diff --git a/infrahub_sdk/ctl/repository.py b/infrahub_sdk/ctl/repository.py
index 8854e53b..6f69f9a5 100644
--- a/infrahub_sdk/ctl/repository.py
+++ b/infrahub_sdk/ctl/repository.py
@@ -1,12 +1,14 @@
 from pathlib import Path
+from typing import Optional
 
 import typer
 import yaml
 from pydantic import ValidationError
 from rich.console import Console
 
+from infrahub_sdk.ctl.client import initialize_client
+
 from ..async_typer import AsyncTyper
-from ..ctl.client import initialize_client
 from ..ctl.exceptions import FileNotValidError
 from ..ctl.utils import init_logging
 from ..graphql import Mutation
@@ -65,7 +67,7 @@ async def add(
     name: str,
     location: str,
     description: str = "",
-    username: str = "",
+    username: Optional[str] = None,
     password: str = "",
     commit: str = "",
     read_only: bool = False,
@@ -88,10 +90,9 @@ async def add(
 
     client = initialize_client()
 
-    if username:
-        credential = await client.create(kind="CorePasswordCredential", name=name, username=username, password=password)
-        await credential.save()
-        input_data["data"]["credential"] = {"id": credential.id}
+    credential = await client.create(kind="CorePasswordCredential", name=name, username=username, password=password)
+    await credential.save(allow_upsert=True)
+    input_data["data"]["credential"] = {"id": credential.id}
 
