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

# Providers Overview

> Choose the right message transport provider for your needs

SimpleMessageBus supports multiple transport providers, allowing you to choose the best option for your infrastructure and requirements. Each provider has its own strengths and is optimized for specific scenarios.

## Available Providers

<CardGroup cols={2}>
  <Card title="Azure Storage Queue" icon="microsoft" href="/simplemessagebus/providers/azure-storage-queue">
    Reliable, cost-effective queuing using Azure Storage
  </Card>

  <Card title="Amazon SQS" icon="aws" href="/simplemessagebus/providers/amazon-sqs">
    Fully managed message queuing service from AWS
  </Card>

  <Card title="File System" icon="folder" href="/simplemessagebus/providers/filesystem">
    Local file-based messaging for development and on-premises
  </Card>

  <Card title="IndexedDB" icon="globe" href="/simplemessagebus/providers/indexeddb">
    Client-side messaging for Blazor WebAssembly applications
  </Card>
</CardGroup>

## Provider Comparison

<div className="overflow-x-auto">
  <table className="min-w-full">
    <thead>
      <tr>
        <th>Feature</th>
        <th>Azure Storage</th>
        <th>Amazon SQS</th>
        <th>File System</th>
        <th>IndexedDB</th>
      </tr>
    </thead>

    <tbody>
      <tr>
        <td>**Cost**</td>
        <td>Very Low</td>
        <td>Low</td>
        <td>Free</td>
        <td>Free</td>
      </tr>

      <tr>
        <td>**Scalability**</td>
        <td>High</td>
        <td>Very High</td>
        <td>Limited</td>
        <td>Limited</td>
      </tr>

      <tr>
        <td>**Reliability**</td>
        <td>High</td>
        <td>Very High</td>
        <td>Medium</td>
        <td>Medium</td>
      </tr>

      <tr>
        <td>**Latency**</td>
        <td>Low</td>
        <td>Very Low</td>
        <td>Very Low</td>
        <td>Very Low</td>
      </tr>

      <tr>
        <td>**Setup Complexity**</td>
        <td>Low</td>
        <td>Medium</td>
        <td>Very Low</td>
        <td>Low</td>
      </tr>

      <tr>
        <td>**Platform Support**</td>
        <td>All</td>
        <td>All</td>
        <td>All</td>
        <td>Browser Only</td>
      </tr>
    </tbody>
  </table>
</div>

## Choosing a Provider

### Azure Storage Queue

**Best for:**

* Applications already using Azure ecosystem
* Cost-sensitive scenarios (very affordable)
* High-volume, low-complexity messaging
* Integration with Azure Functions

**Limitations:**

* 64KB message size limit
* Basic message ordering (FIFO not guaranteed)
* No advanced routing features

**Example Use Cases:**

* Background job processing
* Event notifications
* Simple workflow coordination

### Amazon SQS

**Best for:**

* Applications in AWS ecosystem
* Mission-critical applications requiring high reliability
* Complex messaging patterns with DLQ support
* Applications requiring message ordering (FIFO queues)

**Limitations:**

* Higher cost than Azure Storage
* More complex IAM configuration
* AWS-specific features and terminology

**Example Use Cases:**

* Microservices communication
* Order processing systems
* High-volume transaction processing

### File System

**Best for:**

* Development and testing
* On-premises deployments
* Simple applications with low message volume
* Azure Functions with custom triggers

**Limitations:**

* Not suitable for production at scale
* No built-in redundancy
* Platform-dependent file locking

**Example Use Cases:**

* Local development
* Simple background processing
* File-based integrations
* Proof of concepts

### IndexedDB

**Best for:**

* Blazor WebAssembly applications
* Client-side background processing
* Offline-capable applications
* Browser-based workflows

**Limitations:**

* Browser storage quotas
* Single-user scenarios only
* No cross-browser synchronization
* Limited to WebAssembly context

**Example Use Cases:**

* Client-side data processing
* Offline message queuing
* Browser-based workflows
* Progressive Web Apps (PWAs)

