feat: support env field in config file (#79)

README.md

@@ -196,6 +196,9 @@ The JSON file should follow this structure:
         "-y",
         "@modelcontextprotocol/server-github"
       ],
+      "env": {
+        "GITHUB_PERSONAL_ACCESS_TOKEN": "<YOUR_TOKEN>"
+      },
       "transportType": "stdio"
     }
   }
@@ -392,6 +395,9 @@ Examples:
         "-y",
         "@modelcontextprotocol/server-github"
       ],
+      "env": {
+        "GITHUB_PERSONAL_ACCESS_TOKEN": "<YOUR_TOKEN>"
+      },
       "transportType": "stdio"
     }
   }

src/mcp_proxy/config_loader.py

@@ -69,6 +69,7 @@ def load_named_server_configs_from_file(
 
         command = server_config.get("command")
         command_args = server_config.get("args", [])
+        env = server_config.get("env", {})
 
         if not command:
             logger.warning(
@@ -83,10 +84,13 @@ def load_named_server_configs_from_file(
             )
             continue
 
+        new_env = base_env.copy()
+        new_env.update(env)
+
         named_stdio_params[name] = StdioServerParameters(
             command=command,
             args=command_args,
-            env=base_env.copy(),
+            env=new_env,
             cwd=None,
         )
         logger.info(

tests/test_config_loader.py

@@ -43,6 +43,7 @@ def test_load_valid_config(create_temp_config_file: Callable[[dict], str]) -> No
             "server1": {
                 "command": "echo",
                 "args": ["hello"],
+                "env": {"FOO": "bar"},
                 "enabled": True,
             },
             "server2": {
@@ -53,6 +54,7 @@ def test_load_valid_config(create_temp_config_file: Callable[[dict], str]) -> No
     }
     tmp_config_path = create_temp_config_file(config_content)
     base_env = {"PASSED": "env_value"}
+    base_env_with_added_env = {"PASSED": "env_value", "FOO": "bar"}
 
     loaded_params = load_named_server_configs_from_file(tmp_config_path, base_env)
 
@@ -60,7 +62,7 @@ def test_load_valid_config(create_temp_config_file: Callable[[dict], str]) -> No
     assert loaded_params["server1"].command == "echo"
     assert loaded_params["server1"].args == ["hello"]
     assert (
-        loaded_params["server1"].env == base_env
+        loaded_params["server1"].env == base_env_with_added_env
     )  # Env is a copy, check if it contains base_env items
 
     assert "server2" in loaded_params