BUGFIX
MCP sign-in to Slack no longer stops at a mismatched URL
If you tried to connect Slack to Claude and were sent from sign-in straight back to an error, your account may not have been the problem. During MCP (Model Context Protocol, the protocol that connects AI to external tools) sign-in, the server compares the return URL. Some servers, including Slack, use a pre-registered OAuth client, and that comparison could fail. The redirect URI mismatch is now fixed. It was like a mail sorter rejecting a letter whose address was right but written in a format it did not expect; it can now send the letter to the proper entrance.