VS Code 1.141: where to see a Sume MCP server in Customizations

In VS Code 1.141, run **Chat: Open Customizations** and select **MCP Servers** to see every server the editor knows about, including ones that did not come from your workspace mcp.json. If you added Sume's hosted MCP at https://mcp.sume.com/mcp, it appears there, and you confirm the connection by calling the read-only tools_list or mcp_health tool.

The release notes (VS Code 1.141, read 2026-10-10) mark this as a Preview feature. The note says servers supplied by plugins, extensions and built-in integrations now show next to your configured servers, so you no longer need **MCP: List Servers** to find them.

What changed in 1.141

Before this release, the quickest way to answer "which MCP servers are active in this window" was the **MCP: List Servers** command. A server that came from an extension or plugin could be active without any line in your own mcp.json, which made it hard to tell where a tool came from.

The Customizations editor now merges those sources. For a Sume user the practical effect is an audit view: you can see whether Sume's endpoint is configured once, by you, or also supplied by something else. Two entries pointing at one endpoint would double the tool list the model sees.

Confirm the Sume server is the one you set up

Sume's own quickstart uses one URL for every remote client: https://mcp.sume.com/mcp. Sume also lists a development endpoint, https://mcp.dev.sume.com/mcp, and says public configs must use mcp.sume.com. If the Customizations editor shows a second Sume-like entry, check that its URL is the production one.

Then ask the agent to call mcp_health. The tool answers with the endpoint readiness and authenticated.auth_source; for an OAuth session the docs say it should read mcp_oauth. After that, tools_list shows only the tools your session can see.

• OAuth with Read only: you see read-only tools; a write or paid call returns insufficient_scope.
• OAuth with Write on, or an API key: the full hosted tool set.
• Spend is a wallet and admission matter. There is no mcp:paid scope.
• Paid and write tools need an idempotency_key on every call.

What this does not tell you

The Customizations view shows that a server exists and where it came from. It does not prove the credential is right. A server can be listed and still fail its sign-in, and a key pasted with hidden whitespace fails differently from an expired OAuth grant. Test with account_me or balance_get, which are read-only and free.

It also does not say anything about cost. Sume's tools and gates page says dry_run=true previews admission and cost without submitting a job, and that max_spend_usd is enforced only when you pass it. Before the first paid generation from a new editor, run one dry_run call so you know the gate works the way you expect.

A short audit routine for a team

If several people share a repository, add Sume once in the workspace mcp.json and let everyone else rely on it. The new view then answers two review questions quickly: is the endpoint present exactly once, and did anyone add a second copy through a plugin? Duplicate registrations are the usual reason a tool list looks bloated.

Keep the routine short. Open the Customizations editor, read the MCP Servers section, note the Sume URL, and run tools_list once per session. If the list differs between teammates, the difference is almost always the auth mode: one person has an OAuth Read-only session and another has a key or a Write grant. Sume's docs say a write or paid call from a read-only OAuth session returns insufficient_scope, which is a sign-in problem, not an outage.