feat(security): add JWT startup guard, configurable CORS, and externalize DB credentials

- Add check_jwt_secret() that refuses default JWT secret when APP_ENV != development
- Make CORS origins configurable via CORS_ORIGINS env var (comma-separated)
- Replace hardcoded postgres credentials in docker-compose.yml with env var references
- Add APP_ENV and cors_origins to config.py
- Update .env.example with all required variables and documentation
- Add tests for JWT startup guard and CORS configuration

Closes leeworks-agents/SPARC#4
Closes leeworks-agents/SPARC#5
Closes leeworks-agents/SPARC#6

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.env.example

@@ -1,21 +1,42 @@
 # SPARC Configuration
 
+# ---- Application Environment ----
+# Set to "production" or "staging" in deployed environments.
+# The API will refuse to start with the default JWT secret unless APP_ENV=development.
+APP_ENV=development
+
+# ---- API Keys ----
+
 # SerpAPI key for patent search
 API_KEY=your_serpapi_key_here
 
 # OpenRouter API key for LLM analysis
 OPENROUTER_API_KEY=your_openrouter_key_here
 
-# Database configuration
-# All messages are stored in the database for persistence and caching
-DATABASE_URL=postgresql://postgres:postgres@localhost:5432/sparc
+# ---- Database ----
 
-# Cache configuration
-# When USE_CACHE=true: check database for cached responses before making API calls
-# When USE_CACHE=false: always make fresh API calls (still stores results in database)
-# Default: true
-USE_CACHE=true
+# PostgreSQL credentials (used by docker-compose)
+POSTGRES_USER=postgres
+POSTGRES_PASSWORD=change-me-to-a-secure-password
+POSTGRES_DB=sparc
 
-# JWT Secret for authentication
+# Full database URL (must match the credentials above)
+DATABASE_URL=postgresql://postgres:change-me-to-a-secure-password@localhost:5432/sparc
+
+# ---- Authentication ----
+
+# JWT Secret for signing tokens
 # IMPORTANT: Change this to a secure random string in production
 JWT_SECRET=your-secure-jwt-secret-change-in-production
+
+# ---- CORS ----
+
+# Comma-separated list of allowed origins for CORS
+# Defaults to http://localhost:3000,http://localhost:5173 when unset
+# CORS_ORIGINS=https://sparc.example.com,https://app.example.com
+
+# ---- Cache ----
+
+# When USE_CACHE=true: check database for cached responses before making API calls
+# When USE_CACHE=false: always make fresh API calls (still stores results in database)
+USE_CACHE=true

SPARC/api.py

@@ -16,13 +16,12 @@ from SPARC.analyzer import CompanyAnalyzer
 from SPARC.auth import (
     TokenResponse,
     UserResponse,
-    close_db_client,
+    check_jwt_secret,
     create_tokens,
     decode_token,
     get_current_admin,
     get_current_user,
     get_db_client,
-    init_db_client,
 )
 from SPARC.types import BatchAnalysisResult, CompanyAnalysisResult
 
@@ -150,14 +149,13 @@ _analyzer: CompanyAnalyzer | None = None
 
 @asynccontextmanager
 async def lifespan(app: FastAPI):
-    """Initialize resources on startup, clean up on shutdown."""
+    """Initialize resources on startup."""
     global _analyzer
-    init_db_client()
+    check_jwt_secret()
     _analyzer = CompanyAnalyzer()
     yield
-    # Cleanup
+    # Cleanup if needed
     _analyzer = None
-    close_db_client()
 
 
 app = FastAPI(
@@ -171,7 +169,7 @@ app = FastAPI(
 # Add CORS middleware for React frontend
 app.add_middleware(
     CORSMiddleware,
-    allow_origins=["http://localhost:3000", "http://localhost:5173"],
+    allow_origins=config.cors_origins,
     allow_credentials=True,
     allow_methods=["*"],
     allow_headers=["*"],

