Claude Code MCP server connected twice: duplicate connector fix

Claude Code used to connect the same MCP server twice when a plugin or a claude.ai connector wrote its URL differently from a server you had configured. Version 2.1.281 fixed that for differences in host letter case, default port and trailing slash. For Sume there is one URL to use everywhere, https://mcp.sume.com/mcp, so the simplest way to never see a duplicate is to write it the same way in every place.

What did Claude Code 2.1.281 fix?

The changelog entry says the same MCP server was being connected twice when a plugin or claude.ai connector and a configured server spell its URL differently, and lists three kinds of difference. If you are on an older version, update first; the duplicate then collapses without any config change.

Which Sume URL should every config use?

Sume's MCP overview gives one production endpoint, https://mcp.sume.com/mcp, and says to use that URL in Cursor, Claude Code, Codex and other remote MCP clients. The OAuth page names the same string as the resource audience. Copy it exactly from the MCP quickstart into your user config, a project file and any plugin, rather than retyping it.

How does a duplicate happen in practice?

The changelog names two paths: a plugin, and a claude.ai connector. Each brings its own URL string, and a server you added by hand with claude mcp add brings a third. Sume's quickstart uses the hand-added form, claude mcp add --transport http sume https://mcp.sume.com/mcp, followed by claude mcp login sume. Adding the same server again through a plugin is where two entries used to appear.

Does a second connection change how I sign in?

The hosted endpoint accepts either OAuth access tokens or API keys, and the docs say they are not interchangeable credentials. Two entries pointing at the same server are two things to keep signed in, which is one more reason to keep a single entry. Paid tools need an idempotency_key on every write, which the docs describe as a key for transport and dedup.

How do I audit for duplicates?

Look at the list of configured servers in Claude Code and compare the URLs character by character. On a build before 2.1.281, two entries whose only difference is host capitalization, an explicit default port or a trailing slash are the same server connected twice. Remove the extra entry, keeping the one you can manage centrally, then confirm with tools_list that one Sume tool list comes back.

If two entries point at genuinely different Sume environments, they are not duplicates. The overview page says the development host is for Sume development environments and that customer configs should use mcp.sume.com, so a customer setup should have exactly one Sume URL.