diff --git a/backend/oasst_backend/api/v1/admin.py b/backend/oasst_backend/api/v1/admin.py
index 6dd593f5d6..6ae753352c 100644
--- a/backend/oasst_backend/api/v1/admin.py
+++ b/backend/oasst_backend/api/v1/admin.py
@@ -8,13 +8,14 @@
 from oasst_backend.api import deps
 from oasst_backend.config import Settings, settings
 from oasst_backend.models import ApiClient, User
-from oasst_backend.prompt_repository import PromptRepository
+from oasst_backend.prompt_repository import PromptRepository, UserRepository
 from oasst_backend.tree_manager import TreeManager
 from oasst_backend.utils.database_utils import CommitMode, managed_tx_function
 from oasst_shared import utils
 from oasst_shared.exceptions.oasst_api_error import OasstError, OasstErrorCode
 from oasst_shared.schemas.protocol import PageResult, SystemStats
-from oasst_shared.utils import ScopeTimer, unaware_to_utc
+from oasst_shared.utils import ScopeTimer, log_timing, unaware_to_utc
+from starlette.status import HTTP_204_NO_CONTENT
 
 router = APIRouter()
 
@@ -263,7 +264,7 @@ async def get_flagged_messages(
     return resp
 
 
-@router.post("/admin/flagged_messages/{message_id}/processed", response_model=FlaggedMessageResponse)
+@router.post("/flagged_messages/{message_id}/processed", response_model=FlaggedMessageResponse)
 async def process_flagged_messages(
     message_id: UUID,
     session: deps.Session = Depends(deps.get_db),
@@ -275,3 +276,24 @@ async def process_flagged_messages(
     flagged_msg = pr.process_flagged_message(message_id=message_id)
     resp = FlaggedMessageResponse(**flagged_msg.__dict__)
     return resp
+
+
+class MergeUsersRequest(pydantic.BaseModel):
+    destination_user_id: UUID
+    source_user_ids: list[UUID]
+
+
+@log_timing(level="INFO")
+@router.post("/merge_users", response_model=None, status_code=HTTP_204_NO_CONTENT)
+def merge_users(
+    request: MergeUsersRequest,
+    api_client: ApiClient = Depends(deps.get_trusted_api_client),
+) -> None:
+    @managed_tx_function(CommitMode.COMMIT)
+    def merge_users_tx(session: deps.Session):
+        ur = UserRepository(session, api_client)
+        ur.merge_users(destination_user_id=request.destination_user_id, source_user_ids=request.source_user_ids)
+
+    merge_users_tx()
+
+    logger.info(f"Merged users: {request=}")
diff --git a/backend/oasst_backend/user_repository.py b/backend/oasst_backend/user_repository.py
index 3c326afb4a..cdea17bf44 100644
--- a/backend/oasst_backend/user_repository.py
+++ b/backend/oasst_backend/user_repository.py
@@ -1,6 +1,7 @@
 from typing import Optional
 from uuid import UUID
 
+import oasst_backend.models as models
 from oasst_backend.config import settings
 from oasst_backend.models import ApiClient, User
 from oasst_backend.utils.database_utils import CommitMode, managed_tx_method
@@ -9,7 +10,7 @@
 from oasst_shared.schemas import protocol as protocol_schema
 from oasst_shared.utils import utcnow
 from sqlalchemy.exc import IntegrityError
-from sqlmodel import Session, and_, or_
+from sqlmodel import Session, and_, delete, or_, update
 from starlette.status import HTTP_403_FORBIDDEN, HTTP_404_NOT_FOUND
 
 
@@ -346,3 +347,36 @@ def update_user_last_activity(self, user: User, update_streak: bool = False) ->
                 user.streak_days = (current_time - user.streak_last_day_date).days
 
         self.db.add(user)
+
+    @managed_tx_method(CommitMode.FLUSH)
+    def merge_users(self, destination_user_id: UUID, source_user_ids: list[UUID]) -> None:
+        source_user_ids = list(filter(lambda x: x != destination_user_id, source_user_ids))
+        if not source_user_ids:
+            return
+
+        # ensure the destination user exists
+        self.get_user(id=destination_user_id)
+
+        # update rows in tables that have affected users_ids as FK
+        models_to_update = [
+            models.Message,
+            models.MessageRevision,
+            models.MessageReaction,
+            models.MessageEmoji,
+            models.TextLabels,
+            models.Task,
+            models.Journal,
+        ]
+        for table in models_to_update:
+            qry = update(table).where(table.user_id.in_(source_user_ids)).values(user_id=destination_user_id)
+            self.db.execute(qry)
+
+        # delete rows in user stats tables
+        models_to_delete = [models.UserStats, models.TrollStats]
+        for table in models_to_delete:
+            qry = delete(table).where(table.user_id.in_(source_user_ids))
+            self.db.execute(qry)
+
+        # finally delete source users from main user table
+        qry = delete(User).where(User.id.in_(source_user_ids))
+        self.db.execute(qry)