{ "openapi": "3.1.1", "info": { "title": "Subscription Stack API", "version": "1.0.0", "summary": "Add up every subscription, spot overlaps and see which ones to cancel and what you save.", "description": "Every endpoint performs the same calculation as the human page and returns inputs, result, units, assumptions, sources, warnings and computedAt. MCP endpoint: /mcp." }, "servers": [ { "url": "https://subscriptionstack.usefulweb.site" } ], "paths": { "/api/v1/calculate": { "post": { "operationId": "calculate", "summary": "Add up every subscription, spot overlaps and see which ones to cancel and what you save.", "description": "List your subscriptions with price, billing cycle, category, how often you use them and how many people share them. Subscription Stack converts everything to monthly and yearly totals, groups by category, flags overlapping services, computes cost per use and lists cancellation candidates with the savings.\n\nMethodology:\n- Monthly price = weekly × (365.25/12)/7 (≈ 4.348), monthly × 1, quarterly ÷ 3, yearly ÷ 12.\n- Your share = monthly price ÷ number of people sharing; annual = your monthly share × 12.\n- Cost per use = your monthly share ÷ uses per month (not computed when uses are unknown or zero).\n- Overlap = two or more subscriptions in the same category (excluding “other”).\n- Cancel candidate if uses per month < your threshold, or cost per use > your threshold, or it is the most expensive per use (or least used) service within an overlapping category.\n- Savings if cancelled = sum of your monthly shares of all candidates; annual = × 12.", "tags": [ "money" ], "x-mcp-tool": "subscription_stack", "requestBody": { "required": true, "content": { "application/json": { "schema": { "$ref": "#/components/schemas/SubscriptionStackInput" }, "examples": { "example1": { "summary": "Typical household stack", "value": { "currency": "EUR", "minUsesPerMonth": 2, "maxCostPerUse": 5, "subscriptions": [ { "name": "Netflix", "price": 13.99, "billing": "monthly", "category": "video", "usesPerMonth": 12, "sharedBy": 2 }, { "name": "Disney+", "price": 89.9, "billing": "yearly", "category": "video", "usesPerMonth": 2 }, { "name": "Spotify", "price": 10.99, "billing": "monthly", "category": "music", "usesPerMonth": 40 }, { "name": "Gym", "price": 34.9, "billing": "monthly", "category": "fitness", "usesPerMonth": 3 }, { "name": "Cloud 2 TB", "price": 9.99, "billing": "monthly", "category": "cloud-storage", "usesPerMonth": 30 }, { "name": "Newspaper", "price": 29.97, "billing": "quarterly", "category": "news", "usesPerMonth": 1 } ] } }, "example2": { "summary": "Freelancer software stack", "value": { "currency": "USD", "minUsesPerMonth": 4, "maxCostPerUse": 3, "subscriptions": [ { "name": "Design suite", "price": 59.99, "billing": "monthly", "category": "software", "usesPerMonth": 20 }, { "name": "Second design app", "price": 99, "billing": "yearly", "category": "software", "usesPerMonth": 1 }, { "name": "Cloud backup", "price": 6, "billing": "monthly", "category": "cloud-storage", "usesPerMonth": 30 }, { "name": "Extra cloud drive", "price": 2.99, "billing": "monthly", "category": "cloud-storage" } ] } } } } } }, "responses": { "200": { "description": "Calculation result envelope.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/SubscriptionStackResult" } } } }, "400": { "description": "Malformed JSON body.", "content": { "application/problem+json": { "schema": { "$ref": "#/components/schemas/Problem" } } } }, "422": { "description": "Invalid input (see errors[]).", "content": { "application/problem+json": { "schema": { "$ref": "#/components/schemas/Problem" } } } }, "429": { "description": "Rate limit exceeded (see Retry-After).", "content": { "application/problem+json": { "schema": { "$ref": "#/components/schemas/Problem" } } } } } } }, "/api/v1/tool": { "get": { "operationId": "getToolDefinition", "summary": "Inputs, output schema and examples for this tool", "responses": { "200": { "description": "Tool definition.", "content": { "application/json": { "schema": { "type": "object" } } } } } } } }, "components": { "schemas": { "Problem": { "type": "object", "description": "RFC 9457 problem details. 422 responses include per-field `errors`.", "required": [ "type", "title", "status", "detail" ], "properties": { "type": { "type": "string" }, "title": { "type": "string" }, "status": { "type": "integer" }, "detail": { "type": "string" }, "code": { "type": "string" }, "errors": { "type": "array", "items": { "type": "object", "required": [ "field", "message" ], "properties": { "field": { "type": "string" }, "message": { "type": "string" } } } } } }, "SubscriptionStackInput": { "type": "object", "additionalProperties": false, "properties": { "currency": { "title": "Currency", "description": "Shown in results only; no conversion is performed.", "type": "string", "maxLength": 8, "default": "EUR" }, "minUsesPerMonth": { "title": "Flag if used fewer than", "type": "number", "minimum": 0, "maximum": 1000, "default": 2, "x-unit": "times/month" }, "maxCostPerUse": { "title": "Flag if cost per use is above", "description": "In your currency, for your share.", "type": "number", "minimum": 0, "default": 5 }, "subscriptions": { "title": "Subscriptions", "description": "Price is the full