Agoric Documentation

Appearance

Issuer Object ​

An Issuer is the authority on what holds digital assets of its kind. While it cannot create new value by creating digital assets like a Mint can, it recognizes and identifies Purses and Payments that carry actual value. It can create empty Purses and burn Payments.

An Issuer has an unchangeable one-to-one relationship with the Mint and Brand that were created with it. For any Brands for which you will accept Payments in, you should obtain its Issuer from a trusted source. You can then rely on that Issuer as the authority to validate an untrusted Payment of that Brand.

Note: You should not create an Issuer in a deploy script. Deploy scripts are ephemeral, so any object created there dies as soon as the script ends.

makeIssuerKit(allegedName, assetKind?, displayInfo?, optShutdownWithFailure?, issuerOptionsRecord?) ​

  • allegedName: String
  • assetKind: AssetKind - Optional, defaults to AssetKind.NAT.
  • displayInfo: DisplayInfo - Optional, defaults to undefined.
  • optShutdownWithFailure - Optional, defaults to undefined.
  • issuerOptionsRecord - Optional, defaults to {}. An object that may carry:
    • elementShape: Pattern - Optional, defaults to undefined.
    • recoverySetsOption: RecoverySetsOption - Optional, defaults to undefined.
  • Returns IssuerKit. This is an object with five properties:

Creates and returns a new Issuer and its associated Mint and Brand. All three are in unchangeable one-to-one relationships with each other.

makeIssuerKit() makes an issuer kit that is not durable; it does not survive an upgrade of the vat that holds it. Contracts, which must survive upgrade, instead use prepareIssuerKit() or makeDurableIssuerKit(), which take a Baggage as their first argument and are otherwise parameterized the same way. See Durable Issuers.

The allegedName becomes part of the Brand in asset descriptions. It doesn't have to be a String, but it will only be used for its value. It is useful for debugging and double-checking assumptions, but should not be trusted.

The optional assetKind parameter specifies the kind of asset associated with the Issuer about to be created. If no AssetKind argument is passed into the method, then the Issuer's asset kind defaults to AssetKind.NAT. AmountMath's methods work with all the kinds of assets, but exactly what math or manipulation is performed varies depending on the AssetKind.

The optional displayInfo parameter tells the UI how to display Amounts of this Brand.

The optional optShutdownWithFailure parameter should be used for mission-critical Issuers. This parameter is a function that will stop the vat hosting the Issuer if Issuer invariants are violated.

The optional issuerOptionsRecord parameter's elementShape property is only used when creating an Issuer for a non-fungible or semi-fungible asset (an AssetKind of COPY_SET or COPY_BAG). When present, it is a Pattern that every element of this Issuer's amounts must satisfy; for example, the Zoe Invitation issuer uses an elementShape describing the shape of an individual invitation's details. Its recoverySetsOption property controls whether the issuer maintains recovery sets; see Durable Issuers.

js
import { AssetKind, makeIssuerKit } from '@agoric/ertp';
makeIssuerKit('quatloos'); // Defaults to AssetKind.NAT
makeIssuerKit('title', AssetKind.COPY_SET);
js
import { AssetKind, AmountMath, makeIssuerKit } from '@agoric/ertp';
import { makeCopySet } from '@endo/patterns';

const {
  issuer: quatloosIssuer,
  mint: quatloosMint,
  brand: quatloosBrand,
} = makeIssuerKit('quatloos');
// This is merely an amount, describing assets, not minting assets
const quatloos2 = AmountMath.make(quatloosBrand, 2n);

const {
  issuer: titleIssuer,
  mint: titleMint,
  brand: titleBrand,
} = makeIssuerKit('propertyTitle', AssetKind.COPY_SET);
// These are merely amounts describing digital assets, not minting assets.
const cornerProperty = AmountMath.make(titleBrand, makeCopySet(['1292826']));
const adjacentProperty = AmountMath.make(titleBrand, makeCopySet(['1028393']));
const combinedProperty = AmountMath.make(
  titleBrand,
  makeCopySet(['1292826', '1028393']),
);

anIssuer.getAllegedName() ​

  • Returns: allegedName

Returns the allegedName for the Issuer.

