diff --git a/src/promptforge/providers/factory.py b/src/promptforge/providers/factory.py
index 9e04515..c8919de 100644
--- a/src/promptforge/providers/factory.py
+++ b/src/promptforge/providers/factory.py
@@ -1,4 +1,8 @@
-from typing import Optional
+"""Provider factory for instantiating LLM providers."""
+
+from typing import Dict, Optional
+
+from .base import ProviderBase
 from .openai import OpenAIProvider
 from .anthropic import AnthropicProvider
 from .ollama import OllamaProvider
@@ -6,21 +10,67 @@ from ..core.exceptions import ProviderError
 
 
 class ProviderFactory:
-    @staticmethod
+    """Factory for creating LLM provider instances."""
+
+    _providers: Dict[str, type] = {
+        "openai": OpenAIProvider,
+        "anthropic": AnthropicProvider,
+        "ollama": OllamaProvider,
+    }
+
+    @classmethod
+    def register(cls, name: str, provider_class: type) -> None:
+        """Register a new provider.
+
+        Args:
+            name: Provider identifier.
+            provider_class: Provider class to register.
+        """
+        if not issubclass(provider_class, ProviderBase):
+            raise TypeError("Provider must be a subclass of ProviderBase")
+        cls._providers[name.lower()] = provider_class
+
+    @classmethod
     def create(
+        cls,
         provider_name: str,
+        api_key: Optional[str] = None,
         model: Optional[str] = None,
         temperature: float = 0.7,
-        api_key: Optional[str] = None,
         **kwargs,
-    ):
-        provider_name = provider_name.lower()
+    ) -> ProviderBase:
+        """Create a provider instance.
 
-        if provider_name in ("openai", "gpt-4", "gpt-3.5"):
-            return OpenAIProvider(api_key=api_key, model=model or "gpt-4", temperature=temperature)
-        elif provider_name in ("anthropic", "claude"):
-            return AnthropicProvider(api_key=api_key, model=model or "claude-3-sonnet-20240229", temperature=temperature)
-        elif provider_name in ("ollama", "local"):
-            return OllamaProvider(model=model or "llama2", temperature=temperature, **kwargs)
-        else:
-            raise ProviderError(f"Unknown provider: {provider_name}")
\ No newline at end of file
+        Args:
+            provider_name: Name of the provider to create.
+            api_key: API key for the provider.
+            model: Model to use (uses default if not specified).
+            temperature: Sampling temperature.
+            **kwargs: Additional provider-specific options.
+
+        Returns:
+            Provider instance.
+        """
+        provider_class = cls._providers.get(provider_name.lower())
+        if provider_class is None:
+            available = ", ".join(cls._providers.keys())
+            raise ProviderError(
+                f"Unknown provider: {provider_name}. Available: {available}"
+            )
+
+        return provider_class(
+            api_key=api_key,
+            model=model or getattr(provider_class, "_default_model", "gpt-4"),
+            temperature=temperature,
+            **kwargs,
+        )
+
+    @classmethod
+    def list_providers(cls) -> list[str]:
+        """List available provider names."""
+        return list(cls._providers.keys())
+
+    @classmethod
+    def get_provider_class(cls, name: str) -> Optional[type]:
+        """Get provider class by name."""
+        return cls._providers.get(name.lower())