Existing server configuration overwritten in mcp.json

[amadeann]

Laravel Package Version

1.0.11

Laravel Version

11.44.0

PHP Version

8.2.9

System Info

Windows 11 + WSL2 + Laravel Sail + VSCode (with devcontainer)

Description

Existing "servers" configuration such as:

{
	"servers": {
		"mysql": {
			"type": "stdio",
			"command": "npx",
			"args": [
				"@benborla29/mcp-server-mysql@2.0.3"
			],
			"env": {
				"MYSQL_HOST": "${input:mysql_host}",
				"MYSQL_PORT": "${input:mysql_port}",
				"MYSQL_USER": "${input:mysql_user}",
				"MYSQL_PASS": "${input:mysql_pass}",
				"MYSQL_DB": "${input:mysql_db}"
			}
		}
	},
	"inputs": [
		{
			"id": "mysql_host",
			"type": "promptString",
			"description": "MySQL Hostname"
		},
		{
			"id": "mysql_port",
			"type": "promptString",
			"description": "MySQL Port"
		},
		{
			"id": "mysql_user",
			"type": "promptString",a
			"description": "MySQL Username"
		},
		{
			"id": "mysql_pass",
			"type": "promptString",
			"description": "MySQL Password"
		},
		{
			"id": "mysql_db",
			"type": "promptString",
			"description": "MySQL Database Name (leave blank for multi-DB mode)"
		}
	]
}

gets overwritten on executing php artisan sail:install.

The culprit of this bug is likely here:

boost/src/Install/CodeEnvironment/CodeEnvironment.php

Line 180 in 44f6eff

data_set($config, "{$mcpKey}.{$key}", collect([

Steps To Reproduce

1. Create a new Laravel project in Laravel Sail on Windows 11 with WSL2
2. Open the project in VS Code with GitHub copilot, in a devcontainer
3. Add any MCP server, such as "@benborla29/mcp-server-mysql@2.0.3", and make sure the mcp.json file has an entry under "servers" key
4. Run "php artisan boost:install", and select "VS Code" in the first step as your editor
5. Previous value of "servers" in mcp.json gets replaced

[pushpak1300]

@amadeann,

I tried reproducing the issue by creating a fresh Laravel 11 installation and adding a .vscode/mcp.json file with the following content:

{
    "servers": {
        "mysql": {
            "type": "stdio",
            "command": "npx",
            "args": ["@benborla29/mcp-server-mysql@2.0.3"],
            "env": {
                "MYSQL_HOST": "${input:mysql_host}",
                "MYSQL_PORT": "${input:mysql_port}",
                "MYSQL_USER": "${input:mysql_user}",
                "MYSQL_PASS": "${input:mysql_pass}",
                "MYSQL_DB": "${input:mysql_db}"
            }
        }
    },
    "inputs": [
        {
            "id": "mysql_host",
            "type": "promptString",
            "description": "MySQL Hostname"
        },
        {
            "id": "mysql_port",
            "type": "promptString",
            "description": "MySQL Port"
        },
        {
            "id": "mysql_user",
            "type": "promptString",
            "description": "MySQL Username"
        },
        {
            "id": "mysql_pass",
            "type": "promptString",
            "description": "MySQL Password"
        },
        {
            "id": "mysql_db",
            "type": "promptString",
            "description": "MySQL Database Name (leave blank for multi-DB mode)"
        }
    ]
}

After that, I ran php artisan boost:install and selected VS Code as the IDE.

I also tested with this configuration:

{
    "servers": {
        "mysql": {
            "type": "stdio",
            "command": "npx",
            "args": [
                "@benborla29/mcp-server-mysql@2.0.3"
            ],
            "env": {
                "MYSQL_HOST": "${input:mysql_host}",
                "MYSQL_PORT": "${input:mysql_port}",
                "MYSQL_USER": "${input:mysql_user}",
                "MYSQL_PASS": "${input:mysql_pass}",
                "MYSQL_DB": "${input:mysql_db}"
            }
        },
        "laravel-boost": {
            "command": "php",
            "args": [
                "./artisan",
                "boost:mcp"
            ]
        }
    },
    "inputs": [
        {
            "id": "mysql_host",
            "type": "promptString",
            "description": "MySQL Hostname"
        },
        {
            "id": "mysql_port",
            "type": "promptString",
            "description": "MySQL Port"
        },
        {
            "id": "mysql_user",
            "type": "promptString",
            "description": "MySQL Username"
        },
        {
            "id": "mysql_pass",
            "type": "promptString",
            "description": "MySQL Password"
        },
        {
            "id": "mysql_db",
            "type": "promptString",
            "description": "MySQL Database Name (leave blank for multi-DB mode)"
        }
    ]
}

I ran the same command multiple times, but the content remained exactly the same each time.

Could you please share an example or a repository where this issue can be reproduced?

[adampatterson]

@pushpak1300 I tested a few times, and I think the issue may have to do with invalid JSON.

My MCP file for VS Code had a comment in the top, I use PhpStorm, and the VS Code MCP had a link some documentation to look at later on.

I had that saved as // http://...

With that link, the mcp.json file was overwritten, without that link the Boost MCP was added to the file.

[amadeann]

@pushpak1300
Here's a repository where I see this failing:
https://github.com/amadeann/boost-example/tree/main

[amadeann]

But as @adampatterson says, I think the issue is with invalid JSON indeed. When I remove the trailing coma on this line:
https://github.com/amadeann/boost-example/blob/45a178fab613f692fec15c1b7c77d05ae4e1fe81/.vscode/mcp.json#L16

in my repo, the laravel-boost is correctly added as second config. With the trailing coma, it replaces entire mcp.json.

[amadeann]

VS Code happily accepts both trailing comas, and comments in mcp.json, so I suppose both can be considered "valid syntax", even though it doesn't adhere to strict JSON standards.

[adampatterson]

@amadeann I think that's why I left my link in there as well.

I was like "well it still works", kind of funny because I'd normally add nodes and dump things in there like other MCPs that I don't need.

[ashleyhindle]

Ahhh very interesting, it's probably best we just skip invalid config and output a message at the end saying "Failed to update XXX because it has invalid JSON, please add manually"?

[adampatterson]

Yea, If outputting the MCP details in the CLI people could copy that and paste it manually; I feel like that would work.

Or even a notice saying that you couldn't update the file because of invalid JSON, but we've created mcp.boost.json as a reference.

[ashleyhindle]

@pushpak1300 I tested a few times, and I think the issue may have to do with invalid JSON.

My MCP file for VS Code had a comment in the top, I use PhpStorm, and the VS Code MCP had a link some documentation to look at later on.

I had that saved as // http://...

With that link, the mcp.json file was overwritten, without that link the Boost MCP was added to the file.

Was the // http://... link within the JSON curly brace, or outside of it @adampatterson ?

I've got a working fix for this using a JSON5 parser instead which supports comments and trailing commas, so it will just work for everybody without the warning and manual work. But, it will only work if the comments are within the braces, not outside, so just trying to understand how useful it will be 👌

[adampatterson]

@ashleyhindle yes, I had a note about how Inputs work.

{
  // 💡 Inputs are prompted on first server start, then stored securely by VS Code.
  "inputs": [],
  "servers": {}

[adampatterson]

Even GitHub is upset with me 😂