price per billing period; “Shared by” splits it (you pay price ÷ people). Leave uses empty if unknown.", "type": "array", "minItems": 1, "maxItems": 50, "items": { "type": "object", "additionalProperties": false, "properties": { "name": { "title": "Service", "type": "string" }, "price": { "title": "Price", "type": "number", "minimum": 0 }, "billing": { "title": "Billed", "type": "string", "enum": [ "weekly", "monthly", "quarterly", "yearly" ], "default": "monthly" }, "category": { "title": "Category", "type": "string", "enum": [ "video", "music", "news", "software", "cloud-storage", "fitness", "gaming", "food", "other" ], "default": "other" }, "usesPerMonth": { "title": "Uses / month", "type": "number", "minimum": 0 }, "sharedBy": { "title": "Shared by", "type": "integer", "minimum": 1, "maximum": 20, "default": 1, "x-unit": "people" } }, "required": [ "name", "price" ] } } }, "required": [ "subscriptions" ] }, "SubscriptionStackResult": { "type": "object", "additionalProperties": false, "required": [ "schemaVersion", "tool", "computedAt", "inputs", "summary", "result", "units", "assumptions", "sources", "warnings", "presentation", "links" ], "properties": { "schemaVersion": { "type": "string", "const": "1.0" }, "tool": { "type": "object", "additionalProperties": false, "required": [ "id", "name", "version" ], "properties": { "id": { "type": "string" }, "name": { "type": "string" }, "version": { "type": "string" } } }, "computedAt": { "type": "string", "format": "date-time" }, "inputs": { "type": "object", "description": "Normalised inputs actually used, including applied defaults." }, "summary": { "type": "string" }, "result": { "type": "object", "additionalProperties": false, "required": [ "currency", "monthlyTotal", "annualTotal", "fullPriceMonthlyTotal", "subscriptions", "categories", "overlaps", "cancelCandidates", "savingsIfCancelled" ], "properties": { "currency": { "type": "string" }, "monthlyTotal": { "type": "number", "description": "Your share, per month." }, "annualTotal": { "type": "number" }, "fullPriceMonthlyTotal": { "type": "number", "description": "Before splitting shared subscriptions." }, "subscriptions": { "type": "array", "items": { "type": "object", "additionalProperties": false, "required": [ "name", "category", "billing", "monthlyFullPrice", "monthlyYourShare", "annualYourShare", "usesPerMonth", "costPerUse", "shareOfTotalPercent", "cancelCandidate", "reasons" ], "properties": { "name": { "type": "string" }, "category": { "type": "string", "enum": [ "video", "music", "news", "software", "cloud-storage", "fitness", "gaming", "food", "other" ] }, "billing": { "type": "string", "enum": [ "weekly", "monthly", "quarterly", "yearly" ] }, "monthlyFullPrice": { "type": "number" }, "monthlyYourShare": { "type": "number" }, "annualYourShare": { "type": "number" }, "usesPerMonth": { "type": [ "number", "null" ] }, "costPerUse": { "type": [ "number", "null" ], "description": "Your monthly share ÷ uses per month; null if uses unknown or 0." }, "shareOfTotalPercent": { "type": "number" }, "cancelCandidate": { "type": "boolean" }, "reasons": { "type": "array", "items": { "type": "string" } } } } }, "categories": { "type": "array", "items": { "type": "object", "additionalProperties": false, "required": [ "category", "label", "count", "monthly", "annual" ], "properties": { "category": { "type": "string", "enum": [ "video", "music", "news", "software", "cloud-storage", "fitness", "gaming", "food", "other" ] }, "label": { "type": "string" }, "count": { "type": "integer" }, "monthly": { "type": "number" }, "annual": { "type": "number" } } } }, "overlaps": { "type": "array", "items": { "type": "object", "additionalProperties": false, "required": [ "category", "services", "monthly" ], "properties": { "category": { "type": "string", "enum": [ "video", "music", "news", "software", "cloud-storage", "fitness", "gaming", "food", "other" ] }, "services": { "type": "array", "items": { "type": "string" } }, "monthly": { "type": "number" } } } }, "cancelCandidates": { "type": "array", "items": { "type": "string" } }, "savingsIfCancelled": { "type": "object", "additionalProperties": false, "required": [ "monthly", "annual" ], "properties": { "monthly": { "type": "number" }, "annual": { "type": "number" } } } } }, "units": { "type": "object", "additionalProperties": { "type": "string" } }, "assumptions": { "type": "array", "items": { "type": "string" } }, "sources": { "type": "array", "items": { "type": "object", "additionalProperties": false, "required": [ "title" ], "properties": { "title": { "type": "string" }, "url": { "type": "string" }, "publisher": { "type": "string" }, "retrievedAt": { "type": "string" }, "note": { "type": "string" } } } }, "warnings": { "type": "array", "items": { "type": "string" } }, "presentation": { "type": "array", "items": { "type": "object" }, "description": "Display blocks used by the human page (same data)." }, "links": { "type": "object", "additionalProperties": false, "required": [ "human", "api", "openapi", "methodology" ], "properties": { "human": { "type": "string", "format": "uri" }, "api": { "type": "string", "format": "uri" }, "openapi": { "type": "string", "format": "uri" }, "methodology": { "type": "string", "format": "uri" } } } } } } } }