npm package: @metigan/nestjs
Description: Official Metigan SDK for NestJS - Email, Forms, Contacts, and Audiences management
Author: Metigan
Latest version: 1.0.3

# Metigan NestJS SDK

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Official NestJS SDK for the Metigan API. Send emails, manage contacts, audiences, templates, and forms with ease in your NestJS applications.

## ✨ Features

- 📧 **Send Emails** - Send HTML emails with attachments, CC, BCC, and templates
- 👥 **Manage Contacts** - Create, update, list, and manage contact subscriptions
- 🎯 **Audiences** - Organize contacts into audiences and track statistics
- 📝 **Forms** - Submit and manage form data
- 🎨 **Templates** - Use email templates with dynamic variables
- 🔄 **Automatic Retry** - Built-in retry logic for failed requests
- ⚡ **TypeScript** - Full TypeScript support with type definitions
- 🛡️ **Error Handling** - Comprehensive exception handling
- 🏗️ **NestJS Integration** - Native NestJS module with dependency injection
- 🔌 **Async Configuration** - Support for async module configuration

## 📋 Requirements

- **Node.js**: 16.0.0 or higher
- **NestJS**: 10.0.0 or higher
- **TypeScript**: 4.5.0 or higher
- **RxJS**: 7.8.0 or higher (peer dependency)

## 📦 Installation

Install via npm:

```bash
npm install @metigan/nestjs
```

Or via yarn:

```bash
yarn add @metigan/nestjs
```

Or via pnpm:

```bash
pnpm add @metigan/nestjs
```

## 🔑 Getting Your API Key

Get your API key from the [Metigan Dashboard](https://app.metigan.com/api-keys).

1. Sign in to your Metigan account
2. Navigate to **Settings** → **API Keys**
3. Create a new API key or use an existing one
4. Copy the API key and use it in your application

> ⚠️ **Security Note**: Never expose your API key in client-side code. Use environment variables for configuration.

## 🚀 Quick Start

### 1. Import the Module

In your `app.module.ts`:

```typescript
import { Module } from '@nestjs/common';
import { MetiganModule } from '@metigan/nestjs';

@Module({
  imports: [
    MetiganModule.forRoot({
      apiKey: process.env.METIGAN_API_KEY,
    }),
  ],
})
export class AppModule {}
```

### 2. Use in Your Service

```typescript
import { Injectable } from '@nestjs/common';
import { MetiganService } from '@metigan/nestjs';

@Injectable()
export class EmailService {
  constructor(private readonly metigan: MetiganService) {}

  async sendWelcomeEmail(email: string) {
    const result = await this.metigan.email.sendEmail({
      from: 'Sender <sender@example.com>',
      recipients: [email],
      subject: 'Welcome!',
      content: '<h1>Hello!</h1><p>Thank you for signing up.</p>',
    });

    if (result.success) {
      console.log('Email sent successfully!');
      console.log(`Emails remaining: ${result.emailsRemaining}`);
    }

    return result;
  }
}
```

## ⚙️ Configuration

### Basic Configuration

```typescript
MetiganModule.forRoot({
  apiKey: process.env.METIGAN_API_KEY,
  timeout: 30000,     // Optional, defaults to 30000ms
  retryCount: 3,      // Optional, defaults to 3 retries
  retryDelay: 2000,   // Optional, defaults to 2000ms between retries
  debug: false,       // Optional, enables debug logging
})
```

### Async Configuration

For dynamic configuration using `@nestjs/config`:

```typescript
import { Module } from '@nestjs/common';
import { ConfigModule, ConfigService } from '@nestjs/config';
import { MetiganModule } from '@metigan/nestjs';

@Module({
  imports: [
    ConfigModule.forRoot(),
    MetiganModule.forRootAsync({
      useFactory: (configService: ConfigService) => ({
        apiKey: configService.get<string>('METIGAN_API_KEY'),
        timeout: configService.get<number>('METIGAN_TIMEOUT', 30000),
        retryCount: configService.get<number>('METIGAN_RETRY_COUNT', 3),
        retryDelay: configService.get<number>('METIGAN_RETRY_DELAY', 2000),
        debug: configService.get<boolean>('METIGAN_DEBUG', false),
      }),
      inject: [ConfigService],
    }),
  ],
})
export class AppModule {}
```

### Environment Variables

Create a `.env` file:

```env
METIGAN_API_KEY=your-api-key-here
METIGAN_TIMEOUT=30000
METIGAN_RETRY_COUNT=3
METIGAN_RETRY_DELAY=2000
METIGAN_DEBUG=false
```

## 📧 Sending Emails

### Basic Email

```typescript
const result = await this.metigan.email.sendEmail({
  from: 'Sender <sender@example.com>',
  recipients: ['recipient@example.com'],
  subject: 'Email Subject',
  content: '<h1>HTML Content</h1><p>This is the email body.</p>',
});

if (result.success) {
  console.log(`Email sent! Remaining: ${result.emailsRemaining}`);
}
```

