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Dependency Manager

The Dependency Manager in the Flow CLI streamlines the development process when you use contracts from outside your project. It eliminates the manual tasks of copying, pasting, and updating contracts that you use or build upon, such as core contracts or any other ecosystem contracts.

For example, if you wanted to build a new application using the FlowToken contract, you would traditionally need to locate the contract on the network, copy it into your local project, and add it to your flow.json. You would repeat this process for each import (dependency) it relies on, like the NonFungibleToken contract. The Dependency Manager simplifies this process with a few straightforward commands.

install​

The install command allows you to install dependencies and all their sub-dependencies with ease. You can use it to install specific dependencies or to install all dependencies listed in your flow.json.

Installing Specific Dependencies​

If you know the address and name of the contract you want to install (which can often be found via the Contract Browser), you can use the following syntax:


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flow dependencies install testnet://7e60df042a9c0868.FlowToken

In this command, the string testnet://7e60df042a9c0868.FlowToken used as the source in the flow.json is broken down as:

  • Network: testnet
  • Address: 7e60df042a9c0868
  • Contract Name: FlowToken

This specifies the remote source of the contract on the network that will be used as the source of truth.

Installing Core Contracts Using Simplified Syntax​

For core contracts, you can use a simplified syntax that defaults to the Flow Mainnet:


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flow dependencies install FlowToken

This command is functionally equivalent to:


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flow dependencies install mainnet://1654653399040a61.FlowToken

Installing Multiple Dependencies​

You can also install multiple dependencies at once. For example:


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flow dependencies install testnet://7e60df042a9c0868.FlowToken NonFungibleToken

This command installs both the FlowToken contract from Testnet and the NonFungibleToken contract from Mainnet.

Installing All Dependencies From an Address​

Sometimes you may want to install all the contracts that exist at a particular address, rather than specifying each contract name individually. You can do this by omitting the contract name in the dependency source. For example:


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flow dependencies install testnet://7e60df042a9c0868

This tells the Dependency Manager to fetch every contract deployed at the 7e60df042a9c0868 address on testnet and store them in your imports folder. You can later import these contracts in your code or use them in your deployments as needed.

Installing Dependencies from flow.json​

If you run the install command without specifying any dependencies, it will install all the dependencies listed in your flow.json file and ensure they are up to date:


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flow dependencies install

This command checks all the dependencies specified in your flow.json, installs them, and updates them if there have been changes on the network.

Example flow.json Entry​

After installing, your flow.json might include an entry like:


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{
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"dependencies": {
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"FlowToken": {
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"source": "testnet://7e60df042a9c0868.FlowToken",
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"aliases": {
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"emulator": "0ae53cb6e3f42a79"
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}
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}
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}
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}

Other Things to Note​

  • After installation, a local folder named imports will be created. It's recommended to add this folder to your .gitignore, as it stores your dependencies locally.
  • If the contracts change on the network, the Dependency Manager will prompt you to update the local dependencies in your imports folder. The hash saved in the dependency object is used for this check, so avoid removing it.
  • Dependencies function just like local contracts. You can add them to deployments in your flow.json and run flow project deploy. You can also import them in your scripts, transactions, and contracts (e.g., import "FlowToken").
  • Core contract aliases are automatically added for you across all networks.

discover​

The discover command helps you interactively find and install core contracts for your project. Core contracts are standard smart contracts maintained by the Flow Foundation and are commonly used across the Flow ecosystem (learn more about core contracts here).

To use the discover command, run:


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flow dependencies discover

You'll be presented with a list of available core contracts to install:


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Select any core contracts you would like to install or skip to continue.
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Use arrow keys to navigate, space to select, enter to confirm or skip, q to quit:
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> [ ] FlowEpoch
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[ ] FlowIDTableStaking
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[ ] FlowClusterQC
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[ ] FlowDKG
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[ ] FlowServiceAccount
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[ ] NodeVersionBeacon
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[ ] RandomBeaconHistory
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[ ] FlowStorageFees
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[ ] FlowFees
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[ ] FungibleTokenSwitchboard
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[ ] EVM
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[ ] Crypto

After selecting the contracts, press enter to confirm. The selected contracts will be added to your flow.json file and will be accessible in your project.

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