An alleged name is a human-readable string name of a kind of digital asset. An alleged name should not be trusted as accurate because there is no public registry or expectation of uniqueness. This means there can be multiple Issuers, Mints, or Brands with the same alleged name, and thus the name by itself does not uniquely identify an Issuer. Rather, the Brand does that.

To put it another way, nothing stops anyone from creating an Issuer with the alleged name Quatloos (or BTC, or whatever), regardless of whether or not such a name is already in use. The alleged name is just a human readable string which is helpful for debugging.

js
const { issuer: quatloosIssuer } = makeIssuerKit('quatloos');
const quatloosIssuerAllegedName = quatloosIssuer.getAllegedName();
// quatloosIssuerAllegedName === 'quatloos'

anIssuer.getAssetKind() ​

Returns the kind of the Issuer's asset.

The AssetKind specifies what kind of values are used in Amounts for this Issuer.

js
const { issuer: quatloosIssuer } = makeIssuerKit('quatloos');
quatloosIssuer.getAssetKind(); // Returns 'nat', also known as AssetKind.NAT, the default value.
const { issuer: moolaIssuer } = makeIssuerKit('moola', AssetKind.COPY_SET);
moolaIssuer.getAssetKind(); // Returns 'copySet', also known as AssetKind.COPY_SET

anIssuer.getAmountOf(payment) ​

Describes the Payment's balance as an Amount. Because a Payment from an untrusted source cannot be trusted to provide its own true value, the Issuer must be used to validate its Brand and report how much the returned Amount contains.

js
const {
  issuer: quatloosIssuer,
  mint: quatloosMint,
  brand: quatloosBrand,
} = makeIssuerKit('quatloos');
const quatloosPayment = quatloosMint.mintPayment(
  AmountMath.make(quatloosBrand, 100n),
);
quatloosIssuer.getAmountOf(quatloosPayment); // returns an amount of 100 Quatloos

anIssuer.getBrand() ​

Returns the Brand for the Issuer. The Brand indicates the kind of digital asset and is the same for the Issuer's associated Mint, and any Purses and Payments of this particular kind. The Brand is not closely held, so this method should not be trusted to identify an Issuer alone. Fake digital assets and amounts can use another Issuer's Brand.

js
const { issuer: quatloosIssuer, brand: quatloosBrand } =
  makeIssuerKit('quatloos');
const quatloosBrand = quatloosIssuer.getBrand();
// brand === quatloosBrand

anIssuer.makeEmptyPurse() ​

Makes and returns an empty Purse that holds assets of the Brand associated with the Issuer.

js
const { issuer: quatloosIssuer } = makeIssuerKit('quatloos');
const quatloosPurse = quatloosIssuer.makeEmptyPurse();

anIssuer.burn(payment, optAmount?) ​

Destroys all of the digital assets in the Payment, making it unavailable for later use, and returns an Amount of what was burned.

If an optAmount argument is passed into the method, payment's balance must be equal to optAmount in order to prevent claiming the wrong Payment. If optAmount does not equal the balance in the original Payment an error is thrown, and the original Payment is unmodified.

If payment is a promise, the operation proceeds after it resolves to a Payment.

js
const {
  issuer: quatloosIssuer,
  mint: quatloosMint,
  brand: quatloosBrand,
} = makeIssuerKit('quatloos');
const amountToBurn = AmountMath.make(quatloosBrand, 10n);
const paymentToBurn = quatloosMint.mintPayment(amountToBurn);

// burntAmount should equal 10 Quatloos
const burntAmount = quatloosIssuer.burn(paymentToBurn, amountToBurn);

anIssuer.isLive(payment) ​

Returns true if the payment was created by the Issuer and is available for use (i.e., it hasn't been consumed).

If payment is a promise, the method proceeds after it resolves to a Payment.

Removed methods ​

claim, combine, split, and splitMany are no longer Issuer methods. They live on as standalone, deprecated helper functions with a different, recoveryPurse-first signature; see Legacy Payment Helpers.

© 2026 Agoric Systems Operating Company. All Rights Reserved.