diff --git a/changelog.md b/changelog.md
index 169fa8a..579efe5 100644
--- a/changelog.md
+++ b/changelog.md
@@ -5,3 +5,4 @@
 - Captured current implementation status, requirements coverage, missing features, and prioritized roadmap in `calminer-docs/implementation_status.md` to guide future development.
 - Added core SQLAlchemy domain models, shared metadata descriptors, and Alembic migration setup (with initial schema snapshot) to establish the persistence layer foundation.
 - Introduced repository and unit-of-work helpers for projects, scenarios, financial inputs, and simulation parameters to support service-layer operations.
+- Added SQLite-backed pytest coverage for repository and unit-of-work behaviours to validate persistence interactions.
diff --git a/tests/test_repositories.py b/tests/test_repositories.py
new file mode 100644
index 0000000..23ae50f
--- /dev/null
+++ b/tests/test_repositories.py
@@ -0,0 +1,156 @@
+from __future__ import annotations
+
+from collections.abc import Iterator
+
+import pytest
+from sqlalchemy import create_engine
+from sqlalchemy.orm import Session, sessionmaker
+
+from config.database import Base
+from models import (
+    DistributionType,
+    FinancialCategory,
+    FinancialInput,
+    MiningOperationType,
+    Project,
+    Scenario,
+    ScenarioStatus,
+    SimulationParameter,
+    StochasticVariable,
+)
+from services.repositories import (
+    FinancialInputRepository,
+    ProjectRepository,
+    ScenarioRepository,
+    SimulationParameterRepository,
+)
+from services.unit_of_work import UnitOfWork
+
+
+@pytest.fixture()
+def engine():
+    engine = create_engine("sqlite:///:memory:", future=True)
+    Base.metadata.create_all(bind=engine)
+    try:
+        yield engine
+    finally:
+        Base.metadata.drop_all(bind=engine)
+
+
+@pytest.fixture()
+def session(engine) -> Iterator[Session]:
+    TestingSession = sessionmaker(bind=engine, expire_on_commit=False, future=True)
+    session = TestingSession()
+    try:
+        yield session
+    finally:
+        session.close()
+
+
+def test_project_repository_create_and_list(session: Session) -> None:
+    repo = ProjectRepository(session)
+    project = Project(name="Project Alpha", operation_type=MiningOperationType.OPEN_PIT)
+    repo.create(project)
+
+    projects = repo.list()
+
+    assert len(projects) == 1
+    assert projects[0].name == "Project Alpha"
+
+
+def test_scenario_repository_get_with_children(session: Session) -> None:
+    project = Project(name="Project Beta", operation_type=MiningOperationType.UNDERGROUND)
+    scenario = Scenario(name="Scenario 1", project=project, status=ScenarioStatus.ACTIVE)
+    scenario.financial_inputs.append(
+        FinancialInput(
+            name="Lease Payment",
+            category=FinancialCategory.OPERATING_EXPENDITURE,
+            amount=10000,
+            currency="usd",
+        )
+    )
+    scenario.simulation_parameters.append(
+        SimulationParameter(
+            name="Copper Price",
+            distribution=DistributionType.NORMAL,
+            mean_value=3.5,
+            variable=StochasticVariable.METAL_PRICE,
+        )
+    )
+
+    session.add(project)
+    session.flush()
+
+    repo = ScenarioRepository(session)
+    retrieved = repo.get(scenario.id, with_children=True)
+
+    assert retrieved.project.name == "Project Beta"
+    assert len(retrieved.financial_inputs) == 1
+    assert retrieved.financial_inputs[0].currency == "USD"
+    assert len(retrieved.simulation_parameters) == 1
+    assert (
+        retrieved.simulation_parameters[0].variable
+        == StochasticVariable.METAL_PRICE
+    )
+
+    param_repo = SimulationParameterRepository(session)
+    params = param_repo.list_for_scenario(scenario.id)
+    assert len(params) == 1
+
+
+def test_financial_input_repository_bulk_upsert(session: Session) -> None:
+    project = Project(name="Project Gamma", operation_type=MiningOperationType.QUARRY)
+    scenario = Scenario(name="Scenario Bulk", project=project)
+    session.add(project)
+    session.flush()
+
+    repo = FinancialInputRepository(session)
+    created = repo.bulk_upsert(
+        [
+            FinancialInput(
+                scenario_id=scenario.id,
+                name="Explosives",
+                category=FinancialCategory.OPERATING_EXPENDITURE,
+                amount=5000,
+                currency="cad",
+            ),
+            FinancialInput(
+                scenario_id=scenario.id,
+                name="Equipment Lease",
+                category=FinancialCategory.OPERATING_EXPENDITURE,
+                amount=12000,
+                currency="cad",
+            ),
+        ]
+    )
+
+    assert len(created) == 2
+    stored = repo.list_for_scenario(scenario.id)
+    assert len(stored) == 2
+    assert all(item.currency == "CAD" for item in stored)
+
+
+def test_unit_of_work_commit_and_rollback(engine) -> None:
+    TestingSession = sessionmaker(bind=engine, expire_on_commit=False, future=True)
+
+    # Commit path
+    with UnitOfWork(session_factory=TestingSession) as uow:
+        uow.projects.create(
+            Project(name="Project Delta", operation_type=MiningOperationType.PLACER)
+        )
+
+    with TestingSession() as session:
+        projects = ProjectRepository(session).list()
+        assert len(projects) == 1
+
+    # Rollback path
+    with pytest.raises(RuntimeError):
+        with UnitOfWork(session_factory=TestingSession) as uow:
+            uow.projects.create(
+                Project(name="Project Epsilon", operation_type=MiningOperationType.OTHER)
+            )
+            raise RuntimeError("trigger rollback")
+
+    with TestingSession() as session:
+        projects = ProjectRepository(session).list()
+        assert len(projects) == 1
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