Add provider registry system with custom provider support

Implements extensible provider registry allowing users to register custom providers (e.g., Cloudflare, Ollama) alongside built-in providers. Updates `providers` CLI command to show registered/builtin/custom providers with `list` and `info` subcommands. Enhances `createProvider()` to accept provider instances, spec objects, or strings. Updates `hasApiKey()` to support provider aliases and custom env vars. Exports registry functions (`register

Author: MervinPraison

examples/provider-registry/custom_provider_example.py

@@ -0,0 +1,225 @@
+"""
+Custom Provider Registry Example (Python)
+
+This example demonstrates how to register and use custom LLM providers
+with the PraisonAI Python wrapper.
+
+Note: The Python provider registry is for custom provider extensions.
+Built-in providers (OpenAI, Anthropic, Google) are handled by LiteLLM
+in praisonaiagents automatically.
+"""
+
+import sys
+sys.path.insert(0, '../../src/praisonai')
+
+from praisonai.llm import (
+    LLMProviderRegistry,
+    register_llm_provider,
+    unregister_llm_provider,
+    has_llm_provider,
+    list_llm_providers,
+    create_llm_provider,
+    get_default_llm_registry,
+    parse_model_string
+)
+
+
+# Example 1: Simple Custom Provider
+# ---------------------------------
+
+class SimpleCustomProvider:
+    """A minimal custom provider example."""
+    
+    provider_id = "simple-custom"
+    
+    def __init__(self, model_id: str, config: dict = None):
+        self.model_id = model_id
+        self.config = config or {}
+        self.api_endpoint = self.config.get('api_endpoint', 'https://api.example.com')
+    
+    def generate(self, prompt: str) -> str:
+        """Generate a response (simulated)."""
+        print(f"[SimpleCustomProvider] Generating with model: {self.model_id}")
+        print(f"[SimpleCustomProvider] Prompt: {prompt[:50]}...")
+        return f"Response from {self.provider_id}/{self.model_id}: Hello! This is a simulated response."
+
+
+# Example 2: Ollama Provider
+# --------------------------
+
+class OllamaProvider:
+    """Custom provider for local Ollama integration."""
+    
+    provider_id = "ollama"
+    
+    def __init__(self, model_id: str, config: dict = None):
+        self.model_id = model_id
+        self.config = config or {}
+        self.base_url = self.config.get('base_url', 'http://localhost:11434')
+    
+    def generate(self, prompt: str) -> str:
+        """Generate a response using Ollama API."""
+        import requests
+        
+        response = requests.post(
+            f"{self.base_url}/api/generate",
+            json={
+                "model": self.model_id,
+                "prompt": prompt,
+                "stream": False
+            }
+        )
+        
+        if response.status_code != 200:
+            raise Exception(f"Ollama API error: {response.text}")
+        
+        return response.json().get("response", "")
+    
+    def generate_stream(self, prompt: str):
+        """Generate a streaming response using Ollama API."""
+        import requests
+        
+        response = requests.post(
+            f"{self.base_url}/api/generate",
+            json={
+                "model": self.model_id,
+                "prompt": prompt,
+                "stream": True
+            },
+            stream=True
+        )
+        
+        for line in response.iter_lines():
+            if line:
+                import json
+                data = json.loads(line)
+                yield data.get("response", "")
+                if data.get("done"):
+                    break
+
+
+# Example 3: Cloudflare Workers AI Provider
+# -----------------------------------------
+
+class CloudflareProvider:
+    """Custom provider for Cloudflare Workers AI."""
+    
+    provider_id = "cloudflare"
+    
+    def __init__(self, model_id: str, config: dict = None):
+        self.model_id = model_id
+        self.config = config or {}
+        self.account_id = self.config.get('account_id')
