> ## Documentation Index > Fetch the complete documentation index at: https://docs.famulor.io/llms.txt > Use this file to discover all available pages before exploring further. # Confirm subscription change > Applies a reviewed existing subscription change only after explicit approval. May charge the chosen saved card and select it for future renewals. References are bound to the workspace, user and exact selection. The amount is verified again; an increase, currency change, stale reference or changed subscription requires a new review. A lower refreshed amount is allowed. No card is required for a change with no payment due. Pending payments do not grant upgrades; open the returned app billing link to complete payment. Requires a user-owned credential with billing:write scope and owner, admin or billing access in the active workspace. API Access must be enabled. ## OpenAPI ````yaml /api-reference/openapi.json post /billing/subscription-change/confirm openapi: 3.1.0 info: title: Famulor API version: 1.0.0 description: >- REST API for Famulor. Authenticate with an API key (`fam_...`, created under **Settings → API Keys**) or an OAuth 2.0 access token (`fam_at_...`) as a Bearer token. Every response uses a consistent envelope: `{ "data": ... , "meta": { ... } }` on success and `{ "error": { "code", "message" } }` on failure. List endpoints paginate with `?limit=` (default 50, max 200) and `?offset=`; `meta.pagination.total` carries the total match count. REST operations require API Access through the workspace plan or a recurring add-on. Without it, regular operations return `403 api_access_required`. The invoice-payment and billing-portal operations remain available with a valid `billing:write` credential after a failed plan payment so an authorized owner, admin, or billing member can recover billing. The same customer-facing capabilities are available as MCP tools at `https://app.famulor.io/mcp` (Model Context Protocol, streamable HTTP) using the same credentials, scopes, and workspace access. MCP availability is controlled separately by Connect AI / MCP, not by API Access. servers: - url: https://app.famulor.io/api/v1 description: Hosted platform. - url: https://{domain}/api/v1 description: White-label tenant domain — same paths, tenant branding. variables: domain: default: app.famulor.io description: Your white-label tenant domain. security: - bearerAuth: [] tags: - name: Account description: Self-inspection of the calling credential. - name: Migrations description: Preview and import data from supported legacy platforms. - name: Assistants description: Create and manage voice assistants. - name: Tools description: >- Reusable tools (HTTP APIs and external MCP servers) assistants can call mid-conversation. - name: Voices description: Browse the text-to-speech voice library. - name: Calls description: Start outbound calls and read call history, transcripts and recordings. - name: History description: Unified conversation history across calls, messaging and assistant emails. - name: Campaigns description: Outbound calling campaigns with a compliant power dialer. - name: Leads description: Manage Audience contacts across campaigns, channels and Call QA metrics. - name: Segments description: >- Saved, dynamic lead filters — reusable audience definitions used for Audience search and campaign lead assignment. - name: Suppression description: Cross-channel marketing opt-outs and active workspace suppression records. - name: Callbacks description: >- Scheduled callbacks booked by the Schedule callback tool across voice, chat, and email. - name: Phone Numbers description: Marketplace numbers and customer-provided numbers. - name: Famulor Loop description: >- Personal business-phone access, directory, presence, devices, and Loop call recents. - name: SIP Trunks description: Bring your own SIP provider and numbers. - name: Carrier Connections description: Connect a supported carrier account and import its existing phone numbers. - name: Knowledge Bases description: RAG knowledge bases and documents for assistants. - name: Settings description: Workspace-level settings such as caller-memory defaults. - name: Billing description: Balance and minutes ledger of the key owner. - name: Automations description: >- Native workspace automations — list, create, update, trigger. Plan gate: automation_platform. - name: Milian Missions description: Recurring jobs that Milian runs unattended on schedule. - name: Integrations description: >- Calendar integrations (Cal.com, Calendly, Acuity Scheduling, Google Calendar, Outlook, native booking engine). Assign them to assistants to provide availability and booking tools, plus provider-supported appointment lookup, cancellation, and rescheduling. - name: Bookings description: >- Native booking engine — event types with weekly availability, public booking pages at /book/{workspace}/{slug}, and the bookings they produce. - name: Dashboards description: >- Custom analytics dashboards, reusable widgets, and tenant-scoped performance analytics. Requires the custom_dashboards plan feature. - name: Catalog description: >- Read-only platform catalogs — available models, supported assistant languages, and prompt templates. - name: Simulations description: Assistant simulation tests (plan-gated). - name: Versions description: Assistant configuration version history. - name: Caller IDs description: Outbound caller ID verification. - name: Widgets description: Web widget connectors. - name: Messaging description: >- Telegram, Slack, and Messenger text bots linked to