espocrm-base/schema/metadata/app/emailTemplate.json

{
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "$id": "https://www.espocrm.com/schema/metadata/app/emailTemplates.json",
    "title": "app/databasePlatforms",
    "description": "Email template definitions.",
    "type": "object",
    "properties": {
        "placeholders": {
            "description": "Placeholders.",
            "additionalProperties": {
                "description": "A placeholder.",
                "type": "object",
                "properties": {
                    "className": {
                        "type": "string",
                        "description": "A class. Should implement Espo\\Tools\\EmailTemplate\\Placeholder."
                    },
                    "order": {
                        "type": "integer",
                        "description": "An order position."
                    }
                }
            }
        }
    }
}