MCP Server syntax keeps changing

Support Bug Reports
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1

Why do you guys keep changing the way MCP servers are called. For example. I use an app called tynn.ai to handle my project scope. I had a entry in the allow list for tynn:* and that was working perfectly for all projects. Now every project I have is asking permission to run the mcp tools and it’s using a funky syntax like project-0_app-tynn:next. This should just be tynn:next

What’s going on? I’m seeing this same issue with other mcp servers as well.

2 Likes
3

Hey, thanks for the report.

The team is working on fixing the auto-run allowlist system for MCP tools.

To help with debugging, can you share:

  • Your Cursor version (Help > About)
  • A screenshot of the permissions prompt window that shows the new syntax

As a temporary workaround, try updating the allowlist patterns using the new format with project prefixes.

4

Version: 2.3.34 (user setup)
VSCode Version: 1.105.1
Commit: 643ba67cd252e2888e296dd0cf34a0c5d7625b90
Date: 2026-01-10T21:17:10.428Z
Electron: 37.7.0
Chromium: 138.0.7204.251
Node.js: 22.20.0
V8: 13.8.258.32-electron.0
OS: Windows_NT x64 10.0.26100

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And here is it requesting to use a tool from a different mcp server.

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1 Like
5

Ok now a funny thing keeps happening. In a single chat using Opus4.5, the agent used the mcp tool calls like that showed in the OP. I switched to auto to have it create the individual work in tynn and it changed the format it uses. I clicked the Allowlist MCP Tool option AND I added this format with wildcard to the allow list but it is asking me for permission on every single attempt. I’m loading up a new version in my roadmap that will have over 14 stories and nearly 100 tasks. This is so annoying.

First calls using Opus4.5.

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Second request using Auto
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EDIT: After 15 or so tool run requests, it started following the allow list.

6

I’ve been investigating this issue and found that the server identifier format changes based on how you open the project:

Single folder workspace: project-{N}-{server_name}

Example: project-0-pw-git

Multi-root workspace (when you add directories to workspace): {folder_name}-{server_name}

Example: project-pw-git

So the project-0 prefix disappears when using multi-root workspaces, but the core problem remains — each project folder still gets its own unique identifier due to the folder name being included in multi-root mode.

7

this issue is hit and miss. Sometimes I open a project and it requests using the project-0 pattern. another day I will open the same single folder project and it is using the correct pattern without this project-0 nonsense. I have even had this happen within the same chat but when changing models.

8

I’m running into the same issue. I’m heavily using worktrees and the id is different for each one.

I would like to globally allow some MCP tools without having to re-allow them whenever I create a new worktree.

2 Likes