Laravel MCP is using outdated MCP protocol version (0.0.x) → Cannot connect to modern MCP clients (Unsupported protocol version)

[bloodykheeng]

Laravel Package Version

"laravel/mcp": "^0.3.4",

Laravel Version

"laravel/framework": "^12.0",

PHP Version

PHP 8.4.5

Database Driver & Version

No response

Description

I'm trying to use Laravel MCP with the MCP SuperAssistant proxy:
https://mcpsuperassistant.ai/docs/getting-started/installation

When I connect my Laravel MCP server through the proxy using:

npx @srbhptl39/mcp-superassistant-proxy@latest --config ./config.json

I get the following error:

McpError: MCP error -32602: Unsupported protocol version

Steps To Reproduce

1. Install Laravel MCP
2. Create an MCP server (example: SmsNotificationServer)
3. Expose endpoint:
   http://localhost:8000/mcp/documents
   i had to use ngrok to get a url with https
   using this command

ngrok http 8000

4. Create config.json:

{
    "mcpServers": {
        "default-server": {
            "type": "streamable-http",
            "url": "https://hylomorphic-overfruitful-leigha.ngrok-free.dev/mcp/documents",
            "note": "For Streamable HTTP connections, add this URL directly in your MCP Client"
        }
    }
}

5. Run proxy:

npx @srbhptl39/mcp-superassistant-proxy@latest --config ./config.json

Actual Result

The proxy connects, but then fails with:

Failed to connect to server default-server: McpError: MCP error -32602: Unsupported protocol version

full error

PS D:\coding\bloodykheeng projects\laravel-ai\laravel with ollama\mcp super assistant> npx @srbhptl39/mcp-superassistant-proxy@latest --config ./config.json
[mcp-superassistant-proxy] Starting...
[mcp-superassistant-proxy] Starting mcp-superassistant-proxy ...
[mcp-superassistant-proxy]   - outputTransport: sse
[mcp-superassistant-proxy]   - config: ./config.json
[mcp-superassistant-proxy]   - Headers: (none)
[mcp-superassistant-proxy]   - host: localhost
[mcp-superassistant-proxy]   - port: 3006
[mcp-superassistant-proxy]   - ssePath: /sse
[mcp-superassistant-proxy]   - messagePath: /message
[mcp-superassistant-proxy]   - CORS: enabled ("*")
[mcp-superassistant-proxy]   - Health endpoints: (none)
[mcp-superassistant-proxy] Loaded config with 1 servers
[mcp-superassistant-proxy] Connecting to streamable HTTP server default-server: https://hylomorphic-overfruitful-leigha.ngrok-free.dev/mcp/documents
[mcp-superassistant-proxy] With headers: (none)
[mcp-superassistant-proxy] Failed to initialize server default-server: Error: Failed to connect to server default-server: McpError: MCP error -32602: Unsupported protocol version

Expected Result

The Laravel MCP server should return the stable MCP protocol version:

"protocolVersion": "0.1.0"

Root Cause

It appears the current Laravel MCP package is still responding using the older pre-release MCP protocol (0.0.x) during the handshake.

This makes Laravel MCP incompatible with MCP clients and proxies that expect the final MCP spec (0.1.0), released by OpenAI.

Request

Can the Laravel MCP package be updated to:

1. Return protocolVersion: "0.1.0" in the handshake

2. Match the current MCP request/response schema used by:

   • mcp-superassistant-proxy
   • OpenAI-compliant MCP clients
   • MCP browser extensions

3. Provide a way to override/extend the protocol adapter until native support is available

[pushpak1300]

Can you just try override protected string $version = '0.1.0'; in your MCP Server.php file and let me know if it's working correctly with it ?

[TonsiTT]

Can you just try override protected string $version = '0.1.0'; in your MCP Server.php file and let me know if it's working correctly with it ?

that didnt do anything for me but adding 2025-11-25 to supportedProtocolVersion did help. Probably gonna break later down the line if an mcp client uses latest methods but working fine for now in vscode.

