From f03e860425ac2263a9feccd554ce598974dec25a Mon Sep 17 00:00:00 2001
From: AkhileshNegi <akhileshnegi.an3@gmail.com>
Date: Sat, 14 Mar 2026 12:52:11 +0530
Subject: [PATCH 1/8] added signed url for tts dataset

---
 .../app/api/routes/tts_evaluations/dataset.py | 31 +++++++++++++++++--
 backend/app/crud/tts_evaluations/dataset.py   | 11 +++----
 backend/app/models/tts_evaluation.py          |  9 +++++-
 3 files changed, 41 insertions(+), 10 deletions(-)

diff --git a/backend/app/api/routes/tts_evaluations/dataset.py b/backend/app/api/routes/tts_evaluations/dataset.py
index c08d4e68e..2005a4dc3 100644
--- a/backend/app/api/routes/tts_evaluations/dataset.py
+++ b/backend/app/api/routes/tts_evaluations/dataset.py
@@ -6,6 +6,7 @@
 
 from app.api.deps import AuthContextDep, SessionDep
 from app.api.permissions import Permission, require_permission
+from app.core.cloud import get_cloud_storage
 from app.crud.language import get_language_by_id
 from app.crud.tts_evaluations import (
     get_tts_dataset_by_id,
@@ -71,6 +72,9 @@ def list_datasets(
     auth_context: AuthContextDep,
     limit: int = Query(50, ge=1, le=100, description="Maximum results to return"),
     offset: int = Query(0, ge=0, description="Number of results to skip"),
+    include_signed_url: bool = Query(
+        False, description="Include signed URL for dataset files"
+    ),
 ) -> APIResponse[list[TTSDatasetPublic]]:
     """List TTS evaluation datasets."""
     datasets, total = list_tts_datasets(
@@ -81,8 +85,21 @@ def list_datasets(
         offset=offset,
     )
 
+    storage = None
+    if include_signed_url:
+        storage = get_cloud_storage(
+            session=session, project_id=auth_context.project_.id
+        )
+
+    data = []
+    for dataset in datasets:
+        signed_url = None
+        if storage and dataset.object_store_url:
+            signed_url = storage.get_signed_url(dataset.object_store_url)
+        data.append(TTSDatasetPublic.from_model(dataset, signed_url=signed_url))
+
     return APIResponse.success_response(
-        data=datasets,
+        data=data,
         metadata={"total": total, "limit": limit, "offset": offset},
     )
 
@@ -98,6 +115,9 @@ def get_dataset(
     session: SessionDep,
     auth_context: AuthContextDep,
     dataset_id: int,
+    include_signed_url: bool = Query(
+        False, description="Include signed URL for dataset file"
+    ),
 ) -> APIResponse[TTSDatasetPublic]:
     """Get a TTS evaluation dataset."""
     dataset = get_tts_dataset_by_id(
@@ -110,8 +130,15 @@ def get_dataset(
     if not dataset:
         raise HTTPException(status_code=404, detail="Dataset not found")
 
+    signed_url = None
+    if include_signed_url and dataset.object_store_url:
+        storage = get_cloud_storage(
+            session=session, project_id=auth_context.project_.id
+        )
+        signed_url = storage.get_signed_url(dataset.object_store_url)
+
     return APIResponse.success_response(
-        data=TTSDatasetPublic.from_model(dataset),
+        data=TTSDatasetPublic.from_model(dataset, signed_url=signed_url),
         metadata={
             "sample_count": (dataset.dataset_metadata or {}).get("sample_count", 0)
         },
diff --git a/backend/app/crud/tts_evaluations/dataset.py b/backend/app/crud/tts_evaluations/dataset.py
index e2956885d..c81007e92 100644
--- a/backend/app/crud/tts_evaluations/dataset.py
+++ b/backend/app/crud/tts_evaluations/dataset.py
@@ -10,7 +10,6 @@
 from app.core.util import now
 from app.models import EvaluationDataset
 from app.models.stt_evaluation import EvaluationType
-from app.models.tts_evaluation import TTSDatasetPublic
 
 logger = logging.getLogger(__name__)
 
@@ -121,7 +120,7 @@ def list_tts_datasets(
     project_id: int,
     limit: int = 50,
     offset: int = 0,
-) -> tuple[list[TTSDatasetPublic], int]:
+) -> tuple[list[EvaluationDataset], int]:
     """List TTS datasets for a project.
 