     query = Mutation(
         mutation="CoreReadOnlyRepositoryCreate" if read_only else "CoreRepositoryCreate",
diff --git a/tests/unit/ctl/test_repository_app.py b/tests/unit/ctl/test_repository_app.py
new file mode 100644
index 00000000..fd558dc2
--- /dev/null
+++ b/tests/unit/ctl/test_repository_app.py
@@ -0,0 +1,273 @@
+"""Integration tests for infrahubctl commands."""
+
+from unittest import mock
+
+import pytest
+from typer.testing import CliRunner
+
+from infrahub_sdk.client import InfrahubClient
+from infrahub_sdk.ctl.cli_commands import app
+
+runner = CliRunner()
+
+
+@pytest.fixture
+def mock_client() -> mock.Mock:
+    """Fixture for a mocked InfrahubClient."""
+    client = mock.create_autospec(InfrahubClient)
+    return client
+
+
+# ---------------------------------------------------------
+# infrahubctl  repository command tests
+# ---------------------------------------------------------
+@mock.patch("infrahub_sdk.ctl.repository.initialize_client")
+class TestInfrahubctlRepository:
+    """Groups the 'infrahubctl repository' test cases."""
+
+    def test_repo_no_username(self, mock_init_client, mock_client) -> None:
+        """Case allow no username to be passed in and set it as None rather than blank string that fails."""
+        mock_cred = mock.AsyncMock()
+        mock_cred.id = "1234"
+        mock_client.create.return_value = mock_cred
+
+        mock_init_client.return_value = mock_client
+        output = runner.invoke(
+            app,
+            [
+                "repository",
+                "add",
+                "Gitlab",
+                "https://gitlab.com/FragmentedPacket/nautobot-plugin-ansible-filters.git",
+                "--password",
+                "mySup3rSecureP@ssw0rd",
+            ],
+        )
+        assert output.exit_code == 0
+        mock_client.create.assert_called_once()
+        mock_client.create.assert_called_with(
+            name="Gitlab",
+            kind="CorePasswordCredential",
+            password="mySup3rSecureP@ssw0rd",
+            username=None,
+        )
+        mock_cred.save.assert_called_once()
+        mock_cred.save.assert_called_with(allow_upsert=True)
+        mock_client.execute_graphql.assert_called_once()
+        mock_client.execute_graphql.assert_called_with(
+            query="""
+mutation {
+    CoreRepositoryCreate(
+        data: {
+            name: {
+                value: "Gitlab"
+            }
+            location: {
+                value: "https://gitlab.com/FragmentedPacket/nautobot-plugin-ansible-filters.git"
+            }
+            description: {
+                value: ""
+            }
+            commit: {
+                value: ""
+            }
+            credential: {
+                id: "1234"
+            }
+        }
+    ){
+        ok
+    }
+}
+""",
+            branch_name="main",
+            tracker="mutation-repository-create",
+        )
+
+    def test_repo_username(self, mock_init_client, mock_client) -> None:
+        """Case allow no username to be passed in and set it as None rather than blank string that fails."""
+        mock_cred = mock.AsyncMock()
+        mock_cred.id = "1234"
+        mock_client.create.return_value = mock_cred
+
+        mock_init_client.return_value = mock_client
+        output = runner.invoke(
+            app,
+            [
+                "repository",
+                "add",
+                "Gitlab",
+                "https://gitlab.com/FragmentedPacket/nautobot-plugin-ansible-filters.git",
+                "--password",
+                "mySup3rSecureP@ssw0rd",
+                "--username",
+                "opsmill",
+            ],
+        )
+        assert output.exit_code == 0
+        mock_client.create.assert_called_once()
+        mock_client.create.assert_called_with(
+            name="Gitlab",
+            kind="CorePasswordCredential",
+            password="mySup3rSecureP@ssw0rd",
+            username="opsmill",
+        )
+        mock_cred.save.assert_called_once()
+        mock_cred.save.assert_called_with(allow_upsert=True)
+        mock_client.execute_graphql.assert_called_once()
+        mock_client.execute_graphql.assert_called_with(
+            query="""
+mutation {
+    CoreRepositoryCreate(
+        data: {
+            name: {
+                value: "Gitlab"
+            }
+            location: {
+                value: "https://gitlab.com/FragmentedPacket/nautobot-plugin-ansible-filters.git"
+            }
+            description: {
+                value: ""
+            }
+            commit: {
+                value: ""
+            }
+            credential: {
+                id: "1234"
+            }
+        }
+    ){
+        ok
+    }
+}
+""",
+            branch_name="main",
+            tracker="mutation-repository-create",
+        )
+
+    def test_repo_readonly_true(self, mock_init_client, mock_client) -> None:
+        """Case allow no username to be passed in and set it as None rather than blank string that fails."""
+        mock_cred = mock.AsyncMock()
+        mock_cred.id = "1234"
+        mock_client.create.return_value = mock_cred
+
+        mock_init_client.return_value = mock_client
+        output = runner.invoke(
+            app,
+            [
+                "repository",
+                "add",
+                "Gitlab",
+                "https://gitlab.com/FragmentedPacket/nautobot-plugin-ansible-filters.git",
+                "--password",
+                "mySup3rSecureP@ssw0rd",
+                "--read-only",
+            ],
+        )
+        assert output.exit_code == 0
+        mock_client.create.assert_called_once()
+        mock_client.create.assert_called_with(
+            name="Gitlab",
+            kind="CorePasswordCredential",
+            password="mySup3rSecureP@ssw0rd",
+            username=None,
+        )
+        mock_cred.save.assert_called_once()
+        mock_cred.save.assert_called_with(allow_upsert=True)
+        mock_client.execute_graphql.assert_called_once()
+        mock_client.execute_graphql.assert_called_with(
+            query="""
+mutation {
+    CoreReadOnlyRepositoryCreate(
+        data: {
+            name: {
+                value: "Gitlab"
+            }
+            location: {
+                value: "https://gitlab.com/FragmentedPacket/nautobot-plugin-ansible-filters.git"
+            }
+            description: {
+                value: ""
+            }
+            commit: {
+                value: ""
+            }
+            credential: {
+                id: "1234"
+            }
+        }
+    ){
+        ok
+    }
+}
+""",
+            branch_name="main",
+            tracker="mutation-repository-create",
+        )
+
+    def test_repo_description_commit_branch(self, mock_init_client, mock_client) -> None:
+        """Case allow no username to be passed in and set it as None rather than blank string that fails."""
+        mock_cred = mock.AsyncMock()
+        mock_cred.id = "1234"
+        mock_client.create.return_value = mock_cred
+
+        mock_init_client.return_value = mock_client
+        output = runner.invoke(
+            app,
+            [
+                "repository",
+                "add",
+                "Gitlab",
+                "https://gitlab.com/FragmentedPacket/nautobot-plugin-ansible-filters.git",
+                "--password",
+                "mySup3rSecureP@ssw0rd",
+                "--username",
+                "opsmill",
+                "--description",
+                "This is a test description",
+                "--commit",
+                "myHashCommit",
+                "--branch",
+                "develop",
+            ],
+        )
+        assert output.exit_code == 0
+        mock_client.create.assert_called_once()
+        mock_client.create.assert_called_with(
+            name="Gitlab",
+            kind="CorePasswordCredential",
+            password="mySup3rSecureP@ssw0rd",
+            username="opsmill",
+        )
+        mock_cred.save.assert_called_once()
+        mock_cred.save.assert_called_with(allow_upsert=True)
+        mock_client.execute_graphql.assert_called_once()
+        mock_client.execute_graphql.assert_called_with(
+            query="""
+mutation {
+    CoreRepositoryCreate(
+        data: {
+            name: {
+                value: "Gitlab"
+            }
+            location: {
+                value: "https://gitlab.com/FragmentedPacket/nautobot-plugin-ansible-filters.git"
+            }
+            description: {
+                value: "This is a test description"
+            }
+            commit: {
+                value: "myHashCommit"
+            }
+            credential: {
+                id: "1234"
+            }
+        }
+    ){
+        ok
+    }
+}
+""",
+            branch_name="develop",
+            tracker="mutation-repository-create",
+        )