automatically connect if config connection string is provided

Author: nirinchev

src/common/mongodb/connect.ts

@@ -0,0 +1,20 @@
+import { NodeDriverServiceProvider } from "@mongosh/service-provider-node-driver";
+import { State } from "../../state.js";
+import config from "../../config.js";
+
+export async function connectToMongoDB(connectionString: string, state: State): Promise<void> {
+    const provider = await NodeDriverServiceProvider.connect(connectionString, {
+        productDocsLink: "https://docs.mongodb.com/todo-mcp",
+        productName: "MongoDB MCP",
+        readConcern: config.connectOptions.readConcern,
+        readPreference: config.connectOptions.readPreference,
+        writeConcern: {
+            w: config.connectOptions.writeConcern,
+        },
+        timeoutMS: config.connectOptions.timeoutMS,
+    });
+
+    state.serviceProvider = provider;
+    state.credentials.connectionString = connectionString;
+    await state.persistCredentials();
+}

src/tools/mongodb/connect.ts

@@ -5,6 +5,7 @@ import { DbOperationType, MongoDBToolBase } from "./mongodbTool.js";
 import { ToolArgs } from "../tool.js";
 import { ErrorCodes, MongoDBError } from "../../errors.js";
 import config from "../../config.js";
+import { connectToMongoDB } from "../../common/mongodb/connect.js";
 
 export class ConnectTool extends MongoDBToolBase {
     protected name = "connect";
@@ -58,27 +59,10 @@ export class ConnectTool extends MongoDBToolBase {
             throw new MongoDBError(ErrorCodes.InvalidParams, "Invalid connection options");
         }
 
-        await this.connect(connectionString);
+        await connectToMongoDB(connectionString, this.state);
 
         return {
             content: [{ type: "text", text: `Successfully connected to ${connectionString}.` }],
         };
     }
-
-    private async connect(connectionString: string): Promise<void> {
-        const provider = await NodeDriverServiceProvider.connect(connectionString, {
-            productDocsLink: "https://docs.mongodb.com/todo-mcp",
-            productName: "MongoDB MCP",
-            readConcern: config.connectOptions.readConcern,
-            readPreference: config.connectOptions.readPreference,
-            writeConcern: {
-                w: config.connectOptions.writeConcern,
-            },
-            timeoutMS: config.connectOptions.timeoutMS,
-        });
-
-        this.state.serviceProvider = provider;
-        this.state.credentials.connectionString = connectionString;
-        await this.state.persistCredentials();
-    }
 }

src/tools/mongodb/mongodbTool.ts

@@ -4,6 +4,8 @@ import { State } from "../../state.js";
 import { NodeDriverServiceProvider } from "@mongosh/service-provider-node-driver";
 import { CallToolResult } from "@modelcontextprotocol/sdk/types.js";
 import { ErrorCodes, MongoDBError } from "../../errors.js";
+import config from "../../config.js";
+import { connectToMongoDB } from "../../common/mongodb/connect.js";
 
 export const DbOperationArgs = {
     database: z.string().describe("Database name"),
@@ -19,8 +21,12 @@ export abstract class MongoDBToolBase extends ToolBase {
 
     protected abstract operationType: DbOperationType;
 
-    protected ensureConnected(): NodeDriverServiceProvider {
+    protected async ensureConnected(): Promise<NodeDriverServiceProvider> {
         const provider = this.state.serviceProvider;
+        if (!provider && config.connectionString) {
+            await connectToMongoDB(config.connectionString, this.state);
+        }
+
         if (!provider) {
             throw new MongoDBError(ErrorCodes.NotConnectedToMongoDB, "Not connected to MongoDB");
         }