fix(backend): restrict CORS to configurable origins and explicit methods/headers

backend/README.md

@@ -2,6 +2,12 @@
 uv run uvicorn main:api --port 5001
 ```
 
+### CORS
+
+CORS is restricted to avoid allowing arbitrary origins. Configure allowed browser origins in `~/.eigent/.env`:
+
+- **`CORS_ORIGINS`** (optional): Comma-separated list of origins, e.g. `http://localhost:5173,http://localhost:3000`. In development, if unset, common localhost origins are allowed; in production, no origins are allowed until you set this.
+
 i18n operation process: https://github.com/Anbarryprojects/fastapi-babel
 
 ```bash

backend/app/__init__.py

@@ -12,17 +12,55 @@
 # limitations under the License.
 # ========= Copyright 2025-2026 @ Eigent.ai All Rights Reserved. =========
 
+import logging
+import os
+
+from dotenv import load_dotenv
 from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
 
+# Load env so CORS_ORIGINS is available when this module is imported (before main runs).
+load_dotenv(dotenv_path=os.path.join(os.path.expanduser("~"), ".eigent", ".env"))
+
+logger = logging.getLogger(__name__)
+
 # Initialize FastAPI with title
 api = FastAPI(title="Eigent Multi-Agent System API")
 
-# Add CORS middleware
-api.add_middleware(
-    CORSMiddleware,
-    allow_origins=["*"],
-    allow_credentials=True,
-    allow_methods=["*"],
-    allow_headers=["*"],
-)
+
+def _get_cors_origins() -> list[str]:
+    """
+    CORS allowed origins. Avoids overly permissive '*' to prevent unwanted origins.
+    Set CORS_ORIGINS (comma-separated) in ~/.eigent/.env or environment;
+    in development only, defaults to common localhost origins if unset.
+    """
+    raw = os.environ.get("CORS_ORIGINS")
+    if raw is not None and raw.strip():
+        origins = [o.strip() for o in raw.split(",") if o.strip()]
+        if origins:
+            return origins
+    if os.environ.get("ENVIRONMENT", "development").lower() == "development":
+        return [
+            "http://localhost:5173",
+            "http://127.0.0.1:5173",
+            "http://localhost:3000",
+            "http://127.0.0.1:3000",
+        ]
+    return []
+
+
+_cors_origins = _get_cors_origins()
+if _cors_origins:
+    api.add_middleware(
+        CORSMiddleware,
+        allow_origins=_cors_origins,
+        allow_credentials=True,
+        allow_methods=["GET", "POST", "PUT", "DELETE", "OPTIONS"],
+        allow_headers=["Content-Type", "Authorization", "x-stack-auth"],
+    )
+    logger.info("CORS enabled for origins: %s", _cors_origins)
+else:
+    logger.info(
+        "CORS disabled (no CORS_ORIGINS set in non-development). "
+        "Set CORS_ORIGINS (comma-separated) to allow browser origins."
+    )