Configure and pass dynamic headers in mcp configuration

[kaustubh-lgtm]

Is it possible to pass header value dynamically to mcp server? So basically I need to pass bearer token for user to mcp server as each user might have different one

From what I see in documentation, mcp server configuration is loaded once and there seems to be no way to modify header information when invoking it

There is way to populate header through environment variable but its loaded only at startup and it can't be modified per request basis

mcp:
  servers:
    streambale_http__server:
      transport: "http"
      url: "http://localhost:8000/mcp"
      read_transport_sse_timeout_seconds: 300  # Timeout for HTTP connections
      headers: 
        Authorization: "Bearer ${MY_TOKEN}"

Is there any other way to do this? or support needs to be added for this?

[evalstate]

The MCP SDK takes the headers when you connect to the Server, so we either need to:

1. Create a per-user connection
2. Modify the SDK to manipulate headers.

Option 1 is the most sensible; if you need to do this programmatically, the best way to go is to use the AgentConfig class directly and dynamically create the servers. There's some code in server_helpers.py that does this sort of thing for the go command.

The other alternative is that 0.3.0 will break out the tool calling loop to make it easier to manage your own tool calls if you want. That should be ready fairly soon.

[jdecker76]

#340

This was just merged in. I'm using this feature in lieu of per request headers

[kaustubh-lgtm]

@evalstate @jdecker76 can you have a look at #361

i was unable to use mcp_metadata with anthropic