OpenAPI

    {
      "swagger": "2.0",
      "host": "businessmessages.googleapis.com",
      "info": {
        "title": "Business Messages API",
        "description": "",
        "version": "v1"
      },
      "paths": {
        "/v1/conversations/{conversationsId}/messages": {
          "post": {
            "description": "Sends a message from an agent to a user.",
            "parameters": [
              {
                "description": "Part of `parent`. Required. The conversation that contains the message. Resolves to \"conversations/{conversationId}\".",
                "type": "string",
                "in": "path",
                "required": true,
                "name": "conversationsId"
              },
              {
                "description": "Optional. A flag to send the specified fallback text instead of other message content.",
                "name": "forceFallback",
                "type": "boolean",
                "in": "query"
              },
              {
                "name": "message",
                "schema": {
                  "$ref": "#/definitions/BusinessMessagesMessage"
                },
                "in": "body",
                "description": "Required. The content of a message."
              }
            ],
            "tags": [
              "businessmessages"
            ],
            "operationId": "CreateMessage",
            "responses": {
              "default": {
                "schema": {
                  "$ref": "#/definitions/BusinessMessagesMessage"
                },
                "description": "Successful operation"
              }
            }
          }
        }
      }
    }