Read Tool & Reasoning Tokens from GenAI API instead of Catalog Metadata

sdk_v2/cpp/src/inferencing/generative/chat/chat_session.cc

@@ -117,51 +117,34 @@ ToolCallContext ChatSession::BuildToolCallContext(const Request& request) const
   tool_ctx.tool_call_start = get_param(FOUNDRY_LOCAL_MODEL_PROP_TOOL_CALL_START_STR);
   tool_ctx.tool_call_end = get_param(FOUNDRY_LOCAL_MODEL_PROP_TOOL_CALL_END_STR);
 
-  // Fall back to model info properties if not specified in the request
-  const auto& info = CatalogModel().Info();
-
-  // Check if the model supports tool calling
-  const auto* tool_calling_val = info.GetPropertyInt(FOUNDRY_LOCAL_MODEL_PROP_SUPPORTS_TOOL_CALLING_INT);
-  if (tool_calling_val && *tool_calling_val == 1) {
-    tool_ctx.supports_tool_calling = true;
-  }
-
+  // Fall back to GenAI model API (reads genai_config.json + model-family fallback map)
   if (tool_ctx.tool_call_start.empty()) {
-    const auto* val = info.GetPropertyStr(FOUNDRY_LOCAL_MODEL_PROP_TOOL_CALL_START_STR);
-    if (val) {
-      tool_ctx.tool_call_start = *val;
-    }
+    tool_ctx.tool_call_start = Model().GetGenerationTag("tool_call_start");
   }
-
   if (tool_ctx.tool_call_end.empty()) {
-    const auto* val = info.GetPropertyStr(FOUNDRY_LOCAL_MODEL_PROP_TOOL_CALL_END_STR);
-    if (val) {
-      tool_ctx.tool_call_end = *val;
-    }
+    tool_ctx.tool_call_end = Model().GetGenerationTag("tool_call_end");
   }
 
-  // Check if the model supports chain-of-thought reasoning
-  const auto* reasoning_val = info.GetPropertyInt(FOUNDRY_LOCAL_MODEL_PROP_SUPPORTS_REASONING_INT);
-  if (reasoning_val && *reasoning_val == 1) {
-    tool_ctx.supports_reasoning = true;
+  // Non-empty tool_call_start implies the model supports tool calling
+  if (!tool_ctx.tool_call_start.empty()) {
+    tool_ctx.supports_tool_calling = true;
   }
 
   // Read reasoning marker tokens — same pattern as tool_call tokens
   tool_ctx.reasoning_start = get_param(FOUNDRY_LOCAL_MODEL_PROP_REASONING_START_STR);
   tool_ctx.reasoning_end = get_param(FOUNDRY_LOCAL_MODEL_PROP_REASONING_END_STR);
 
+  // Fall back to GenAI model API for reasoning tokens
   if (tool_ctx.reasoning_start.empty()) {
-    const auto* val = info.GetPropertyStr(FOUNDRY_LOCAL_MODEL_PROP_REASONING_START_STR);
-    if (val) {
-      tool_ctx.reasoning_start = *val;
-    }
+    tool_ctx.reasoning_start = Model().GetGenerationTag("reasoning_start");
   }
-
   if (tool_ctx.reasoning_end.empty()) {
-    const auto* val = info.GetPropertyStr(FOUNDRY_LOCAL_MODEL_PROP_REASONING_END_STR);
-    if (val) {
-      tool_ctx.reasoning_end = *val;
-    }
+    tool_ctx.reasoning_end = Model().GetGenerationTag("reasoning_end");
+  }
+
+  // Non-empty reasoning_start implies the model supports reasoning
+  if (!tool_ctx.reasoning_start.empty()) {
+    tool_ctx.supports_reasoning = true;
   }
 
   // Accumulate tool definitions from the session.

sdk_v2/cpp/src/inferencing/generative/genai_model_instance.cc

@@ -111,6 +111,15 @@ OgaModel& GenAIModelInstance::GetOgaModel() {
   return *oga_model_;
 }
 
+std::string GenAIModelInstance::GetGenerationTag(const char* tag_name) const {
+  if (!oga_model_) {
+    return {};
+  }
+  OgaString tag = oga_model_->GetGenerationTag(tag_name);
+  const char* p = tag;
+  return p ? std::string(p) : std::string();
+}
+
 OgaTokenizer& GenAIModelInstance::GetOgaTokenizer() {
   if (!tokenizer_) {
     FL_THROW(FOUNDRY_LOCAL_ERROR_INTERNAL, "OGA tokenizer is null");

sdk_v2/cpp/src/inferencing/generative/genai_model_instance.h

@@ -36,6 +36,11 @@ class GenAIModelInstance {
   ExecutionProvider EP() const { return ep_; }
   bool IsMultiModal() const;
 
+  /// Query a generation tag from the GenAI model (reads genai_config.json with model-family fallback).
+  /// Returns the tag value or empty string if not found.  Supported keys:
+  /// "tool_call_start", "tool_call_end", "reasoning_start", "reasoning_end".
+  std::string GetGenerationTag(const char* tag_name) const;
+
   /// Access the underlying OGA objects (for future chat generation work).
   OgaModel& GetOgaModel();
   OgaTokenizer& GetOgaTokenizer();