Historical FX observations are live
Paginated historical exchange-rate observations are available through REST and MCP with genuine dates and sparse currency coverage.
FX now includes current rates, decimal-safe conversion, and historical observations through the same Narwhal key and quota.
Available through REST and MCP
The REST operation is GET /v1/fx/rates/{base}/observations. The matching MCP tool is fx_get_rate_history. Both return the same schema and consume one request from the shared monthly quota.
Open the historical FX API reference for parameters, examples, errors, and coverage limits.
Full-history backfills use bounded pages
Callers select a base, currencies, and inclusive date range. Each page contains at most 366 dates. An opaque cursor advances through the same filter-bound request until the backfill is complete.
Missing dates remain missing
Historical responses contain genuine stored observation dates only. Narwhal does not create weekend or holiday rows and does not carry a weekly currency forward across daily dates. A date may honestly contain only a subset of the requested currencies.
The public response stays selective
Each public record contains its date, currency, and decimal-string rate. Provider identity, routing, licences, derivation, and internal audit fields remain outside the customer response. The FX methodology explains that policy and the history limitations.