> ## Documentation Index > Fetch the complete documentation index at: https://docs-pos.solya.app/llms.txt > Use this file to discover all available pages before exploring further. # Open a count session > Opens a physical inventory count for one shop from a seeded set of lines (each a SKU with its book quantity and unit cost in cents). Every line starts uncounted (`countedQuantity: null`); record counts against it, then close to emit the valued adjustment. 409s when the session id already exists. ## OpenAPI ````yaml /openapi.json post /v1/inventory/counts openapi: 3.0.3 info: title: Solya POS API version: 1.0.0 description: >- The Solya POS backend HTTP surface. Every documented operation is agent-ready: it carries an `operationId`, an agent-facing `description`, the `pos.*` scopes it enforces (`x-required-permissions`) and an `x-agent-tier`. Success responses return the payload as raw JSON; failures return the `ErrorResponse` envelope (`{ error: { code, message, statusCode } }`). servers: - url: / description: The backend, relative to its deployed origin. security: [] paths: /v1/inventory/counts: post: tags: - Inventory summary: Open a count session description: >- Opens a physical inventory count for one shop from a seeded set of lines (each a SKU with its book quantity and unit cost in cents). Every line starts uncounted (`countedQuantity: null`); record counts against it, then close to emit the valued adjustment. 409s when the session id already exists. operationId: openCountSession requestBody: required: true content: application/json: schema: type: object properties: id: type: string minLength: 1 shopId: type: string minLength: 1 lines: minItems: 1 type: array items: type: object properties: skuId: type: string pattern: ^[0-9a-f]{64}$ expectedQuantity: type: integer minimum: 0 maximum: 9007199254740991 unitCostCents: type: integer minimum: 0 maximum: 9007199254740991 required: - skuId - expectedQuantity - unitCostCents required: - id - shopId - lines example: id: count-2026-07-28-001 shopId: shop-paris-01 lines: - skuId: >- e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855 expectedQuantity: 10 unitCostCents: 1500 responses: '201': description: The opened count session (status `open`, every line uncounted). content: application/json: schema: type: object properties: id: type: string minLength: 1 shopId: type: string minLength: 1 status: type: string enum: - open - closed lines: type: array items: type: object properties: skuId: type: string pattern: ^[0-9a-f]{64}$ expectedQuantity: type: integer minimum: 0 maximum: 9007199254740991 countedQuantity: nullable: true type: integer minimum: 0 maximum: 9007199254740991 unitCostCents: type: integer minimum: 0 maximum: 9007199254740991 required: - skuId - expectedQuantity - countedQuantity - unitCostCents additionalProperties: false required: - id - shopId - status - lines additionalProperties: false description: >- The opened count session (status `open`, every line uncounted). example: id: count-2026-07-28-001 shopId: shop-paris-01 status: open lines: - skuId: >- e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855 expectedQuantity: 10 countedQuantity: null unitCostCents: 1500 '400': description: >- The request failed schema validation; `error.fieldErrors` lists the fields. content: application/json: schema: $ref: '#/components/schemas/ValidationErrorResponse' '401': description: No valid credential was presented — send a bearer token. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '403': description: The actor is authenticated but lacks the required `pos.*` scope. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '409': description: >- The request conflicts with current state (duplicate id or stale version). content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '422': description: The request is well-formed but violates a domain rule. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '500': description: An unexpected server error — safe to retry idempotent requests. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' security: - bearerAuth: [] components: schemas: ValidationErrorResponse: type: object required: - error additionalProperties: false description: >- A `VALIDATION_FAILED` envelope carrying the offending fields in `fieldErrors`. properties: error: type: object required: - code - message - statusCode additionalProperties: false properties: code: type: string enum: - VALIDATION_FAILED message: type: string statusCode: type: integer fieldErrors: type: array description: >- One entry per rejected field: the field path and why it was rejected. items: type: object required: - field - message additionalProperties: false properties: field: type: string description: Dot-path of the offending field. message: type: string description: Why the field was rejected. ErrorResponse: type: object required: - error additionalProperties: false description: The uniform failure envelope every non-2xx response returns. properties: error: type: object required: - code - message - statusCode additionalProperties: false properties: code: type: string enum: - VALIDATION_FAILED - UNAUTHORIZED - FORBIDDEN - NOT_FOUND - CONFLICT - BUSINESS_RULE_VIOLATION - INTERNAL_ERROR description: >- Machine-readable kernel `ResultCode` — branch on this, not on `message`. message: type: string description: >- Human-readable explanation. Safe to surface; never leaks server internals. statusCode: type: integer description: >- The HTTP status, mirrored into the body so a client need not read headers. securitySchemes: bearerAuth: type: http scheme: bearer bearerFormat: JWT description: >- `Authorization: Bearer `. Accepts EITHER a Keycloak access token (scopes-in-token) OR an opaque POS session token; both resolve to the same `pos.*` scope vocabulary the route guards enforce. ````