     Args:
@@ -132,7 +131,7 @@ def list_tts_datasets(
         offset: Number of results to skip
 
     Returns:
-        tuple[list[TTSDatasetPublic], int]: Datasets and total count
+        tuple[list[EvaluationDataset], int]: Datasets and total count
     """
     base_filter = (
         EvaluationDataset.organization_id == org_id,
@@ -151,8 +150,6 @@ def list_tts_datasets(
         .limit(limit)
     )
 
-    datasets = session.exec(statement).all()
+    datasets = list(session.exec(statement).all())
 
-    result = [TTSDatasetPublic.from_model(dataset) for dataset in datasets]
-
-    return result, total
+    return datasets, total
diff --git a/backend/app/models/tts_evaluation.py b/backend/app/models/tts_evaluation.py
index 3ee796759..e1222ab97 100644
--- a/backend/app/models/tts_evaluation.py
+++ b/backend/app/models/tts_evaluation.py
@@ -179,6 +179,7 @@ class TTSDatasetPublic(BaseModel):
     type: str
     language_id: int | None
     object_store_url: str | None
+    signed_url: str | None = None
     dataset_metadata: dict[str, Any]
     organization_id: int
     project_id: int
@@ -186,7 +187,12 @@ class TTSDatasetPublic(BaseModel):
     updated_at: datetime
 
     @classmethod
-    def from_model(cls, dataset: EvaluationDataset) -> TTSDatasetPublic:
+    def from_model(
+        cls,
+        dataset: EvaluationDataset,
+        *,
+        signed_url: str | None = None,
+    ) -> TTSDatasetPublic:
         """Create from an EvaluationDataset model instance."""
         return cls(
             id=dataset.id,
@@ -195,6 +201,7 @@ def from_model(cls, dataset: EvaluationDataset) -> TTSDatasetPublic:
             type=dataset.type,
             language_id=dataset.language_id,
             object_store_url=dataset.object_store_url,
+            signed_url=signed_url,
             dataset_metadata=dataset.dataset_metadata,
             organization_id=dataset.organization_id,
             project_id=dataset.project_id,

From f9ecdb7e0117ed798c0f1481663f1e8fe9e065b9 Mon Sep 17 00:00:00 2001
From: AkhileshNegi <akhileshnegi.an3@gmail.com>
Date: Sat, 14 Mar 2026 13:16:11 +0530
Subject: [PATCH 2/8] added API to update STT samples

---
 .../api/docs/stt_evaluation/update_sample.md  |  3 +
 .../app/api/routes/stt_evaluations/dataset.py | 53 ++++++++++++
 backend/app/crud/stt_evaluations/__init__.py  |  4 +
 backend/app/crud/stt_evaluations/dataset.py   | 83 +++++++++++++++++++
 backend/app/models/stt_evaluation.py          |  7 ++
 5 files changed, 150 insertions(+)
 create mode 100644 backend/app/api/docs/stt_evaluation/update_sample.md

