> ## Documentation Index > Fetch the complete documentation index at: https://docs.suby.fi/llms.txt > Use this file to discover all available pages before exploring further. # Update a discount code > Partial update. Changing `discountType` rewrites the whole type block, so the opposite kind's fields are cleared · a code switched to `PERCENTAGE` never keeps the amount it carried as a `FIXED` one. Set `isActive: false` to stop a code without deleting it; already-issued links then fail with `DISCOUNT_CODE_INACTIVE` rather than silently charging full price. ## OpenAPI ````yaml /v3-beta/api-reference/openapi.yaml patch /v3/discount-codes/{id} openapi: 3.1.0 info: title: Suby.fi Merchant API version: 3.0.0-beta description: > The **v3** public merchant API for Suby.fi. RESTful (plural, resource-oriented endpoints under the `/v3` prefix). Authenticate every request with your secret API key in the `X-Suby-Api-Key` header. - `sk_live_…` keys operate in **production** (real funds). - `sk_sandbox_…` keys operate in a fully simulated **sandbox** (test cards, Base Sepolia crypto, no real money). The environment is derived from the key prefix. contact: email: contact@suby.fi url: https://suby.fi servers: - url: https://api.beta.suby.fi description: Production + sandbox (environment selected by API key prefix) security: - ApiKeyAuth: [] tags: - name: Products description: Manage your product catalog (one-time and recurring). - name: Checkout description: >- Hosted checkout · signed session tokens (`cs_…`). Every card Suby holds was collected here, which is what keeps card data out of your systems. - name: Payments description: >- Read payments and receipts, refund them, and debit a stored instrument off-session (pay-as-you-go). Collecting a card happens on the hosted checkout, never here. - name: Subscriptions description: >- Drive a live subscription · read it, change its plan, end it. Subscriptions are opened by a checkout session, not by this API. - name: Discount Codes description: Promo codes, redeemed at checkout. - name: Crypto description: >- The headless rail · quote, charge, and settle on-chain from inside your own site. No card data is involved, so none of the constraints that keep card collection on a Suby page apply here. - name: Customers description: First-class customer records with billing address. - name: Payment Methods description: >- Read and detach the cards a customer has stored. They are created by a checkout session (`savePaymentMethod`, or `mode=setup`) · the only place a card is collected. - name: Licence Key description: >- The licence server · validate a key, take a seat, free one. Authenticated with your API key like everything else, and scoped to the licences you issued, so your backend relays the check rather than your customer's software calling it directly. paths: /v3/discount-codes/{id}: parameters: - name: id in: path required: true schema: type: string example: disc_abc123 patch: tags: - Discount Codes summary: Update a discount code description: > Partial update. Changing `discountType` rewrites the whole type block, so the opposite kind's fields are cleared · a code switched to `PERCENTAGE` never keeps the amount it carried as a `FIXED` one. Set `isActive: false` to stop a code without deleting it; already-issued links then fail with `DISCOUNT_CODE_INACTIVE` rather than silently charging full price. operationId: updateDiscountCode requestBody: required: true content: application/json: schema: type: object description: >- Partial · every field is optional, `name` included. Omitted fields keep their stored value. Not an `allOf` on the create body: that would inherit its `required`, and a PATCH that has to resend the name to change an expiry is a replace wearing a PATCH's name. properties: name: type: string minLength: 2 maxLength: 40 pattern: ^[A-Z0-9][A-Z0-9_-]*$ example: NOEL2026 discountType: type: string enum: - PERCENTAGE - FIXED description: >- Changing it rewrites the whole type block · the opposite kind's fields are cleared. discountPercent: type: integer nullable: true minimum: 1 maximum: 99 discountAmountCents: type: string pattern: ^[1-9]\d*$ nullable: true example: '500' currency: type: string pattern: ^[A-Z]{3}$ nullable: true productIds: type: array items: type: string example: pro_abc123 description: Replaces the whole scope. Empty = the entire catalogue. maxUses: type: integer minimum: 1 nullable: true expiresAt: type: string format: date-time nullable: true preApply: type: boolean isActive: type: boolean responses: '200': description: Code updated content: application/json: schema: allOf: - $ref: '#/components/schemas/SuccessEnvelope' - properties: data: $ref: '#/components/schemas/DiscountCode' '401': $ref: '#/components/responses/Unauthorized' '404': $ref: '#/components/responses/NotFound' '409': description: The new name is already taken (`DISCOUNT_CODE_NAME_TAKEN`). '422': description: > Invalid body, or the code AS PATCHED would price in one currency while scoped to a product priced in another (`DISCOUNT_CODE_PRODUCT_CURRENCY_MISMATCH`). Judged on the resulting code, so re-scoping a `FIXED` code with `productIds` alone is refused too. content: application/json: schema: $ref: '#/components/schemas/ValidationErrorEnvelope' components: schemas: SuccessEnvelope: type: object required: - success - data properties: success: type: boolean example: true message: type: string data: description: Endpoint-specific payload. DiscountCode: type: object properties: id: type: string example: disc_abc123 name: type: string example: NOEL2026 discountType: type: string enum: - PERCENTAGE - FIXED discountPercent: type: integer nullable: true minimum: 1 maximum: 99 discountAmountCents: type: string nullable: true example: '500' currency: type: string nullable: true productIds: type: array items: type: string example: pro_abc123 description: Eligible products. **Empty means the whole catalogue.** maxUses: type: integer nullable: true usedCount: type: integer description: >- Redemptions counted against `maxUses` · payments that reached an authorized or settled state. Attempts that never settled are not counted, so an abandoned checkout leaves this untouched. expiresAt: type: string format: date-time nullable: true isActive: type: boolean preApply: type: boolean description: >- The hosted checkout applies this code on its own, with nothing for the payer to type. createdAt: type: string format: date-time updatedAt: type: string format: date-time ValidationErrorEnvelope: allOf: - $ref: '#/components/schemas/Error' - type: object properties: data: type: object properties: fieldErrors: type: array items: type: object properties: field: type: string message: type: string Error: type: object required: - success - error properties: success: type: boolean example: false error: type: string description: Machine-readable error code. example: NOT_FOUND message: type: string example: Resource not found data: description: Optional error detail. responses: Unauthorized: description: Invalid or missing API key content: application/json: schema: $ref: '#/components/schemas/Error' example: success: false error: UNAUTHORIZED message: Invalid or missing API key NotFound: description: Resource not found content: application/json: schema: $ref: '#/components/schemas/Error' example: success: false error: NOT_FOUND message: Resource not found securitySchemes: ApiKeyAuth: type: apiKey in: header name: X-Suby-Api-Key description: Secret API key. `sk_live_…` (production) or `sk_sandbox_…` (sandbox). ````