There are two main Internet Computer (IC) environments that you will generally interact with: the local replica and mainnet.

When developing on your local machine, our recommended flow is to start up a local replica in your project's root directoy and then deploy to it for local testing.

Starting the local replica

Open a terminal and navigate to your project's root directory:

dfx start

Alternatively you can start the local replica as a background process:

dfx start --background

If you want to stop a local replica running in the background:

dfx stop

If you ever see this error after dfx stop:

Error: Failed to kill all processes.  Remaining: 627221 626923 627260

Then try this:

sudo kill -9 627221
sudo kill -9 626923
sudo kill -9 627260

If your replica starts behaving strangely, we recommend starting the replica clean, which will clean the dfx state of your project:

dfx start --clean

Deploying to the local replica

To deploy all canisters defined in your dfx.json:

dfx deploy

To deploy an individual canister:

dfx deploy canister_name

Interacting with your canister

As a developer you can generally interact with your canister in three ways:

dfx command line

You can see a more complete reference here.

The commands you are likely to use most frequently are:

# assume a canister named my_canister

# builds and deploys all canisters specified in dfx.json
dfx deploy

# builds all canisters specified in dfx.json
dfx build

# builds and deploys my_canister
dfx deploy my_canister

# builds my_canister
dfx build my_canister

# removes the Wasm binary and state of my_canister
dfx uninstall-code my_canister

# calls the methodName method on my_canister with a string argument
dfx canister call my_canister methodName '("This is a Candid string argument")'

dfx web UI

After deploying your canister, you should see output similar to the following in your terminal:

Deployed canisters.
  Backend canister via Candid interface:

Open up to access the web UI.


@dfinity/agent is the TypeScript/JavaScript client library for interacting with canisters on the IC. If you are building a client web application, this is probably what you'll want to use.

There are other agents for other languages as well:

Deploying to mainnet

Assuming you are setup with cycles, then you are ready to deploy to mainnet.

To deploy all canisters defined in your dfx.json:

dfx deploy --network ic

To deploy an individual canister:

dfx deploy --network ic canister_name

Common deployment issues

If you run into an error during deployment, try the following:

  1. Ensure that you have followed the instructions correctly in the installation chapter, especially noting the build dependencies
  2. Start the whole deployment process from scratch by running the following commands: dfx stop or simply terminate dfx in your terminal, dfx start --clean, npx azle clean, dfx deploy
  3. Look for more error output by adding the --verbose flag to the build command in your dfx.json file like so: "build": "npx azle build hello_world --verbose
  4. Look for errors in each of the files in ~/.config/azle/rust/[rust_version]/logs
  5. Reach out in the Discord channel