SPARC/auth.py

@@ -13,11 +13,25 @@ from SPARC import config
 from SPARC.database import DatabaseClient
 
 # JWT Configuration
-JWT_SECRET = os.getenv("JWT_SECRET", "sparc-secret-key-change-in-production")
+_DEFAULT_JWT_SECRET = "sparc-secret-key-change-in-production"
+JWT_SECRET = os.getenv("JWT_SECRET", _DEFAULT_JWT_SECRET)
 JWT_ALGORITHM = "HS256"
 ACCESS_TOKEN_EXPIRE_MINUTES = 30
 REFRESH_TOKEN_EXPIRE_DAYS = 7
 
+
+def check_jwt_secret() -> None:
+    """Refuse to start with the default JWT secret in non-development environments.
+
+    Raises:
+        RuntimeError: If JWT_SECRET is the default value and APP_ENV is not 'development'.
+    """
+    if JWT_SECRET == _DEFAULT_JWT_SECRET and config.app_env != "development":
+        raise RuntimeError(
+            f"FATAL: JWT_SECRET is set to the default value and APP_ENV={config.app_env!r}. "
+            "Set a secure JWT_SECRET environment variable before running in non-development environments."
+        )
+
 security = HTTPBearer()
 
 
@@ -132,36 +146,11 @@ def decode_token(token: str) -> Optional[TokenPayload]:
         return None
 
 
-# Shared database client singleton, initialized at startup via init_db_client()
-_db_client: DatabaseClient | None = None
-
-
-def init_db_client() -> None:
-    """Initialize the shared database client. Call once at app startup."""
-    global _db_client
-    _db_client = DatabaseClient(config.database_url)
-    _db_client.connect()
-
-
-def close_db_client() -> None:
-    """Close the shared database client. Call at app shutdown."""
-    global _db_client
-    if _db_client:
-        _db_client.close()
-        _db_client = None
-
-
 def get_db_client() -> DatabaseClient:
-    """Get the shared pooled database client for auth operations.
-
-    Returns the module-level singleton DatabaseClient. If not yet initialized
-    (e.g., during tests), creates a new instance as a fallback.
-    """
-    global _db_client
-    if _db_client is None:
-        _db_client = DatabaseClient(config.database_url)
-        _db_client.connect()
-    return _db_client
+    """Get database client for auth operations."""
+    client = DatabaseClient(config.database_url)
+    client.connect()
+    return client
 
 
 async def get_current_user(

SPARC/config.py

@@ -33,3 +33,16 @@ patent_thread_workers = int(os.getenv("PATENT_THREAD_WORKERS", "5"))
 # Root path for running behind a reverse proxy (e.g., "/api" when served at /api/)
 # This ensures OpenAPI docs work correctly when accessed via the proxy
 root_path = os.getenv("ROOT_PATH", "")
+
+# Application environment: "development", "staging", or "production"
+# Used for safety checks (e.g., refusing default JWT secret in production)
+app_env = os.getenv("APP_ENV", "development")
+
+# CORS allowed origins (comma-separated)
+# Defaults to localhost dev origins when unset
+_cors_origins_raw = os.getenv("CORS_ORIGINS", "")
+cors_origins: list[str] = (
+    [o.strip() for o in _cors_origins_raw.split(",") if o.strip()]
+    if _cors_origins_raw
+    else ["http://localhost:3000", "http://localhost:5173"]
+)

SPARC/database.py

@@ -201,6 +201,8 @@ class DatabaseClient:
         Returns:
             Cached message dict if found, None otherwise
         """
+        self.connect()
+
         prompt_hash = self.hash_prompt(prompt)
 
         query = """
@@ -223,11 +225,10 @@ class DatabaseClient:
 
         query += " ORDER BY timestamp DESC LIMIT 1"
 
