> ## Documentation Index > Fetch the complete documentation index at: https://docs.filexpress.app/llms.txt > Use this file to discover all available pages before exploring further. # Evaluate promotions > Calculates promotions over a cart with the same engine as the POS, without recording anything. **Required permission:** `pricing` ## OpenAPI ````yaml /api-reference/openapi.en.json post /pricing/promotions/evaluate openapi: 3.0.3 info: title: FileXpress External API version: 1.0.0 description: >- API for integrating third-party systems with FileXpress: billing, HR, accounting, inventory, projects, accounts receivable and payable, treasury, pricing and promotions, and cash. Current base URL: /api/external/v1. The legacy unversioned path (/api/external) will be removed on January 1, 2027; migrate to /api/external/v1 (same endpoints, only the base URL changes). The v2 API (/api/external/v2) exposes currencies and exchange rates, sales and purchases in foreign currency, taxes by id, payrolls with branch, and errors with a stable `code`; its operations carry the /v2 prefix in the path. We suggest migrating to the available v2 routes before March 30, 2027. servers: - url: https://api.filexpress.app/api/external/v1 description: Production security: - ApiKey: [] tags: - name: General - name: Billing · Sales - name: Billing · Purchases - name: Billing · Customers - name: Billing · Suppliers - name: Billing · Products - name: Catalogs - name: HR · Employees - name: HR · Attendance - name: HR · Labor rules - name: HR · Schedules - name: HR · Holidays - name: HR · Attendance results - name: HR · Leave requests - name: HR · Payrolls - name: Accounting - name: Inventory - name: Projects - name: Accounts receivable - name: Accounts payable - name: Treasury - name: Pricing and promotions - name: Cash - name: Points of sale - name: API v2 · General - name: API v2 · Currencies and rates - name: API v2 · Countries - name: API v2 · Sales - name: API v2 · Purchases - name: API v2 · Payrolls paths: /pricing/promotions/evaluate: post: tags: - Pricing and promotions summary: Evaluate promotions description: >- Calculates promotions over a cart with the same engine as the POS, without recording anything. **Required permission:** `pricing` requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/PromotionEvaluateRequest' example: branch_id: 9d1c5a3e-4b7f-4e2a-9c1d-2f6b8a0e7c11 items: - product_id: 9d1c5a3e-4b7f-4e2a-9c1d-2f6b8a0e7c11 quantity: 2 unit_price: 1.25 - product_id: 3b8e2f10-7c4d-4a9e-b1f2-5d6c7e8f9a01 quantity: 1 unit_price: 12 responses: '200': description: Success content: application/json: schema: type: object required: - status - data properties: status: type: boolean example: true data: $ref: '#/components/schemas/PromotionEvaluation' example: status: true data: items: - product_id: 9d1c5a3e-4b7f-4e2a-9c1d-2f6b8a0e7c11 quantity: 2 unit_price: 1.25 promo_discount: 0.125 promo_id: 3b8e2f10-7c4d-4a9e-b1f2-5d6c7e8f9a01 promo_name: 2x1 en bebidas promo_type: percentage order_discounts: - promo_id: 3b8e2f10-7c4d-4a9e-b1f2-5d6c7e8f9a01 promo_name: Combo desayuno promo_type: combo discount: 1 totals: subtotal: 14.5 item_discounts: 0.25 order_discounts: 1 total: 13.25 '401': $ref: '#/components/responses/E401' '403': $ref: '#/components/responses/E403' '404': description: Not found or belongs to another business content: application/json: schema: $ref: '#/components/schemas/Error' example: status: false message: Branch not found '422': description: Validation error content: application/json: schema: $ref: '#/components/schemas/Error' example: status: false message: Validation errors errors: items: - The items field is required. '429': $ref: '#/components/responses/E429' components: schemas: PromotionEvaluateRequest: type: object properties: branch_id: type: string format: uuid items: type: array minItems: 1 maxItems: 500 items: type: object properties: product_id: type: string format: uuid quantity: type: number minimum: 0 unit_price: type: number minimum: 0 required: - product_id - quantity - unit_price required: - branch_id - items PromotionEvaluation: type: object properties: items: type: array items: type: object properties: product_id: type: string format: uuid quantity: type: number unit_price: type: number promo_discount: type: number description: Discount per unit (apply_on unit_price promotions). promo_id: type: string format: uuid nullable: true promo_name: type: string nullable: true promo_type: type: string nullable: true order_discounts: type: array items: type: object properties: promo_id: type: string format: uuid promo_name: type: string promo_type: type: string discount: type: number totals: type: object properties: subtotal: type: number item_discounts: type: number order_discounts: type: number total: type: number description: subtotal − item_discounts − order_discounts (minimum 0). required: - items - order_discounts - totals Error: type: object properties: status: type: boolean example: false message: type: string errors: type: object additionalProperties: type: array items: type: string description: Errors per field (validation only). required: - status - message responses: E401: description: Missing or invalid API Key content: application/json: example: status: false message: Invalid API Key. E403: description: Integration without the required permission or deactivated content: application/json: example: status: false message: This integration does not have the 'hr.employees' permission. required_scope: hr.employees E429: description: Rate limit exceeded content: application/json: example: status: false message: Rate limit exceeded. Please try again later. rate_limit: 100 securitySchemes: ApiKey: type: apiKey in: header name: X-API-Key description: Integration API Key (Integrations → New Integration). ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.