{"openapi":"3.1.0","info":{"title":"POST /api/v1/billing/addon/preview","version":"1.0.0","description":"Preview Addon Change"},"servers":[{"url":"https://api.ondayzero.com","description":"Production"}],"paths":{"/api/v1/billing/addon/preview":{"post":{"tags":["billing"],"summary":"Preview Addon Change","description":"Preview the billing impact of adding or removing an add-on.\n\n**Request Body:**\n- `addon_slug`: Add-on module slug from AddOnModule enum\n- `action`: 'add' or 'remove'\n\n**Returns:** Prorated amount (cents; `null` when Stripe could not\nproduce a preview), addon price, and effective date for removals.\nRefused (400 `BILLING_023`) on a business billed under a partner\nagreement.","operationId":"preview_addon_change","parameters":[{"name":"authorization","in":"header","required":false,"schema":{"anyOf":[{"type":"string"},{"type":"null"}],"title":"Authorization"}},{"name":"x-business-id","in":"header","required":false,"schema":{"anyOf":[{"type":"string"},{"type":"null"}],"title":"X-Business-Id"}}],"requestBody":{"required":true,"content":{"application/json":{"schema":{"$ref":"#/components/schemas/AddonPreviewRequest"}}}},"responses":{"201":{"description":"Successful Response","content":{"application/json":{"schema":{"$ref":"#/components/schemas/SuccessEnvelope_PreviewAddonChangeResponse_"}}}},"422":{"description":"Validation Error","content":{"application/json":{"schema":{"$ref":"#/components/schemas/ErrorResponse"},"example":{"error":"validation_error","message":"Validation failed: amount: Input should be a valid integer","errors":{"amount":"Input should be a valid integer"},"code":"GEN_002","request_id":"3f0e7c2a-9b4d-4e1a-8c6f-2d5b7a1e9c30"}}}},"401":{"description":"Unauthorized - Missing or expired token, an MCP OAuth token used against the REST API, or no access to this business","content":{"application/json":{"schema":{"$ref":"#/components/schemas/ErrorResponse"},"example":{"error":"unauthorized","message":"Authentication required","code":"AUTH_001","request_id":"3f0e7c2a-9b4d-4e1a-8c6f-2d5b7a1e9c30"}}}},"403":{"description":"Forbidden - Insufficient permissions","content":{"application/json":{"schema":{"$ref":"#/components/schemas/ErrorResponse"},"example":{"error":"forbidden","message":"You don't have permission to access this resource","code":"AUTH_002","request_id":"3f0e7c2a-9b4d-4e1a-8c6f-2d5b7a1e9c30"}}}}},"x-fastapi-operation-id":"preview_addon_change_api_v1_billing_addon_preview_post"}}},"components":{"schemas":{"AddonPreviewRequest":{"properties":{"addon_slug":{"type":"string","title":"Addon Slug","description":"Add-on module slug (e.g. 'ai_pro')."},"action":{"type":"string","enum":["add","remove"],"title":"Action","description":"'add' or 'remove'."}},"type":"object","required":["addon_slug","action"],"title":"AddonPreviewRequest"},"PreviewAddonChangeResponse":{"properties":{"prorated_amount":{"anyOf":[{"type":"integer"},{"type":"null"}],"title":"Prorated Amount"},"addon_price":{"type":"integer","title":"Addon Price"},"action":{"type":"string","enum":["add","remove"],"title":"Action"},"effective_date":{"anyOf":[{"type":"string"},{"type":"null"}],"title":"Effective Date"}},"additionalProperties":true,"type":"object","required":["addon_price","action"],"title":"PreviewAddonChangeResponse","description":"Response for ``preview_addon_change``.\n\n``prorated_amount`` is ``None`` when Stripe could not produce a proration\npreview (or there is no subscription to preview against). Clients must\nrender that as \"calculated by Stripe\" — never as ``$0.00``."},"SuccessEnvelope_PreviewAddonChangeResponse_":{"properties":{"success":{"type":"boolean","title":"Success","default":true},"message":{"anyOf":[{"type":"string"},{"type":"null"}],"title":"Message"},"code":{"anyOf":[{"type":"string"},{"type":"null"}],"title":"Code"},"data":{"anyOf":[{"$ref":"#/components/schemas/PreviewAddonChangeResponse"},{"type":"null"}]}},"additionalProperties":true,"type":"object","title":"SuccessEnvelope[PreviewAddonChangeResponse]"},"ErrorResponse":{"title":"ErrorResponse","type":"object","description":"Envelope returned by every non-2xx response. Branch on `code` (stable) rather than `message` (human-readable, may change).","required":["error","message","code"],"properties":{"error":{"type":"string","description":"Error category: `validation_error`, `unauthorized`, `forbidden`, `not_found`, `conflict`, `rate_limited`, `server_error`, or `service_unavailable`."},"message":{"type":"string","description":"Human-readable explanation, safe to show to end users."},"code":{"type":"string","description":"Stable machine-readable code in `CATEGORY_NNN` form (e.g. `NOT_FOUND_006`, `AUTH_010`, `GEN_002`)."},"request_id":{"type":"string","description":"Correlation id for support requests. Echoes the `x-request-id` request header when one was supplied."},"errors":{"type":"object","additionalProperties":{"type":"string"},"description":"Field-level validation messages keyed by field name. Present on 400/422 validation failures only."}}}},"securitySchemes":{"BearerAuth":{"type":"http","scheme":"bearer","bearerFormat":"API Token","description":"API token authentication. Format: `Bearer dz_...`"}}},"security":[{"BearerAuth":[]}]}