mcp-stdio-to-streamable-http-adapter MCP Server
About
Proxy through a STDIO MCP Server to interact with Streamable HTTP MCP Servers
Details
- License
- MIT
Explore
- Relays STDIO MCP calls to a Streamable HTTP MCP server
- Supports optional bearer token authentication
- Allows multiple Streamable HTTP servers via repeated configuration
- Works with any STDIO-compatible MCP client
- Installs via npx or local build
Setting up with Highlight
This MCP is not yet compatible with Highlight’s one-click setup. However, you can still use it with Highlight by following these steps:
- Download and install Highlight from highlightai.com/download
- Navigate to the plugins tab and select "Add Custom Plugin"
-
Configure the plugin with the settings below
Plugin Name
mcp-stdio-to-streamable-http-adapter MCP ServerCommand (node, npx, python, etc.)Please refer to the README for specific instructions on how to obtain API keys or other required environment variables.
- Enable "Start Automatically" if you want the plugin to start when Highlight launches
From the repository
To add OpenAI to Claude Desktop, add the server config:
On MacOS: ~/Library/Application Support/Claude/claude_desktop_config.json
On Windows: %APPDATA%/Claude/claude_desktop_config.json
Claude Desktop / Cursor
Paste into your MCP client config file to install this server.
{
"mcpServers": {
"mcp-stdio-to-streamable-http-adapter mcp server": {
"my-saas-app-development": {
"command": "node",
"args": [
"/path/to/mcp-stdio-to-streamable-http-adapter/build/index.js"
],
"env": {
"URI": "http://localhost:3002/mcp",
"MCP_NAME": "local-custom-streamable-http-adapter"
}
},
"pyroprompts": {
"command": "node",
"args": [
"/path/to/mcp-stdio-to-streamable-http-adapter/build/index.js"
],
"env": {
"URI": "https://api.pyroprompts.com/mcp",
"MCP_NAME": "pyroprompts",
"BEARER_TOKEN": "abcdefg"
}
}
}
}
}McpServers
{
"my-saas-app-development": {
"command": "node",
"args": [
"/path/to/mcp-stdio-to-streamable-http-adapter/build/index.js"
],
"env": {
"URI": "http://localhost:3002/mcp",
"MCP_NAME": "local-custom-streamable-http-adapter"
}
},
"pyroprompts": {
"command": "node",
"args": [
"/path/to/mcp-stdio-to-streamable-http-adapter/build/index.js"
],
"env": {
"URI": "https://api.pyroprompts.com/mcp",
"MCP_NAME": "pyroprompts",
"BEARER_TOKEN": "abcdefg"
}
}
}Integrate any MCP Client that has STDIO MCP Server Support (most do) with the Streamable HTTP MCP Servers
If you have a Streamable HTTP MCP Server, forking this, hardcoding the URI and publishing will give you a repo that you can point to, add to directories and let people use via STDIO.
_Note_: This has similarities to the mcp-remote package
Why?
The MCP Spec to add a Streamable HTTP Transport landed end of March 2025 and as of the end of April, no clients have adopted support. The typescript-sdk has merged the code, but not released. The Python SDK is still in development to support it. The Inspector supports it, but that's it.
This leaves developers in an awkward position. Develop the MCP Server using STDIO or SSE (deprecated) so it works with clients or develop with Streamable HTTP transport, but nobody can use it.
I (ferrants) want to start integrating the Streamable HTTP MCP Servers beyond just the inspector, so I need a way to connect them to clients and LLMs right away!
This package aims to bridge the cap by being a STDIO MCP Server that relays to your Streamable HTTP MCP Server. This makes all MCP Clients support Streamable HTTP right away. And now developers can develop the Streamable HTTP MCP Servers and provide an installation method.
Installation
To add OpenAI to Claude Desktop, add the server config:
On MacOS: ~/Library/Application Support/Claude/claude_desktop_config.json
On Windows: %APPDATA%/Claude/claude_desktop_config.json
Env Vars
- URI: The URL of the Streamable HTTP MCP Server. This is required.
- MCP_NAME: The name of the MCP Server. This is optional. If you configure multiple, this is required so they do not have the same names.
- BEARER_TOKEN: The Bearer token for the Streamable HTTP MCP Server. This is optional. If specified, this will be sent along in the Authorization header.
Configuration
You can use it via npx in your Claude Desktop configuration like this:
{
"mcpServers": {
"my-saas-app-development": {
"command": "npx",
"args": [
"@pyroprompts/mcp-stdio-to-streamable-http-adapter"
],
"env": {
"URI": "http://localhost:3002/mcp",
"MCP_NAME": "local-custom-streamable-http-adapter"
}
}
}
}
Or, if you clone the repo, you can build and use in your Claude Desktop configuration like this:
{
"mcpServers": {
"my-saas-app-development": {
"command": "node",
"args": [
"/path/to/mcp-stdio-to-streamable-http-adapter/build/index.js"
],
"env": {
"URI": "http://localhost:3002/mcp",
"MCP_NAME": "local-custom-streamable-http-adapter"
}
}
}
}
You can add multiple providers by referencing the same MCP server multiple times, but with different env arguments:
{
"mcpServers": {
"my-saas-app-development": {
"command": "node",
"args": [
"/path/to/mcp-stdio-to-streamable-http-adapter/build/index.js"
],
"env": {
"URI": "http://localhost:3002/mcp",
"MCP_NAME": "local-custom-streamable-http-adapter"
}
},
"pyroprompts": {
"command": "node",
"args": [
"/path/to/mcp-stdio-to-streamable-http-adapter/build/index.js"
],
"env": {
"URI": "https://api.pyroprompts.com/mcp",
"MCP_NAME": "pyroprompts",
"BEARER_TOKEN": "abcdefg"
}
}
}
}
With these three, you'll see a tool for each in the Claude Desktop Home:
And then you can chat with other LLMs and it shows in chat like this:
Or, configure in LibreChat like:
my-saas-app-development:
type: stdio
command: npx
args:
- -y
- @pyroprompts/mcp-stdio-to-streamable-http-adapter
env:
URI: "http://localhost:3002/mcp",
MCP_NAME: "my-custom-saas-app"
PATH: '/usr/local/bin:/usr/bin:/bin'
And it shows in LibreChat:
Development
Install dependencies:
npm install
Build the server:
npm run build
For development with auto-rebuild:
npm run watch
Debugging
Since MCP servers communicate over stdio, debugging can be challenging. We recommend using the MCP Inspector, which is available as a package script:
npm run inspector
The Inspector will provide a URL to access debugging tools in your browser.
Acknowledgements
- Obviously the modelcontextprotocol and Anthropic teams for the MCP Specification and integration into Claude Desktop. https://modelcontextprotocol.io/introduction
- PyroPrompts for sponsoring this project. Use code
MCPSTREAMABLEADAPTER` for 20 free automation credits on Pyroprompts.Sign in to leave a review
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