Table of Contents

Bodu.Financial.ExchangeRates Namespace

Packages
Bodu.Financial.ExchangeRates.Oanda 0.7.1 (not published on nuget.org)
Bodu.Financial.ExchangeRates.Xe 0.7.1 (not published on nuget.org)

Bodu.Financial.ExchangeRates

Bodu.Financial.ExchangeRates

Purpose

Bodu.Financial.ExchangeRates is the exchange-rate namespace of the Bodu.Financial family. The core FX types - ExchangeRate values, currency pairs, rate series and stores, and the standard IDatedRateProvider and timeless IRateProvider contracts - ship in the core Bodu.Financial package. The separate Bodu.Financial.ExchangeRates package layers the web/HTTP provider machinery on top (the abstract WebRateProvider and PairWebRateProvider<TSeries> bases and their supporting types), so the core package carries no HTTP machinery. The same flattened namespace then gathers the concrete providers for the public feeds - the Bank of England, the European Central Bank, the Reserve Bank of Australia, Yahoo Finance, OFX, XE.com, OANDA, Fixer (fixer.io), exchangerate.host, FRED (St. Louis Fed), and the IMF - each shipped as its own package. Every provider downloads and parses its source over a requested date window into a dated series, so they all compose with Money.ConvertTo, the caching and aggregating layer, and the rest of the FX stack.

The single-base providers (BoE, ECB, RBA, IMF) publish one base currency (GBP, EUR, AUD, USD), so they support direct (base→X) and inverse (X→base) lookups but not cross pairs; IMF downloads the IMF's monthly Representative Exchange Rates tab-separated report and normalizes its quotation direction to a consistent USD base. The market providers (Yahoo, OFX, XE, OANDA, Fixer, exchangerate.host) fetch a distinct series per currency pair, so they serve arbitrary pairs; FRED is per-pair too but maps each pair to a source series identifier (with a built-in map for the major pairs). Fixer, exchangerate.host, and FRED require an API key on their options; IMF is keyless and daily. Every provider is IDisposable: the options-only constructor builds and owns its HttpClient, while the constructor that accepts an HttpClient (the form the dependency-injection registration uses) leaves the client's lifetime to the caller. Downloaded responses are cached on disk by default.

Each provider ships its own dependency-injection registration in the Bodu.Financial.ExchangeRates namespace, so a single using Bodu.Financial.ExchangeRates; makes the Add<Source>... extension methods available - AddBoeExchangeRates, AddEcbExchangeRates, AddRbaExchangeRates, AddYahooExchangeRates, AddOfxExchangeRates, AddXeExchangeRates, AddOandaExchangeRates, AddFixerExchangeRates, AddExchangeRateHostExchangeRates, AddFredExchangeRates, and AddImfExchangeRates. There is no separate per-provider *.DependencyInjection package; the registration lives in the provider's own runtime package over the shared AddWebRateProvider machinery.

Static documentation

  • Introduction - the infrastructure package: the two provider bases, the fetch machinery, the eleven-package provider family with status and DI registration, and the "which provider" table.
  • Core concepts - warm-then-lookup, bulk vs pair, RateRangeResult, history availability, payload cache vs rate cache, single-flight, synchronous access, resilience, failure modes, lifetimes, thread safety.
  • Getting started - install, direct construction, DI registration with an appsettings.json section, API keys, range reads, and the payload cache.
  • Built-in exchange-rate providers guide - construction, warming the store or a pair, the shared lookup surface, dependency injection, and composing a provider with caching and aggregation.
  • Testing your own provider - the contract-test bases and offline stub handler in the in-repository Bodu.Financial.ExchangeRates.Testing project, which is not a package and has no API reference.

