Group of 2 Under the hood
Claude Code's own bundled skills and commands are now flagged so name clashes with user or plugin ones resolve predictably
What
- The
reload_skillsresponse the CLI sends now includes abuiltin: truefield on each skill entry whose resolved name matches one of Claude Code's own bundled skills. - The schema describing an available skill or command gained an optional
builtinboolean, true only for Claude Code's own built-in commands, used to decide which command a bare/nameinvocation runs when a user, project, plugin, and MCP command all share the same name.
Why
This removes ambiguity when a skill or command name collides with one of Claude Code's own: it's now possible to tell that a /name invocation is running the built-in version rather than a same-named user, project, plugin, or MCP one.
Names in the bundlebuiltin
The entry above is what we published on the day. These lines were added later, as Anthropic's own pages caught up, and they sit beside the original rather than replacing it.
Confirmed since
Anthropic's documentation has since written up builtin, on Telemetry and egress.
| Web Fetch domain check in [Code](/docs/third-party/claude-desktop/code) sessions | The hostname of each page Claude Code fetches, sent to `api.anthropic.com` before the fetch. See [Web Fetch](/docs/third-party/claude-desktop/web-tools#we…third-party/claude-desktop/telemetry see the edit
One source agreesOne thing we can check says the same as this entry.
Anthropic's documentation agrees
Anthropic's documentation has since written up builtin, on Telemetry and egress.