Claude Code 2.1.x changed the flag's signature to require an allowlist
of tagged entries — `server:<name>` for manually-configured MCP
servers, `plugin:<name>@<marketplace>` for plugin channels. The
previous bare-switch form was rejected with `argument missing`, and
an untagged value returns `entries must be tagged`.
Doc updates:
- Replace bare-flag references with tagged form throughout (env-var
table, push-path narrative, capability matrix)
- Add a worked example showing `claude --dangerously-load-development-
channels server:molecule` and the `Listening for channel messages
from: server:molecule` confirmation header so operators have a
visible signal that push is live
- Note the multi-server form (space-separated tagged entries)
- Three new troubleshooting entries:
* `argument missing` → forgot the value
* `entries must be tagged` → forgot the tag
* `Control request timeout: initialize` → embedded the flag in an
SDK options bundle as `{flag: None}` instead of `{flag:
"server:molecule"}` — covers the workspace-side regression we
caught live on dd40faf8 on 2026-05-01
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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