Smithery's MCP proxy is now shut down, so run.tools and server.smithery.ai URLs have stopped working
As of Oct 31, Smithery's proxy, accounts, API keys, Connect, Toolbox, CLI and SDKs are gone, and smithery.ai stays only as a public directory now powered by Arcade.dev, with paid plans refunded back to Aug 5. Search your .mcp.json or .cursor/mcp.json for run.tools, server.smithery.ai and @smithery/cli and swap each for the vendor's official URL, like https://mcp.linear.app/mcp (migration list).