> ## 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. # Register purchase > Registers a supplier purchase with calculated tax breakdowns. **Required permission:** `expenses` ## OpenAPI ````yaml /api-reference/openapi.en.json post /expenses 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: /expenses: post: tags: - Billing · Purchases summary: Register purchase description: |- Registers a supplier purchase with calculated tax breakdowns. **Required permission:** `expenses` requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/ExpenseRequest' example: branch_id: 9d1c5a3e-4b7f-4e2a-9c1d-2f6b8a0e7c11 provider_id: 9d1c5a3e-4b7f-4e2a-9c1d-2f6b8a0e7c11 document_type: ccf date: '2026-10-01' observation: Compra de insumos is_credit: false credit_days: 0 number_control: DTE-03-M001P001-000000000000123 generation_code: A1B2C3D4-... stamp: 2026XYZ... products: - sku: INS-001 name: Insumo A type: goods quantity: 5 price_before_taxes: 8 expense_not_suject: 0 expense_exent: 0 expense_taxed: 40 subtotal: 40 totals: netTotals: 40 charge_1: 0 charge_2: 0 expenseTotalTax: 40 totalRent: 0 totalTax: 5.2 totalRetein: 0 expenseTotalToPayment: 45.2 responses: '200': description: Purchase registered content: application/json: example: status: true message: Expense created successfully data: expense_id: 9d1c5a3e-4b7f-4e2a-9c1d-2f6b8a0e7c11 generation_code: A1B2C3D4-... control_number: DTE-03-M001P001-000000000000123 status: processed issue_time: '2026-10-01 10:00:00' total: 45.2 '401': $ref: '#/components/responses/E401' '403': $ref: '#/components/responses/E403' '404': $ref: '#/components/responses/E404' '422': $ref: '#/components/responses/E422' '429': $ref: '#/components/responses/E429' '500': $ref: '#/components/responses/E500' components: schemas: ExpenseRequest: type: object properties: branch_id: type: string format: uuid description: Branch. provider_id: type: string format: uuid description: Supplier. document_type: type: string description: Document type. enum: - ccf - fse - ticket date: type: string format: date description: Date. is_credit: type: boolean description: On credit. credit_days: type: integer description: Credit days. observation: type: string description: Notes. number_control: type: string description: DTE control number. generation_code: type: string description: Generation code. stamp: type: string description: Stamp. cost_center_id: type: string format: uuid description: >- Cost center of the purchase (leaf and active; GET /accounting/cost-centers). products: type: array items: type: object properties: sku: type: string name: type: string type: type: string description: Good or service. enum: - goods - services quantity: type: number price_before_taxes: type: number expense_not_suject: type: number expense_exent: type: number expense_taxed: type: number subtotal: type: number cost_center_id: type: string format: uuid description: >- Cost center of the line; if missing, that of the purchase. The expense is grouped by account and center. cost_center_distribution_id: type: string format: uuid nullable: true description: >- Distribution of the line; if the line has neither a center nor a distribution, the purchase's is used. Mutually exclusive with `cost_center_id` at the same level (422 `Indique centro de costo o distribución, no ambos.`). required: - sku - name - type - quantity - price_before_taxes - expense_not_suject - expense_exent - expense_taxed - subtotal totals: type: object properties: netTotals: type: number charge_1: type: number charge_2: type: number expenseTotalTax: type: number totalRent: type: number totalTax: type: number totalRetein: type: number expenseTotalToPayment: type: number required: - netTotals - charge_1 - charge_2 - expenseTotalTax - totalRent - totalTax - totalRetein - expenseTotalToPayment cost_center_distribution_id: type: string format: uuid nullable: true description: >- Active distribution: the expense is split among its centers by percentage. Mutually exclusive with `cost_center_id` at the same level (422 `Indique centro de costo o distribución, no ambos.`). required: - branch_id - provider_id - document_type - date - is_credit - products - totals 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 E404: description: Resource does not exist or belongs to another business content: application/json: example: status: false message: Not found. E422: description: Validation error content: application/json: example: status: false message: Validation errors errors: start_date: - The start date field is required. E429: description: Rate limit exceeded content: application/json: example: status: false message: Rate limit exceeded. Please try again later. rate_limit: 100 E500: description: Internal error content: application/json: example: status: false message: An error occurred while creating the invoice 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.