# Vue frontend

Welcome to this tutorial on using Ignite to develop a web application for your
blockchain with Vue 3. Ignite is a tool that simplifies the process of building
a blockchain application by providing a set of templates and generators that can
be used to get up and running quickly.

One of the features of Ignite is its support for [Vue 3](https://vuejs.org/), a
popular JavaScript framework for building user interfaces. In this tutorial, you
will learn how to use Ignite to create a new blockchain and scaffold a Vue
frontend template. This will give you a basic foundation for your web
application and make it easier to get started building out the rest of your
application.

Once you have your blockchain and Vue template set up, the next step is to
generate an API client. This will allow you to easily interact with your
blockchain from your web application, enabling you to retrieve data and make
transactions. By the end of this tutorial, you will have a fully functional web
application that is connected to your own blockchain.

Prerequisites:

* [Node.js](https://nodejs.org/en/)
* [Keplr](https://www.keplr.app/) Chrome extension

## Create a blockchain and a Vue app

Create a new blockchain project:

```
ignite scaffold chain example
```

To create a Vue frontend template, go to the `example` directory and run the
following command:

```
ignite scaffold vue
```

This will create a new Vue project in the `vue` directory. This project can be
used with any blockchain, but it depends on an API client to interact with the
blockchain. To generate an API client, run the following command in the
`example` directory:

```
ignite generate composables
```

This command generates two directories:

* `ts-client`: a framework-agnostic TypeScript client that can be used to
  interact with your blockchain. You can learn more about how to use this client
  in the [TypeScript client tutorial](/clients/typescript).
* `vue/src/composables`: a collection of Vue 3
  [composables](https://vuejs.org/guide/reusability/composables.html) that wrap
  the TypeScript client and make it easier to interact with your blockchain from
  your Vue application.

## Set up Keplr and an account

Open your browser with the Keplr wallet extension installed. Follow [the
instructions](https://keplr.crunch.help/en/getting-started/creating-a-new-keplr-account)
to create a new account or use an existing one. Make sure to save the mnemonic
phrase as you will need it in the next step.

Do not use a mnemonic phrase that is associated with an account that holds
assets you care about. If you do, you risk losing those assets. It's a good
practice to create a new account for development purposes.

Add the account you're using in Keplr to your blockchain's `config.yml` file:

```yml
accounts:
  - name: alice
    coins: [20000token, 200000000stake]
  - name: bob
    coins: [10000token, 100000000stake]
    # highlight-start
  - name: frank
    coins: [10000token, 100000000stake]
    mnemonic: struggle since inmate safe logic kite tag web win stay security wonder
    # highlight-end
```

Replace the `struggle since...` mnemonic with the one you saved in the previous
step.

Adding an account with a mnemonic to the config file will tell Ignite CLI to add
the account to the blockchain when you start it. This is useful for development
purposes, but you should not do this in production.

## Start a blockchain and a Vue app

In the `example` directory run the following command to start your blockchain:

```bash
ignite chain serve
```

To start your Vue application, go to the `vue` directory and run the following
command in a separate terminal window:

:::note
Make sure you have [pnpm](https://pnpm.io/) installed.
:::

```bash
pnpm install && pnpm dev
```

It is recommended to run `pnpm install` before starting your app with `pnpm dev` to ensure that all dependencies are installed (including the ones that the API client has, see `vue/postinstall.js`).

Open your browser and navigate to
[http://localhost:5173/](http://localhost:5173/).

![Web app](/img/web-1.png)

Press "Connect wallet", enter your password into Keplr and press "Approve" to
add your blockchain to Keplr.

<img src="/img/web-4.png" width="300"/>

Make sure to select the account you're using for development purposes and the
"Example Network" in Keplr's blockchain dropdown. You should see a list of
assets in your Vue app.

![Web app](/img/web-5.png)

Congratulations! You have successfully created a client-side Vue application and
connected it to your blockchain. You can modify the source code of your Vue
application to build out the rest of your project.

## Setting the address prefix

It is necessary to set the correct address prefix in order for the Vue app to
properly interact with a Cosmos chain. The address prefix is used to identify
the chain that the app is connected to, and must match the prefix used by the
chain.

By default, Ignite creates a chain with the `cosmos` prefix. If you have
created your chain with `ignite scaffold chain ... --address-prefix foo` or
manually changed the prefix in the source code of the chain, you need to set the
prefix in the Vue app.

There are two ways to set the address prefix in a Vue app.

### Using an environment variable

You can set the `VITE_ADDRESS_PREFIX` environment variable to the correct
address prefix for your chain. This will override the default prefix used by the
app.

To set the `VITE_ADDRESS_PREFIX` environment variable, you can use the following
command:

```bash
export VITE_ADDRESS_PREFIX=your-prefix
```

Replace `your-prefix` with the actual address prefix for your chain.

### Setting address prefix in the code

Alternatively, you can manually set the correct address prefix by replacing the
fallback value of the `prefix` variable in the file `./vue/src/env.ts`.

To do this, open the file `./vue/src/env.ts` and find the following line:

```ts title="./vue/src/env.ts"
const prefix = process.env.VITE_ADDRESS_PREFIX || 'your-prefix';
```

Replace `your-prefix` with the actual address prefix for your chain.

Save the file and restart the Vue app to apply the changes.
