Historical observations

Compare prices across time without losing their identity.

GET /v1/observations is the proposed interface for retained observations. There is no comprehensive historical archive available today.

Two different dates

Observation time tells you when a fare was collected. Travel date tells you when the passenger would fly. Keep these independent in your queries and charts.

Compare like with like

A comparison should match carrier/source, airports, departure and return dates, passenger mix, cabin, market, original currency, price basis and available fare conditions. Different departures or baggage allowances are different series.

Preserve the original price

Amounts are decimal strings. Retain original currency even when providing an optional converted display price. A conversion needs the rate, rate date and source. Exchange-rate movement is not an airline price change.

Retention and completeness

Your agreement defines retained sources, dates, fields and delivery method. Queries should expose coverage start/end and collection gaps. A missing observation is not proof that a route had no flights.

Historical data can support your own trend analysis. A low current observation alone does not prove a market discount or seasonal pattern.