@dfinity/cmc

cmc-js

A library for interfacing with the cycle minting canister.

Table of contents

• Installation
• Usage
• Features

Installation

You can use cmc-js by installing it in your project.

npm i @dfinity/cmc

The bundle needs peer dependencies, be sure that following resources are available in your project as well.

npm i @dfinity/agent @dfinity/candid @dfinity/principal @dfinity/utils

Usage

The features are available through the class CMCCanister. It has to be instantiated with the canister ID of the cycles minting canister. On mainnet, its ID is rkp4c-7iaaa-aaaaa-aaaca-cai.

e.g. querying the current Icp to cycles conversion rate.

import { CMCCanister } from "@dfinity/cmc";
import { createAgent } from "@dfinity/utils";

const agent = await createAgent({
  identity,
  host: HOST,
});

const { getIcpToCyclesConversionRate } = CMCCanister.create({
  agent,
  canisterId: CYCLES_MINTING_CANISTER_ID,
});

const rate = await getIcpToCyclesConversionRate();

Features

cmc-js implements following features:

:factory: CMCCanister

:link: Source

Methods

• create
• getIcpToCyclesConversionRate
• notifyCreateCanister
• notifyTopUp
• getDefaultSubnets

:gear: create

Method	Type
create	(options: CMCCanisterOptions) => CMCCanister

:link: Source

:gear: getIcpToCyclesConversionRate

Returns conversion rate of ICP to Cycles

Method	Type
getIcpToCyclesConversionRate	() => Promise<bigint>

:link: Source

:gear: notifyCreateCanister

Notifies Cycles Minting Canister of the creation of a new canister. It returns the new canister principal.

Method	Type
notifyCreateCanister	(request: NotifyCreateCanisterArg) => Promise<Principal>

:link: Source

:gear: notifyTopUp

Notifies Cycles Minting Canister of new cycles being added to canister. It returns the new Cycles of the canister.

Method	Type
notifyTopUp	(request: NotifyTopUpArg) => Promise<bigint>

:link: Source

:gear: getDefaultSubnets

This function calls the get_default_subnets method of the CMC canister, which returns a list of default subnets as Principal objects. It can be called as query or update.

Method	Type
getDefaultSubnets	({ certified }?: QueryParams) => Promise<Principal[]>

Parameters:

• params: - The query parameters for the call.
• params.certified: - Determines whether the response should be certified (default: non-certified if not specified).

:link: Source