## Multi-Provider Architecture

You can use multiple providers in the same application for different scenarios:

```csharp theme={"dark"}
// Configure multiple publishers
services.AddSimpleMessageBusAzureStoragePublisher("primary", options =>
{
    options.ConnectionString = azureConnectionString;
});

services.AddSimpleMessageBusFileSystemPublisher("local", options =>
{
    options.RootPath = localPath;
});

// Use named publishers
public class OrderService
{
    private readonly IMessagePublisher _primaryPublisher;
    private readonly IMessagePublisher _localPublisher;

    public OrderService(
        [FromKeyedServices("primary")] IMessagePublisher primaryPublisher,
        [FromKeyedServices("local")] IMessagePublisher localPublisher)
    {
        _primaryPublisher = primaryPublisher;
        _localPublisher = localPublisher;
    }
}
```

## Migration Between Providers

SimpleMessageBus makes it easy to migrate between providers:

1. **Add the new provider** alongside the existing one
2. **Gradually migrate message types** to the new provider
3. **Update handlers** to process from both providers during transition
4. **Remove the old provider** once migration is complete

```csharp theme={"dark"}
// Phase 1: Add new provider
services.AddSimpleMessageBusAmazonSQSPublisher(newOptions);
services.AddSimpleMessageBusAzureStoragePublisher(oldOptions);

// Phase 2: Dual publishing during migration
await _newPublisher.PublishAsync(message);
await _oldPublisher.PublishAsync(message); // Remove when ready

// Phase 3: Remove old provider
services.RemoveSimpleMessageBusAzureStorage();
```

## Provider-Specific Features

Each provider offers unique features that you can leverage:

### Azure Storage Queue Features

* **Poison message handling**: Automatic dead letter queue support
* **Message TTL**: Configurable time-to-live for messages
* **Peek operations**: Non-destructive message inspection
* **Batch operations**: Process multiple messages efficiently

### Amazon SQS Features

* **FIFO queues**: Guaranteed message ordering
* **Message deduplication**: Automatic duplicate detection
* **Dead letter queues**: Sophisticated error handling
* **Long polling**: Efficient message retrieval

### File System Features

* **Azure Functions triggers**: Custom trigger bindings
* **File watching**: Real-time processing of new files
* **Structured storage**: Organized file hierarchies
* **Cross-platform compatibility**: Works on all operating systems

### IndexedDB Features

* **Offline support**: Works without network connectivity
* **Large storage**: Gigabytes of client-side storage
* **Transaction support**: ACID properties for data integrity
* **Asynchronous operations**: Non-blocking browser operations

## Configuration Patterns

### Environment-Based Configuration

Use different providers based on environment:

```csharp theme={"dark"}
if (builder.Environment.IsDevelopment())
{
    builder.Services.AddSimpleMessageBusFileSystemProvider();
}
else if (builder.Environment.IsProduction())
{
    builder.Services.AddSimpleMessageBusAzureStorageProvider();
}
```

### Feature Flag Configuration

Use feature flags to switch providers:

```csharp theme={"dark"}
var useAmazonSQS = builder.Configuration.GetValue<bool>("Features:UseAmazonSQS");

if (useAmazonSQS)
{
    builder.Services.AddSimpleMessageBusAmazonSQSProvider();
}
else
{
    builder.Services.AddSimpleMessageBusAzureStorageProvider();
}
```

## Next Steps

Choose your provider and dive into the detailed configuration:

<CardGroup cols={2}>
  <Card title="Azure Storage Queue" icon="microsoft" href="/simplemessagebus/providers/azure-storage-queue">
    Configure Azure Storage Queue provider
  </Card>

  <Card title="Amazon SQS" icon="aws" href="/simplemessagebus/providers/amazon-sqs">
    Set up Amazon SQS provider
  </Card>

  <Card title="File System" icon="folder" href="/simplemessagebus/providers/filesystem">
    Use File System provider
  </Card>

  <Card title="IndexedDB" icon="globe" href="/simplemessagebus/providers/indexeddb">
    Implement IndexedDB provider
  </Card>
</CardGroup>