What
When an MCP server session expires, Claude Code now automatically reconnects and retries the failed tool call.
Details
- Detects session expiration via 404 status with error code -32001 or connection close
- Clears connection cache and triggers re-initialization
- Automatically retries the tool call that failed due to session expiration
- New
McpSessionExpiredErrorerror type for proper error handling
Evidence
MCP session recovery (search for "MCP session expired during tool call" and "Retrying tool")
Strings lifted out of the shipped bundle, so the claim above can be checked against them.