assistants (Chat SDK). Includes conversation delay, inactivity end, and conversation-ended webhooks. - name: QA description: Cohort AI Quality Assurance runs over call transcripts. - name: White Label description: >- Manage white-label customer accounts, defaults, credit transfers and customer plan offers. Each endpoint documents its required scope and workspace eligibility. - name: API Keys description: >- Self-service API keys for the calling workspace or a same-brand workspace where the credential's user is owner/admin. A key can only mint further keys with a scope subset of its own. - name: Workspaces description: >- List visible workspaces, create an additional workspace for the key owner, and mint a dedicated credential for a selected owner/admin workspace. - name: SMS description: Outbound SMS from workspace phone numbers. paths: /billing/subscription-change/confirm: post: tags: - Billing summary: Confirm subscription change description: >- Applies a reviewed existing subscription change only after explicit approval. May charge the chosen saved card and select it for future renewals. References are bound to the workspace, user and exact selection. The amount is verified again; an increase, currency change, stale reference or changed subscription requires a new review. A lower refreshed amount is allowed. No card is required for a change with no payment due. Pending payments do not grant upgrades; open the returned app billing link to complete payment. Requires a user-owned credential with billing:write scope and owner, admin or billing access in the active workspace. API Access must be enabled. operationId: confirmSubscriptionPaymentChange requestBody: required: true content: application/json: schema: type: object additionalProperties: false required: - review_ref - confirm properties: review_ref: type: string maxLength: 16000 payment_method_ref: type: string maxLength: 4000 description: >- Reference from the same review, required when payment is due. Omit when no payment is due. confirm: type: boolean enum: - true description: >- Explicit approval of the reviewed selection, amount, currency and selected card. The selected card also becomes the subscription renewal method. responses: '200': description: Confirm subscription change. content: application/json: schema: type: object required: - data properties: data: type: object required: - updated - pending_payment properties: updated: type: boolean pending_payment: type: boolean description: >- Payment is not yet confirmed; requested upgrades remain unavailable until confirmed payment. warnings: type: array items: type: string billing_url: type: string format: uri description: >- Sign in to the workspace to complete a pending payment. '400': description: Invalid request or missing explicit confirmation. '401': $ref: '#/components/responses/Unauthorized' '403': $ref: '#/components/responses/Forbidden' '409': description: >- Review expired, terms changed, method unavailable or billing needs attention. '429': $ref: '#/components/responses/RateLimited' components: responses: Unauthorized: description: Missing, invalid, expired or revoked API key / access token. content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' example: error: code: unauthorized message: Invalid API key. Forbidden: description: >- The credential lacks the required scope or role, or the workspace does not have the required capability. content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' examples: scopeDenied: summary: Required scope is missing value: error: code: forbidden message: >- This API key is missing the required scope "assistants:write". apiAccessRequired: summary: API Access is not available value: error: code: api_access_required message: >- API Access is not available for this workspace. Review Settings → Plan. RateLimited: description: Too many requests. Retry after the indicated delay. headers: Retry-After: description: Seconds to wait before retrying. schema: type: integer minimum: 1 content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' example: error: code: rate_limited message: Too many requests. Retry after the indicated delay. schemas: ErrorEnvelope: type: object description: Error envelope returned by every /api/v1 endpoint on failure. required: - error properties: error: type: object required: - code - message properties: code: type: string enum: - unauthorized - forbidden - api_access_required - not_found - invalid_request - rate_limited - conflict - telephony_configuration_error - telephony_unavailable - destination_forbidden - internal_error description: Stable, machine-readable error code. message: type: string description: Human-readable description of the error. securitySchemes: bearerAuth: type: http scheme: bearer bearerFormat: API key description: >- API key (`fam_...`, created under **Settings → API Keys**) or an OAuth 2.0 access token (`fam_at_...`). REST operations also require API Access for the credential's workspace. Keys can be restricted to scopes such as `assistants:read`, `calls:write`, `campaigns:write`, `automations:read`, `dashboards:read`, `dashboards:write`, `leads:write`, `segments:write`, `loop:read`, `loop:write`, `phone_numbers:write`, `sip_trunks:write`, `knowledge:write`, `voices:read`, `billing:read`, `billing:write`, `settings:write`, `platform:read`, `platform:write`; a `*:write` scope implies the matching `*:read`. Automation and dashboard endpoints also accept the legacy `calls:*` scope. Keys without scope restrictions have full access within the workspace's available capabilities. ````