Multicall allows multiple smart contract constant function calls to be grouped into a single call and the results aggregated into a single result. This reduces the number of separate JSON RPC requests that need to be sent over the network if using a remote node like Infura, and provides the guarantee that all values returned are from the same block. The latest block number is also returned along with the aggregated results.
- Get the return value(s) of multiple smart contract function calls in a single call
- Guarantee that all values are from the same block
- Use watchers to poll for multiple blockchain state variables/functions
- Get updates when a watcher detects state has changed
- Results from out of sync nodes are automatically ignored
- Get new block updates
yarn add @makerdao/multicall
;// Contract addresses used in this exampleconst MKR_TOKEN = '0xaaf64bfcc32d0f15873a02163e7e500671a4ffcd';const MKR_WHALE = '0xdb33dfd3d61308c33c63209845dad3e6bfb2c674';const MKR_FISH = '0x2dfcedcb401557354d0cf174876ab17bfd6f4efd';// Preset can be 'mainnet', 'kovan', 'rinkeby', 'goerli' or 'xdai'const config = preset: 'kovan' ;// Create watcherconst watcher =;// Subscribe to state updateswatcher;// Subscribe to batched state updateswatcher;// Subscribe to new block number updateswatcher;// Start the watcher pollingwatcherstart;
// The JSON RPC URL and multicall contract address can also be specified in the config:const config =rpcUrl: ''multicallAddress: '0xc49ab4d7de648a97592ed3d18720e00356b4a806';
// Update the watcher calls using tap()const fetchWaiter = watcher;// This promise resolves when the first fetch completesfetchWaiter;
// Recreate the watcher with new calls and config (allowing the network to be changed)const config = preset: 'mainnet' ;watcher;
Special variables and functions (e.g.
block.timestamp) can be accessed by calling their corresponding helper function.
To call these helper functions simply omit the
target property (and it will default to multicall's contract address).
const watcher =;
Check out this CodePen example for a working front-end example.
To run the example in the project, first clone this repo:
git clone https://github.com/makerdao/multicall.js
Then install the dependencies:
Finally run the example script (
To run tests use: