Load atlas-local tools async

Author: jeroenvervaeke

src/server.ts

@@ -19,7 +19,7 @@ import {
     UnsubscribeRequestSchema,
 } from "@modelcontextprotocol/sdk/types.js";
 import assert from "assert";
-import type { ToolBase } from "./tools/tool.js";
+import type { ToolBase, ToolConstructor } from "./tools/tool.js";
 import { validateConnectionString } from "./helpers/connectionOptions.js";
 
 export interface ServerOptions {
@@ -61,11 +61,12 @@ export class Server {
 
         this.mcpServer.server.registerCapabilities({ logging: {}, resources: { listChanged: true, subscribe: true } });
 
-        await this.tryInitializeAtlasLocalClient();
-
         // TODO: Eventually we might want to make tools reactive too instead of relying on custom logic.
         this.registerTools();
 
+        // Atlas Local tools are optional and require async initialization
+        void this.registerAtlasLocalTools();
+
         // This is a workaround for an issue we've seen with some models, where they'll see that everything in the `arguments`
         // object is optional, and then not pass it at all. However, the MCP server expects the `arguments` object to be if
         // the tool accepts any arguments, even if they're all optional.
@@ -195,13 +196,27 @@ export class Server {
         this.telemetry.emitEvents([event]).catch(() => {});
     }
 
-    private async tryInitializeAtlasLocalClient(): Promise<void> {
+    private async registerAtlasLocalTools(): Promise<void> {
         try {
+            // Import Atlas Local client asyncronously
+            // This will fail on unsupported platforms
             const { Client: AtlasLocalClient } = await import("@mongodb-js-preview/atlas-local");
 
+            // Connect to Atlas Local client
+            // This will fail if docker is not running
             const client = AtlasLocalClient.connect();
+
+            // Set Atlas Local client
             this.session.setAtlasLocalClient(client);
+
+            // Register Atlas Local tools
+            this.registerToolInstances(AtlasLocalTools);
         } catch (error) {
+            // If Atlas Local tools are disabled, don't log an error
+            if (this.userConfig.disabledTools.includes("atlas-local")) {
+                return;
+            }
+
             console.warn(
                 "Failed to initialize Atlas Local client, atlas-local tools will be disabled (error: ",
                 error,
@@ -211,7 +226,11 @@ export class Server {
     }
 
     private registerTools(): void {
-        for (const toolConstructor of [...AtlasTools, ...AtlasLocalTools, ...MongoDbTools]) {
+        this.registerToolInstances([...AtlasTools, ...MongoDbTools]);
+    }
+
+    private registerToolInstances(tools: Array<ToolConstructor>): void {
+        for (const toolConstructor of tools) {
             const tool = new toolConstructor(this.session, this.userConfig, this.telemetry);
             if (tool.register(this)) {
                 this.tools.push(tool);

src/tools/tool.ts

@@ -18,6 +18,8 @@ export type TelemetryToolMetadata = {
     orgId?: string;
 };
 
+export type ToolConstructor = new (session: Session, config: UserConfig, telemetry: Telemetry) => ToolBase;
+
 export abstract class ToolBase {
     public abstract name: string;