> ## Documentation Index > Fetch the complete documentation index at: https://novu-c5de82d9-docs-homepage-redesign.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # Message schema > Reference the Novu message schema used in API requests and responses. Review fields, data types, and object structure for this resource. ### Message Message is a single notification that is sent to a subscriber. Each channel step in the workflow generates a message. Unique identifier for the message Template ID associated with the message Environment ID where the message is sent Message template ID Organization ID associated with the message Notification ID associated with the message Subscriber ID associated with the message Subscriber details, if available Workflow template associated with the message Identifier for the message template Creation date of the message Array of delivery dates for the message, if the message has multiple delivery dates, for example after being snoozed Last seen date of the message, if available Last read date of the message, if available Content of the message, can be an email block or a string Transaction ID associated with the message Subject of the message, if applicable Channel type through which the message is sent Indicates if the message has been read Indicates if the message has been seen Date when the message will be unsnoozed Email address associated with the message, if applicable Phone number associated with the message, if applicable Direct webhook URL for the message, if applicable Provider ID associated with the message, if applicable Device tokens associated with the message, if applicable Title of the message, if applicable Call to action associated with the message Feed ID associated with the message, if applicable Status of the message Error ID if the message has an error Error text if the message has an error The payload that was used to send the notification trigger Provider specific overrides used when triggering the notification Context (single or multi) in which the message was sent ### ChannelTypeEnum ```typescript theme={null} ChannelTypeEnum { IN_APP = "in_app", EMAIL = "email", SMS = "sms", CHAT = "chat", PUSH = "push" } ``` ### Workflow Workflow is a collection of steps that are executed in order to send a notification. ### Actor Actor is the user who is skipped from sending the notification when workflow is triggered to a [topic](/platform/concepts/topics). Actor can be a **string** (subscriber ID) or a **SubscriberPayloadDto** object with the following fields: Unique identifier of the subscriber First name of the subscriber Last name of the subscriber Email address of the subscriber Phone number of the subscriber Avatar URL or identifier Locale of the subscriber Timezone of the subscriber Additional custom data associated with the subscriber ### MessageCTA MessageCTA is a call to action that is displayed in the [Inbox](/platform/inbox) message. It can be used to redirect the user to a specific URL when the message is clicked. Type of call to action Data associated with the call to action Action associated with the call to action