fix: Better error message if cognee is run without cognee.add and cognee.cognify (#1940)

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<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

* **Bug Fixes**
* Improved error messaging in search functionality with clearer,
actionable feedback when database or user configuration prerequisites
are not met
* Standardized error response format for consistent and informative
error reporting across search operations

<sub>✏️ Tip: You can customize this high-level summary in your review
settings.</sub>

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

cognee/api/v1/search/routers/get_search_router.py

@@ -8,12 +8,14 @@ from fastapi.encoders import jsonable_encoder
 
 from cognee.modules.search.types import SearchType, SearchResult, CombinedSearchResult
 from cognee.api.DTO import InDTO, OutDTO
-from cognee.modules.users.exceptions.exceptions import PermissionDeniedError
+from cognee.modules.users.exceptions.exceptions import PermissionDeniedError, UserNotFoundError
 from cognee.modules.users.models import User
 from cognee.modules.search.operations import get_history
 from cognee.modules.users.methods import get_authenticated_user
 from cognee.shared.utils import send_telemetry
 from cognee import __version__ as cognee_version
+from cognee.infrastructure.databases.exceptions import DatabaseNotCreatedError
+from cognee.exceptions import CogneeValidationError
 
 
 # Note: Datasets sent by name will only map to datasets owned by the request sender
@@ -138,6 +140,17 @@ def get_search_router() -> APIRouter:
             )
 
             return jsonable_encoder(results)
+        except (DatabaseNotCreatedError, UserNotFoundError, CogneeValidationError) as e:
+            # Return a clear 422 with actionable guidance instead of leaking a stacktrace
+            status_code = getattr(e, "status_code", 422)
+            return JSONResponse(
+                status_code=status_code,
+                content={
+                    "error": "Search prerequisites not met",
+                    "detail": str(e),
+                    "hint": "Run `await cognee.add(...)` then `await cognee.cognify()` before searching.",
+                },
+            )
         except PermissionDeniedError:
             return []
         except Exception as error:

cognee/api/v1/search/search.py

@@ -11,6 +11,9 @@ from cognee.modules.data.methods import get_authorized_existing_datasets
 from cognee.modules.data.exceptions import DatasetNotFoundError
 from cognee.context_global_variables import set_session_user_context_variable
 from cognee.shared.logging_utils import get_logger
+from cognee.infrastructure.databases.exceptions import DatabaseNotCreatedError
+from cognee.exceptions import CogneeValidationError
+from cognee.modules.users.exceptions.exceptions import UserNotFoundError
 
 logger = get_logger()
 
@@ -176,7 +179,18 @@ async def search(
         datasets = [datasets]
 
     if user is None:
-        user = await get_default_user()
+        try:
+            user = await get_default_user()
+        except (DatabaseNotCreatedError, UserNotFoundError) as error:
+            # Provide a clear, actionable message instead of surfacing low-level stacktraces
+            raise CogneeValidationError(
+                message=(
+                    "Search prerequisites not met: no database/default user found. "
+                    "Initialize Cognee before searching by:\n"
+                    "• running `await cognee.add(...)` followed by `await cognee.cognify()`."
+                ),
+                name="SearchPreconditionError",
+            ) from error
 
     await set_session_user_context_variable(user)