> ## Documentation Index > Fetch the complete documentation index at: https://docs.finsync.ar/llms.txt > Use this file to discover all available pages before exploring further. # Open a mesa period > Opens a period. At most one open period per mesa. opening_quote / opening_local are signed blotter inventory (negative = carried long/short, not physical cash). opening_fx is required when opening stock is not zero. opened_by is null for API-key opens. opened_at defaults to 05:00 ART (America/Argentina/Buenos_Aires) of today, not now and not midnight. ## OpenAPI ````yaml /docs/openapi.json post /api/mesas/{id}/periods openapi: 3.0.0 info: title: FinSync API Documentation version: 1.0.0 description: API documentation for FinSync application contact: name: FinSync Support email: support@finsync.com servers: - url: https://api.finsync.ar description: Direct Fly API (preferred for API keys and webhooks) - url: https://finsync.ar description: Same-origin via finsync.ar (Vercel rewrite) security: - apiKey: [] tags: - name: Clients description: Operations related to clients and their accounts - name: Tags description: >- Company-scoped client labels (Configuración > Etiquetas). Distinct from the special Centro de resultados / Centro de costos tag used for budget clients. - name: Accounts description: Operations related to account balances - name: Cost Centers description: Company centros de resultados (cost_center_id) and their budgets - name: Operations description: Operations for creating and managing financial operations - name: Operation Types description: Company operation types management - name: Transaction Types description: Company transaction types management - name: WhatsApp Tools description: >- Company-scoped WhatsApp bot operation tools (Configuración > WhatsApp > Tools). Same WhatsAppOperationTool rows as the dashboard. Authenticate with x-api-key. - name: External client description: >- Exports for external (portal-linked) clients. Authenticate with `x-api-key` (company-owned client ID) or `Authorization: Bearer` (Auth.js session for an ExternalAccessGrant). - name: Mesas description: >- Company FX trading desks (mesas). Same records and paths as the dashboard Mesas module. Integrators authenticate with x-api-key; the dashboard uses an employee session. Superadmin must set mesas_enabled first; there is no public PATCH for that flag. created_by / opened_by / closed_by are null for API-key callers. - name: Home metrics description: >- Named dashboard home metrics (list + values). API keys receive the Métricas-group cards (day P&L, commissions, cost centers) without the metrics-password cookie. Employee sessions need the matching view permission; they still skip the UI password gate on this surface. paths: /api/mesas/{id}/periods: post: tags: - Mesas summary: Open a mesa period description: >- Opens a period. At most one open period per mesa. opening_quote / opening_local are signed blotter inventory (negative = carried long/short, not physical cash). opening_fx is required when opening stock is not zero. opened_by is null for API-key opens. opened_at defaults to 05:00 ART (America/Argentina/Buenos_Aires) of today, not now and not midnight. parameters: - in: path name: id required: true schema: type: integer description: Mesa ID requestBody: required: false content: application/json: schema: type: object properties: opening_quote: type: number example: -7016 description: >- Signed quote inventory carry. Negative = net long quote leftover. opening_local: type: number example: 1000000 opening_fx: type: number nullable: true example: 1200 description: Required when opening stock is not zero (local per 1 quote) opened_at: type: string format: date-time nullable: true example: '2026-03-01T08:00:00.000Z' description: >- ISO instant. Defaults to 05:00 ART of today (08:00Z). Avoid 00:00 UTC/ART — those midnights cross the Argentine day boundary. example: opening_local: 1000000 opening_fx: 1200 opened_at: '2026-03-01T08:00:00.000Z' responses: '201': description: Period opened content: application/json: schema: $ref: '#/components/schemas/MesaPeriod' example: id: 5 mesa_id: 1 status: open opened_at: '2026-03-01T00:00:00.000Z' closed_at: null opening_local: 1000000 opening_fx: 1200 closing_local: null closing_avg_fx: null pnl_local: null pnl_quote: null closing_report: null opened_by: null closed_by: null created_at: '2026-03-01T00:00:00.000Z' updated_at: '2026-03-01T00:00:00.000Z' '400': description: Invalid body or opened_at overlaps previous period '401': description: Unauthorized - Missing or invalid API key '403': description: >- Mesas module not enabled for this company (superadmin must set mesas_enabled). No public PATCH for that flag. content: application/json: schema: $ref: '#/components/schemas/MesasDisabledError' example: error: Mesas module not enabled for this company code: MESAS_DISABLED '404': description: Mesa not found '409': description: There is already an open period '500': description: Server error security: - apiKey: [] components: schemas: MesaPeriod: type: object description: Trading session. opened_by / closed_by are null for x-api-key callers. properties: id: type: integer example: 5 mesa_id: type: integer example: 1 status: type: string enum: - open - closed opened_at: type: string format: date-time closed_at: type: string format: date-time nullable: true opening_local: type: number example: 1000000 opening_fx: type: number nullable: true example: 1200 closing_local: type: number nullable: true closing_avg_fx: type: number nullable: true pnl_local: type: number nullable: true pnl_quote: type: number nullable: true closing_report: type: object nullable: true opened_by: type: integer nullable: true example: null closed_by: type: integer nullable: true example: null created_at: type: string format: date-time updated_at: type: string format: date-time example: id: 5 mesa_id: 1 status: open opened_at: '2026-03-01T00:00:00.000Z' closed_at: null opening_local: 1000000 opening_fx: 1200 closing_local: null closing_avg_fx: null pnl_local: null pnl_quote: null closing_report: null opened_by: null closed_by: null created_at: '2026-03-01T00:00:00.000Z' updated_at: '2026-03-01T00:00:00.000Z' MesasDisabledError: type: object properties: error: type: string example: Mesas module not enabled for this company code: type: string example: MESAS_DISABLED securitySchemes: apiKey: type: apiKey in: header name: x-api-key description: API Key for authentication ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.