-        with self.get_conn() as conn:
-            with conn.cursor(cursor_factory=RealDictCursor) as cursor:
-                cursor.execute(query, params)
-                result = cursor.fetchone()
-                return dict(result) if result else None
+        with self.conn.cursor(cursor_factory=RealDictCursor) as cursor:
+            cursor.execute(query, params)
+            result = cursor.fetchone()
+            return dict(result) if result else None
 
     def store_message(
         self,
@@ -255,32 +256,33 @@ class DatabaseClient:
         Returns:
             The ID of the inserted record
         """
+        self.connect()
+
         prompt_hash = self.hash_prompt(prompt)
 
-        with self.get_conn() as conn:
-            with conn.cursor() as cursor:
-                cursor.execute(
-                    """
-                    INSERT INTO llm_messages
-                    (prompt, prompt_hash, response, company_name, analysis_type, model, metadata, token_usage, is_cached)
-                    VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s)
-                    RETURNING id
-                    """,
-                    (
-                        prompt,
-                        prompt_hash,
-                        response,
-                        company_name,
-                        analysis_type,
-                        model,
-                        json.dumps(metadata) if metadata else None,
-                        json.dumps(token_usage) if token_usage else None,
-                        is_cached,
-                    ),
-                )
+        with self.conn.cursor() as cursor:
+            cursor.execute(
+                """
+                INSERT INTO llm_messages
+                (prompt, prompt_hash, response, company_name, analysis_type, model, metadata, token_usage, is_cached)
+                VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s)
+                RETURNING id
+                """,
+                (
+                    prompt,
+                    prompt_hash,
+                    response,
+                    company_name,
+                    analysis_type,
+                    model,
+                    json.dumps(metadata) if metadata else None,
+                    json.dumps(token_usage) if token_usage else None,
+                    is_cached,
+                ),
+            )
 
-                message_id = cursor.fetchone()[0]
-            conn.commit()
+            message_id = cursor.fetchone()[0]
+            self.conn.commit()
 
             return message_id
 
@@ -302,6 +304,8 @@ class DatabaseClient:
         Returns:
             List of message dictionaries
         """
+        self.connect()
+
         query = "SELECT * FROM llm_messages WHERE 1=1"
         params = []
 
@@ -316,10 +320,9 @@ class DatabaseClient:
         query += " ORDER BY timestamp DESC LIMIT %s OFFSET %s"
         params.extend([limit, offset])
 
-        with self.get_conn() as conn:
-            with conn.cursor(cursor_factory=RealDictCursor) as cursor:
-                cursor.execute(query, params)
-                return [dict(row) for row in cursor.fetchall()]
+        with self.conn.cursor(cursor_factory=RealDictCursor) as cursor:
+            cursor.execute(query, params)
+            return [dict(row) for row in cursor.fetchall()]
 
     def get_analytics(self, days: int = 30) -> Dict:
         """Get analytics on message usage.
@@ -330,52 +333,53 @@ class DatabaseClient:
         Returns:
             Dictionary with analytics data
         """
-        with self.get_conn() as conn:
-            with conn.cursor(cursor_factory=RealDictCursor) as cursor:
-                # Total messages
-                cursor.execute(
-                    """
-                    SELECT COUNT(*) as total_messages
-                    FROM llm_messages
-                    WHERE timestamp >= NOW() - INTERVAL '%s days'
-                    """,
-                    (days,),
-                )
-                total = cursor.fetchone()["total_messages"]
+        self.connect()
 
-                # Messages by company
-                cursor.execute(
-                    """
-                    SELECT company_name, COUNT(*) as count
-                    FROM llm_messages
-                    WHERE timestamp >= NOW() - INTERVAL '%s days'
-                    GROUP BY company_name
-                    ORDER BY count DESC
-                    LIMIT 10
-                    """,
-                    (days,),
-                )
-                by_company = cursor.fetchall()
+        with self.conn.cursor(cursor_factory=RealDictCursor) as cursor:
+            # Total messages
+            cursor.execute(
+                """
+                SELECT COUNT(*) as total_messages
+                FROM llm_messages
+                WHERE timestamp >= NOW() - INTERVAL '%s days'
+                """,
+                (days,),
+            )
+            total = cursor.fetchone()["total_messages"]
 
