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2026-04-26 21:52:23 +03:00

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HTTP MCP Server Without Ping Support

This is a sample MCP server implementation that runs over HTTP but does not support the optional ping method. This demonstrates how to configure Bifrost to use the listTools health check method instead of ping.

What is This?

Many MCP servers may not implement the optional ping method from the MCP specification. This example shows:

How to build an MCP server that only supports the core methods (list_tools, call_tool) but not ping
How to configure Bifrost to work with such servers using is_ping_available: false
Why this matters: When is_ping_available is false, Bifrost will use listTools for health checks instead of the lightweight ping method

Running the Server

Prerequisites

go 1.26.1+

Start the Server

# From this directory
go run main.go

Output:

MCP server listening on http://localhost:3001/mcp
Note: This server does NOT support ping. Use is_ping_available=false in Bifrost config.

Connecting via Bifrost

Configuration (config.json)

{
  "mcp": {
    "client_configs": [
      {
        "name": "http_no_ping_server",
        "connection_type": "http",
        "connection_string": "http://localhost:3001/mcp",
        "is_ping_available": false,
        "tools_to_execute": ["*"]
      }
    ]
  }
}

Via API

curl -X POST http://localhost:8080/api/mcp/client \
  -H "Content-Type: application/json" \
  -d '{
    "name": "http_no_ping_server",
    "connection_type": "http",
    "connection_string": "http://localhost:3001/mcp",
    "is_ping_available": false,
    "tools_to_execute": ["*"]
  }'

Via Web UI

Navigate to MCP Gateway
Click New MCP Server
Fill in:
- Name: http_no_ping_server
- Connection Type: HTTP
- Connection URL: http://localhost:3001/mcp
- Ping Available for Health Check: Toggle OFF (disabled)
Click Create

Available Tools

This server provides three simple tools for testing:

1. echo

Echoes back the input message.

{
  "name": "echo",
  "arguments": {
    "message": "Hello, World!"
  }
}

2. add

Adds two numbers together.

{
  "name": "add",
  "arguments": {
    "a": 5,
    "b": 3
  }
}

3. greet

Greets someone by name.

{
  "name": "greet",
  "arguments": {
    "name": "Alice"
  }
}

Health Check Behavior

When you add this server to Bifrost with is_ping_available: false:

Bifrost will NOT send ping requests (since the server doesn't support them)
Instead, Bifrost will use listTools every 10 seconds to check server health
If listTools fails 5 consecutive times, the server will be marked as disconnected

Why listTools instead of ping?

ping is lighter and faster, but optional in MCP
listTools is heavier but guaranteed to exist on all MCP servers
Using listTools for health checks is a fallback for servers without ping support

Implementation Notes

This example intentionally:

✅ Supports all core MCP methods (list_tools, call_tool)
✅ Returns proper JSON-RPC responses
✅ Works over HTTP
❌ Does NOT implement the ping method
❌ Returns a JSON-RPC method-not-found error (-32601) when ping is attempted

How Ping is Blocked

The mcp-go library's NewStreamableHTTPServer automatically includes ping support by default. To demonstrate a server without ping, this example uses HTTP middleware that:

Intercepts all POST requests
Checks if the request is a ping method call
If it's a ping request, returns a JSON-RPC error: {"code": -32601, "message": "Method not found: ping is not supported by this server"}
For all other requests (list_tools, call_tool), passes them through normally

This allows us to:

✅ Keep the simple mcp-go server implementation
✅ Transparently block ping requests at the HTTP layer
✅ Return proper JSON-RPC error responses
✅ Demonstrate the is_ping_available=false behavior in Bifrost

Key Learning: is_ping_available

The is_ping_available setting is important because:

Setting	Health Check Method	When to Use
`true` (default)	Lightweight `ping`	When your server supports ping (recommended)
`false`	Heavier `listTools`	When your server doesn't support ping

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