> ## Documentation Index
> Fetch the complete documentation index at: https://doc.howen.ink/llms.txt
> Use this file to discover all available pages before exploring further.

# Quickstart

> Install, configure, and run Japanese Text Analyzer locally from source.

This guide walks you through starting the app from source. When you finish, you can enter a Japanese sentence in your browser and see the analysis.

## Prerequisites

Before you start, make sure you have:

* [Node.js 22](https://nodejs.org/) and npm
* Git
* A DeepSeek API key or a Gemini API key

<Tip>
  We recommend setting up DeepSeek first. It is the default provider and handles analysis, translation, definitions, and image recognition. Only Gemini TTS requires a Gemini API key.
</Tip>

## Start the app

<Steps>
  <Step title="Clone the repository">
    ```bash theme={null}
    git clone https://github.com/cokice/japanese-analyzer.git
    cd japanese-analyzer
    ```
  </Step>

  <Step title="Install dependencies">
    ```bash theme={null}
    npm ci
    ```
  </Step>

  <Step title="Create the environment file">
    <CodeGroup>
      ```bash macOS / Linux theme={null}
      cp .env.example .env.local
      ```

      ```powershell Windows PowerShell theme={null}
      Copy-Item .env.example .env.local
      ```
    </CodeGroup>
  </Step>

  <Step title="Add an API key">
    Open `.env.local` and fill in at least one key:

    ```env .env.local theme={null}
    DEEPSEEK_API_KEY=your_deepseek_api_key
    ```

    All other variables are optional. For the full list, see [Configuration](/en/configuration).
  </Step>

  <Step title="Start the development server">
    ```bash theme={null}
    npm run dev
    ```

    Open [http://localhost:3000](http://localhost:3000).
  </Step>
</Steps>

<Check>
  Enter a Japanese sentence, such as 「天気がいいから、散歩しましょう」, and click **Analyze**. If you see word-by-word readings and a translation in your interface language, your setup works. You can also click **Sentence of the day** on the home page to analyze it directly.
</Check>

## Access from your phone

To open the development server from a phone on the same local network, make the server listen on all network interfaces:

```bash theme={null}
npm run dev -- --hostname 0.0.0.0
```

Then open `http://<your-computer-IP>:3000` in your phone's browser.

## Only a Gemini key is configured

The app uses DeepSeek by default. If you only filled in `GEMINI_API_KEY`, open the page and click **Settings** in the top-right corner. Switch **AI provider** to **Gemini**, then click **Save settings**.

## Run a production build

To try the production build on your machine, run:

```bash theme={null}
npm run build
npm start
```

`npm start` listens on port `3000` by default.

## What's next

<Columns cols={2}>
  <Card title="User guide" icon="book-open" href="/en/features/analysis">
    Learn how to use analysis, word details, and multi-word selection.
  </Card>

  <Card title="Deployment" icon="server" href="/en/deployment">
    Publish to Vercel, or run it on a server with Docker.
  </Card>
</Columns>