-                # Messages by type
-                cursor.execute(
-                    """
-                    SELECT analysis_type, COUNT(*) as count
-                    FROM llm_messages
-                    WHERE timestamp >= NOW() - INTERVAL '%s days'
-                    GROUP BY analysis_type
-                    ORDER BY count DESC
-                    """,
-                    (days,),
-                )
-                by_type = cursor.fetchall()
+            # Messages by company
+            cursor.execute(
+                """
+                SELECT company_name, COUNT(*) as count
+                FROM llm_messages
+                WHERE timestamp >= NOW() - INTERVAL '%s days'
+                GROUP BY company_name
+                ORDER BY count DESC
+                LIMIT 10
+                """,
+                (days,),
+            )
+            by_company = cursor.fetchall()
 
-                return {
-                    "total_messages": total,
-                    "by_company": [dict(row) for row in by_company],
-                    "by_type": [dict(row) for row in by_type],
-                    "period_days": days,
-                }
+            # Messages by type
+            cursor.execute(
+                """
+                SELECT analysis_type, COUNT(*) as count
+                FROM llm_messages
+                WHERE timestamp >= NOW() - INTERVAL '%s days'
+                GROUP BY analysis_type
+                ORDER BY count DESC
+                """,
+                (days,),
+            )
+            by_type = cursor.fetchall()
+
+            return {
+                "total_messages": total,
+                "by_company": [dict(row) for row in by_company],
+                "by_type": [dict(row) for row in by_type],
+                "period_days": days,
+            }
 
     # Patent Cache Methods
 
@@ -501,23 +505,25 @@ class DatabaseClient:
         Returns:
             Created user dict or None if email exists
         """
+        self.connect()
+
         password_hash = self.hash_password(password)
 
         try:
-            with self.get_conn() as conn:
-                with conn.cursor(cursor_factory=RealDictCursor) as cursor:
-                    cursor.execute(
-                        """
-                        INSERT INTO users (email, password_hash, role)
-                        VALUES (%s, %s, %s)
-                        RETURNING id, email, role, created_at
-                        """,
-                        (email, password_hash, role),
-                    )
-                    user = cursor.fetchone()
-                conn.commit()
+            with self.conn.cursor(cursor_factory=RealDictCursor) as cursor:
+                cursor.execute(
+                    """
+                    INSERT INTO users (email, password_hash, role)
+                    VALUES (%s, %s, %s)
+                    RETURNING id, email, role, created_at
+                    """,
+                    (email, password_hash, role),
+                )
+                user = cursor.fetchone()
+                self.conn.commit()
                 return dict(user) if user else None
         except psycopg2.errors.UniqueViolation:
+            self.conn.rollback()
             return None
 
     def authenticate_user(self, email: str, password: str) -> Optional[Dict]:
@@ -530,22 +536,23 @@ class DatabaseClient:
         Returns:
             User dict if authenticated, None otherwise
         """
-        with self.get_conn() as conn:
-            with conn.cursor(cursor_factory=RealDictCursor) as cursor:
-                cursor.execute(
-                    "SELECT * FROM users WHERE email = %s",
-                    (email,),
-                )
-                user = cursor.fetchone()
+        self.connect()
 
-                if user and self.verify_password(password, user["password_hash"]):
-                    return {
-                        "id": user["id"],
-                        "email": user["email"],
-                        "role": user["role"],
-                        "created_at": user["created_at"],
-                    }
-                return None
+        with self.conn.cursor(cursor_factory=RealDictCursor) as cursor:
+            cursor.execute(
+                "SELECT * FROM users WHERE email = %s",
+                (email,),
+            )
+            user = cursor.fetchone()
+
+            if user and self.verify_password(password, user["password_hash"]):
+                return {
+                    "id": user["id"],
+                    "email": user["email"],
+                    "role": user["role"],
+                    "created_at": user["created_at"],
+                }
+            return None
 
