Dynamic JWT header injection in MultiServerMCPClient

[edwinchana]

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Example Code

const client = new MultiServerMCPClient({
  // Global tool configuration options
  // Whether to throw on errors if a tool fails to load (optional, default: true)
  throwOnLoadError: true,
  // Whether to prefix tool names with the server name (optional, default: true)
  prefixToolNameWithServerName: true,
  // Optional additional prefix for tool names (optional, default: "mcp")
  additionalToolNamePrefix: "mcp",
  
  // Use standardized content block format in tool outputs
  useStandardContentBlocks: true,

  // Server configuration
  mcpServers: {
    // Sreamable HTTP transport example, with auth headers and automatic SSE fallback disabled (defaults to enabled)
    weather: {
      url: "https://example.com/weather/mcp",
      headers: {
        Authorization: "Bearer token123",
      },
      automaticSSEFallback: false,
    },
  },
});

Description

Refs: langchain-ai/langchain-mcp-adapters#194

There appears to be a mismatch between documentation/discussion content and the actual JavaScript implementation of @langchain/mcp-adapters. A discussion snippet mentions using httpx_client_factory for dynamic JWT header injection, but this functionality doesn't exist in the current JavaScript implementation.

Current Behavior

The shows that MultiServerMCPClient doesn't support an httpx_client_factory parameter.

The current authentication methods available are:

1. Static headers configuration
2. OAuth providers

System Info

The latest version of the langgraph.js