[DOCS] CLI reference missing `--channels` flag for MCP server push messages

Documentation Type

Missing documentation (feature not documented)

Documentation Location

https://code.claude.com/docs/en/cli-reference

Section/Topic

CLI flags table and MCP server configuration

Current Documentation

No documentation currently exists for the --channels flag. It does not appear in the CLI reference flags table, the MCP documentation, or the headless mode documentation.

What's Wrong or Missing?

Changelog v2.1.80 added --channels as a research preview feature that allows MCP servers to push messages into a Claude Code session. This flag is not documented anywhere:

• The CLI reference does not list --channels in its flags table
• The MCP documentation does not describe server-to-session push messaging
• No documentation explains the concept, usage, or limitations of channels

Users have no way to discover this feature, understand how MCP servers can push messages into sessions, or learn how to use it.

Suggested Improvement

Add --channels to the CLI reference flags table:

| Flag | Description |
|------|-------------|
| --channels | (Research preview) Allow MCP servers to push messages into your session |

Add a section to the MCP documentation explaining the channels feature:

• What channels are and how MCP servers use them to push messages
• How to enable channels with the --channels flag
• Research preview status and any known limitations

Note: Since this is labeled "research preview," the documentation should clearly indicate the feature's experimental status and that behavior may change.

Impact

High - Prevents users from using a feature

Additional Context

Affected Pages:

| Page | Context |
|------|---------|
| https://code.claude.com/docs/en/cli-reference | CLI flags table |
| https://code.claude.com/docs/en/mcp | MCP server configuration and capabilities |

Total scope: 2 pages affected

Source: Changelog v2.1.80

Added --channels (research preview) — allow MCP servers to push messages into your session