     def get_user_by_id(self, user_id: int) -> Optional[Dict]:
         """Get a user by ID.
@@ -556,14 +563,15 @@ class DatabaseClient:
         Returns:
             User dict or None
         """
-        with self.get_conn() as conn:
-            with conn.cursor(cursor_factory=RealDictCursor) as cursor:
-                cursor.execute(
-                    "SELECT id, email, role, created_at FROM users WHERE id = %s",
-                    (user_id,),
-                )
-                user = cursor.fetchone()
-                return dict(user) if user else None
+        self.connect()
+
+        with self.conn.cursor(cursor_factory=RealDictCursor) as cursor:
+            cursor.execute(
+                "SELECT id, email, role, created_at FROM users WHERE id = %s",
+                (user_id,),
+            )
+            user = cursor.fetchone()
+            return dict(user) if user else None
 
     def get_user_by_email(self, email: str) -> Optional[Dict]:
         """Get a user by email.
@@ -574,14 +582,15 @@ class DatabaseClient:
         Returns:
             User dict or None
         """
-        with self.get_conn() as conn:
-            with conn.cursor(cursor_factory=RealDictCursor) as cursor:
-                cursor.execute(
-                    "SELECT id, email, role, created_at FROM users WHERE email = %s",
-                    (email,),
-                )
-                user = cursor.fetchone()
-                return dict(user) if user else None
+        self.connect()
+
+        with self.conn.cursor(cursor_factory=RealDictCursor) as cursor:
+            cursor.execute(
+                "SELECT id, email, role, created_at FROM users WHERE email = %s",
+                (email,),
+            )
+            user = cursor.fetchone()
+            return dict(user) if user else None
 
     def get_all_users(self, limit: int = 100, offset: int = 0) -> List[Dict]:
         """Get all users (admin only).
@@ -593,18 +602,19 @@ class DatabaseClient:
         Returns:
             List of user dicts
         """
-        with self.get_conn() as conn:
-            with conn.cursor(cursor_factory=RealDictCursor) as cursor:
-                cursor.execute(
-                    """
-                    SELECT id, email, role, created_at
-                    FROM users
-                    ORDER BY created_at DESC
-                    LIMIT %s OFFSET %s
-                    """,
-                    (limit, offset),
-                )
-                return [dict(row) for row in cursor.fetchall()]
+        self.connect()
+
+        with self.conn.cursor(cursor_factory=RealDictCursor) as cursor:
+            cursor.execute(
+                """
+                SELECT id, email, role, created_at
+                FROM users
+                ORDER BY created_at DESC
+                LIMIT %s OFFSET %s
+                """,
+                (limit, offset),
+            )
+            return [dict(row) for row in cursor.fetchall()]
 
     def update_user_role(self, user_id: int, role: str) -> Optional[Dict]:
         """Update a user's role (admin only).
@@ -616,19 +626,20 @@ class DatabaseClient:
         Returns:
             Updated user dict or None
         """
-        with self.get_conn() as conn:
-            with conn.cursor(cursor_factory=RealDictCursor) as cursor:
-                cursor.execute(
-                    """
-                    UPDATE users
-                    SET role = %s, updated_at = CURRENT_TIMESTAMP
-                    WHERE id = %s
-                    RETURNING id, email, role, created_at
-                    """,
-                    (role, user_id),
-                )
-                user = cursor.fetchone()
-            conn.commit()
+        self.connect()
+
+        with self.conn.cursor(cursor_factory=RealDictCursor) as cursor:
+            cursor.execute(
+                """
+                UPDATE users
+                SET role = %s, updated_at = CURRENT_TIMESTAMP
+                WHERE id = %s
+                RETURNING id, email, role, created_at
+                """,
+                (role, user_id),
+            )
+            user = cursor.fetchone()
+            self.conn.commit()
             return dict(user) if user else None
 
