A new repl_mcp_needs_auth message kind exists internally but currently renders no content and nothing creates it
What
A new event/message kind called repl_mcp_needs_auth was added internally alongside existing kinds like max_turns_reached and poll_events. It appears in the enumerations/state-key lists used for these message kinds, and in the renderer map that turns message kinds into visible content, repl_mcp_needs_auth is wired to a handler that always returns an empty array, meaning it produces no visible content.
Why
Nothing in the current code actually constructs a message of this kind, so this has no visible effect yet. It looks like groundwork for a future feature (likely related to an MCP server, a way of connecting external tools, needing authentication) that has not been wired up to actually fire.
The finding does not say what the message kind will eventually be used to display.