discourse/spec/requests/api/schemas/json/topic_create_request.json

{
  "additionalProperties": false,
  "properties": {
    "title": {
      "type": "string",
      "description": "Required if creating a new topic or new private message."
    },
    "raw": {
      "type": "string"
    },
    "topic_id": {
      "type": "integer",
      "description": "Required if creating a new post."
    },
    "category": {
      "type": "integer",
      "description": "Optional if creating a new topic, and ignored if creating a new post."
    },
    "target_recipients": {
      "type": "string",
      "description": "Required for private message, comma separated.",
      "example": "blake,sam"
    },
    "target_usernames": {
      "type": "string",
      "description": "Deprecated. Use target_recipients instead.",
      "deprecated": true
    },
    "archetype": {
      "type": "string",
      "description": "Required for new private message.",
      "example": "private_message"
    },
    "created_at": {
      "type": "string"
    },
    "embed_url": {
      "type": "string",
      "description": "Provide a URL from a remote system to associate a forum topic with that URL, typically for using Discourse as a comments system for an external blog."
    }
  },
  "required": [
    "raw"
  ]
}