A personal VSCode extension: a copy button in the title bar of every Claude
Code tab that puts the session's name (or UUID) on the clipboard — no
need to ask the model with /whoami.
What it does
A $(copy) button appears in the editor title bar whenever a Claude Code
session tab is active.
Clicking it copies the session name (e.g. hermes-monorepo-dd), the
address SendMessage uses. The notification offers Copy UUID as a
second action.
Setting claudeSessionId.copyField flips the default to the UUID (what
claude --resume takes).
Command Palette: Copy Claude Code Session Name / … UUID.
How it finds the session
Claude Code keeps one record per live session in ~/.claude/sessions/<pid>.json.
The Claude Code extension exposes no API, so this extension reads those files,
keeps only sessions whose process is alive and whose parent is this window's
extension host, and sorts them by last activity.
Each session's tab title comes from its transcript
(~/.claude/projects/<cwd slug>/<sessionId>.jsonl): the last custom-title
record (manual rename) wins, else the last ai-title, else "Untitled".
Which session is the active tab? VSCode does not tell other extensions which
session a webview tab holds, so the extension compares the active tab's label
with the session titles:
one session in the window → copies it directly;
exactly one session whose title equals the active tab label → copies it
directly;
otherwise (duplicate or "Untitled" titles) → a Quick Pick lists the sessions
with title, name, UUID, status, last activity and cwd, and you choose.
Test (dev)
Open this folder in VSCode.
F5 → launches an "Extension Development Host" window with the extension active.
In that window, open a Claude Code tab and click the copy icon in its title bar.
Install
Build the package (needs Node; uses @vscode/vsce via npx):
./package.sh
This produces claude-session-id-<version>.vsix in the repo root.