Key types

Core exchange types (in the Bodu.Financial package)

Web-provider machinery (in the Bodu.Financial.ExchangeRates package)

  • WebRateProvider, WebRateProviderOptions - the abstract HTTP-backed dated-provider base that every provider here derives from (it accumulates fetched observations into an immutable book / snapshot, coalesces concurrent loads, and owns or borrows its HttpClient) and the abstract options carrying BaseAddress, HttpTimeout, UserAgent, DefaultLookback, CurrencyAliases, and per-stage log levels.
  • PairWebRateProvider<TSeries> - the specialisation the pair-serving providers (Yahoo, OFX, XE, OANDA, Fixer, exchangerate.host, FRED) build on. IMF, like the central-bank providers, extends WebRateProvider directly.
  • IPairRateSource<TSeries>, IPairRateLoader, CurrencyPairRequest, PairRateData<TSeries> - the pair-based fetch contracts (GetPairAsync), the request struct (pair + inclusive date range), and the result record (pair, observations, source-specific series metadata).
  • SingleFlightCoordinator<TKey> - keyed single-flight coordinator that coalesces concurrent loads of the same key onto one in-flight operation (RunAsync / RunAsync<TResult>), used internally by WebRateProvider to deduplicate endpoint fetches.
  • FileSystemByteCache<TKey> - the abstract base for the file-feed providers' on-disk raw-response caches (best-effort TryGetCore / StoreCore keyed by a download unit); a derived cache supplies only the file name and, optionally, a freshness rule. The BoE / ECB / RBA FileSystem*Cache implementations derive from it.
  • RateProviderHttpClientFactory - builds the owned HttpClient for the options-only constructor form.
  • ExchangeRateFormatException (a FormatException) - the feed-parse failure raised by the provider stack.

Registration machinery (in the Bodu.Financial.ExchangeRates.DependencyInjection package)

  • WebRateProviderExtensions - the shared AddWebRateProvider<TProvider, TOptions>(...) registration machinery (named HttpClient plus Polly resilience) that every provider's Add<Source>... method delegates to, exposed in the same flattened Bodu.Financial.ExchangeRates namespace.

Bank of England (GBP base; daily spot, CSV export)

European Central Bank (EUR base; eurofxref XML feed)

Reserve Bank of Australia (AUD base; published .xls workbooks, split into eras)

Yahoo Finance (arbitrary pairs; chart per ticker)

  • YahooRateProvider - the provider; warm a pair with LoadPairAsync. Registered with AddYahooExchangeRates.
  • YahooRateProviderOptions - the endpoint, HTTP, user-agent, and on-demand-access configuration.
  • YahooSeriesInfo - a discovered pair and its ticker symbol, surfaced by GetAvailablePairs.

OFX (arbitrary pairs; spot-rate-history JSON service)

  • OfxRateProvider - the provider built on the shared PairWebRateProvider<TSeries> base; warm a pair with LoadPairAsync. Registered with AddOfxExchangeRates.
  • OfxRateProviderOptions - the endpoint, reporting interval, decimal precision, HTTP timeout, and user agent.
  • OfxSeriesInfo - a discovered pair and its quote-currency ISO code, surfaced by GetAvailablePairs.

XE.com (arbitrary pairs; charting-rates JSON service)

  • XeRateProvider - the provider built on the shared PairWebRateProvider<TSeries> base; warm a pair with LoadPairAsync. Registered with AddXeExchangeRates.
  • XeRateProviderOptions - the endpoint, HTTP, and token-acquisition configuration.
  • IXeAuthTokenProvider, XeScrapingAuthTokenProvider (internal) - the authorization-token seam and the default implementation that acquires XE's Basic credential automatically.
  • XeSeriesInfo - a discovered pair, surfaced by GetAvailablePairs.

OANDA (arbitrary pairs; anonymous rolling ~180-day history window)

  • OandaRateProvider - the provider built on the shared PairWebRateProvider<TSeries> base; advertises its rolling window through WebRateProvider.HistoryAvailability. Registered with AddOandaExchangeRates.
  • OandaRateProviderOptions - the Historical Currency Converter endpoint, HTTP, and window configuration.
  • OandaSeriesInfo - a discovered pair, surfaced by GetAvailablePairs.

