Documentation
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Overview ¶
Package price values assets on a given day, in a given currency, from free public market data: Binance and OKX daily candles for crypto, justETF's daily quotes for stocks and ETFs by ISIN (Yahoo Finance as a fallback), the European Central Bank's reference rates (through Frankfurter) between currencies. No account or key is needed. Prices are kept in memory and, with a Cache, across restarts: each day is asked once.
p := price.New(nil, http.DefaultClient) // memory only
eur, err := p.Price(ctx, model.CryptoOrFiat("BTC"), day, "EUR")
UnitPrice adapts a Service to what pkg/portfolio expects; any other source of prices with that signature works too.
Index ¶
- Variables
- type Cache
- type Service
- func (s *Service) Price(ctx context.Context, a model.Asset, at time.Time, ccy string) (decimal.Decimal, error)
- func (s *Service) UnitPrice(ctx context.Context, ccy string) func(a model.Asset, at time.Time) (decimal.Decimal, bool)
- func (s *Service) Valuer(ctx context.Context, ccy string) model.Valuer
- type Window
Constants ¶
This section is empty.
Variables ¶
var ErrNoPrice = errors.New("no price known")
ErrNoPrice is returned when no provider knows the asset that day.
Functions ¶
This section is empty.
Types ¶
type Cache ¶
type Cache interface {
PriceSeries(ctx context.Context, pair string) (map[string]string, error)
PriceWindows(ctx context.Context, pair string) ([]Window, error)
PutPrices(ctx context.Context, pair string, w Window, closes map[string]string) error
}
Cache keeps closes between runs. Pairs are a provider and a market ("binance:BTCEUR", "fx:USDEUR"); days are YYYY-MM-DD and closes decimal strings. Fundarr's store is one.
type Service ¶
type Service struct {
Cache Cache // nil: memory only
HTTP *http.Client
Now func() time.Time
// Provider endpoints, replaceable in tests.
BinanceURL, OKXURL, FXURL, JustETFURL string
YahooURLs []string // tried in turn
// Market, when set, answers instead of the providers (no network): the
// closes of pair ("binance:BTCEUR", "fx:USDEUR"…) from from to to. A
// market it does not know has no closes.
Market func(pair string, from, to time.Time) map[string]decimal.Decimal
// contains filtered or unexported fields
}
Service answers "what was this worth that day". Safe for concurrent use.
func (*Service) Price ¶
func (s *Service) Price(ctx context.Context, a model.Asset, at time.Time, ccy string) (decimal.Decimal, error)
Price of one unit of asset on the day of at, in ccy (a fiat code).
Source Files