Architecture

AI Providers is a provider-asset abstraction plus a shared request service. The design stays intentionally independent of Dialogue Graph System and AI Extension so other tools can reuse the same provider and transport layer.

High-level architecture

Caller
  -> AiProvidersService
  -> LlmProviderDefinitionBase
  -> LlmHttpRequest
  -> UnityWebRequest
  -> Provider API
  -> provider-specific response extraction

Division of ownership

• Provider asset builds the concrete HTTP request and parses the provider-specific response.
• Service layer owns transport execution, timeout/retry behavior, and normalized HTTP error handling.
• DTO layer carries chat messages, model overrides, and the built request definition.

Base class contract

public abstract class LlmProviderDefinitionBase : ScriptableObject
{
    public abstract LlmHttpRequest BuildHttpRequest(LlmChatRequest chat);
    public abstract string ExtractTextFromResponse(string responseJson);
}

Why provider assets matter

New providers are added as assets and subclasses rather than as giant switch statements in the service. That keeps endpoint rules, model defaults, and response parsing close to the specific provider implementation.