Aggregate European rail booking content and understand the core flow

Verified steps

1. European rail content is fragmented across national operators (SNCF, DB, Renfe, Trenitalia, Eurostar, etc.) with no single open API covering all; primary aggregation options include Trainline Partner API, Distribusion, and Rail Europe API — each with different carrier coverage.
2. Authenticate and search by POSTing origin and destination station codes (UIC codes or the aggregator's internal station ids), travel date, passenger types, and optionally a specific departure time range.
3. Inspect each fare in the results for: carrier_code, service_class, flexibility (refundable/non-refundable/exchangeable), comfort_class, and whether seat reservation is included or mandatory.
4. For cross-border journeys (e.g. Paris→Barcelona), results may combine segments from multiple carriers — verify each segment's carrier and whether the ticket is a single through-ticket or separate tickets requiring re-validation.
5. Create a booking by POSTing the selected fare offer id plus passenger details (name, date of birth, loyalty card numbers if applicable); store both the aggregator booking reference and the carrier's own booking code.
6. Issue the ticket: many rail aggregators require a separate 'confirm' or 'ticket issuance' call after booking; the ticket document (PDF or barcode) is only generated after this step.