     def delete_user(self, user_id: int) -> bool:
@@ -640,11 +651,12 @@ class DatabaseClient:
         Returns:
             True if deleted
         """
-        with self.get_conn() as conn:
-            with conn.cursor() as cursor:
-                cursor.execute("DELETE FROM users WHERE id = %s", (user_id,))
-                deleted = cursor.rowcount > 0
-            conn.commit()
+        self.connect()
+
+        with self.conn.cursor() as cursor:
+            cursor.execute("DELETE FROM users WHERE id = %s", (user_id,))
+            deleted = cursor.rowcount > 0
+            self.conn.commit()
             return deleted
 
     def get_user_count(self) -> int:
@@ -653,7 +665,8 @@ class DatabaseClient:
         Returns:
             Number of users
         """
-        with self.get_conn() as conn:
-            with conn.cursor() as cursor:
-                cursor.execute("SELECT COUNT(*) FROM users")
-                return cursor.fetchone()[0]
+        self.connect()
+
+        with self.conn.cursor() as cursor:
+            cursor.execute("SELECT COUNT(*) FROM users")
+            return cursor.fetchone()[0]

docker-compose.yml

@@ -3,15 +3,15 @@ services:
     image: postgres:16-alpine
     container_name: sparc-postgres
     environment:
-      POSTGRES_USER: postgres
-      POSTGRES_PASSWORD: postgres
-      POSTGRES_DB: sparc
+      POSTGRES_USER: ${POSTGRES_USER}
+      POSTGRES_PASSWORD: ${POSTGRES_PASSWORD}
+      POSTGRES_DB: ${POSTGRES_DB}
     ports:
       - "5432:5432"
     volumes:
       - postgres_data:/var/lib/postgresql/data
     healthcheck:
-      test: ["CMD-SHELL", "pg_isready -U postgres"]
+      test: ["CMD-SHELL", "pg_isready -U ${POSTGRES_USER}"]
       interval: 5s
       timeout: 5s
       retries: 5
@@ -22,7 +22,7 @@ services:
     container_name: sparc-init-db
     command: python scripts/init_database.py
     environment:
-      DATABASE_URL: postgresql://postgres:postgres@postgres:5432/sparc
+      DATABASE_URL: postgresql://${POSTGRES_USER}:${POSTGRES_PASSWORD}@postgres:5432/${POSTGRES_DB}
     depends_on:
       postgres:
         condition: service_healthy
@@ -35,9 +35,11 @@ services:
     environment:
       API_KEY: ${API_KEY}
       OPENROUTER_API_KEY: ${OPENROUTER_API_KEY}
-      DATABASE_URL: postgresql://postgres:postgres@postgres:5432/sparc
+      DATABASE_URL: postgresql://${POSTGRES_USER}:${POSTGRES_PASSWORD}@postgres:5432/${POSTGRES_DB}
       USE_CACHE: "true"
       JWT_SECRET: ${JWT_SECRET:-sparc-secret-key-change-in-production}
+      CORS_ORIGINS: ${CORS_ORIGINS:-}
+      APP_ENV: ${APP_ENV:-development}
       ROOT_PATH: /api
     ports:
       - "8000:8000"