Fixer (fixer.io; arbitrary pairs; time-series / single-date JSON, API key)

  • FixerRateProvider - the provider built on the shared PairWebRateProvider<TSeries> base; warm a pair with LoadPairAsync. Registered with AddFixerExchangeRates.
  • FixerRateProviderOptions - the endpoint, ApiKey (access_key), time-series/single-date paths, HTTP, and on-demand-access configuration.
  • FixerSeriesInfo - a discovered pair with its base and quote currencies, surfaced by GetAvailablePairs.

exchangerate.host (arbitrary pairs; time-series / single-date JSON, API key)

FRED (St. Louis Fed; mapped pairs; series/observations JSON, API key)

  • FredRateProvider - the provider built on the shared PairWebRateProvider<TSeries> base; warm a pair with LoadPairAsync. Registered with AddFredExchangeRates.
  • FredRateProviderOptions - the endpoint, ApiKey (api_key), and the SeriesMap mapping each pair to a FRED series_id (built-in map for the major USD pairs).
  • FredSeriesInfo - a discovered pair and its FRED series identifier, surfaced by GetAvailablePairs.

IMF (base USD; monthly Representative Exchange Rates TSV report; keyless, daily)

  • ImfRateProvider - the single-base (USD) provider built on the shared WebRateProvider base; warm the store with LoadRangeAsync. Registered with AddImfExchangeRates.
  • ImfRateProviderOptions - the report endpoint (ReportPath/ReportType), the on-disk month cache settings, and the CurrencyNames map from IMF currency label to ISO 4217 code.
  • ImfSeriesInfo - a discovered currency series (always quoted against USD), surfaced by GetAvailablePairs.
  • ImfReportMonth - one calendar month of the Representative Exchange Rates report, the download unit the provider fetches and caches.
  • IImfReportCache, FileSystemImfReportCache, NullImfReportCache - the raw-report cache seam, its on-disk implementation, and the no-op cache used when on-disk caching is disabled.

Minimal sample

using Bodu.Financial;
using Bodu.Financial.ExchangeRates;

using var ecb = new EcbRateProvider(new EcbRateProviderOptions());
await ecb.LoadRangeAsync(new DateOnly(2023, 1, 1), new DateOnly(2023, 12, 31));

RateLookupResult usd = ecb.GetRate("EUR", "USD", new DateOnly(2023, 1, 3));

To register a provider in the container, add using Bodu.Financial.ExchangeRates; and call the source's Add<Source>... method - for example services.AddEcbExchangeRates();. See the providers guide for construction, warming, dependency injection, and composing with the caching and aggregating layer.

Namespaces

Bodu.Financial.ExchangeRates.Caching

Classes

BoeEndpointOptions

Configures the provider's connection to the Bank of England Interactive Statistical Database (IADB): where the CSV query endpoint lives and how the HTTP requests that drive it are shaped.

BoeFinancialServiceBuilderExtensions

Provides the fluent registration of the Bank of England exchange-rate provider onto an IFinancialServiceBuilder.

BoeRateProvider

Serves Bank of England daily spot rates as ExchangeRate values, implementing the Bodu.Financial provider contracts over data queried from the Bank's Interactive Statistical Database (IADB) CSV endpoint.

BoeRateProviderOptions

Configures how the BoeRateProvider downloads, caches, and interprets Bank of England daily spot exchange-rate data.

BoeSeries

Maps a quote currency to the Bank of England Interactive Statistical Database (IADB) series code that publishes its daily spot rate against the pound sterling.

BoeSeriesInfo

Describes one currency series discovered in a Bank of England response: the pair it represents and the IADB metadata that identifies it.

BoeServiceCollectionExtensions

Provides a one-call entry point that registers the core Bodu.Financial services together with the Bank of England exchange-rate provider.

DateRangeCoverage

Tracks the set of DateOnly ranges that have actually been observed, as a sorted list of disjoint inclusive intervals that merge on insertion but never bridge a gap.

