> ## Documentation Index > Fetch the complete documentation index at: https://docs.shoply.gg/llms.txt > Use this file to discover all available pages before exploring further. # Set a variant's cost > What one sale of a variant costs the store, as an amount or as a share of what it sold for: what the buyer paid for it, after its sale price and discounts, without tax. Send neither to clear it. The cost is stamped onto each order line when the order is paid, so a later change does not rewrite old months. Refused with `business_details_required` until the store has its business details. Needs the `finance.write` permission (Change Finance). ## OpenAPI ````yaml /api-reference/openapi.json put /stores/{storeId}/finance/costs/{variantId} openapi: 3.1.0 info: title: Shoply API version: '1' description: >- Everything a store's own server can do with a secret API key: its catalogue, orders, customers, marketing, finance and the rest of what the dashboard does. And the Customer API, which a buyer's own device asks with a token of theirs. servers: - url: https://api.shoply.gg/v1 security: - apiKey: [] tags: - name: API key - name: Store - name: Domain - name: Payment methods - name: Analytics - name: Storefronts - name: Storefront code - name: Payment Routing - name: Custom payment methods - name: Products - name: Product pictures - name: Stock - name: Categories - name: Upsells - name: Subscriptions - name: Orders - name: Invoices - name: Reviews - name: Coupons - name: Coupon categories - name: Coupon pop-up - name: Sales - name: Blog - name: Search settings - name: Redirects - name: Sitemap - name: Cart Recovery - name: Email Marketing - name: Email Templates - name: Customers - name: Affiliates - name: Support Tickets - name: Blacklist - name: Fraud protection - name: Disputes - name: Finance - name: Tax - name: Expenses - name: Expense setup - name: API requests - name: Webhook endpoints - name: Webhook deliveries - name: Customer API paths: /stores/{storeId}/finance/costs/{variantId}: put: tags: - Finance summary: Set a variant's cost description: >- What one sale of a variant costs the store, as an amount or as a share of what it sold for: what the buyer paid for it, after its sale price and discounts, without tax. Send neither to clear it. The cost is stamped onto each order line when the order is paid, so a later change does not rewrite old months. Refused with `business_details_required` until the store has its business details. Needs the `finance.write` permission (Change Finance). operationId: finance.setCost parameters: - name: storeId in: path required: true description: >- The store's ID. A key reaches the store it was made in: `GET /key` answers which. schema: type: string - name: variantId in: path required: true description: The variant. schema: type: string - $ref: '#/components/parameters/IdempotencyKey' requestBody: required: true content: application/json: schema: type: object properties: amount: type: number description: The cost of one, in the store's currency. percent: type: number description: Or the cost as a percent of what each one sold for. applyToPast: type: boolean description: >- Whether to give this cost to the lines already sold that have none. `past` in the answer says how many such lines there are. default: false responses: '200': description: It worked. content: application/json: schema: type: object properties: success: type: boolean message: nullable: true code: nullable: true data: type: object properties: variantId: type: string costAmount: type: number costPercent: nullable: true stamped: type: integer past: type: integer example: success: true message: null code: null data: variantId: 00e1d395-9ba2-4db3-900a-cb5e2811a2a9 costAmount: 2.5 costPercent: null stamped: 0 past: 5 '401': $ref: '#/components/responses/NoKey' '403': $ref: '#/components/responses/NotAllowed' '404': $ref: '#/components/responses/NotFound' '422': $ref: '#/components/responses/Refused' '429': $ref: '#/components/responses/TooMany' x-codeSamples: - lang: javascript label: Node.js source: | import Shoply from "@shoplygg/node"; const shoply = new Shoply({ apiKey: process.env.SHOPLY_API_KEY }); const result = await shoply.finance.setCost("VARIANT_ID"); - lang: php label: PHP source: | getenv('SHOPLY_API_KEY')]); $result = $shoply->finance->setCost('VARIANT_ID'); - lang: python label: Python source: | import shoply client = shoply.Client() # reads SHOPLY_API_KEY result = client.finance.setCost("VARIANT_ID") components: parameters: IdempotencyKey: name: Idempotency-Key in: header required: false description: >- A word of your own for this one change, up to 180 letters, digits, dots, dashes, underscores and colons. Sent again with the same key, the request is not carried out twice: the first answer comes back, with `Idempotent-Replay: true`. schema: type: string responses: NoKey: description: >- No API key was sent, or the one sent is not a live key: `api_key_required`, `invalid_api_key`. content: application/json: schema: $ref: '#/components/schemas/Refusal' NotAllowed: description: >- The key is real and may not do this: `missing_scope` (with `requiredScope`), `ip_not_allowed`, `account_unavailable`, or `dashboard_only` for something only a person in the dashboard may do. content: application/json: schema: $ref: '#/components/schemas/Refusal' NotFound: description: >- There is no such thing in this store: `not_found`. A store that is not the key's own is answered the same way. content: application/json: schema: $ref: '#/components/schemas/Refusal' Refused: description: >- The request was understood and not carried out. `validation_failed` says what is wrong with each field under `errors`; other codes are the route's own. content: application/json: schema: $ref: '#/components/schemas/Refusal' TooMany: description: >- The key has used up its budget for now: `rate_limited`. `Retry-After` says how many seconds to wait. content: application/json: schema: $ref: '#/components/schemas/Refusal' schemas: Refusal: type: object properties: success: type: boolean example: false message: type: string description: What is wrong, in words for a person. code: type: string description: What is wrong, as a word that does not change. data: nullable: true errors: type: object description: >- For `validation_failed`: what is wrong with each field, by the field's name. additionalProperties: type: string required: - success - message - code securitySchemes: apiKey: type: http scheme: bearer description: >- A secret API key, made under Developers in the dashboard: `Authorization: Bearer shoply_sk_...` ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.