fix: address comments

Author: fmenezes

README.md

@@ -304,22 +304,47 @@ The MongoDB MCP Server can be configured using multiple methods, with the follow
 | `apiClientId`      | <not set>  | Atlas API client ID for authentication. Required for running Atlas tools.                                                                                     |
 | `apiClientSecret`  | <not set>  | Atlas API client secret for authentication. Required for running Atlas tools.                                                                                 |
 | `connectionString` | <not set>  | MongoDB connection string for direct database connections. Optional, if not set, you'll need to call the `connect` tool before interacting with MongoDB data. |
-| `logPath`          | see note\* | Folder to store logs.                                                                                                                                         |
+| `loggers`          | disk,mcp   | Comma separated values, possible values are `mcp`, `disk` and `stderr`. See [Logger Options](#logger-options) for details.                                    |
+| `logPath`          | see note*  | Folder to store logs.                                                                                                                                         |
 | `disabledTools`    | <not set>  | An array of tool names, operation types, and/or categories of tools that will be disabled.                                                                    |
 | `readOnly`         | false      | When set to true, only allows read, connect, and metadata operation types, disabling create/update/delete operations.                                         |
 | `indexCheck`       | false      | When set to true, enforces that query operations must use an index, rejecting queries that perform a collection scan.                                         |
 | `telemetry`        | enabled    | When set to disabled, disables telemetry collection.                                                                                                          |
 | `transport`        | stdio      | Either 'stdio' or 'http'.                                                                                                                                     |
 | `httpPort`         | 3000       | Port number.                                                                                                                                                  |
 | `httpHost`         | 127.0.0.1  | Host to bind the http server.                                                                                                                                 |
-| `logger`           | disk,mcp   | Comma separated values, possible values are `mcp`, `disk` and `stderr`.                                                                                       |
 
-#### Log Path
+#### Logger Options
 
-Default log location is as follows:
+The `loggers` configuration option controls where logs are sent. You can specify one or more logger types as a comma-separated list. The available options are:
 
-- Windows: `%LOCALAPPDATA%\mongodb\mongodb-mcp\.app-logs`
-- macOS/Linux: `~/.mongodb/mongodb-mcp/.app-logs`
+- `mcp`: Sends logs to the MCP client (if supported by the client/transport).
+- `disk`: Writes logs to disk files. Log files are stored in the log path (see `logPath` above).
+- `stderr`: Outputs logs to standard error (stderr), useful for debugging or when running in containers.
+
+**Default:** `disk,mcp` (logs are written to disk and sent to the MCP client).
+
+You can combine multiple loggers, e.g. `--loggers disk,stderr` or `export MDB_MCP_LOGGERS="mcp,stderr"`.
+
+##### Example: Set logger via environment variable
+
+```shell
+export MDB_MCP_LOGGERS="disk,stderr"
+```
+
+##### Example: Set logger via command-line argument
+
+```shell
+npx -y mongodb-mcp-server --loggers mcp,stderr
+```
+
+##### Log File Location
+
+When using the `disk` logger, log files are stored in:
+- **Windows:** `%LOCALAPPDATA%\mongodb\mongodb-mcp\.app-logs`
+- **macOS/Linux:** `~/.mongodb/mongodb-mcp/.app-logs`
+
+You can override the log directory with the `logPath` option.
 
 #### Disabled Tools
 

src/transports/streamableHttpTransport.ts

@@ -4,9 +4,10 @@ import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/
 import { config } from "../common/config.js";
 import logger, { LogId } from "../common/logger.js";
 
+const JSON_RPC_ERROR_CODE_PROCESSING_REQUEST_FAILED = -32000;
+
 export function createHttpTransport(): StreamableHTTPServerTransport {
     const app = express();
-    app.use(express.json());
     app.enable("trust proxy"); // needed for reverse proxy support
     app.use(express.urlencoded({ extended: true }));
     app.use(express.json());
@@ -24,7 +25,13 @@ export function createHttpTransport(): StreamableHTTPServerTransport {
                 "streamableHttpTransport",
                 `Error handling request: ${error instanceof Error ? error.message : String(error)}`
             );
-            res.sendStatus(400);
+            res.status(400).json({
+                jsonrpc: "2.0",
+                error: {
+                    code: JSON_RPC_ERROR_CODE_PROCESSING_REQUEST_FAILED,
+                    message: `Error handling request: ${error instanceof Error ? error.message : String(error)}`,
+                },
+            });
         }
     });
 
@@ -37,7 +44,13 @@ export function createHttpTransport(): StreamableHTTPServerTransport {
                 "streamableHttpTransport",
                 `Error handling request: ${error instanceof Error ? error.message : String(error)}`
             );
-            res.sendStatus(400);
+            res.status(400).json({
+                jsonrpc: "2.0",
+                error: {
+                    code: JSON_RPC_ERROR_CODE_PROCESSING_REQUEST_FAILED,
+                    message: `Error handling request: ${error instanceof Error ? error.message : String(error)}`,
+                },
+            });
         }
     });
 
@@ -50,7 +63,13 @@ export function createHttpTransport(): StreamableHTTPServerTransport {
                 "streamableHttpTransport",
                 `Error handling request: ${error instanceof Error ? error.message : String(error)}`
             );
-            res.sendStatus(400);
+            res.status(400).json({
+                jsonrpc: "2.0",
+                error: {
+                    code: JSON_RPC_ERROR_CODE_PROCESSING_REQUEST_FAILED,
+                    message: `Error handling request: ${error instanceof Error ? error.message : String(error)}`,
+                },
+            });
         }
     });