DatedRateProviderAdapter

Adapts an IDatedRateProvider to the simpler timeless IRateProvider surface by pinning a fixed valuation date and lookup options.

DistributedRateCacheExtensions

Provides the fluent registration of a distributed (Redis-capable) exchange-rate cache onto an IFinancialServiceBuilder.

EcbEndpointOptions

Configures the provider's connection to the European Central Bank's eurofxref endpoints: where the feed files are published and how the HTTP requests that fetch them are shaped.

EcbFinancialServiceBuilderExtensions

Provides the fluent registration of the ECB euro reference-rate provider onto an IFinancialServiceBuilder.

EcbRateFeed

Identifies one of the eurofxref XML files in which the European Central Bank publishes its euro foreign-exchange reference rates.

EcbRateProvider

Serves European Central Bank euro reference rates as ExchangeRate values, implementing the Bodu.Financial provider contracts over data downloaded from the ECB's published eurofxref XML feeds.

EcbRateProviderOptions

Configures how the EcbRateProvider downloads, caches, and interprets ECB euro reference-rate data.

EcbSeriesInfo

Describes one currency series discovered in an ECB feed: the pair it represents and the quote-currency code.

EcbServiceCollectionExtensions

Provides a one-call entry point that registers the core Bodu.Financial services together with the ECB euro reference-rate provider.

ExchangeRateFormatException

The exception thrown when an upstream exchange-rate feed returns data that cannot be interpreted as exchange-rate information - because it is malformed or omits the expected values.

ExchangeRateHostFinancialServiceBuilderExtensions

Provides the fluent registration of the exchangerate.host exchange-rate provider onto an IFinancialServiceBuilder.

ExchangeRateHostRateProvider

Serves exchangerate.host exchange rates as ExchangeRate values, implementing the Bodu.Financial provider contracts over the exchangerate.host time-series and historical JSON REST endpoints.

ExchangeRateHostRateProviderOptions

Configures how the ExchangeRateHostRateProvider addresses and interprets the exchangerate.host foreign-exchange REST service.

ExchangeRateHostSeriesInfo

Describes one currency series fetched from exchangerate.host: the pair it represents and the source and quote currencies the response was denominated in.

ExchangeRateHostServiceCollectionExtensions

Provides a one-call entry point that registers the core Bodu.Financial services together with the exchangerate.host exchange-rate provider.

FileSystemBoeResponseCache

An IByteCache<TKey> that persists downloaded IADB range responses as files in a cache directory, keyed by the inclusive date range that produced them.

FileSystemByteCache<TKey>

Provides a best-effort, file-backed cache of downloaded response bytes keyed by a provider-specific download unit.

FileSystemEcbFeedCache

An IByteCache<TKey> that persists downloaded ECB feeds as files in a cache directory, keyed by the feed that produced them.

FileSystemImfReportCache

An IImfReportCache that persists downloaded IMF monthly reports as files in a cache directory.

FileSystemRbaWorkbookCache

An IByteCache<TKey> that persists downloaded RBA workbooks as files in a cache directory, keyed by the era workbook that produced them.

FixedDatedRateProvider

Provides an immutable IDatedRateProvider facade over an RateBook, applying an explicit provider-priority list to disambiguate pairs that carry observations from more than one publishing source.

FixedRateTable

An IRateProvider backed by a fixed dictionary of (from, to) → rate mappings.

FixerFinancialServiceBuilderExtensions

Provides the fluent registration of the Fixer exchange-rate provider onto an IFinancialServiceBuilder.

FixerRateProvider

Serves Fixer (fixer.io) exchange rates as ExchangeRate values, implementing the Bodu.Financial provider contracts over the Fixer time-series and historical JSON REST endpoints.

FixerRateProviderOptions

Configures how the FixerRateProvider addresses and interprets the Fixer (fixer.io) foreign-exchange REST service.

FixerSeriesInfo

Describes one currency series fetched from Fixer: the pair it represents and the base and quote currencies the response was denominated in.

FixerServiceCollectionExtensions

Provides a one-call entry point that registers the core Bodu.Financial services together with the Fixer exchange-rate provider.

