diff --git a/backend/app/spec/relationship_inference.py b/backend/app/spec/relationship_inference.py
index da55119e0..6d1e9671c 100644
--- a/backend/app/spec/relationship_inference.py
+++ b/backend/app/spec/relationship_inference.py
@@ -42,8 +42,6 @@ def infer_relationships(snapshot: dict[str, Any] | None) -> list[dict[str, Any]]
     pk_columns = snapshot.get("pk_columns") or []
     fk_edges = snapshot.get("fk_edges") or []
 
-    rel_by_oid: dict[Any, dict[str, Any]] = {r.get("relation_oid"): r for r in relations}
-
     # relation_name (lower) -> list of relation dicts (there may be same name in
     # multiple schemas; we only infer within the same schema to avoid noise).
     by_name: dict[str, list[dict[str, Any]]] = {}
diff --git a/backend/tests/test_api_projects.py b/backend/tests/test_api_projects.py
new file mode 100644
index 000000000..da73adb73
--- /dev/null
+++ b/backend/tests/test_api_projects.py
@@ -0,0 +1,143 @@
+"""Integration tests for the authenticated project-list endpoint."""
+
+from __future__ import annotations
+
+import datetime as dt
+from typing import Any
+import uuid
+
+from fastapi import FastAPI
+from fastapi.testclient import TestClient
+import pytest
+
+from app.api.projects import router
+from app.auth import CurrentUser, get_current_user
+from app.db import get_read_session
+from app.models import ProjectSpace
+
+
+class _FakeScalars:
+    """Minimal scalar-result adapter for the project-list query."""
+
+    def __init__(self, projects: list[ProjectSpace]) -> None:
+        self._projects = projects
+
+    def all(self) -> list[ProjectSpace]:
+        """Return the configured project rows in database order."""
+
+        return list(self._projects)
+
+
+class _FakeResult:
+    """Minimal SQLAlchemy result surface used by the route."""
+
+    def __init__(self, projects: list[ProjectSpace]) -> None:
+        self._projects = projects
+
+    def scalars(self) -> _FakeScalars:
+        """Expose project rows through SQLAlchemy's scalar-result shape."""
+
+        return _FakeScalars(self._projects)
+
+
+class _FakeReadSession:
+    """Record the query and return a deterministic project result."""
+
+    def __init__(self, projects: list[ProjectSpace]) -> None:
+        self._projects = projects
+        self.executed_statements: list[Any] = []
+
+    async def execute(self, statement: Any) -> _FakeResult:
+        """Record one statement and return the configured rows."""
+
+        self.executed_statements.append(statement)
+        return _FakeResult(self._projects)
+
+
+def _project(project_uuid: str, name: str, created_at: dt.datetime) -> ProjectSpace:
+    """Build one deterministic project row for endpoint projection tests."""
+
+    return ProjectSpace(
+        project_space_uuid=uuid.UUID(project_uuid),
+        project_name=name,
+        created_by_user_uuid=uuid.UUID(
+            "018f5f45-9f18-7b65-b9d8-8d9acbc4ed43"
+        ),
+        created_at=created_at,
+    )
+
+
+@pytest.mark.parametrize(
+    ("projects", "expected_payload"),
+    [
+        ([], []),
+        (
+            [
+                _project(
+                    "018f5f45-a0a1-7a2b-91bd-c1fc65b9b111",
+                    "Newest Project",
+                    dt.datetime(2026, 8, 15, 12, 0, tzinfo=dt.timezone.utc),
+                ),
+                _project(
+                    "018f5f45-a0a1-7a2b-91bd-c1fc65b9b222",
+                    "Older Project",
+                    dt.datetime(2026, 8, 14, 12, 0, tzinfo=dt.timezone.utc),
+                ),
+            ],
+            [
+                {
+                    "project_space_uuid": (
+                        "018f5f45-a0a1-7a2b-91bd-c1fc65b9b111"
+                    ),
+                    "project_name": "Newest Project",
+                },
+                {
+                    "project_space_uuid": (
+                        "018f5f45-a0a1-7a2b-91bd-c1fc65b9b222"
+                    ),
+                    "project_name": "Older Project",
+                },
+            ],
+        ),
+    ],
+)
+def test_list_projects_returns_exact_authorized_projection(
+    projects: list[ProjectSpace],
+    expected_payload: list[dict[str, str]],
+) -> None:
+    """Return empty and populated lists through the public HTTP boundary."""
+
+    current_user = CurrentUser(
+        user_account_uuid=uuid.UUID(
+            "018f5f45-9f18-7b65-b9d8-8d9acbc4ed43"
+        ),
+        subject="test_subject",
+        display_name="Test User",
+    )
+    session = _FakeReadSession(projects)
+    application = FastAPI()
+    application.include_router(router)
+
+    def current_user_override() -> CurrentUser:
+        """Return the deterministic authenticated principal."""
+
+        return current_user
+
+    def read_session_override() -> _FakeReadSession:
+        """Return the isolated deterministic read session."""
+
+        return session
+
+    application.dependency_overrides[get_current_user] = current_user_override
+    application.dependency_overrides[get_read_session] = read_session_override
+
+    with TestClient(application) as client:
+        response = client.get("/api/projects")
+
+    assert response.status_code == 200
+    assert response.json() == expected_payload
+    assert len(session.executed_statements) == 1
+
+    compiled = session.executed_statements[0].compile()
+    assert current_user.user_account_uuid in compiled.params.values()
+    assert "project_member.user_account_uuid" in str(compiled)