Select a format
Use?format=json|csv|xml or the Accept header (application/json, text/csv, application/xml, text/xml). The query parameter takes precedence. Without an explicit selection, JSON is the default; do not rely on a browser’s Accept header to select formats automatically.
Plan access
CSV and XML require Esencial or higher. JSON is available on all plans, subject to endpoint and market access. Choosing JSON does not remove normal quota usage.CSV structure
CSV uses commas as delimiters and decimal points. Objects are flattened with names such asfrom.currency. With one object collection, each item becomes a row and other fields repeat; collection columns use a prefix such as rates.mid. Columns include the union of present fields and can grow.
Multiple object collections cannot fit into one table: they may produce 406 format_not_available. For /route, use JSON or XML. In spreadsheets, select the delimiter and number format explicitly when importing.
XML structure
The root is<response>. Each key becomes an element and array entries are named <item>. A null field becomes an empty element; an absent field is omitted. Illustrative fragment:
Check status before parsing
API-generated errors remain JSON even when requesting CSV/XML; a proxy may use another format.400 invalid_format indicates an unknown format, 402 feature_not_in_plan missing access, and 406 format_not_available an incompatible representation. The quickstart JSON clients are for JSON; do not pass them format=csv or xml.