I Built an AI Writing Tool That Works With Any Provider — Here's How

I Built an AI Writing Tool That Works With Any Provider — Here's How

I was tired of paying for multiple AI subscriptions just to handle different writing tasks. So I built Lubb Writer — an open-source tool that gives you 13 different text enhancement modes through a single interface.

Home page: [https://lubb-writer.adelpro.us.kg/](https://lubb-writer.adelpro.us.kg/)

The Problem

Most AI writing tools are:

* Expensive ($20-50/month)

* Single-provider (you're locked in)

* Desktop-only or require copy-pasting

I wanted something that:

* Works with any AI provider

* Integrates into my browser

* Costs nothing if I already have API keys

* Can be self-hosted

The Solution

Lubb Writer — a full-stack project with:

lubb-writer/

├── api/ # Express + TypeScript REST API

├── extension/ # Plasmo framework (Chrome, Firefox, Edge)

└── docker-compose.yml

Key Technical Features

Multi-Provider Abstraction

// provider-adapter.ts (simplified)

interface AIProvider {

 enhance(text: string, mode: WritingMode): Promise<EnhancedText>;

}

class ProviderFactory {

 static create(provider: ProviderType): AIProvider {

 switch (provider) {

 case 'openai': return new OpenAIAdapter();

 case 'anthropic': return new ClaudeAdapter();

 case 'gemini': return new GeminiAdapter();

 case 'custom': return new CustomAdapter();

 }

 }

}

Each adapter handles:

* API authentication

* Request/response transformation

* Error handling

* Token counting

Browser Extension with Plasmo

Plasmo makes cross-browser extensions painless:

// popup.tsx

function Popup() {

 const [text, setText] = useState('');

 

 return (

 <div className="w-80 p-4">

 <textarea 

 value={text}

 onChange={(e) => setText(e.target.value)}

 placeholder="Enter text to enhance..."

 />

 <ModeSelector onSelect={handleMode} />

 <EnhanceButton onClick={() => enhance(text)} />

 </div>

 );

}

One-Command Deployment

# Deploy the API

git clone https://github.com/YOUR_USERNAME/lubb-writer.git

cd lubb-writer/api

cp .env.example .env

# Add your API keys

docker compose up -d

# Install the extension

# Chrome: Load from build/chrome directory

# Firefox: Load from build/firefox directory

13 Writing Modes

• rewrite: Paraphrase while keeping meaning

• summarize : Condense text

• humanize: Make AI text sound natural

• grammar: Fix errors

• formal: Professional tone

• casual: Conversational tone

• academic: Scholarly writing

• SEO: Optimize for search

• persuasive: Marketing copy

• creative: Creative writing

• Twitter: Character-limited posts

• LinkedIn: Professional content

• story: Narrative content

What I Learned

1. Provider abstraction is 60% of the work — each AI has different quirks

2. Keyboard shortcuts > click paths — Ctrl+Shift+Y is much faster than navigating menus

3. Docker is non-negotiable for easy self-hosting

4. Plasmo > vanilla extension APIs — cross-browser support without the headache

Try It

GitHub: https://github.com/adelpro/lubb-writer

Clone it, run it, break it, improve it. PRs welcome!

What's Next?

* [ ] Streaming responses for longer texts

* [ ] Team collaboration features

* [ ] API key management dashboard

* [ ] More writing modes

What features would you want to see? Drop a comment!