{ "openapi": "3.1.1", "info": { "title": "Travel Exchange Fee Calculator API", "version": "1.0.0", "summary": "Compare what cards, ATMs, DCC and exchange bureaus really cost abroad vs the ECB reference rate.", "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://travelexchangefeecalculator.usefulweb.site" } ], "paths": { "/api/v1/calculate": { "post": { "operationId": "calculate", "summary": "Compare what cards, ATMs, DCC and exchange bureaus really cost abroad vs the ECB reference rate.", "description": "Enter what you spend abroad and the terms of your payment options – foreign transaction fee, exchange-rate mark-up, ATM fees, “pay in your currency” (dynamic currency conversion) and exchange-bureau spreads. The calculator converts at the ECB reference rate (or your own rate) and shows the effective rate, total cost and extra cost of each option, cheapest first.\n\nMethodology:\n- Reference cost = amount ÷ reference rate (the ECB euro reference rate, cross-calculated via EUR for non-euro pairs, or your manual rate).\n- Each option: cost at its own rate = reference cost × (1 + mark-up %); plus the percentage fee on that amount; plus fixed fees (ATM fixed fees × number of withdrawals). Effective rate = amount ÷ total cost; extra cost = total − reference cost.\n- Dynamic currency conversion (DCC, “pay in your currency”) means the shop’s or ATM operator’s provider converts instead of your card issuer; its mark-up is entered as a rate mark-up. Under Regulation (EU) 2019/518 DCC providers and card issuers in the EU must express their conversion charges as a mark-up over the latest ECB reference rate before you pay, which is the comparison this tool makes.\n- The default rows are illustrative example values, not market data. Replace them with your card’s published terms and the mark-up shown on the terminal or at the exchange counter.\n\nAn estimate: the rate your card network applies on the booking day and any fees not entered here change the final amount.", "tags": [ "money" ], "x-mcp-tool": "travel_exchange_fee_calculator", "requestBody": { "required": true, "content": { "application/json": { "schema": { "$ref": "#/components/schemas/TravelExchangeFeeCalculatorInput" }, "examples": { "example1": { "summary": "500 USD with the example options (manual rate 1 EUR = 1.10 USD)", "value": { "amount": 500, "spendCurrency": "USD", "homeCurrency": "EUR", "rateSource": "manual", "manualRate": 1.1 } }, "example2": { "summary": "20,000 JPY, 2 ATM withdrawals (manual rate 1 GBP = 190 JPY)", "value": { "amount": 20000, "spendCurrency": "JPY", "homeCurrency": "GBP", "rateSource": "manual", "manualRate": 190, "atmWithdrawals": 2, "options": [ { "name": "Travel card", "method": "card", "feePercent": 0, "markupPercent": 0.4, "fixedFee": 0 }, { "name": "High-street bank ATM", "method": "atm", "feePercent": 2.99, "markupPercent": 0, "fixedFee": 1.5 }, { "name": "DCC offer at the ATM", "method": "dcc", "feePercent": 0, "markupPercent": 8, "fixedFee": 1.5 } ] } } } } } }, "responses": { "200": { "description": "Calculation result envelope.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/TravelExchangeFeeCalculatorResult" } } } }, "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" } } } } } }, "TravelExchangeFeeCalculatorInput": { "type": "object", "additionalProperties": false, "properties": { "amount": { "title": "Amount spent abroad", "description": "In the local (spending) currency.", "type": "number", "minimum": 0.01, "maximum": 1000000000, "default": 500 }, "spendCurrency": { "title": "Spending currency", "type": "string", "maxLength": 3, "default": "USD" }, "homeCurrency": { "title": "Home (account) currency", "type": "string", "maxLength": 3, "default": "EUR" }, "rateSource": { "title": "Reference rate", "type": "string", "enum": [ "ecb", "manual" ], "default": "ecb" }, "manualRate": { "title": "Manual rate: 1 home-currency unit =", "description": "…units of the spending currency (e.g. 1 EUR = 1.10 USD → 1.10). Used with \"Enter a rate manually\", or as fallback when the ECB is unreachable.", "type": "number", "minimum": 0.000001, "maximum": 1000000000 }, "options": { "title": "Payment options", "description": "Example values – replace them with your own card’s and provider’s terms. EU card issuers must state their conversion mark-up over the ECB rate.", "type": "array", "maxItems": 12, "items": { "type": "object", "additionalProperties": false, "properties": { "name": { "title": "Option", "type": "string", "maxLength": 80 }, "method": { "title": "Type", "type": "string", "enum": [ "card", "atm", "dcc", "exchange" ], "default": "card" }, "feePercent": { "title": "Fee %", "type": "number", "minimum": 0, "maximum": 50, "x-unit": "%" }, "markupPercent": { "title": "Rate mark-up %", "type": "number", "minimum": 0, "maximum": 50, "x-unit": "%" }, "fixedFee": { "title": "Fixed fee (home currency)", "type": "number", "minimum": 0, "maximum": 10000 } }, "required": [] }, "default": [ { "name": "Card without foreign transaction fee", "method": "card", "feePercent": 0, "markupPercent": 0, "fixedFee": 0 }, { "name": "Card with foreign transaction fee", "method": "card", "feePercent": 1.75, "markupPercent": 0, "fixedFee": 0 }, { "name": "ATM cash withdrawal", "method": "atm", "feePercent": 1, "markupPercent": 0, "fixedFee": 4 }, { "name": "\"Pay in your currency\" (DCC) at the terminal", "method": "dcc", "feePercent": 0, "markupPercent": 5, "fixedFee": 0 }, { "name": "Exchange bureau cash", "method": "exchange", "feePercent": 0, "markupPercent": 7, "fixedFee": 0 } ] }, "atmWithdrawals": { "title": "Number of ATM withdrawals", "description": "The fixed fee of ATM options is charged per withdrawal.", "type": "integer", "minimum": 1, "maximum": 100, "default": 1 } }, "required": [ "amount", "spendCurrency", "homeCurrency" ] }, "TravelExchangeFeeCalculatorResult": { "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": [ "amount", "spendCurrency", "homeCurrency", "referenceRate", "referenceCost", "rates", "options", "cheapest", "mostExpensive" ], "properties": { "amount": { "type": "number" }, "spendCurrency": { "type": "string" }, "homeCurrency": { "type": "string" }, "referenceRate": { "type": "number", "description": "Spending-currency units per 1 home-currency unit." }, "referenceCost": { "type": "number" }, "rates": { "type": "object", "additionalProperties": false, "required": [ "date", "source", "url", "fetchedAt", "stale" ], "properties": { "date": { "type": "string", "description": "Reference date of the rates." }, "requestedDate": { "type": [ "string", "null" ] }, "source": { "type": "string", "enum": [ "ecb-daily", "ecb-sdmx", "manual" ] }, "url": { "type": [ "string", "null" ] }, "fetchedAt": { "type": [ "string", "null" ] }, "stale": { "type": "boolean" } } }, "options": { "type": "array", "items": { "type": "object", "additionalProperties": false, "required": [ "name", "method", "homeCost", "extraCost", "extraPercent", "effectiveRate", "breakdown" ], "properties": { "name": { "type": "string" }, "method": { "type": "string" }, "homeCost": { "type": "number" }, "extraCost": { "type": "number" }, "extraPercent": { "type": "number" }, "effectiveRate": { "type": "number" }, "breakdown": { "type": "object", "additionalProperties": false, "required": [ "atReference", "markup", "percentFee", "fixedFees" ], "properties": { "atReference": { "type": "number" }, "markup": { "type": "number" }, "percentFee": { "type": "number" }, "fixedFees": { "type": "number" } } } } } }, "cheapest": { "type": "string" }, "mostExpensive": { "type": "string" } } }, "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" } } } } } } } }