diff --git a/backend/app/api/docs/stt_evaluation/update_sample.md b/backend/app/api/docs/stt_evaluation/update_sample.md
new file mode 100644
index 000000000..4360c5695
--- /dev/null
+++ b/backend/app/api/docs/stt_evaluation/update_sample.md
@@ -0,0 +1,3 @@
+Update an STT sample's language and/or ground truth transcription.
+
+Only the provided fields will be updated. Fields set to `null` in the request will not modify the existing value.
diff --git a/backend/app/api/routes/stt_evaluations/dataset.py b/backend/app/api/routes/stt_evaluations/dataset.py
index ea6ee9362..fb18f4843 100644
--- a/backend/app/api/routes/stt_evaluations/dataset.py
+++ b/backend/app/api/routes/stt_evaluations/dataset.py
@@ -12,13 +12,16 @@
 from app.crud.stt_evaluations import (
     get_samples_by_dataset_id,
     get_stt_dataset_by_id,
+    get_stt_sample_by_id,
     list_stt_datasets,
+    update_stt_sample,
 )
 from app.models.stt_evaluation import (
     STTDatasetCreate,
     STTDatasetPublic,
     STTDatasetWithSamples,
     STTSamplePublic,
+    STTSampleUpdate,
 )
 from app.services.stt_evaluations.dataset import upload_stt_dataset
 from app.utils import APIResponse, load_description
@@ -209,3 +212,53 @@ def get_dataset(
         ),
         metadata={"samples_total": samples_total},
     )
+
+
+@router.patch(
+    "/samples/{sample_id}",
+    response_model=APIResponse[STTSamplePublic],
+    dependencies=[Depends(require_permission(Permission.REQUIRE_PROJECT))],
+    summary="Update STT sample",
+    description=load_description("stt_evaluation/update_sample.md"),
+)
+def update_sample(
+    session: SessionDep,
+    auth_context: AuthContextDep,
+    sample_id: int,
+    sample_update: STTSampleUpdate = Body(...),
+) -> APIResponse[STTSamplePublic]:
+    """Update an STT sample's language and/or ground truth."""
+    logger.info(f"[update_sample] Updating sample | " f"sample_id: {sample_id}")
+
+    if sample_update.language_id is not None:
+        language = get_language_by_id(
+            session=session, language_id=sample_update.language_id
+        )
+        if not language:
+            raise HTTPException(
+                status_code=400, detail="Invalid language_id: language not found"
+            )
+
+    sample = update_stt_sample(
+        session=session,
+        sample_id=sample_id,
+        org_id=auth_context.organization_.id,
+        project_id=auth_context.project_.id,
+        language_id=sample_update.language_id,
+        ground_truth=sample_update.ground_truth,
+    )
+
+    return APIResponse.success_response(
+        data=STTSamplePublic(
+            id=sample.id,
+            file_id=sample.file_id,
+            language_id=sample.language_id,
+            ground_truth=sample.ground_truth,
+            sample_metadata=sample.sample_metadata,
+            dataset_id=sample.dataset_id,
+            organization_id=sample.organization_id,
+            project_id=sample.project_id,
+            inserted_at=sample.inserted_at,
+            updated_at=sample.updated_at,
+        )
+    )
diff --git a/backend/app/crud/stt_evaluations/__init__.py b/backend/app/crud/stt_evaluations/__init__.py
index 7cc235e65..071d168bf 100644
--- a/backend/app/crud/stt_evaluations/__init__.py
+++ b/backend/app/crud/stt_evaluations/__init__.py
@@ -6,8 +6,10 @@
     create_stt_dataset,
     create_stt_samples,
     get_stt_dataset_by_id,
+    get_stt_sample_by_id,
     list_stt_datasets,
     get_samples_by_dataset_id,
+    update_stt_sample,
 )
 from .run import (
     create_stt_run,
@@ -30,8 +32,10 @@
     "create_stt_dataset",
     "create_stt_samples",
     "get_stt_dataset_by_id",
+    "get_stt_sample_by_id",
     "list_stt_datasets",
     "get_samples_by_dataset_id",
+    "update_stt_sample",
     # Run
     "create_stt_run",
     "get_stt_run_by_id",
diff --git a/backend/app/crud/stt_evaluations/dataset.py b/backend/app/crud/stt_evaluations/dataset.py
index c30d615d7..665c65239 100644
--- a/backend/app/crud/stt_evaluations/dataset.py
+++ b/backend/app/crud/stt_evaluations/dataset.py
@@ -204,6 +204,89 @@ def create_stt_samples(
     return created_samples
 
 
+def get_stt_sample_by_id(
+    *,
+    session: Session,
+    sample_id: int,
+    org_id: int,
+    project_id: int,
+) -> STTSample | None:
+    """Get an STT sample by ID.
+
+    Args:
+        session: Database session
+        sample_id: Sample ID
+        org_id: Organization ID
+        project_id: Project ID
+
+    Returns:
+        STTSample | None: Sample if found
+    """
+    statement = select(STTSample).where(
+        STTSample.id == sample_id,
+        STTSample.organization_id == org_id,
+        STTSample.project_id == project_id,
+    )
+
+    return session.exec(statement).one_or_none()
+
+
+def update_stt_sample(
+    *,
+    session: Session,
+    sample_id: int,
+    org_id: int,
+    project_id: int,
+    language_id: int | None = None,
+    ground_truth: str | None = None,
+) -> STTSample:
+    """Update an STT sample's language and/or ground truth.
+
+    Args:
+        session: Database session
+        sample_id: Sample ID
+        org_id: Organization ID
+        project_id: Project ID
+        language_id: Optional new language ID
+        ground_truth: Optional new ground truth transcription
+
+    Returns:
+        STTSample: Updated sample
+
+    Raises:
+        HTTPException: If sample not found
+    """
+    sample = get_stt_sample_by_id(
+        session=session,
+        sample_id=sample_id,
+        org_id=org_id,
+        project_id=project_id,
+    )
+
+    if not sample:
+        raise HTTPException(status_code=404, detail="Sample not found")
+
+    if language_id is not None:
+        sample.language_id = language_id
+
+    if ground_truth is not None:
+        sample.ground_truth = ground_truth
+
+    sample.updated_at = now()
+
+    session.add(sample)
+    session.commit()
+    session.refresh(sample)
+
+    logger.info(
+        f"[update_stt_sample] Sample updated | "
+        f"sample_id: {sample_id}, language_id: {language_id}, "
+        f"ground_truth_updated: {ground_truth is not None}"
+    )
+
+    return sample
+
+
 def get_stt_dataset_by_id(
     *,
     session: Session,
diff --git a/backend/app/models/stt_evaluation.py b/backend/app/models/stt_evaluation.py
index 7d0bd75f7..5e953e36d 100644
--- a/backend/app/models/stt_evaluation.py
+++ b/backend/app/models/stt_evaluation.py
@@ -268,6 +268,13 @@ class STTResultWithSample(STTResultPublic):
     sample: STTSamplePublic
 