+        self.api_token = self.config.get('api_token')
+    
+    def generate(self, prompt: str) -> str:
+        """Generate a response using Cloudflare Workers AI."""
+        import requests
+        
+        if not self.account_id or not self.api_token:
+            raise ValueError("Cloudflare account_id and api_token are required")
+        
+        response = requests.post(
+            f"https://api.cloudflare.com/client/v4/accounts/{self.account_id}/ai/run/{self.model_id}",
+            headers={
+                "Authorization": f"Bearer {self.api_token}",
+                "Content-Type": "application/json"
+            },
+            json={"prompt": prompt}
+        )
+        
+        if response.status_code != 200:
+            raise Exception(f"Cloudflare API error: {response.text}")
+        
+        return response.json().get("result", {}).get("response", "")
+
+
+def main():
+    print("=== Provider Registry Example (Python) ===\n")
+    
+    # Check initial state
+    print("Initial providers:", list_llm_providers())
+    print()
+    
+    # Register custom providers
+    print("Registering custom providers...")
+    register_llm_provider("simple-custom", SimpleCustomProvider)
+    register_llm_provider("ollama", OllamaProvider, aliases=["local"])
+    register_llm_provider("cloudflare", CloudflareProvider, aliases=["cf", "workers-ai"])
+    print()
+    
+    # Check providers after registration
+    print("Providers after registration:", list_llm_providers())
+    print("Has ollama:", has_llm_provider("ollama"))
+    print("Has local (alias):", has_llm_provider("local"))
+    print("Has cloudflare:", has_llm_provider("cloudflare"))
+    print("Has cf (alias):", has_llm_provider("cf"))
+    print()
+    
+    # Parse model strings
+    print("=== Model String Parsing ===\n")
+    
+    test_strings = [
+        "openai/gpt-4o-mini",
+        "gpt-4o-mini",
+        "claude-3-5-sonnet-latest",
+        "gemini-2.0-flash",
+        "ollama/llama2",
+        "cloudflare/workers-ai-model"
+    ]
+    
+    for model_str in test_strings:
+        parsed = parse_model_string(model_str)
+        print(f"  '{model_str}' -> provider={parsed['provider_id']}, model={parsed['model_id']}")
+    print()
+    
+    # Create and use providers
+    print("=== Using Custom Providers ===\n")
+    
+    # Use simple custom provider
+    provider = create_llm_provider("simple-custom/test-model")
+    print(f"Created provider: {provider.provider_id}/{provider.model_id}")
+    response = provider.generate("Hello, world!")
+    print(f"Response: {response}")
+    print()
+    
+    # Use ollama provider via alias
+    provider = create_llm_provider("local/llama2", config={"base_url": "http://localhost:11434"})
+    print(f"Created provider: {provider.provider_id}/{provider.model_id}")
+    print()
+    
+    # Demonstrate error handling
+    print("=== Error Handling ===\n")
+    try:
+        create_llm_provider("unknown-provider/model")
+    except ValueError as e:
+        print(f"Expected error: {e}")
+    print()
+    
+    # Demonstrate isolated registries
+    print("=== Isolated Registries ===\n")
+    
+    # Create isolated registry
+    isolated_registry = LLMProviderRegistry()
+    isolated_registry.register("isolated-provider", SimpleCustomProvider)
+    
+    print(f"Default registry providers: {list_llm_providers()}")
+    print(f"Isolated registry providers: {isolated_registry.list()}")
+    
+    # Use isolated registry
+    provider = create_llm_provider("isolated-provider/model", registry=isolated_registry)
+    print(f"Created from isolated registry: {provider.provider_id}/{provider.model_id}")
+    print()
+    
+    # Cleanup
+    print("=== Cleanup ===\n")
+    unregister_llm_provider("simple-custom")
+    unregister_llm_provider("ollama")
+    unregister_llm_provider("cloudflare")
+    print(f"Providers after cleanup: {list_llm_providers()}")
+    
+    print("\n=== Example Complete ===")
+
+
+if __name__ == "__main__":
+    main()