### Email with CC and BCC

```typescript
const result = await this.metigan.email.sendEmail({
  from: 'Company <company@example.com>',
  recipients: ['main@example.com'],
  subject: 'Meeting Invitation',
  content: 'You\'re invited to our meeting.',
  cc: ['copy@example.com'],
  bcc: ['hidden@example.com'],
  replyTo: 'reply@example.com',
});
```

### Email with Attachments

```typescript
import * as fs from 'fs';

const fileData = fs.readFileSync('document.pdf');

const result = await this.metigan.email.sendEmail({
  from: 'Company <company@example.com>',
  recipients: ['customer@example.com'],
  subject: 'Important Document',
  content: 'Please find the document attached.',
  attachments: [
    {
      buffer: fileData,
      originalname: 'document.pdf',
      mimetype: 'application/pdf',
    },
  ],
});
```

### Email with Template

```typescript
const variables = {
  name: 'John Doe',
  company: 'Acme Inc',
};

const result = await this.metigan.email.sendEmailWithTemplate(
  'template-123',
  variables,
  {
    from: 'Sender <sender@example.com>',
    recipients: ['recipient@example.com'],
    replyTo: 'reply@example.com',
  },
);
```

## 👥 Managing Contacts

### Create Contact

```typescript
const contact = await this.metigan.contacts.create({
  email: 'new@example.com',
  audienceId: 'audience-123',
  firstName: 'Jane',
  lastName: 'Doe',
  phone: '+1234567890',
  tags: ['customer', 'newsletter'],
  customFields: { company: 'Acme Inc' },
  status: 'subscribed',
});
```

### Get Contact

```typescript
// Get by ID
const contact = await this.metigan.contacts.get('contact-456');

// Get by email
const contact = await this.metigan.contacts.getByEmail(
  'jane@example.com',
  'audience-123',
);
```

### Update Contact

```typescript
const updated = await this.metigan.contacts.update('contact-456', {
  firstName: 'Jane Marie',
  lastName: 'Smith',
  tags: ['customer', 'vip'],
  status: 'subscribed',
});
```

### List Contacts

```typescript
const result = await this.metigan.contacts.list({
  audienceId: 'audience-123',
  status: 'subscribed',
  tag: 'customer',
  search: 'john',
  page: 1,
  limit: 50,
});

console.log(`Total contacts: ${result.pagination.total}`);
result.contacts.forEach((contact) => {
  console.log(`${contact.email}: ${contact.firstName}`);
});
```

### Manage Subscription

```typescript
// Subscribe
await this.metigan.contacts.subscribe('contact-456');

// Unsubscribe
await this.metigan.contacts.unsubscribe('contact-456');
```

### Manage Tags

```typescript
// Add tags
await this.metigan.contacts.addTags('contact-456', ['vip', 'black-friday']);

// Remove tags
await this.metigan.contacts.removeTags('contact-456', ['test']);
```

### Delete Contact

```typescript
await this.metigan.contacts.delete('contact-456');
```

## 🎯 Managing Audiences

### Create Audience

```typescript
const audience = await this.metigan.audiences.create({
  name: 'Main Newsletter',
  description: 'Main subscriber list',
});
```

### Get Audience

```typescript
const audience = await this.metigan.audiences.get('audience-123');
```

### List Audiences

```typescript
const result = await this.metigan.audiences.list({
  page: 1,
  limit: 10,
});

result.audiences.forEach((audience) => {
  console.log(`${audience.name}: ${audience.count} contacts`);
});
```

### Get Audience Statistics

```typescript
const stats = await this.metigan.audiences.getStats('audience-123');

console.log(`Total: ${stats.total}`);
console.log(`Subscribed: ${stats.subscribed}`);
console.log(`Unsubscribed: ${stats.unsubscribed}`);
```

### Delete Audience

```typescript
await this.metigan.audiences.delete('audience-123');
```

## 🎨 Managing Templates

### Get Template

```typescript
const template = await this.metigan.templates.get('template-123');
```

### List Templates

```typescript
const templates = await this.metigan.templates.list({
  page: 1,
  limit: 10,
});

templates.forEach((template) => {
  console.log(`${template.name}: ${template.id}`);
});
```

## 📝 Managing Forms

### Submit Form

```typescript
const result = await this.metigan.forms.submit({
  formId: 'form-123', // or form slug
  data: {
    name: 'John Doe',
    email: 'john@example.com',
    message: 'Hello, I would like more information.',
  },
});

console.log(result.message);
```

### Get Form

```typescript
const form = await this.metigan.forms.get('form-123');
```

### List Forms

```typescript
const result = await this.metigan.forms.list({
  page: 1,
  limit: 10,
});

result.forms.forEach((form) => {
  console.log(`${form.title}: ${form.id}`);
});
```