 
+class STTSampleUpdate(BaseModel):
+    """Request model for updating an STT sample's language and ground truth."""
+
+    language_id: int | None = Field(None, description="Language ID for this sample")
+    ground_truth: str | None = Field(None, description="Reference transcription")
+
+
 class STTFeedbackUpdate(BaseModel):
     """Request model for updating human feedback on a result."""
 

From 33db59e59ae06457a8725dd083f06fd0a02c45f8 Mon Sep 17 00:00:00 2001
From: AkhileshNegi <akhileshnegi.an3@gmail.com>
Date: Sat, 14 Mar 2026 21:17:21 +0530
Subject: [PATCH 3/8] updated TTS feedback results

---
 .../api/docs/tts_evaluation/update_feedback.md  | 17 ++++++++++++++++-
 .../app/api/routes/tts_evaluations/result.py    |  2 ++
 backend/app/crud/tts_evaluations/result.py      |  3 +++
 backend/app/models/tts_evaluation.py            | 10 ++++++++++
 4 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/backend/app/api/docs/tts_evaluation/update_feedback.md b/backend/app/api/docs/tts_evaluation/update_feedback.md
index 7701bb52a..910227f83 100644
--- a/backend/app/api/docs/tts_evaluation/update_feedback.md
+++ b/backend/app/api/docs/tts_evaluation/update_feedback.md
@@ -1,5 +1,20 @@
-Update human feedback on a TTS synthesis result.
+Update human feedback and score on a TTS synthesis result.
+
+Only the provided fields will be updated. Fields omitted from the request will not modify the existing value. Sending a field as `null` will clear its value.
 
 Fields:
 - **is_correct**: Whether the synthesized audio quality is acceptable (null to clear)
 - **comment**: Optional feedback comment
+- **score**: Evaluation metrics for the synthesized audio
+
+**Example request:**
+```json
+{
+  "is_correct": true,
+  "comment": "string",
+  "score": {
+    "Speech Naturalness": "low | medium | high",
+    "Pronunciation Accuracy": "low | medium | high"
+  }
+}
+```
diff --git a/backend/app/api/routes/tts_evaluations/result.py b/backend/app/api/routes/tts_evaluations/result.py
index 2f1998fd0..92a82b002 100644
--- a/backend/app/api/routes/tts_evaluations/result.py
+++ b/backend/app/api/routes/tts_evaluations/result.py
@@ -70,6 +70,8 @@ def update_result_feedback(
         update_kwargs["is_correct"] = feedback.is_correct
     if "comment" in feedback.model_fields_set:
         update_kwargs["comment"] = feedback.comment
+    if "score" in feedback.model_fields_set:
+        update_kwargs["score"] = feedback.score
 
     result = update_tts_human_feedback(
         session=session,
diff --git a/backend/app/crud/tts_evaluations/result.py b/backend/app/crud/tts_evaluations/result.py
index 2095f7def..b13b5a62e 100644
--- a/backend/app/crud/tts_evaluations/result.py
+++ b/backend/app/crud/tts_evaluations/result.py
@@ -237,6 +237,9 @@ def update_tts_human_feedback(
     if "comment" in kwargs:
         result.comment = kwargs["comment"]
 