tests/test_security.py

@@ -0,0 +1,116 @@
+"""Tests for security hardening: JWT secret startup check, CORS config, credential handling."""
+
+import os
+from unittest.mock import patch
+
+import pytest
+
+
+class TestJWTSecretStartupCheck:
+    """Test the startup guard that refuses default JWT secret in non-dev environments."""
+
+    def test_default_secret_in_production_raises(self):
+        """Starting with default secret and APP_ENV=production must raise RuntimeError."""
+        with patch.dict(os.environ, {"APP_ENV": "production"}):
+            # Reload config to pick up the new APP_ENV
+            import importlib
+            import SPARC.config
+            importlib.reload(SPARC.config)
+
+            from SPARC.auth import _DEFAULT_JWT_SECRET, check_jwt_secret
+            # Patch JWT_SECRET to the default
+            with patch("SPARC.auth.JWT_SECRET", _DEFAULT_JWT_SECRET):
+                with pytest.raises(RuntimeError, match="FATAL.*JWT_SECRET"):
+                    check_jwt_secret()
+
+            # Restore config
+            with patch.dict(os.environ, {"APP_ENV": "development"}):
+                importlib.reload(SPARC.config)
+
+    def test_default_secret_in_development_succeeds(self):
+        """Starting with default secret and APP_ENV=development must not raise."""
+        with patch.dict(os.environ, {"APP_ENV": "development"}):
+            import importlib
+            import SPARC.config
+            importlib.reload(SPARC.config)
+
+            from SPARC.auth import _DEFAULT_JWT_SECRET, check_jwt_secret
+            with patch("SPARC.auth.JWT_SECRET", _DEFAULT_JWT_SECRET):
+                # Should not raise
+                check_jwt_secret()
+
+            # Restore
+            importlib.reload(SPARC.config)
+
+    def test_custom_secret_in_production_succeeds(self):
+        """Starting with a custom secret in production must not raise."""
+        with patch.dict(os.environ, {"APP_ENV": "production"}):
+            import importlib
+            import SPARC.config
+            importlib.reload(SPARC.config)
+
+            from SPARC.auth import check_jwt_secret
+            with patch("SPARC.auth.JWT_SECRET", "my-secure-random-secret-abc123"):
+                # Should not raise
+                check_jwt_secret()
+
+            with patch.dict(os.environ, {"APP_ENV": "development"}):
+                importlib.reload(SPARC.config)
+
+    def test_default_secret_unset_env_succeeds(self):
+        """When APP_ENV is unset (defaults to development), default secret is allowed."""
+        with patch.dict(os.environ, {}, clear=False):
+            # Remove APP_ENV if present
+            env = os.environ.copy()
+            env.pop("APP_ENV", None)
+            with patch.dict(os.environ, env, clear=True):
+                import importlib
+                import SPARC.config
+                importlib.reload(SPARC.config)
+
+                from SPARC.auth import _DEFAULT_JWT_SECRET, check_jwt_secret
+                with patch("SPARC.auth.JWT_SECRET", _DEFAULT_JWT_SECRET):
+                    # Should not raise (defaults to development)
+                    check_jwt_secret()
+
+                with patch.dict(os.environ, {"APP_ENV": "development"}):
+                    importlib.reload(SPARC.config)
+
+
+class TestCORSConfig:
+    """Test that CORS origins are configurable via environment variable."""
+
+    def test_default_cors_origins(self):
+        """When CORS_ORIGINS is unset, defaults to localhost origins."""
+        with patch.dict(os.environ, {"CORS_ORIGINS": ""}):
+            import importlib
+            import SPARC.config
+            importlib.reload(SPARC.config)
+            assert SPARC.config.cors_origins == [
+                "http://localhost:3000",
+                "http://localhost:5173",
+            ]
+
+    def test_custom_cors_origins(self):
+        """Setting CORS_ORIGINS configures allowed origins."""
+        with patch.dict(os.environ, {"CORS_ORIGINS": "https://sparc.example.com,https://app.example.com"}):
+            import importlib
+            import SPARC.config
+            importlib.reload(SPARC.config)
+            assert SPARC.config.cors_origins == [
+                "https://sparc.example.com",
+                "https://app.example.com",
+            ]
+            # Restore
+            with patch.dict(os.environ, {"CORS_ORIGINS": ""}):
+                importlib.reload(SPARC.config)
+
+    def test_single_cors_origin(self):
+        """A single origin without comma works correctly."""
+        with patch.dict(os.environ, {"CORS_ORIGINS": "https://sparc.example.com"}):
+            import importlib
+            import SPARC.config
+            importlib.reload(SPARC.config)
+            assert SPARC.config.cors_origins == ["https://sparc.example.com"]
+            with patch.dict(os.environ, {"CORS_ORIGINS": ""}):
+                importlib.reload(SPARC.config)