Fix empty provider causing wiki generation failure

When navigating to a repo URL without a ?provider= param, the provider
state initialized as '' (empty string). The async fetch to resolve the
default provider from /api/models/config hadn't completed before wiki
generation started, sending provider='' to the backend. Pydantic accepted
the empty string (not triggering the "google" default), causing
"Configuration for provider '' not found" errors.

Fixes:
- Backend: fall back to configured default_provider when provider is empty
- Frontend: synchronously resolve provider before starting generation

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: 2 people

api/websocket_wiki.py

@@ -138,6 +138,14 @@ async def handle_websocket_chat(websocket: WebSocket):
         request_data = await websocket.receive_json()
         request = ChatCompletionRequest(**request_data)
 
+        # Fall back to default provider if none specified
+        if not request.provider:
+            from api.config import configs as app_configs
+            request.provider = app_configs.get("default_provider", "google")
+            logger.info(f"No provider specified, falling back to default: {request.provider}")
+        if not request.model:
+            request.model = None  # Let get_model_config pick the default
+
         # Check if request contains very large input
         input_too_large = False
         if request.messages and len(request.messages) > 0:

src/hooks/useWikiGeneration.ts

@@ -435,6 +435,24 @@ Remember:
       return;
     }
 
+    // Wait for provider to be resolved if it's still empty (async fetch in useModelSelection)
+    let resolvedProvider = selectedProviderState;
+    if (!resolvedProvider) {
+      console.log('Provider not yet resolved, fetching default...');
+      try {
+        const res = await fetch('/api/models/config');
+        if (res.ok) {
+          const data = await res.json();
+          resolvedProvider = data.defaultProvider || 'google';
+        } else {
+          resolvedProvider = 'google';
+        }
+      } catch {
+        resolvedProvider = 'google';
+      }
+      console.log(`Provider resolved to: ${resolvedProvider}`);
+    }
+
     try {
       setStructureRequestInProgress(true);
       setGenerationPhase('planning');
@@ -580,7 +598,7 @@ IMPORTANT:
         }]
       };
 
-      addTokensToRequestBody(requestBody, currentToken, effectiveRepoInfo.type, selectedProviderState, selectedModelState, isCustomSelectedModelState, customSelectedModelState, language, modelExcludedDirs, modelExcludedFiles, modelIncludedDirs, modelIncludedFiles);
+      addTokensToRequestBody(requestBody, currentToken, effectiveRepoInfo.type, resolvedProvider, selectedModelState, isCustomSelectedModelState, customSelectedModelState, language, modelExcludedDirs, modelExcludedFiles, modelIncludedDirs, modelIncludedFiles);
 
       let responseText = '';