Amulet

The amulet namespace is used for Canton coin specific operations.

Availability and extensibility

The amulet namespace is an extended namespace that requires configuration. You can initialize it either during SDK creation or later using the extend() method.

Option 1: Initialize during SDK creation

const sdk = await SDK.create({
    auth: authConfig,
    ledgerClientUrl: 'http://localhost:2975',
    amulet: {
        validatorUrl: 'http://localhost:2000/api/validator',
        scanApiUrl: 'http://localhost:2000/api/scan',
        auth: amuletAuthConfig,
        registryUrl: 'http://localhost:2000/api/registry'
    }
})

// amulet namespace is now available
await sdk.amulet.traffic.status()

Option 2: Add amulet namespace later using extend()

// Create basic SDK first
const basicSDK = await SDK.create({
    auth: authConfig,
    ledgerClientUrl: 'http://localhost:2975'
})

// Extend with amulet namespace when needed
const extendedSDK = await basicSDK.extend({
    amulet: {
        validatorUrl: 'http://localhost:2000/api/validator',
        scanApiUrl: 'http://localhost:2000/api/scan',
        auth: amuletAuthConfig,
        registryUrl: 'http://localhost:2000/api/registry'
    }
})

// Now amulet namespace is available
await extendedSDK.amulet.traffic.status()

Configuration

The AmuletConfig type defines the configuration for the amulet namespace:

type AmuletConfig = {
    auth: TokenProviderConfig
    validatorUrl: string | URL
    scanApiUrl: string | URL
    registryUrl: URL
}

  • auth: Authentication configuration for accessing the validator and scan services

  • validatorUrl: URL of the validator service

  • scanApiUrl: URL of the scan API

  • registryUrl: URL of the amulet registry

Key changes from v0 to v1

v0 used the tokenStandard controller with implicit party context set via sdk.setPartyId() and the instrumentId and instrumentAdmin were passed in explicitly to each function.

v1 uses the amulet namespace where you:

  • Pass partyId explicitly to each operation

  • Initialize the namespace with configuration, which determines the instrumentAdmin and instrumentId

  • Access operations through logical groupings (traffic and preapproval)

Creating preapprovals

The below example demonstrates the full process of renewing and cancelling preapprovals:

Buy Member Traffic

Check Traffic Status

Refer to the following example for more information:

Tap

The is useful for testing against LocalNet or Devnet.

Migration reference

Amulet namespace migration

v0 method

v1 method

sdk.tokenStandard.getMemberTrafficStatus

sdk.amulet.traffic.status

sdk.tokenStandard.buyMemberTraffic

sdk.amulet.traffic.buy

sdk.userLedger.createTransferPreapprovalCommand

sdk.amulet.preapproval.command.create

sdk.tokenStandard.getTransferPreApprovalByParty

sdk.amulet.preapproval.fetchStatus

sdk.tokenStandard.createRenewTransferPreapproval

sdk.amulet.preapproval.renew

sdk.tokenStandard.createCancelTransferPreapproval

sdk.amulet.preapproval.command.cancel

sdk.tokenStandard.createTap

sdk.amulet.tap

sdk.tokenStandard.lookupFeaturedApps

sdk.amulet.featuredApp.rights

sdk.tokenStandard.selfGrantFeatureAppRights

sdk.amulet.featuredApp.grant

See also