> ## Documentation Index > Fetch the complete documentation index at: https://docs.beinfi.com/llms.txt > Use this file to discover all available pages before exploring further. # Create a coupon > Creates a percentage-off coupon. The buyer enters its `code` at checkout to apply it to the invoice. ## OpenAPI ````yaml /api-reference/openapi.en.json post /billing/coupons openapi: 3.1.0 info: title: Infi API version: 0.0.1 description: > The Infi REST API: catalog, customers, usage metering, subscriptions, invoices, payments and checkout. **Authentication.** Send your secret key as `Authorization: Bearer sk_test_…` (sandbox) or `sk_live_…` (production). The key prefix selects the environment. Checkout routes (`/pay/*`) and `/public/*` take no key: they run in the payer's browser. **Idempotency.** Every request that changes data requires an `Idempotency-Key` header. A retry with the same key returns the original response instead of running again. **Amounts.** Money and quantities travel as decimal strings (`"150.00"`, `"0.0001"`), never as floating-point numbers. **Errors.** The body carries `error_code` (stable, branch on it), `message` (for humans) and `tracer_id` (send it to support). Rate-limit and idempotency errors are nested under `error`, with `code` and `request_id`. servers: - url: https://api-sandbox.beinfi.com description: Sandbox - url: https://api.beinfi.com description: Production security: - bearerAuth: [] tags: - name: Catalog - name: Customers - name: Metering - name: Subscriptions - name: Invoices - name: Payments - name: Checkout - name: Coupons - name: Billing - name: Account - name: Webhooks - name: Test account - name: Rail - name: Storefronts paths: /billing/coupons: post: tags: - Coupons summary: Create a coupon description: > Creates a percentage-off coupon. The buyer enters its `code` at checkout to apply it to the invoice. operationId: createCoupon requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/CreateCouponRequest' responses: '201': content: application/json: schema: $ref: '#/components/schemas/Coupon' description: Created. '401': $ref: '#/components/responses/Unauthorized' '422': $ref: '#/components/responses/ValidationFailed' components: schemas: CreateCouponRequest: type: object required: - code - percentOff - duration properties: code: type: string description: >- Coupon code: 3 to 32 characters from uppercase letters, digits, `_` and `-` (e.g. `BLACKFRIDAY-20`). percentOff: type: string description: Discount percentage, as a decimal string, above 0 and up to 100. duration: type: string enum: - once - repeating - forever description: >- `once` (first invoice only), `repeating` (for `durationInCycles` cycles) or `forever` (every invoice). durationInCycles: type: - integer - 'null' description: >- Required (1 or more) when `duration` is `repeating`; omit it otherwise. maxRedemptions: type: - integer - 'null' description: Total redemption limit. Omit for no limit. redeemBy: type: - string - 'null' format: date-time description: Deadline for applying the coupon. Omit for no deadline. description: A new coupon's details. Coupon: type: object required: - id - code - percentOff - duration - timesRedeemed - status - createdAt - updatedAt properties: id: type: string format: uuid code: type: string description: The code the buyer enters at checkout. percentOff: type: string description: Discount percentage, as a decimal string (`"15"` = 15%). duration: type: string enum: - once - repeating - forever description: >- `once` (first invoice only), `repeating` (for `durationInCycles` cycles) or `forever` (every invoice). durationInCycles: type: - integer - 'null' description: How many cycles the discount lasts. Only on `repeating` coupons. maxRedemptions: type: - integer - 'null' description: How many times the coupon can be used in total. `null` = no limit. timesRedeemed: type: integer description: How many times the coupon has been used. redeemBy: type: - string - 'null' format: date-time description: Last moment the coupon can be applied. `null` = no deadline. status: type: string enum: - active - archived description: '`active` (accepted at checkout) or `archived` (no longer accepted).' createdAt: type: string format: date-time updatedAt: type: string format: date-time description: >- A percentage discount the buyer applies at checkout with its `code`. On subscriptions, `duration` sets how many cycles the discount lasts. Error: type: object required: - message - error_code - tracer_id properties: message: type: string description: Human-readable sentence. error_code: $ref: '#/components/schemas/ErrorCode' description: Stable error code. Branch on it. tracer_id: type: string description: Request id. Include it when contacting support. description: >- The standard error body. It is flat (no `error` wrapper) and the trace id is `tracer_id`. ValidationError: type: object required: - message - error_code - tracer_id - errors properties: message: type: string error_code: $ref: '#/components/schemas/ErrorCode' tracer_id: type: string errors: type: array items: type: object required: - field - value - constraint - description properties: field: type: string value: type: string constraint: type: string description: type: string description: >- Per-field detail (`field`, `description`). Always present on a `422`; may be empty. description: >- Body of a `422`. Same shape as `Error`, plus `errors[]` with per-field detail. That is where the sentence telling you what to fix lives (for example, "product has no published version"). ErrorCode: type: string examples: - internal_error - validation_failed - bad_request - unauthorized - forbidden - not_found - conflict - rate_limited description: >- Stable error code. The list is open: besides the generic codes, each area defines its own (`coupon_expired`, `insufficient_balance`, `version_not_draft`, `idempotency_key_reused`…). Handle a code you do not recognize by its HTTP status and show `message`; do not fail parsing the response. responses: Unauthorized: content: application/json: schema: $ref: '#/components/schemas/Error' description: Missing or invalid API key. ValidationFailed: content: application/json: schema: $ref: '#/components/schemas/ValidationError' description: One or more fields are invalid. Per-field detail is in `errors[]`. securitySchemes: bearerAuth: type: http scheme: bearer description: >- Your account's secret key: `Authorization: Bearer sk_test_…` or `sk_live_…`. Server-side only. ````