+    if "score" in kwargs:
+        result.score = kwargs["score"]
+
     result.updated_at = now()
 
     session.add(result)
diff --git a/backend/app/models/tts_evaluation.py b/backend/app/models/tts_evaluation.py
index e1222ab97..a0bbdb054 100644
--- a/backend/app/models/tts_evaluation.py
+++ b/backend/app/models/tts_evaluation.py
@@ -267,6 +267,16 @@ class TTSFeedbackUpdate(BaseModel):
         None, description="Is the synthesized audio correct?"
     )
     comment: str | None = Field(None, description="Feedback comment")
+    score: dict[str, Any] | None = Field(
+        None,
+        description="Evaluation metrics",
+        json_schema_extra={
+            "example": {
+                "Speech Naturalness": "low | medium | high",
+                "Pronunciation Accuracy": "low | medium | high",
+            }
+        },
+    )
 
 
 class TTSEvaluationRunCreate(BaseModel):

From bdc8133edeb85e597fb81445268f53822e687b0b Mon Sep 17 00:00:00 2001
From: AkhileshNegi <akhileshnegi.an3@gmail.com>
Date: Sun, 15 Mar 2026 23:24:41 +0530
Subject: [PATCH 4/8] added description and headers validation

---
 backend/app/api/routes/evaluations/dataset.py  |  1 +
 backend/app/models/evaluation.py               |  1 +
 backend/app/services/evaluations/validators.py | 15 +++++++++++----
 3 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/backend/app/api/routes/evaluations/dataset.py b/backend/app/api/routes/evaluations/dataset.py
index a63eeba42..202774da2 100644
--- a/backend/app/api/routes/evaluations/dataset.py
+++ b/backend/app/api/routes/evaluations/dataset.py
@@ -42,6 +42,7 @@ def _dataset_to_response(
     return DatasetUploadResponse(
         dataset_id=dataset.id,
         dataset_name=dataset.name,
+        description=dataset.description,
         total_items=dataset.dataset_metadata.get("total_items_count", 0),
         original_items=dataset.dataset_metadata.get("original_items_count", 0),
         duplication_factor=dataset.dataset_metadata.get("duplication_factor", 1),
diff --git a/backend/app/models/evaluation.py b/backend/app/models/evaluation.py
index 18e7749bf..d2d2beecc 100644
--- a/backend/app/models/evaluation.py
+++ b/backend/app/models/evaluation.py
@@ -28,6 +28,7 @@ class DatasetUploadResponse(BaseModel):
 
     dataset_id: int = Field(..., description="Database ID of the created dataset")
     dataset_name: str = Field(..., description="Name of the created dataset")
+    description: str | None = Field(None, description="Description of the dataset")
     total_items: int = Field(
         ..., description="Total number of items uploaded (after duplication)"
     )
diff --git a/backend/app/services/evaluations/validators.py b/backend/app/services/evaluations/validators.py
index 92733a2f8..61d0c3b06 100644
--- a/backend/app/services/evaluations/validators.py
+++ b/backend/app/services/evaluations/validators.py
@@ -137,12 +137,19 @@ def parse_csv_items(csv_content: bytes) -> list[dict[str, str]]:
             field.strip().lower(): field for field in csv_reader.fieldnames
         }
 
-        # Validate required headers (case-insensitive)
-        if "question" not in clean_headers or "answer" not in clean_headers:
+        # Validate exactly 'question' and 'answer' columns (case-insensitive)
+        if set(clean_headers.keys()) != {"question", "answer"}:
+            extra = set(clean_headers.keys()) - {"question", "answer"}
+            missing = {"question", "answer"} - set(clean_headers.keys())
+            parts = []
+            if missing:
+                parts.append(f"Missing: {sorted(missing)}")
+            if extra:
+                parts.append(f"Unexpected: {sorted(extra)}")
             raise HTTPException(
                 status_code=422,
-                detail=f"CSV must contain 'question' and 'answer' columns "
-                f"Found columns: {csv_reader.fieldnames}",
+                detail=f"CSV must contain exactly 'question' and 'answer' columns. "
+                f"{'. '.join(parts)}. Found columns: {csv_reader.fieldnames}",
             )
 
         question_col = clean_headers["question"]

From 029bb487b75d116ce7bff2daab8aca56c6484d9b Mon Sep 17 00:00:00 2001
From: AkhileshNegi <akhileshnegi.an3@gmail.com>
Date: Sun, 15 Mar 2026 23:29:33 +0530
Subject: [PATCH 5/8] using cosine similarity naming for consistency

