--debug
A Claude Code CLI flag, read out of the shipped bundle. It has been in the build since v2.1.138, including the newest one read.
What it is
Enable debug mode with optional category filtering, such as --debug='mcp,startup' or --debug='!1p'. The filter binds only in the = form; a space-separated filter enables debug mode without filtering
Anthropic's own wording. Read off CLI reference, captured 2026-08-28.
Presence across releases
| Releases | Reading | Declared type | Default |
|---|---|---|---|
| 2.1.245 – 2.1.250 5 releases | never mined | — | — |
| 2.1.138 – 2.1.243 95 releases | in the build | — | — |
A row reading never mined is a release with no archived bundle behind it. Nothing was read out of it, so nothing here says whether the name was in it. A declared type or a default is only ever what that release's own bundle stated.
Changelog entries naming it
-
v2.1.247Renaming a session warns when other sessions may keep the old name
Renaming a session now warns you when the new name didn't reach other running sessions, pointing at --debug.
named in this entry
-
v2.1.232Gateway settings failures now say what actually went wrong
Gateway settings failures now name the exact cause, from TLS mismatch to a rejected credential.
named in this entry
Documentation pages
- CLI reference reference table Claude Code CLI
- errors mentions it Claude Developer Platform
- using mentions it Claude Developer Platform
- workspaces mentions it Claude Developer Platform
- Authentication mentions it Claude Code CLI
- Claude Code changelog mentions it Claude Code CLI
- Claude apps gateway deployment and operations mentions it Claude Code CLI
- Explore the .claude directory mentions it Claude Code CLI
- Commands mentions it Claude Code CLI
- Manage costs effectively mentions it Claude Code CLI
- Message your other Claude Code sessions mentions it Claude Code CLI
- Debug your configuration mentions it Claude Code CLI
- Environment variables mentions it Claude Code CLI
A reference table page is one whose own table defines this name, and it is where the description above came from. A page that mentions it carries the name somewhere in its text and may say nothing about it at all. Every page carrying it.
Read out of the published npm bundle release by release, and out of Anthropic's own documentation as this site captured it. Nothing on this page is a description anybody here wrote about what the CLI flag does. All CLI flags.