For a proposal to be created in Proposales, first you need to prepare a library of the products that you have available for sale. The library enables you to manage your products in one place, without having to update every proposal that your users will send. If you maintain a library of products already outside of Proposales, you can synchronize your products from there, and into the Proposales library. This webhook is called when an user clicks the “Import Content” button in the content page (url for admin users: /content). The returned list of products will then be added to the content library.
Content Import Request
{
  id: string;
  created: number;
  type: 'content.import';
  integration: IntegrationSessionData;
}
The expected response to this is a json object with the following format 

type LocalizedField = { [langCode: string]: string } | string;
interface ProductVariation {
  unit:
    | 'day'
    | 'h'
    | 'kg'
    | 'm'
    | 'month'
    | 'person'
    | 'sqm'
    | 'unit'
    | 'year'
    | 'night';
  package_split: {
    type:
      | 'other'
      | 'food',
      | 'meetingRoom'
      | 'accommodation',
    enable_discount?: boolean,
    fixed?: boolean
    value_saved_with_tax?: boolean;
    value_with_tax?: number;
    value_without_tax?: number;
    vat?: number;
  }
}

interface IntegrationProduct {
  title: LocalizedField;
  description: LocalizedField;
  uniqueId: string;
  currency?: string;
  product_variation: ProductVariation;
  metadata: { [key: string]: unknown };
}

type ContentImportResponse = {
  data: IntegrationProduct[];
}
It is important that the uniqueId is unique, and stays the same for a specific product, since it’s used to determine whether or not a product exists in the content library. Once a product is added to a proposal, its integration data will be included in its sources.integration property. sources.integration.metadata will contain the optional metadata provided during import.