> ## 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. # Open cash register > Opens the branch's cash register for a cashier (`user_id`, a FileXpress user with access to the branch). One open shift per point of sale: `point_of_sale_id` is required if the branch has more than one active point of sale. `user_id` is recorded as the opener (`opened_by_user`). **Required permission:** `cash_register.operate` ## OpenAPI ````yaml /api-reference/openapi.en.json post /cash-registers/open 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: /cash-registers/open: post: tags: - Cash summary: Open cash register description: >- Opens the branch's cash register for a cashier (`user_id`, a FileXpress user with access to the branch). One open shift per point of sale: `point_of_sale_id` is required if the branch has more than one active point of sale. `user_id` is recorded as the opener (`opened_by_user`). **Required permission:** `cash_register.operate` parameters: - $ref: '#/components/parameters/IdempotencyKey' requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/CashRegisterOpenRequest' example: branch_id: 3b8e2f10-7c4d-4a9e-b1f2-5d6c7e8f9a01 user_id: 3b8e2f10-7c4d-4a9e-b1f2-5d6c7e8f9a01 point_of_sale_id: 3b8e2f10-7c4d-4a9e-b1f2-5d6c7e8f9a01 opening_amount: 100 notes: Turno mañana responses: '201': description: Open cash register content: application/json: schema: type: object required: - status - data properties: status: type: boolean example: true data: $ref: '#/components/schemas/CashRegister' example: status: true data: id: 9d1c5a3e-4b7f-4e2a-9c1d-2f6b8a0e7c11 branch_id: 3b8e2f10-7c4d-4a9e-b1f2-5d6c7e8f9a01 point_of_sale: id: 3b8e2f10-7c4d-4a9e-b1f2-5d6c7e8f9a01 code: P001 name: Caja principal opened_by_user: id: 3b8e2f10-7c4d-4a9e-b1f2-5d6c7e8f9a01 name: Ana Martínez closed_by_user: null status: open cashier: id: 3b8e2f10-7c4d-4a9e-b1f2-5d6c7e8f9a01 name: Ana Martínez opening_date: '2026-10-06T08:00:00-06:00' closing_date: null opening_amount: 100 declared_amount: null difference_amount: null total_sales: null total_cash_sales: null total_card_sales: null total_other_sales: null total_expenses: null total_other_incomes: null notes: null opened_by: 'API: Mi POS' closed_by: null headers: Idempotent-Replayed: $ref: '#/components/headers/IdempotentReplayed' '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 '409': description: A cash register is already open or idempotency conflict content: application/json: schema: $ref: '#/components/schemas/Error' examples: open: summary: Turno ya abierto en el punto de venta value: status: false message: Ya hay un turno de caja abierto en este punto de venta. open_branch: summary: Caja ya abierta (sucursal sin puntos de venta) value: status: false message: There is already an open cash register for this branch. idem_body: summary: Idempotency-Key reutilizada con otro cuerpo value: status: false message: >- This Idempotency-Key was already used with a different request. idem_busy: summary: Petición con la misma llave en proceso value: status: false message: >- A request with this Idempotency-Key is already being processed. '422': description: Validation, invalid point of sale or cashier content: application/json: schema: $ref: '#/components/schemas/Error' examples: cashier: summary: Cajero sin acceso value: status: false message: The user does not exist or has no access to this branch. pos_required: summary: Varios puntos de venta activos value: status: false message: Seleccione el punto de venta. pos_invalid: summary: Punto de venta inválido value: status: false message: >- El punto de venta no pertenece a la sucursal o está inactivo. '429': $ref: '#/components/responses/E429' components: parameters: IdempotencyKey: name: Idempotency-Key in: header required: false description: >- Optional. Unique key per operation (max. 100 characters, valid for 24 h per integration). A retry with the same key and the same body returns the original response (header `Idempotent-Replayed: true`) without repeating the operation; with a different body, or while the first is still in progress, it returns 409. schema: type: string maxLength: 100 example: pago-2026-10-06-000123 schemas: CashRegisterOpenRequest: type: object properties: branch_id: type: string format: uuid user_id: type: string format: uuid description: 'Cashier: FileXpress user with access to the branch.' point_of_sale_id: type: string format: uuid description: Point of sale. Required if the branch has more than one active. opening_amount: type: number minimum: 0 notes: type: string maxLength: 500 required: - branch_id - user_id - opening_amount CashRegister: type: object properties: id: type: string format: uuid branch_id: type: string format: uuid point_of_sale: type: object properties: id: type: string format: uuid code: type: string name: type: string required: - id - code nullable: true opened_by_user: type: object properties: id: type: string format: uuid name: type: string nullable: true required: - id nullable: true closed_by_user: type: object properties: id: type: string format: uuid name: type: string nullable: true required: - id nullable: true description: null while open. status: type: string description: Status. enum: - open - closed cashier: type: object properties: id: type: string format: uuid name: type: string nullable: true required: - id opening_date: type: string format: date-time closing_date: type: string format: date-time nullable: true opening_amount: type: number nullable: true declared_amount: type: number nullable: true difference_amount: type: number nullable: true description: Declared − expected. total_sales: type: number nullable: true total_cash_sales: type: number nullable: true total_card_sales: type: number nullable: true total_other_sales: type: number nullable: true total_expenses: type: number nullable: true total_other_incomes: type: number nullable: true notes: type: string nullable: true opened_by: type: string nullable: true description: 'Who opened it (from the API: "API: ").' closed_by: type: string nullable: true required: - id - status 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 headers: IdempotentReplayed: description: >- `true` when the response is the replay of a previous request with the same Idempotency-Key. schema: type: string enum: - 'true' 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.