fp/packages/next/app.json

{
    "healthchecks": {
        "web": [
            {
                "type": "startup",
                "name": "web check",
                "description": "Checking for expecting string at /api",
                "path": "/api",
                "content": "Application Programmable Interface",
                "attempts": 3
            }
        ]
    }
}