Cannot add Teamwork MCP server via UI

[claudiogrimo]

What happened?

I am trying to add the official Teamwork MCP server (https://mcp.ai.teamwork.com) via the LibreChat UI. I selected "Streamable HTTPS", chose "OAuth" authentication, and filled in all the valid OAuth credentials (Client ID, Secret, Authorization URL, Token URL, etc.).

When I click the "Create" (or "Update") button, LibreChat immediately attempts an unauthenticated background ping/connection to the MCP endpoint to validate it or fetch its capabilities. Because Teamwork strictly requires a valid token even for discovery, it instantly returns a 401 Unauthorized error.

LibreChat's UI catches this 401 error, interprets it as a broken server, throws a red "Error" banner, and completely blocks the saving process. Because the server is never saved to the database, I cannot reach the state where the yellow "OAuth Required" dot appears to actually start the authentication flow.

What did you expect to happen:
I expect the UI to save the OAuth configuration successfully without requiring the initial unauthenticated ping to succeed. It should save the configuration, display the yellow "OAuth Required" indicator (key icon), and allow me to click "Authenticate" to complete the OAuth flow.

Version Information

I am using the ghcr.io/danny-avila/librechat-dev-api:latest image via Docker (deployed on Coolify). The UI footer shows LibreChat v0.8.4.

Steps to Reproduce

• Open LibreChat and go to the right sidebar -> MCP Settings -> Click the + to add a new server.
• Set Name: Teamwork and MCP Server URL: https://mcp.ai.teamwork.com
• Select Transport: Streamable HTTPS.
• Select Authentication: OAuth.
• Fill in any valid dummy or real OAuth data (Client ID, Secret, Auth URL, Token URL).
• Click "Create".
• Observe the red "Error" banner at the top of the UI. The configuration is not saved, and the OAuth flow cannot be initiated.

What browsers are you seeing the problem on?

Chrome

Relevant log output

2026-04-01 23:56:37 info: [MCP][teamwork] Creating streamable-http transport: https://mcp.ai.teamwork.com/
2026-04-01 23:56:38 warn: [MCP][teamwork] OAuth authentication error detected
2026-04-01 23:56:38 error: [MCP][teamwork] Transport error (may require manual intervention): Streamable HTTP error: Error POSTing to endpoint: Unauthorized
2026-04-01 23:56:38 info: [MCP][teamwork] Reconnecting 1/3 (delay: 2536ms)
2026-04-01 23:56:38 error: [MCP][teamwork] Ping failed: Streamable HTTP error: Error POSTing to endpoint: Unauthorized
2026-04-01 23:56:38 error: [MCP][teamwork] Connection failed: Connection not established

Screenshots

Code of Conduct

• I agree to follow this project's Code of Conduct

[danny-avila]

According to Teamwork's docs, it requires a Bearer token, not OAuth:

• https://github.com/Teamwork/mcp/blob/main/docs/usage/README.md
• https://github.com/Teamwork/mcp/blob/main/docs/usage/other-platforms.md

LibreChat also supports OAuth auto-discovery, setting authentication to "None (Auto-detect)" is sufficient if the server advertises OAuth. With that setting and Streamable HTTPS, the server connects and lists capabilities without error:

For Teamwork specifically, you'd want to use "API Key" with Bearer format and "Each user provides their own key" checked, if I understand the intent correctly.

Your screenshots show input for an API key, which contradicts your description of selecting "OAuth", can you confirm exactly how you had it configured when first created? It should look like this:

[claudiogrimo]

Ciao @danny-avila, and thanks for your immediate feedback!! I dunno how this could be even possible: I tried for a couple of hours yestertday, and was not working. Still getting the same problem, trying to replicate your setting

MCP settings

API requested

Error given

It's so frustrating, and it has to be related to something I'm missing. For context: I deployed on Hetzner using Coolify image.

Moreover: I can't remove the "old" (from yesterday) MCP connector, even if it confirms the deletion (that's the reason why I opened this as an issue firstly).

Dunno where to look for a solution :((
Anyways, thanks again, so appreciated your effort :)

[claudiogrimo]

Ciao again @danny-avila, following up on my previous message where I was going crazy trying to replicate your setup on my Hetzner/Coolify instance... I finally have the definitive answer, and it's completely out of our control!

I reached out directly to Teamwork's API/Dev team, and they confirmed there is a strict hard-block on their end for self-hosted instances like mine. Here is the exact breakdown from their support Technical support needed_ Connecting Teamwork MCP Server to LibreChat:

Discovery is whitelisted: "We do support initial discovery without a token via OAuth 2.0 Dynamic Client Registration (DCR). However, for security reasons, we currently permit only specific vendors (and their approved redirect URLs) to use this flow. Because LibreChat is not on that list, the connection is instantly rejected." Technical support needed_ Connecting Teamwork MCP Server to LibreChat.

API Keys are blocked for self-hosted: "At this time, the MCP endpoint strictly supports 'Authorization: Bearer authentication' via the standard OAuth flow. We do not currently support Personal Access Tokens or API keys to bypass this for self-hosted instances." Technical support needed_ Connecting Teamwork MCP Server to LibreChat.

This perfectly explains why my standard Teamwork API key (twp_...) gets a 401 when I try your method in the screenshots. It also explains why configuring OAuth from the UI crashes: the initial discovery ping gets blocked before I can even authenticate.
I assume it worked for you because your testing environment/domain is somehow bypassing their self-hosted block, or perhaps you used a manually generated true OAuth token instead of a standard profile API key.

Teamwork support mentioned: "The good news is that our developers are actively investigating the LibreChat solution on our end to determine how we might support this connection in the future." Technical support needed_ Connecting Teamwork MCP Server to LibreChat (401 Unauthorized).pdf]

So, it seems self-hosted LibreChat users are hard-blocked by Teamwork's strict vendor-locking for now. Unless there's a workaround in LibreChat to completely bypass the discovery ping and force a manually generated OAuth token, I guess we just have to wait for Teamwork to whitelist LibreChat.

Thanks again for your time and effort looking into this!