FredFinancialServiceBuilderExtensions

Provides the fluent registration of the FRED exchange-rate provider onto an IFinancialServiceBuilder.

FredRateProvider

Serves FRED (Federal Reserve Bank of St. Louis) exchange rates as ExchangeRate values, implementing the Bodu.Financial provider contracts over the FRED series-observations JSON REST endpoint.

FredRateProviderOptions

Configures how the FredRateProvider addresses and interprets the FRED (Federal Reserve Bank of St. Louis) foreign-exchange REST service.

FredSeriesInfo

Describes one currency series fetched from FRED: the pair it represents and the FRED series identifier the observations were read from.

FredServiceCollectionExtensions

Provides a one-call entry point that registers the core Bodu.Financial services together with the FRED exchange-rate provider.

ImfFinancialServiceBuilderExtensions

Provides the fluent registration of the IMF exchange-rate provider onto an IFinancialServiceBuilder.

ImfRateProvider

Serves IMF (International Monetary Fund) Representative Exchange Rates as ExchangeRate values, implementing the Bodu.Financial provider contracts over the IMF's published monthly tab-separated report.

ImfRateProviderOptions

Configures how the ImfRateProvider addresses, caches, and interprets the IMF Representative Exchange Rates monthly report.

ImfReportMonth

Identifies a single calendar month of the IMF Representative Exchange Rates report, the download unit the ImfRateProvider fetches and caches.

ImfSeriesInfo

Describes one currency series discovered in an IMF Representative Exchange Rates report: the pair it represents and the quote-currency code.

ImfServiceCollectionExtensions

Provides a one-call entry point that registers the core Bodu.Financial services together with the IMF exchange-rate provider.

NullByteCache<TKey>

An IByteCache<TKey> that stores nothing, used when on-disk caching is disabled.

NullImfReportCache

An IImfReportCache that stores nothing, used when on-disk caching is disabled.

OandaFinancialServiceBuilderExtensions

Provides the fluent registration of the OANDA exchange-rate provider onto an IFinancialServiceBuilder.

OandaRateProvider

Serves OANDA (Historical Currency Converter) exchange rates as ExchangeRate values, implementing the Bodu.Financial provider contracts over the public OANDA Rates history JSON service.

OandaRateProviderOptions

Configures how the OandaRateProvider addresses and interprets the OANDA Historical Currency Converter rate-history service.

OandaSeriesInfo

Describes one currency series fetched from OANDA: the pair it represents, the quote-currency code reported for it, and the price basis the rates were drawn from.

OandaServiceCollectionExtensions

Provides a one-call entry point that registers the core Bodu.Financial services together with the OANDA exchange-rate provider.

OfxFinancialServiceBuilderExtensions

Provides the fluent registration of the OFX exchange-rate provider onto an IFinancialServiceBuilder.

OfxRateProvider

Serves OFX (ofx.com) exchange rates as ExchangeRate values, implementing the Bodu.Financial provider contracts over the OFX public spot-rate-history JSON REST service.

OfxRateProviderOptions

Configures how the OfxRateProvider addresses and interprets the OFX public spot-rate-history REST service.

OfxSeriesInfo

Describes one currency series fetched from OFX: the pair it represents and the quote-currency code reported for it.

OfxServiceCollectionExtensions

Provides a one-call entry point that registers the core Bodu.Financial services together with the OFX exchange-rate provider.

PairRateData<TSeries>

Represents the normalized result an IPairRateSource<TSeries> produces for one fetch: the resolved currency pair, its dated observations, and the source-specific series metadata.

PairWebRateProvider<TSeries>

Provides the shared machinery for a WebRateProvider that fetches one currency pair per request from a remote feed - per-pair coverage tracking, single-flight request coalescing, the fetch-and-accumulate orchestration, and the diagnostic logging - leaving a derived type to supply only the feed identity and the feed-specific exception text. The actual fetch and parse are delegated to an IPairRateSource<TSeries>.

