> ## Documentation Index
> Fetch the complete documentation index at: https://docs.t3planet.de/en/latest/llms.txt
> Use this file to discover all available pages before exploring further.

# Architecture

> Architecture of EXT:ns_t3af — services, adapters, caching, and constraints.

## Overview

T3AF is a shared foundation layer:

```php theme={"theme":{"light":"github-light","dark":"github-dark"}}
Consuming Extension Code
        |
        v
AiServiceInterface
        |
        v
AdapterRegistry -> Provider adapters
        |
        v
   Provider APIs
```

Parallel support:

```php theme={"theme":{"light":"github-light","dark":"github-dark"}}
AiStatisticsService -> OpenAiOrganizationUsageService -> OpenAI Usage API
HttpAuthUtility    -> Protected URL fetching with optional Basic Auth
```

## AI Prompts (T3AI)

Management UI for T3AI global and sidebar prompts lives in **T3AF → AI Prompts**.
Built-in defaults are defined in `ns_t3ai` (`PromptContractRegistry`); the database stores custom overrides only.

See `PromptManagementProvidersAndFeatures.md` and `PromptsSystemReference.md` in this directory for routes, UI behaviour, and class reference.

## Main components

* **Request orchestration**: `AiServiceInterface` and `AiService`
* **Provider adapters**: `AdapterRegistry` and `AdapterInterface` implementations
* **Statistics processing**: `AiStatisticsService` and `OpenAiOrganizationUsageService`
* **Engine configuration filtering**: `AiEngineConfiguration`
* **Utility and environment helpers**: `AiUniverseUtilityHelper`
* **HTTP auth helper**: `HttpAuthUtility`

## Configuration model

Runtime behavior is mostly driven by extension configuration keys from
`ext_conf_template.txt`.

This includes:

* provider keys and models
* default engine selection
* token/temperature values
* basic auth settings

## Caching

The extension registers cache `nst3af_statistics` in
`ext_localconf.php`.

Statistics service stores processed data in this cache to reduce repeated
usage API calls.

## Constraints

* No native frontend plugin and no Fluid frontend output in this package.
* Primary role is reusable service infrastructure.