> ## 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. # Get per-channel notification availability > Reports whether e-mail and SMS may be used for a transactional send right now, folding the network settings, the credit wallet and the current-period usage meter into one verdict. ALWAYS call this before `sendSaleReceipt` — it is the only free way to learn that a send would be refused, and the caller holding `pos.notification.send` cannot read the wallet or the settings directly. Each channel returns `available`, plus a typed `reason` when it is false: `disabled` (the `channel.sms.enabled` network flag is off), `insufficient-credits` (the wallet cannot cover one SMS) or `email-quota-exceeded` (the account reached its plan's monthly e-mail fair-use cap). E-mail is fair-use and never costs credits; SMS is metered. This is a point-in-time snapshot of a shared budget — `available: true` is not a reservation, so a send can still be refused a moment later. ## OpenAPI ````yaml /openapi.json get /v1/notifications/channels 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/notifications/channels: get: tags: - Notifications summary: Get per-channel notification availability description: >- Reports whether e-mail and SMS may be used for a transactional send right now, folding the network settings, the credit wallet and the current-period usage meter into one verdict. ALWAYS call this before `sendSaleReceipt` — it is the only free way to learn that a send would be refused, and the caller holding `pos.notification.send` cannot read the wallet or the settings directly. Each channel returns `available`, plus a typed `reason` when it is false: `disabled` (the `channel.sms.enabled` network flag is off), `insufficient-credits` (the wallet cannot cover one SMS) or `email-quota-exceeded` (the account reached its plan's monthly e-mail fair-use cap). E-mail is fair-use and never costs credits; SMS is metered. This is a point-in-time snapshot of a shared budget — `available: true` is not a reservation, so a send can still be refused a moment later. operationId: getNotificationChannels responses: '200': description: >- The per-channel verdict, with a typed reason on each unavailable channel. content: application/json: schema: type: object properties: email: type: object properties: available: type: boolean reason: type: string enum: - disabled - insufficient-credits - email-quota-exceeded required: - available additionalProperties: false sms: type: object properties: available: type: boolean reason: type: string enum: - disabled - insufficient-credits - email-quota-exceeded required: - available additionalProperties: false required: - email - sms additionalProperties: false description: >- The per-channel verdict, with a typed reason on each unavailable channel. example: email: available: true sms: available: false reason: disabled '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' '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. ````