What probably matters to youSection of the release
What
On your first message, Claude Code waits for MCP servers (add-on tool providers) to start. Fetching the configuration for those servers now gets the full connect timeout, MCP_CONNECT_TIMEOUT_MS, which defaults to 5000 ms. Before, it had a fixed 1000 ms. If the fetch fails outright, Claude Code logs it and carries on without waiting.
Why
Slower configuration sources get more time to respond, and you can adjust that time with MCP_CONNECT_TIMEOUT_MS. A failed fetch no longer holds up your first turn.
One source agreesOne thing we can check says the same as this entry.
Anthropic's release notes agreeFixed MCP_CONNECTION_NONBLOCKING=0 giving up on claude.ai connectors after 1s instead of honoring MCP_CONNECT_TIMEOUT_MS
