# Configuration

## Overview
Luna uses the standard .NET Options pattern for managing application settings. The configuration system relies on `IOptions<T>` and `IOptionsMonitor<T>` to provide typed access to settings defined in `appsettings.json`. This approach ensures type safety and allows for easy validation at startup.

The configuration is centralized in the `Luna.Configuration` project. Settings are bound during application startup using the `.BindConfiguration().ValidateDataAnnotations().ValidateOnStart()` pattern.

## Options Classes

### AgentOptions
These settings define the behavior and identity of AI agents like the [[Core]] agent or the Librarian. Agents retrieve their specific configuration using `IOptionsMonitor<AgentOptions>.Get(name)`.

```csharp
public class AgentOptions
{
    public required string Name { get; set; }
    public string? DisplayName { get; init; }
    public string? Description { get; init; }
    public required string Provider { get; init; }
    public required string ModelId { get; init; }
    public required string Instructions { get; init; }
    public required int MaxContextTokens { get; init; }
}
```

### ProviderOptions
Configures the connection details for AI model providers such as Mistral or OpenAI.

```csharp
public class ProviderOptions
{
    public required string ApiKey { get; init; }
    public required string ApiUrl { get; init; }
    public required string[] Models { get; init; }
}
```

### SessionOptions
Controls how [[Memory]] and conversation sessions are managed. It specifically dictates when the session context should be compacted to save tokens.

```csharp
public class SessionOptions
{
    public required float ContextTokenThreshold { get; init; }
    public required int RetainedMessagesAfterCompacting { get; init; }
}
```

### TelegramOptions
Specific settings for the Telegram [[Channels]] adapter, including bot authentication and user access control.

```csharp
public class TelegramOptions
{
    public required string BotToken { get; init; }
    public string? WebhookUrl { get; init; }
    public int PollingTimeoutSeconds { get; init; } = 30;
    public string[] AllowedUserIds { get; init; } = [];
}
```

## Example Configuration

The following `appsettings.json` structure demonstrates how these options are populated:

```json
{
  "Agents": {
    "Core": {
      "Name": "Core",
      "Provider": "Mistral",
      "ModelId": "mistral-small-latest",
      "Instructions": "You are Luna, a helpful AI assistant.",
      "MaxContextTokens": 8192
    },
    "Librarian": {
      "Name": "Librarian",
      "Provider": "Mistral",
      "ModelId": "mistral-small-latest",
      "Instructions": "Summarize conversations concisely.",
      "MaxContextTokens": 4096
    }
  },
  "Providers": {
    "Mistral": {
      "ApiKey": "YOUR_API_KEY",
      "ApiUrl": "https://api.mistral.ai",
      "Models": ["mistral-small-latest"]
    }
  },
  "Session": {
    "ContextTokenThreshold": 0.7,
    "RetainedMessagesAfterCompacting": 5
  },
  "Channels": {
    "Telegram": {
      "BotToken": "YOUR_BOT_TOKEN",
      "PollingTimeoutSeconds": 30,
      "AllowedUserIds": []
    }
  }
}
```

## Dependencies

The configuration module depends on the following NuGet packages:

- Microsoft.Extensions.DependencyInjection.Abstractions
- Microsoft.Extensions.FileProviders.Embedded
- Microsoft.Extensions.Options
- Tomlyn (for parsing embedded TOML resources)