Quickstart: Adapt an existing MCP server for Blaxel

Step-by-step guide to convert an existing stdio-based MCP server to streamable HTTP transport so you can deploy and host it on Blaxel.

MCP (Model Context Protocol) servers provide tools (individual capabilities for accessing specific APIs or databases) that can be used by AI agents. These servers can be hosted on Blaxel’s computing platform and used by AI agents via each server’s global endpoint.

This quickstart walks you through the process of adapting an existing stdio-based MCP server for deployment on Blaxel using the streamable HTTP transport.

Install the Blaxel CLI

Follow the steps below for your platform.

Install on Mac

To install Blaxel CLI with Homebrew, make sure Homebrew is installed on your machine. Homebrew 6.0.0+ requires explicit trust for non-official taps, so use the fully qualified formula name below. We are currently in the process of supporting additional installers. Check out the cURL method down below for general installation.

Install Blaxel CLI by running the following command in a terminal:

brew install blaxel-ai/blaxel/blaxel

Install on Linux

Install Blaxel CLI by running the following command in a terminal (non-sudo alternatives below):

curl -fsSL \\
<https://raw.githubusercontent.com/blaxel-ai/toolkit/main/install.sh> \\
| BINDIR=/usr/local/bin sudo -E sh

If you need a non-sudo alternative (it will ask you questions to configure):

curl -fsSL \\
<https://raw.githubusercontent.com/blaxel-ai/toolkit/main/install.sh> \\
| sh

If you need to install a specific version (e.g. v0.1.21):

curl -fsSL \\
<https://raw.githubusercontent.com/blaxel-ai/toolkit/main/install.sh> \\
| VERSION=v0.1.21 sh

Install with cURL

Install Blaxel CLI by running the following command in a terminal (non-sudo alternatives below):

curl -fsSL \\
<https://raw.githubusercontent.com/blaxel-ai/toolkit/main/install.sh> \\
| BINDIR=/usr/local/bin sudo -E sh

If you need a non-sudo alternative (it will ask you questions to configure):

curl -fsSL \\
<https://raw.githubusercontent.com/blaxel-ai/toolkit/main/install.sh> \\
| sh

If you need to install a specific version (e.g. v0.1.21):

curl -fsSL \\
<https://raw.githubusercontent.com/blaxel-ai/toolkit/main/install.sh> \\
| VERSION=v0.1.21 sh

Install on Windows

Run the following command in PowerShell:

powershell -Command "irm https://raw.githubusercontent.com/blaxel-ai/toolkit/main/install.ps1 | iex"

Alternatively, you can use Windows Subsystem for Linux (WSL) and follow the Linux installation instructions.

Once installed, open a terminal and log in to the Blaxel Console using this command:

bl login

Get the example project

This quickstart adapts the simple stdio-based MCP weather server from the official Model Context Protocol GitHub repository.

TypeScript

Clone the repository and change to the project working directory:

git clone <https://github.com/modelcontextprotocol/quickstart-resources.git>
cd quickstart-resources/weather-server-typescript

Python

Clone the repository and change to the project working directory:

git clone <https://github.com/modelcontextprotocol/quickstart-resources.git>
cd quickstart-resources/weather-server-python

Adapt the server

If your MCP server is already configured to use streamable HTTP, you may skip this step.

Blaxel uses streamable HTTP as the transport layer for MCP servers deployed on its infrastructure. If your MCP server uses stdio (as in this example), you must adapt it to use streamable HTTP instead. The host name and port for the server to bind to are automatically injected by Blaxel during deployment, as HOST and PORT environment variables.

TypeScript

The changes shown below are illustrative only and based on the Blaxel MCP server template for TypeScript.

Add Express to handle HTTP requests and responses:

npm install express
npm install --save-dev @types/express

Here is an example of how you could adapt the existing src/server.ts file for a streamable HTTP server.

import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { StreamableHTTPServerTransport } from '@modelcontextprotocol/sdk/server/streamableHttp.js';
import { z } from "zod";
import express from 'express';

// ... code ...

const app = express();
app.use(express.json());

app.post('/mcp', async (req, res) => {
  const transport = new StreamableHTTPServerTransport({
    sessionIdGenerator: undefined,
    enableJsonResponse: true,
  });

  res.on('close', () => {
    transport.close();
  });

  await server.connect(transport);
  await transport.handleRequest(req, res, req.body);
});

const port = parseInt(process.env.PORT || '8000');
const host = process.env.HOST || '::';

app.listen(port, host, () => {
  console.log(`MCP Server running on <http://$>{host}:${port}/mcp`);
}).on('error', error => {
  console.error('Server error:', error);
  process.exit(1);
});

Python

The changes shown below are illustrative only and based on the Blaxel MCP server template for Python.

Here is an example of how you could adapt the existing weather.py file for a streamable HTTP server.

from typing import Any
import httpx, os
from mcp.server.fastmcp import FastMCP

# Initialize FastMCP server
mcp = FastMCP(
    "weather",
    stateless_http=True,
    host=os.getenv('HOST', "::"),
    port=os.getenv('PORT', "8000")
)

# ... code ...

def main():
    # Initialize and run the server
    mcp.run(transport='streamable-http')

if __name__ == "__main__":
    main()

Create the deployment configuration

Blaxel looks for a blaxel.toml file to configure the deployment of the MCP server on Blaxel. This file is not mandatory; if the file is not found or a required option is not set, you will be prompted for the information during deployment.

Create a new blaxel.toml file with the following content:

type = "function"

[runtime]
transport = "http-stream"

Blaxel also automatically detects a Dockerfile at the root of the project and uses it to create and deploy a container image of your MCP server. This is a very useful feature that allows you to completely customize the deployment environment for your MCP server, including installing additional system dependencies and using specific versions of libraries or tools.

Create a new Dockerfile with the following content:

TypeScript

FROM node:20-alpine

WORKDIR /app

RUN apk update \\
    && apk add build-base curl ca-certificates

COPY . .

RUN npm install

RUN npm run build

EXPOSE 8000

CMD [ "node", "build/index.js" ]

Python

FROM python:3.12-slim

RUN apt-get update && apt-get install -y --no-install-recommends \\
    build-essential curl ca-certificates \\
  && rm -rf /var/lib/apt/lists/*

RUN curl -LsSf <https://astral.sh/uv/install.sh> | sh \\
  && mv /root/.local/bin/uv /usr/local/bin/uv

WORKDIR /app

COPY . .

RUN uv sync --frozen --no-dev

EXPOSE 8000

CMD ["uv", "run", "weather.py"]

Deploy the MCP server on Blaxel

Deploy the server on Blaxel by running the following command:

bl deploy

Blaxel will handle the build and deployment, producing an HTTPS endpoint on Global Agentics Network. The server endpoint looks like this:

<https://run.blaxel.ai/{YOUR-WORKSPACE}/functions/{YOUR-SERVER-NAME}/mcp>

You can now connect to this endpoint from any MCP-aware client.