# Demo: A sale split between seller and buyer: Solidarity sale > A marketplace seller marks a listing as a charity sale and gives 3 % of the price. The buyer picks the charity after paying and can add an extra; each pays on their own account. One variant of **A sale split between seller and buyer**, in Retail: 3 % of the sale, split between seller and buyer. A made-up site, listings.your-marketplace.example, walked through screen by screen with the Charitips API calls the product makes at each step. Rebuild it in your own project to start from a working flow. The charity choice in this demo is the Charitips [charity selection widget](https://www.charitips.com/docs/widgets/charity_selection.md), a ready-made proposal. Use it whole, use parts of it, or build your own experience from scratch with the API: [List charities](https://www.charitips.com/docs/api-reference/list-charities.md) gives the charities to show, and the calls below carry the chosen `charityId`. Charitips widget: the charity cards and their profiles. Your own UI, built with the API: the listing, the checkout and its split, the button that confirms the choice and the order confirmation. The full guide, with edge cases: https://www.charitips.com/docs/use-cases/marketplace-split.md. **Once, before the first customer:** - [`POST /v1/charities-selections`](https://www.charitips.com/docs/api-reference/create-charities-selection.md) Create a charities selection: once: the charities you offer, from the catalog ```json { "name": "Charity sales", "charityIds": [ "" ] } ``` - [`POST /v1/campaigns`](https://www.charitips.com/docs/api-reference/create-campaign.md) Create a campaign: once: the campaign the donations go to ```json { "name": "Charity sales", "charitiesSelectionId": "", "type": "PERMANENT", "amountType": "FREE_AMOUNT" } ``` - [`POST /v1/campaigns/{campaignId}/activate`](https://www.charitips.com/docs/api-reference/activate-campaign.md) Activate a campaign: once: the campaign starts taking donations - [`POST /v1/accounts/{accountId}/child-accounts`](https://www.charitips.com/docs/api-reference/create-child-account.md) Create a child account: once per seller: their own account under yours ```json { "name": "Léa's workshop", "firstName": "Léa", "lastName": "Bernard", "email": "lea.bernard@example.com", "legalRegistrationNumber": "832145678", "street": "8 quai Saint-Vincent", "zip": "69001", "city": "Lyon", "country": "FR" } ``` - [`POST /v1/charities-selections`](https://www.charitips.com/docs/api-reference/create-charities-selection.md) Create a charities selection: once: the charities you offer, from the catalog ```json { "name": "Charity sales", "accountId": "", "charityIds": [ "" ] } ``` - [`POST /v1/campaigns`](https://www.charitips.com/docs/api-reference/create-campaign.md) Create a campaign: once: the campaign the donations go to ```json { "name": "Charity sales", "accountId": "", "charitiesSelectionId": "", "type": "PERMANENT", "amountType": "FREE_AMOUNT" } ``` - [`POST /v1/campaigns/{campaignId}/activate`](https://www.charitips.com/docs/api-reference/activate-campaign.md) Activate a campaign: once: the campaign starts taking donations ## Screens and calls ### 1. When the listing goes live - Button: Publish the listing No call: this screen only shows the result. ### 2. When the order is paid: the seller's part - Button: Pay 65,80 € **Your server calls:** - [`POST /v1/donations`](https://www.charitips.com/docs/api-reference/create-donation.md) Create a donation: from your server, when it happens; amount in cents ```json { "campaignId": "", "amount": 90, "uniqueExternalId": "order_20931_seller", "externalId": "seller_3310" } ``` Charitips then sends the `donation_create` webhook to your endpoint. ### 3. When the order is paid: the buyer's extra - Button: Pay 65,80 € **Your server calls:** - [`POST /v1/donations`](https://www.charitips.com/docs/api-reference/create-donation.md) Create a donation: from your server, when it happens; amount in cents ```json { "campaignId": "", "amount": 90, "uniqueExternalId": "order_20931_buyer", "hasBeenCharged": true, "withFiscalReceipt": true, "donor": { "firstName": "Camille", "lastName": "Martin", "email": "camille.martin@example.com", "street": "12 rue des Lilas", "zip": "75011", "city": "Paris", "country": "FR" } } ``` Charitips then sends the `donation_create` webhook to your endpoint. ### 4. When the charity is chosen - The customer picks a charity from your selection. - Button: Choose the charity **Your server calls:** - [`POST /v1/donations/{donationId}/claim`](https://www.charitips.com/docs/api-reference/claim-donation.md) Claim a donation: donationId from the create-donation response ```json { "charityId": "" } ``` Charitips then sends the `donation_update` webhook to your endpoint. ### 5. The buyer's extra follows the same choice - Button: Start again **Your server calls:** - [`POST /v1/donations/{donationId}/claim`](https://www.charitips.com/docs/api-reference/claim-donation.md) Claim a donation: donationId from the create-donation response ```json { "charityId": "" } ``` Charitips then sends the `donation_update` webhook to your endpoint. ## Clone it with a coding agent ```prompt Clone the Charitips demo "A sale split between seller and buyer: Solidarity sale" into this project. Read https://www.charitips.com/docs/demos/marketplace/shared-sale.md: it lists each screen and the Charitips API calls behind it. Build the same flow in this codebase, on the sandbox (https://api.sandbox.charitips.com), with my client id and secret read from environment variables, and follow the rules of https://www.charitips.com/docs/skill.md. Make every API call from the server, never from the browser. When it works, show me each call and its response. ```