Fix/multiple generation (#104)

* fixes #100

* Fix test

* fix: fix bad configuration issue

api/tests/test_cost_calculator.py

@@ -0,0 +1,31 @@
+from api.services.pricing.cost_calculator import cost_calculator
+
+
+def test_cost_calculator():
+    """Test function to verify cost calculation works"""
+    sample_usage = {
+        "llm": {
+            "OpenAILLMService#0|||gpt-4.1-mini": {
+                "prompt_tokens": 45380,
+                "completion_tokens": 496,
+                "total_tokens": 45876,
+                "cache_read_input_tokens": 0,
+                "cache_creation_input_tokens": 0,
+            }
+        },
+        "tts": {"ElevenLabsTTSService#0|||eleven_flash_v2_5": 2399},
+        "stt": {"DeepgramSTTService#0|||nova-3-general": 177.21536946296692},
+        "call_duration_seconds": 179,
+    }
+
+    result = cost_calculator.calculate_total_cost(sample_usage)
+    assert result["llm_cost"] == 45380 * 0.40 / 1_000_000 + 496 * 1.60 / 1_000_000
+    assert result["tts_cost"] == 2399 * 0.0256 / 1_000
+    assert result["stt_cost"] == 177.21536946296692 / 60 * 0.0077
+    assert (
+        abs(
+            result["total"]
+            - (result["llm_cost"] + result["tts_cost"] + result["stt_cost"])
+        )
+        < 1e-10
+    )