---
 backend/app/crud/evaluations/langfuse.py   | 2 +-
 backend/app/crud/evaluations/processing.py | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/backend/app/crud/evaluations/langfuse.py b/backend/app/crud/evaluations/langfuse.py
index 477de7e57..1dd0c519e 100644
--- a/backend/app/crud/evaluations/langfuse.py
+++ b/backend/app/crud/evaluations/langfuse.py
@@ -209,7 +209,7 @@ def update_traces_with_cosine_scores(
         try:
             langfuse.score(
                 trace_id=trace_id,
-                name="cosine_similarity",
+                name="Cosine Similarity",
                 value=cosine_score,
                 comment=(
                     "Cosine similarity between generated output and "
diff --git a/backend/app/crud/evaluations/processing.py b/backend/app/crud/evaluations/processing.py
index d33207302..1e36fd13b 100644
--- a/backend/app/crud/evaluations/processing.py
+++ b/backend/app/crud/evaluations/processing.py
@@ -392,7 +392,7 @@ async def process_completed_embedding_batch(
         eval_run.score = {
             "summary_scores": [
                 {
-                    "name": "cosine_similarity",
+                    "name": "Cosine Similarity",
                     "avg": round(float(similarity_stats["cosine_similarity_avg"]), 2),
                     "std": round(float(similarity_stats["cosine_similarity_std"]), 2),
                     "total_pairs": similarity_stats["total_pairs"],

From 05ff2c77d6c7363cd0cf9b820bf86048550e5cad Mon Sep 17 00:00:00 2001
From: AkhileshNegi <akhileshnegi.an3@gmail.com>
Date: Tue, 17 Mar 2026 13:21:07 +0530
Subject: [PATCH 6/8] updating testcases

---
 backend/app/tests/crud/evaluations/test_langfuse.py   | 2 +-
 backend/app/tests/crud/evaluations/test_processing.py | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/backend/app/tests/crud/evaluations/test_langfuse.py b/backend/app/tests/crud/evaluations/test_langfuse.py
index 128135f39..4cc1183ca 100644
--- a/backend/app/tests/crud/evaluations/test_langfuse.py
+++ b/backend/app/tests/crud/evaluations/test_langfuse.py
@@ -382,7 +382,7 @@ def test_update_traces_with_cosine_scores_success(self) -> None:
 
         calls = mock_langfuse.score.call_args_list
         assert calls[0].kwargs["trace_id"] == "trace_1"
-        assert calls[0].kwargs["name"] == "cosine_similarity"
+        assert calls[0].kwargs["name"] == "Cosine Similarity"
         assert calls[0].kwargs["value"] == 0.95
         assert "cosine similarity" in calls[0].kwargs["comment"].lower()
 
diff --git a/backend/app/tests/crud/evaluations/test_processing.py b/backend/app/tests/crud/evaluations/test_processing.py
index 8d34900bc..29d62244d 100644
--- a/backend/app/tests/crud/evaluations/test_processing.py
+++ b/backend/app/tests/crud/evaluations/test_processing.py
@@ -580,7 +580,7 @@ async def test_process_completed_embedding_batch_success(
         assert "summary_scores" in result.score
         summary_scores = result.score["summary_scores"]
         cosine_score = next(
-            (s for s in summary_scores if s["name"] == "cosine_similarity"), None
+            (s for s in summary_scores if s["name"] == "Cosine Similarity"), None
         )
         assert cosine_score is not None
         assert cosine_score["avg"] == 0.95

From ad328d5aa179944212617e3186c66d9205d45016 Mon Sep 17 00:00:00 2001
From: AkhileshNegi <akhileshnegi.an3@gmail.com>
Date: Wed, 18 Mar 2026 12:45:54 +0530
Subject: [PATCH 7/8] moved it language exception to language module

---
 backend/app/api/routes/languages.py              |  5 +++--
 .../app/api/routes/stt_evaluations/dataset.py    | 16 ++--------------
 .../app/api/routes/tts_evaluations/dataset.py    |  8 +-------
 backend/app/crud/language.py                     | 12 +++++++++---
 4 files changed, 15 insertions(+), 26 deletions(-)