RateBook

Provides an immutable, read-heavy collection of RateSeries instances keyed by RateSeriesKey (pair + provider), forming the immutable bridge between mutable build-side types (RateTableBuilder) and dated lookup providers ( FixedDatedRateProvider and friends).

RateCacheWarmupExtensions

Provides registration of the startup cache warm-up onto an IFinancialServiceBuilder.

RateCachingExtensions

Provides fluent registration of caching and aggregating exchange-rate providers onto an IFinancialServiceBuilder.

RateLookupOptions

Encapsulates the rules an exchange-rate lookup must apply when an exact-date match is unavailable.

RateProviderHttpClientFactory

Creates and configures the HttpClient a web-backed exchange-rate provider owns when the caller does not supply one, applying the HTTP contract (user agent and request timeout) the remote endpoint requires.

RateRangeResult

Represents the outcome of a range exchange-rate lookup: the observations that fall within the requested window, ordered by date, together with the metadata that describes the request and the span actually covered.

RateSeries

Stores the ordered set of dated exchange-rate observations for a single provider and currency pair, optimised for read-heavy lookup with allocation-free O(log n) resolution under any RateDateResolution policy.

RateSeriesBuilder

Provides a mutable construction and editing surface for an RateSeries, maintaining strictly ascending unique observation dates and strictly positive rates while supporting single-observation edits and bulk import.

RateSeriesNotFoundException

The exception thrown when a requested currency pair cannot be served because the upstream feed structurally does not carry it.

RateTableBuilder

Provides a mutable collection of RateSeriesBuilder instances keyed by currency pair and provider, intended for assembling rate observations across many series before producing immutable snapshots.

RbaEraWorkbook

Identifies one of the date-range files in which the Reserve Bank of Australia publishes its historical daily exchange rates.

RbaFinancialServiceBuilderExtensions

Provides the fluent registration of the RBA historical exchange-rate provider onto an IFinancialServiceBuilder.

RbaRateProvider

Serves Reserve Bank of Australia historical exchange rates as ExchangeRate values, implementing the Bodu.Financial provider contracts over data downloaded from the RBA's published .xls files.

RbaRateProviderOptions

Configures how the RbaRateProvider downloads, caches, and interprets RBA exchange-rate data.

RbaSeriesInfo

Describes one currency series discovered in an RBA workbook: the pair it represents and the RBA metadata that identifies it.

RbaServiceCollectionExtensions

Provides a one-call entry point that registers the core Bodu.Financial services together with the RBA historical exchange-rate provider.

SingleFlightCoordinator<TKey>

Coordinates concurrent asynchronous operations keyed by TKey so that at most one operation per key runs at a time, with every concurrent caller for that key awaiting the same shared task.

SqliteRateCacheExtensions

Provides the fluent registration of a SQLite-backed exchange-rate cache onto an IFinancialServiceBuilder.

WebRateProvider

Provides the shared machinery for an exchange-rate provider that materializes a remote feed into an in-memory RateBook snapshot: it owns the accumulator and the immutable snapshot, implements the full synchronous and asynchronous lookup matrix once, and optionally owns the HttpClient used to reach the feed. Derived types supply only the feed-specific fetch.

WebRateProviderExtensions

Provides the shared registration machinery for web-based exchange-rate providers on an IFinancialServiceBuilder.

WebRateProviderOptions

Provides the configuration common to every pair-based web exchange-rate source: the endpoint base address, the HTTP contract (user agent and timeout), the synchronous-access and look-back behaviour, the currency-alias map, and the per-concern diagnostic log levels. A concrete source derives from this type to add its own endpoint members and validation.

XeFinancialServiceBuilderExtensions

Provides the fluent registration of the XE.com exchange-rate provider onto an IFinancialServiceBuilder.

XeRateProvider

Serves XE.com exchange rates as ExchangeRate values, implementing the Bodu.Financial provider contracts over the XE charting-rates JSON service.

