feat: add fallback embedding provider

agent/memory/embedding.py

@@ -138,24 +138,24 @@ def create_embedding_provider(
 ) -> EmbeddingProvider:
     """
     Factory function to create embedding provider
-    
-    Only supports OpenAI embedding via REST API.
+
+    Supports "openai" and "linkai" providers (both use OpenAI-compatible REST API).
     If initialization fails, caller should fall back to keyword-only search.
-    
+
     Args:
-        provider: Provider name (only "openai" is supported)
+        provider: Provider name ("openai" or "linkai")
         model: Model name (default: text-embedding-3-small)
-        api_key: OpenAI API key (required)
-        api_base: API base URL (default: https://api.openai.com/v1)
+        api_key: API key (required)
+        api_base: API base URL
         
     Returns:
         EmbeddingProvider instance
         
     Raises:
-        ValueError: If provider is not "openai" or api_key is missing
+        ValueError: If provider is unsupported or api_key is missing
     """
-    if provider != "openai":
-        raise ValueError(f"Only 'openai' provider is supported, got: {provider}")
+    if provider not in ("openai", "linkai"):
+        raise ValueError(f"Unsupported embedding provider: {provider}. Use 'openai' or 'linkai'.")
 
     model = model or "text-embedding-3-small"
     return OpenAIEmbeddingProvider(model=model, api_key=api_key, api_base=api_base)

agent/memory/manager.py

@@ -50,28 +50,44 @@ class MemoryManager:
             overlap_tokens=self.config.chunk_overlap_tokens
         )
         
-        # Initialize embedding provider (optional)
+        # Initialize embedding provider (optional, prefer OpenAI, fallback to LinkAI)
         self.embedding_provider = None
         if embedding_provider:
             self.embedding_provider = embedding_provider
         else:
-            # Try to create embedding provider, but allow failure
+            # Try OpenAI first
             try:
-                # Get API key from environment or config
                 api_key = os.environ.get('OPENAI_API_KEY')
                 api_base = os.environ.get('OPENAI_API_BASE')
-                
-                self.embedding_provider = create_embedding_provider(
-                    provider=self.config.embedding_provider,
-                    model=self.config.embedding_model,
-                    api_key=api_key,
-                    api_base=api_base
-                )
+                if api_key:
+                    self.embedding_provider = create_embedding_provider(
+                        provider="openai",
+                        model=self.config.embedding_model,
+                        api_key=api_key,
+                        api_base=api_base
+                    )
             except Exception as e:
-                # Embedding provider failed, but that's OK
-                # We can still use keyword search and file operations
                 from common.log import logger
-                logger.warning(f"[MemoryManager] Embedding provider initialization failed: {e}")
+                logger.warning(f"[MemoryManager] OpenAI embedding failed: {e}")
+
+            # Fallback to LinkAI
+            if self.embedding_provider is None:
+                try:
+                    linkai_key = os.environ.get('LINKAI_API_KEY')
+                    linkai_base = os.environ.get('LINKAI_API_BASE', 'https://api.link-ai.tech')
+                    if linkai_key:
+                        self.embedding_provider = create_embedding_provider(
+                            provider="linkai",
+                            model=self.config.embedding_model,
+                            api_key=linkai_key,
+                            api_base=f"{linkai_base}/v1"
+                        )
+                except Exception as e:
+                    from common.log import logger
+                    logger.warning(f"[MemoryManager] LinkAI embedding failed: {e}")
+
+            if self.embedding_provider is None:
+                from common.log import logger
                 logger.info(f"[MemoryManager] Memory will work with keyword search only (no vector search)")
         
         # Initialize memory flush manager