diff --git a/backend/app/api/routes/languages.py b/backend/app/api/routes/languages.py
index f04896b94..eb0d06042 100644
--- a/backend/app/api/routes/languages.py
+++ b/backend/app/api/routes/languages.py
@@ -37,8 +37,9 @@ def get_language(session: SessionDep, auth_context: AuthContextDep, language_id:
     """
     Retrieve a language by ID.
     """
-    language = get_language_by_id(session=session, language_id=language_id)
-    if language is None:
+    try:
+        language = get_language_by_id(session=session, language_id=language_id)
+    except HTTPException:
         logger.error(f"[get_language] Language not found | language_id={language_id}")
         raise HTTPException(status_code=404, detail="Language not found")
     return APIResponse.success_response(language)
diff --git a/backend/app/api/routes/stt_evaluations/dataset.py b/backend/app/api/routes/stt_evaluations/dataset.py
index fb18f4843..368d8587c 100644
--- a/backend/app/api/routes/stt_evaluations/dataset.py
+++ b/backend/app/api/routes/stt_evaluations/dataset.py
@@ -46,13 +46,7 @@ def create_dataset(
     """Create an STT evaluation dataset."""
     # Validate language_id
     if dataset_create.language_id is not None:
-        language = get_language_by_id(
-            session=session, language_id=dataset_create.language_id
-        )
-        if not language:
-            raise HTTPException(
-                status_code=400, detail="Invalid language_id: language not found"
-            )
+        get_language_by_id(session=session, language_id=dataset_create.language_id)
 
     dataset, samples = upload_stt_dataset(
         session=session,
@@ -231,13 +225,7 @@ def update_sample(
     logger.info(f"[update_sample] Updating sample | " f"sample_id: {sample_id}")
 
     if sample_update.language_id is not None:
-        language = get_language_by_id(
-            session=session, language_id=sample_update.language_id
-        )
-        if not language:
-            raise HTTPException(
-                status_code=400, detail="Invalid language_id: language not found"
-            )
+        get_language_by_id(session=session, language_id=sample_update.language_id)
 
     sample = update_stt_sample(
         session=session,
diff --git a/backend/app/api/routes/tts_evaluations/dataset.py b/backend/app/api/routes/tts_evaluations/dataset.py
index 2005a4dc3..115df8fb5 100644
--- a/backend/app/api/routes/tts_evaluations/dataset.py
+++ b/backend/app/api/routes/tts_evaluations/dataset.py
@@ -39,13 +39,7 @@ def create_dataset(
     """Create a TTS evaluation dataset."""
     # Validate language_id if provided
     if dataset_create.language_id is not None:
-        language = get_language_by_id(
-            session=session, language_id=dataset_create.language_id
-        )
-        if not language:
-            raise HTTPException(
-                status_code=400, detail="Invalid language_id: language not found"
-            )
+        get_language_by_id(session=session, language_id=dataset_create.language_id)
 
     dataset = upload_tts_dataset(
         session=session,
diff --git a/backend/app/crud/language.py b/backend/app/crud/language.py
index eb4f7d273..9585587e2 100644
--- a/backend/app/crud/language.py
+++ b/backend/app/crud/language.py
@@ -1,6 +1,7 @@
 import logging
 from typing import Optional
 
+from fastapi import HTTPException
 from sqlmodel import Session, select
 
 from app.models import Language
@@ -16,10 +17,15 @@ def get_languages(session: Session, skip: int = 0, limit: int = 100) -> list[Lan
     return list(session.exec(statement).all())
 
 
-def get_language_by_id(session: Session, language_id: int) -> Optional[Language]:
-    """Retrieve a language by its ID."""
+def get_language_by_id(session: Session, language_id: int) -> Language:
+    """Retrieve a language by its ID. Raises HTTPException if not found."""
     statement = select(Language).where(Language.id == language_id)
-    return session.exec(statement).first()
+    language = session.exec(statement).first()
+    if not language:
+        raise HTTPException(
+            status_code=400, detail="Invalid language_id: language not found"
+        )
+    return language
 
 
 def get_language_by_locale(session: Session, locale: str) -> Optional[Language]:

From 586f728cc05cd9a3620ff90c744efeca2de6f45a Mon Sep 17 00:00:00 2001
From: AkhileshNegi <akhileshnegi.an3@gmail.com>
Date: Wed, 18 Mar 2026 12:53:33 +0530
Subject: [PATCH 8/8] code cleanups

---
 backend/app/api/routes/languages.py               | 13 +++++++------
 backend/app/api/routes/stt_evaluations/dataset.py |  5 +++--
 backend/app/crud/language.py                      | 12 ++++++++----
 backend/app/crud/stt_evaluations/dataset.py       | 12 ++++--------
 4 files changed, 22 insertions(+), 20 deletions(-)

diff --git a/backend/app/api/routes/languages.py b/backend/app/api/routes/languages.py
index eb0d06042..9a184ea81 100644
--- a/backend/app/api/routes/languages.py
+++ b/backend/app/api/routes/languages.py
@@ -1,6 +1,6 @@
 import logging
 
