Unclear It is not clear where, if anywhere, this status code is shown to the user.
What
MCP servers are outside programs that give Claude Code extra tools. Some networks reach them through a proxy, a middleman server that passes traffic on. When an MCP connection fails because the proxy refused to open a tunnel (error ERR_PROXY_TUNNEL), the failure record now includes proxyConnectStatus. This is the numeric HTTP status code the proxy sent back. Before, the record held only the name, type, config, error and error code.
- If
proxyConnectStatusis 403, meaning the proxy forbids the connection, Claude Code no longer treats the failure as worth retrying automatically. - Connection success and failure records now include
processUptimeAtConnectStartMs, how long Claude Code had been running when the connection attempt began. - A new diagnostic record is written after the first list of tools comes back from a server.
- The connection-timeout retry switch
tengu_mcp_connect_timeout_retryis still checked, and its fallback is still true. Nothing has been read about it or abouttengu_mcp_first_tools_list.
Why
When a proxy blocks an MCP server, the reason is now kept with the failure, which makes it easier to see what went wrong. Claude Code also stops retrying a connection the proxy has already forbidden. The new timing data concerns slow MCP startup.
It is not clear where, if anywhere, this status code is shown to the user.