This MCP server provides an SSE-based transport for Hono applications to connect to an MCP Server. It enables Hono apps to expose and consume MCP capabilities by streaming messages over Server-Sent Events, allowing multiple concurrent sessions and a simple transport layer that integrates with the MCP SDK server-side APIs. To start using it, install the transport in your Hono project, then configure an MCP server instance and begin streaming messages through the /sse and /messages endpoints as demonstrated in the usage example. The transport is intended to work alongside the official MCP TypeScript SDK and the Hono framework, providing a compatible path for Hono users until official SDK support lands.

Prerequisites:

• Node.js (LTS recommended)
• pnpm (as shown in the README example; npm or yarn also work)

Installation steps:

1. Install the transport as a development dependency in your project: pnpm add -D hono-mcp-server-sse-transport

   or: npm install --save-dev hono-mcp-server-sse-transport

2. Ensure you have an MCP server setup (as per your environment) and that your Hono app can reach it.

3. If you are using the MCP server with a module-based setup, you may also need the MCP SDK packages described in the transport's examples.

4. Start your application and observe logs to confirm that the SSE transport is able to connect and handle messages.

Notes and tips:

• This transport is designed for Hono applications and uses SSE streaming to communicate with the MCP server. Ensure your Hono app and network allow SSE connections.
• The example uses a per-session SSETransport stored in a lookup object keyed by sessionId. Adapt session management to fit your application architecture.
• If you encounter issues with headers or binding when integrating with Hono, verify that HttpBinding headers are not modified after the response is sent, as discussed in the transport's motivation.
• Environment variables can be used to tune logging or environment-specific behavior (e.g., NODE_ENV, MCPC_LOG_LEVEL).
• The mcp_config in this README uses npx to install and run the transport package; you can switch to a local installation or a different runner if you prefer (e.g., npm run, or a containerized workflow).
• Ensure to replace placeholders like server name and version with values appropriate for your MCP server deployment.