PriceAuthority Object

We rely on PriceAuthority oracles. A PriceAuthority gives reliable quotes for prices. The quotes might be based on broad surveys of prices across the ecosystem, or might come directly from an AMM (Automatic Market Maker). A PriceAuthority can either give a quote for the current price across any pair of currencies it knows about, or can immediately return a Promise resolved when a condition is true. For example, a price crossing some threshold, or at a particular time. It can also provide a price feed that updates with every price change.

E(PriceAuthority).getQuoteIssuer(brandIn, brandOut)

• brandIn: Brand
• brandOut: Brand
• Returns: Issuer | Promise<Issuer>

Gets the ERTP Issuer of PriceQuotes for a given brandIn/brandOut pair.

const quoteIssuer = await E(PriceAuthority).getQuoteIssuer(
  collateralKit.brand,
  loanKit.brand,
);

E(PriceAuthority).getTimerService(brandIn, brandOut)

• brandIn: Brand
• brandOut: Brand
• Returns: TimerService | Promise<TimerService>

Gets the timer used in PriceQuotes for a given brandIn/brandOut pair.

const myTimer = E(PriceAuthority).getTimerService(
  collateral.brand,
  loanKit.brand,
);

E(PriceAuthority).makeQuoteNotifier(amountIn, brandOut)

• amountIn: Amount
• brandOut: Brand
• Returns: ERef<Notifier<PriceQuote>>

Be notified of the latest PriceQuotes for a given amountIn. The issuing rate may be very different between PriceAuthorities.

const myNotifier = E(PriceAuthority).makeQuoteNotifier(quatloos100, usdBrand);

E(PriceAuthority).quoteGiven(amountIn, brandOut)

• amountIn: Amount
• brandOut: Brand
• Returns: Promise<PriceQuote>

Gets a quote on-demand corresponding to amountIn.

const quote = await E(PriceAuthority).quoteGiven(moola500, quatloosBrand);

E(PriceAuthority).quoteWanted(brandIn, amountOut)

• brandIn: Brand
• amountOut: Amount
• Returns: Promise<PriceQuote>

Gets a quote on-demand corresponding to amountOut.

const quote = await E(PriceAuthority).quoteWanted(quatloosBrand, moola500);

E(PriceAuthority).quoteAtTime(deadline, amountIn, brandOut)

• deadline: Timestamp
• amountIn: Amount
• brandOut: Brand
• Returns: Promise<PriceQuote>

Resolves after deadline passes on the PriceAuthority’s timerService with the PriceQuote of amountIn at that time. Note that deadline's value is a BigInt.

const priceQuoteOnThisAtTime = E(PriceAuthority).quoteAtTime(
  7n,
  quatloosAmount34,
  usdBrand,
);

E(PriceAuthority).quoteWhenGT(amountIn, amountOutLimit)

• amountIn: Amount
• amountOutLimit: Amount
• Returns: Promise<PriceQuote>

Resolves when a PriceQuote of amountIn exceeds amountOutLimit.

const quote = E(PriceAuthority).quoteWhenGT(
  AmountMath.make(brands.In, 29n),
  AmountMath.make(brands.Out, 974n),
);

E(PriceAuthority).quoteWhenGTE(amountIn, amountOutLimit)

• amountIn: Amount
• amountOutLimit: Amount
• Returns: Promise<PriceQuote>

Resolves when a PriceQuote of amountIn reaches or exceeds amountOutLimit.

const quote = E(PriceAuthority).quoteWhenGTE(
  AmountMath.make(brands.In, 29n),
  AmountMath.make(brands.Out, 974n),
);

E(PriceAuthority).quoteWhenLT(amountIn, amountOutLimit)

• amountIn Amount
• amountOutLimit Amount
• Returns: Promise<PriceQuote>

Resolves when a PriceQuote of amountIn drops below amountOutLimit.

const quote = E(PriceAuthority).quoteWhenLT(
  AmountMath.make(brands.In, 29n),
  AmountMath.make(brands.Out, 974n),
);

E(PriceAuthority).quoteWhenLTE(amountIn, amountOutLimit)

• amountIn: Amount
• amountOutLimit: Amount
• Returns: Promise<PriceQuote>

Resolves when a PriceQuote of amountIn reaches or drops below amountOutLimit.

const quote = E(PriceAuthority).quoteWhenLTE(
  AmountMath.make(brands.In, 29n),
  AmountMath.make(brands.Out, 974n),
);

E(PriceAuthority).mutableQuoteWhenGT(amountIn, amountOutLimit)

• amountIn: Amount
• amountOutLimit: Amount
• Returns: Promise<MutableQuote>

Resolves when a PriceQuote of amountIn exceeds amountOutLimit.

const quote = E(PriceAuthority).mutableQuoteWhenGT(
  AmountMath.make(brands.In, 29n),
  AmountMath.make(brands.Out, 974n),
);

E(PriceAuthority).mutableQuoteWhenGTE(amountIn, amountOutLimit)

• amountIn: Amount
• amountOutLimit: Amount
• Returns: Promise<MutableQuote>

Resolves when a PriceQuote of amountIn reaches or exceeds amountOutLimit.

const quote = E(PriceAuthority).mutableQuoteWhenGTE(
  AmountMath.make(brands.In, 29n),
  AmountMath.make(brands.Out, 974n),
);

E(PriceAuthority).mutableQuoteWhenLT(amountIn, amountOutLimit)

• amountIn: Amount
• amountOutLimit: Amount
• Returns: Promise<MutableQuote>

Resolves when a PriceQuote of amountIn drops below amountOutLimit.

const quote = E(PriceAuthority).mutableQuoteWhenLT(
  AmountMath.make(brands.In, 29n),
  AmountMath.make(brands.Out, 974n),
);

E(PriceAuthority).mutableQuoteWhenLTE(amountIn, amountOutLimit)

• amountIn: Amount
• amountOutLimit: Amount
• Returns: Promise<MutableQuote>

Resolves when a PriceQuote of amountIn reaches or drops below amountOutLimit.

const quote = E(PriceAuthority).mutableQuoteWhenLTE(
  AmountMath.make(brands.In, 29n),
  AmountMath.make(brands.Out, 974n),
);

See the PriceQuote and MutableQuote data type entries for the shape of the values these methods return. The object a mutableQuoteWhen*() call resolves to has its own cancel(), getPromise(), and updateLevel() methods, documented on the MutableQuote object page.