## 🛡️ Error Handling

The SDK provides specific error types for different scenarios:

```typescript
import { ApiError, ValidationError } from '@metigan/nestjs';

try {
  const result = await this.metigan.email.sendEmail(options);
} catch (error) {
  if (error instanceof ValidationError) {
    // Handle validation errors (422)
    console.error(`Validation Error: ${error.message}`);
    if (error.field) {
      console.error(`Field: ${error.field}`);
    }
  } else if (error instanceof ApiError) {
    // Handle API errors (4xx, 5xx)
    console.error(`API Error: ${error.statusCode} - ${error.message}`);
    if (error.error) {
      console.error(`Error code: ${error.error}`);
    }
    
    // Handle specific status codes
    if (error.statusCode === 401) {
      // Unauthorized - check API key
    } else if (error.statusCode === 429) {
      // Rate limited - retry after delay
    }
  } else {
    // Handle other errors
    console.error(`Unexpected error: ${error}`);
  }
}
```

### Error Types

- **`ValidationError`** - Thrown when request validation fails (422)
  - `message`: Error message
  - `field`: Field name that failed validation (optional)
  
- **`ApiError`** - Thrown for API errors (4xx, 5xx)
  - `statusCode`: HTTP status code
  - `message`: Error message
  - `error`: Error code (optional)

## 📋 Response Format

**Important:** The API returns all fields in **camelCase** format, not snake_case. Always use camelCase when accessing response data:

```typescript
// ✅ Correct
result.emailsRemaining
result.recipientCount
result.successfulEmails

// ❌ Incorrect
result.emails_remaining  // Will be undefined
result.recipient_count   // Will be undefined
```

## 🧪 Testing

When testing services that use Metigan, you can mock the MetiganService:

```typescript
import { Test, TestingModule } from '@nestjs/testing';
import { MetiganService } from '@metigan/nestjs';

describe('EmailService', () => {
  let service: EmailService;
  let metiganService: jest.Mocked<MetiganService>;

  beforeEach(async () => {
    const mockMetiganService = {
      email: {
        sendEmail: jest.fn().mockResolvedValue({
          success: true,
          message: 'Email sent',
          emailsRemaining: 999,
        }),
      },
    };

    const module: TestingModule = await Test.createTestingModule({
      providers: [
        EmailService,
        {
          provide: MetiganService,
          useValue: mockMetiganService,
        },
      ],
    }).compile();

    service = module.get<EmailService>(EmailService);
    metiganService = module.get(MetiganService);
  });

  it('should send email', async () => {
    const result = await service.sendWelcomeEmail('test@example.com');
    
    expect(metiganService.email.sendEmail).toHaveBeenCalled();
    expect(result.success).toBe(true);
  });
});
```

## 🐛 Troubleshooting

### "API key is required" Error

Make sure you've configured the module with an API key:

```typescript
// Check your .env file
METIGAN_API_KEY=your-api-key-here

// Verify in your module
MetiganModule.forRoot({
  apiKey: process.env.METIGAN_API_KEY, // Make sure this is set
})
```

### Module Not Found

Make sure you've imported `MetiganModule` in your root module:

```typescript
@Module({
  imports: [MetiganModule.forRoot({ apiKey: '...' })],
})
export class AppModule {}
```

### Service Not Injected

The `MetiganService` is available globally after importing `MetiganModule`. Make sure:

1. The module is imported in your root module
2. You're using dependency injection correctly
3. The service is provided in your module (if using a feature module)

### Timeout Errors

If you're experiencing timeout errors, increase the timeout:

```typescript
MetiganModule.forRoot({
  apiKey: '...',
  timeout: 60000, // Increase to 60 seconds
})
```

### Retry Logic

The SDK automatically retries failed requests. Configure retry behavior:

```typescript
MetiganModule.forRoot({
  apiKey: '...',
  retryCount: 5,    // Increase retry attempts
  retryDelay: 3000, // Increase delay between retries
})
```

## 📚 Additional Resources

- [NestJS Documentation](https://docs.nestjs.com/)
- [TypeScript Documentation](https://www.typescriptlang.org/docs/)
- [Axios Documentation](https://axios-http.com/docs/intro) (used internally)

## 📄 License

MIT © Metigan

## 🔗 Links

- [Documentation](https://docs.metigan.com)
- [Dashboard](https://app.metigan.com)
- [API Reference](https://docs.metigan.com/api)
- [GitHub Repository](https://github.com/metigan/nestjs)
- [Issue Tracker](https://github.com/metigan/nestjs/issues)

## 💬 Support

For support, please:
- Check the [Documentation](https://docs.metigan.com)
- Open an issue on [GitHub](https://github.com/metigan/nestjs/issues)
- Contact support at support@metigan.com