-from fastapi import APIRouter, HTTPException
+from fastapi import APIRouter
 
 from app.api.deps import AuthContextDep, SessionDep
 from app.crud.language import get_language_by_id, get_languages
@@ -37,9 +37,10 @@ def get_language(session: SessionDep, auth_context: AuthContextDep, language_id:
     """
     Retrieve a language by ID.
     """
-    try:
-        language = get_language_by_id(session=session, language_id=language_id)
-    except HTTPException:
-        logger.error(f"[get_language] Language not found | language_id={language_id}")
-        raise HTTPException(status_code=404, detail="Language not found")
+    language = get_language_by_id(
+        session=session,
+        language_id=language_id,
+        status_code=404,
+        detail="Language not found",
+    )
     return APIResponse.success_response(language)
diff --git a/backend/app/api/routes/stt_evaluations/dataset.py b/backend/app/api/routes/stt_evaluations/dataset.py
index 368d8587c..b42a4b17e 100644
--- a/backend/app/api/routes/stt_evaluations/dataset.py
+++ b/backend/app/api/routes/stt_evaluations/dataset.py
@@ -12,7 +12,6 @@
 from app.crud.stt_evaluations import (
     get_samples_by_dataset_id,
     get_stt_dataset_by_id,
-    get_stt_sample_by_id,
     list_stt_datasets,
     update_stt_sample,
 )
@@ -162,7 +161,6 @@ def get_dataset(
                 session=session, project_id=auth_context.project_.id
             )
 
-        samples = []
         for s in sample_records:
             signed_url = None
             if storage and s.file_id in file_map:
@@ -236,6 +234,9 @@ def update_sample(
         ground_truth=sample_update.ground_truth,
     )
 
+    if not sample:
+        raise HTTPException(status_code=404, detail="Sample not found")
+
     return APIResponse.success_response(
         data=STTSamplePublic(
             id=sample.id,
diff --git a/backend/app/crud/language.py b/backend/app/crud/language.py
index 9585587e2..765e50542 100644
--- a/backend/app/crud/language.py
+++ b/backend/app/crud/language.py
@@ -17,14 +17,18 @@ def get_languages(session: Session, skip: int = 0, limit: int = 100) -> list[Lan
     return list(session.exec(statement).all())
 
 
-def get_language_by_id(session: Session, language_id: int) -> Language:
+def get_language_by_id(
+    session: Session,
+    language_id: int,
+    *,
+    status_code: int = 400,
+    detail: str = "Invalid language_id: language not found",
+) -> Language:
     """Retrieve a language by its ID. Raises HTTPException if not found."""
     statement = select(Language).where(Language.id == language_id)
     language = session.exec(statement).first()
     if not language:
-        raise HTTPException(
-            status_code=400, detail="Invalid language_id: language not found"
-        )
+        raise HTTPException(status_code=status_code, detail=detail)
     return language
 
 
diff --git a/backend/app/crud/stt_evaluations/dataset.py b/backend/app/crud/stt_evaluations/dataset.py
index 665c65239..2c559fb10 100644
--- a/backend/app/crud/stt_evaluations/dataset.py
+++ b/backend/app/crud/stt_evaluations/dataset.py
@@ -239,7 +239,7 @@ def update_stt_sample(
     project_id: int,
     language_id: int | None = None,
     ground_truth: str | None = None,
-) -> STTSample:
+) -> STTSample | None:
     """Update an STT sample's language and/or ground truth.
 
     Args:
@@ -251,10 +251,7 @@ def update_stt_sample(
         ground_truth: Optional new ground truth transcription
 
     Returns:
-        STTSample: Updated sample
-
-    Raises:
-        HTTPException: If sample not found
+        STTSample | None: Updated sample, or None if not found
     """
     sample = get_stt_sample_by_id(
         session=session,
@@ -264,7 +261,7 @@ def update_stt_sample(
     )
 
     if not sample:
-        raise HTTPException(status_code=404, detail="Sample not found")
+        return None
 
     if language_id is not None:
         sample.language_id = language_id
@@ -275,8 +272,7 @@ def update_stt_sample(
     sample.updated_at = now()
 
     session.add(sample)
-    session.commit()
-    session.refresh(sample)
+    session.flush()
 
     logger.info(
         f"[update_stt_sample] Sample updated | "