[pushpak1300]

Based on this changelog nothing is breaking change so ideally should work.

https://modelcontextprotocol.io/specification/2025-11-25/changelog

[bloodykheeng]

@TonsiTT your right i tried it out and it worked on myside too
so what i did i went into laravel mcp vendor

vendor\laravel\mcp\src\Server.php

and i fount this file server.php
then i changed this

 protected array $supportedProtocolVersion = [
        '2025-06-18',
        '2025-03-26',
        '2024-11-05',
    ];

to this

 protected array $supportedProtocolVersion = [
        '2025-11-25',
        '2025-06-18',
        '2025-03-26',
        '2024-11-05',
    ];

bassically i added in this '2025-11-25',
and 🎉🎉🎉 hurray it worked i was able to use it well with MCP SuperAssistant

so i think that needs to be fixed so that we update our laravel too but why does it have to be manual are guys gona be adding new dates in that array always 🤔🤔🤔🤔

[TonsiTT]

It works on me for all clients Except Codex IDE extension for some reason. Works on Codex Cli but cant get it to work with the ide extension. Always errors out.

[brightantwiboasiako]

You can override the property in your Server class (not the one in vendor) and add the version there. Works fine for me.

<?php

use Laravel\Mcp\Server;

class YourMCPServer extends Server{

     protected array $supportedProtocolVersion = [
        '2025-11-25',
        '2025-06-18',
        '2025-03-26',
        '2024-11-05',
    ];

}

[pushpak1300]

so i think that needs to be fixed so that we update our laravel too but why does it have to be manual are guys gona be adding new dates in that array always 🤔🤔🤔🤔

As per the MCP specification, I believe that’s the only acceptable way. Any version not supported should be rejected and an error thrown.

[bloodykheeng]

@pushpak1300 i think the best way would be to add it in the config whereby incase of any changes or upates we can just edit the conf without needing to go in vendor

[bloodykheeng]

yah @brightantwiboasiako ur right overiding it directly in the mcp server itself works without going into vendor
it worked for me well after adding it here 🎉🎉🎉

<?php

namespace App\Mcp\Servers;

use App\Mcp\Tools\SendSmsNotificationTool;
use Laravel\Mcp\Server;

class SmsNotificationServer extends Server
{

    // this is a manual overide of supported version ive added this myself
    protected array $supportedProtocolVersion = [
        '2025-11-25',
        '2025-06-18',
        '2025-03-26',
        '2024-11-05',
    ];

    /**
     * The MCP server's name.
     */
    protected string $name = 'SMS Notification Server';

    /**
     * The MCP server's version.
     */
    protected string $version = '1.0.0';

    /**
     * The MCP server's instructions for the LLM.
     */
    protected string $instructions = <<<'MARKDOWN'
        This server sends SMS notifications to users in Uganda.

        **IMPORTANT PHONE NUMBER REQUIREMENTS:**
        - All phone numbers MUST start with 256 (Uganda country code)
        - Phone numbers MUST be exactly 12 digits total (256 + 9 digits)
        - Format: 256XXXXXXXXX (e.g., 256701234567, 256771234567)

        **CRITICAL: If the user provides a phone number that does NOT start with 256 or is not 12 digits:**
        - ALWAYS prompt the user to provide a valid Ugandan phone number
        - Explain the correct format: "Please provide a valid Ugandan phone number starting with 256 and containing 12 digits total (e.g., 256701234567)"
        - Do NOT attempt to send SMS until a valid phone number is provided

        You can send to:
        - Single recipient: One phone number
        - Multiple recipients: Comma-separated phone numbers (all must be valid)

        Optional parameters:
        - sender: Custom sender ID
        - sendtime: Schedule SMS for future delivery (format: YYYY-MM-DD HH:MM:SS)
    MARKDOWN;

    /**
     * The tools registered with this MCP server.
     *
     * @var array<int, class-string<\Laravel\Mcp\Server\Tool>>
     */
    protected array $tools = [
        SendSmsNotificationTool::class,
    ];

    /**
     * The resources registered with this MCP server.
     *
     * @var array<int, class-string<\Laravel\Mcp\Server\Resource>>
     */
    protected array $resources = [
        //
    ];

    /**
     * The prompts registered with this MCP server.
     *
     * @var array<int, class-string<\Laravel\Mcp\Server\Prompt>>
     */
    protected array $prompts = [
        //
    ];
}