Ability to pass headers to MCP servers

[ala85]

@danny-avila Can we give opportunity to pass certain headers, like Authorization tokens or others from Librechat MCP Client to the MCP servers?

Main reason is to add an extra layer of authorization to the MCP servers so that they dont rely on API keys only and on hardcoded long-lived credentials in env files.

Or maybe is already possible? Thanks

[danny-avila]

It’s already possible but needs to be documented will work on that soon.

[danny-avila]

Here is the relevant PR before I update the docs: #6610

[danny-avila]

https://www.librechat.ai/docs/configuration/librechat_yaml/object_structure/mcp_servers#headers

[sbruel]

We have an issue with the headers not being passed in the initial call to the MCP server.

This seems to be due to this code in modelcontextprotocol/typescript-sdk

The common headers do not include the headers from requestInit like they do in send

There are a few solutions:

• fix modelcontextprotocol/typescript-sdk to use headers from requestInit in _startOrAuth
• pass an eventSourceInit function to the initialization, like this test does
• pass an authProvider which should work in both cases

[ala85]

@sbruel maybe you can create PR in mcp repo as this seems more something that package should handle, rather than librechat to “patch it”.

[sbruel]

Sure, I'll try to fix it in mcp repo and get back to you if this is rejected.

[danny-avila]

Seems to be reported on the SDK repo already, I wouldn't mind using the workaround for now:

modelcontextprotocol/typescript-sdk#436

[danny-avila]

Implementing in #7246

[ala85]

@danny-avila I see that headers can now be dynamic, but from where should we explicitly pass them from the framework? In my case we want to pass the Bearer token of the current user to the tool, does that require modifications or should be picked up by your changes?

In meanwhile created feature support: #7240