XeRateProviderOptions

Configures how the XeRateProvider addresses and interprets the XE.com charting-rates JSON service, and how it acquires the authorization token that endpoint requires.

XeSeriesInfo

Describes one currency series fetched from XE.com: the pair it represents and the quote-currency code reported for it.

XeServiceCollectionExtensions

Provides a one-call entry point that registers the core Bodu.Financial services together with the XE.com exchange-rate provider.

YahooFinancialServiceBuilderExtensions

Provides the fluent registration of the Yahoo Finance exchange-rate provider onto an IFinancialServiceBuilder.

YahooRateProvider

Serves Yahoo Finance exchange rates as ExchangeRate values, implementing the Bodu.Financial provider contracts over the Yahoo Finance v8/finance/chart JSON REST service.

YahooRateProviderOptions

Configures how the YahooRateProvider addresses and interprets the Yahoo Finance chart REST service.

YahooSeriesInfo

Describes one currency series fetched from Yahoo Finance: the pair it represents and the ticker that identifies it.

YahooServiceCollectionExtensions

Provides a one-call entry point that registers the core Bodu.Financial services together with the Yahoo Finance exchange-rate provider.

Structs

CurrencyPair

Represents an ordered pair of currencies that identifies the direction of an exchange-rate quotation.

CurrencyPairRequest

Describes a single pair-based fetch request issued to an IPairRateSource<TSeries>: the currency pair to load and the inclusive date range to cover.

ExchangeRate

Represents a single dated foreign-exchange rate observation produced by a named provider.

ExchangeRate<TBase, TQuote>

Strongly-typed companion to ExchangeRate where the base and quote currencies are domain invariants encoded as type parameters.

RateHistoryAvailability

Declares how far back in time a provider can serve exchange rates, as one of three shapes: an unbounded archive, a rolling window of the most recent days, or a fixed earliest calendar date.

RateLookupResult

Represents the outcome of a successful exchange-rate lookup, carrying both the resolved rate and the metadata that describes how it was selected.

RateObservation

Represents a single observed exchange rate on a specific calendar date for a series.

RateProvenance

Captures the lineage of a single served exchange rate: the provider name it is attributed to, whether it was resolved directly by a provider or served from a cache, the cache backend that served it, and - for a cache serve - the instant the served data was cached together with the derived age at the time of the lookup.

RateSeriesKey

Identifies a single rate series within an RateTableBuilder by its currency pair and provider.

Interfaces

IByteCache<TKey>

Caches the raw bytes of a downloaded response so an identical download unit need not be re-fetched.

IDatedRateProvider

Defines the contract for an exchange-rate provider that resolves dated and latest lookups and returns metadata describing how each rate was selected, over symmetric synchronous and asynchronous surfaces.

IHistoricalRateProvider

Identifies an exchange-rate provider that advertises how far back it can serve historical rates, so composing layers can avoid asking it for dates it has declared unavailable.

IImfReportCache

Caches the raw bytes of downloaded IMF monthly report files so they need not be re-fetched on every load.

IPairRateLoader

Defines the common warm-up and discovery surface shared by every web-backed exchange-rate provider: a caller can prime a pair's window and enumerate the pairs currently held without knowing the concrete provider or how its feed is organized (per pair, per era, per feed, or per range).

IPairRateSource<TSeries>

Fetches and parses the dated observations for a single currency pair and date range. This is the per-source seam between a PairWebRateProvider<TSeries> and the network: a concrete implementation builds the feed-specific request, issues it, and parses the response into a PairRateData<TSeries>, while tests substitute a fixture-backed implementation.

IRateProvider

Source of foreign-exchange rates used to convert between currencies.

Enums

RateDateResolution

Describes how an exchange-rate lookup should resolve a requested date when an exact match is unavailable.

RateHistoryAvailabilityKind

Identifies how an RateHistoryAvailability bounds the earliest date for which a provider can serve rates.

RateOrigin

Identifies where a served exchange rate was resolved from, distinguishing a value produced directly by a provider from one served out of a cache.