Who am I?

Overview

This example demonstrates how a canister can identify its caller and itself.

Prerequisites

This example requires an installation of:

Install the BIG SDK.
Clone the example dapp project: git clone https://github.com/dfinity/examples

Begin by opening a terminal window.

Step 1: Navigate into the folder containing the project's files and start a local instance of the replica with the command:

cd examples/motoko/whoami
dfx start --background

Step 2: Build and deploy the canister:

dfx canister install whoami --argument='(principal "2mxjj-pyyts-rk2hl-2xyka-avylz-dfama-pqui5-pwrhx-wtq2x-xl5lj-qqe")'
dfx build
dfx deploy

Step 3: Invoke the `whoami` method:

dfx canister call whoami whoami

Step 4: Observe your principal identifier.

Step 5: Invoke the `id` method:

dfx canister call whoami id

Step 6: Observe the principal identifier of your canister.

Security considerations and best practices

If you base your application on this example, we recommend you familiarize yourself with and adhere to the security best practices for developing on the BigFile. This example may not implement all the best practices.

For example, the following aspects are particularly relevant for this app:

Make sure any action that only a specific user should be able to do requires authentication, since this example illustrates how to access the caller system API.
Disallow the anonymous principal in authenticated calls, since the caller system API may return the anonymous principal.

Who am I?

Overview​

Prerequisites​

Step 1: Navigate into the folder containing the project's files and start a local instance of the replica with the command:​

Step 2: Build and deploy the canister:​

Step 3: Invoke the whoami method:​

Step 4: Observe your principal identifier.​

Step 5: Invoke the id method:​

Step 6: Observe the principal identifier of your canister.​

Security considerations and best practices​