2 pages affected

This gap appears when cross-referencing the current session docs with the v2.1.129 changelog entry about /branch success messaging for /resume.