18007165187

Committed 25 Sep 2025 12:17PM UTC coverage: 82.532%. First build

Build # 18007165187

Build Type

Pull #592

github

Committed by

web-flow

Commit Message

Merge 91bffa85d into 91c99e595

Pull Request Pull Request #592: chore: improve descriptions about connection - MCP-224

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80.36

/src/server.ts

import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import type { Session } from "./common/session.js";
import type { Transport } from "@modelcontextprotocol/sdk/shared/transport.js";
import { AtlasTools } from "./tools/atlas/tools.js";
import { MongoDbTools } from "./tools/mongodb/tools.js";
import { Resources } from "./resources/resources.js";
import type { LogLevel } from "./common/logger.js";
import { LogId, McpLogger } from "./common/logger.js";
import type { Telemetry } from "./telemetry/telemetry.js";
import type { UserConfig } from "./common/config.js";
import { type ServerEvent } from "./telemetry/types.js";
import { type ServerCommand } from "./telemetry/types.js";
import type { CallToolResult } from "@modelcontextprotocol/sdk/types.js";
import {
    CallToolRequestSchema,
    SetLevelRequestSchema,
    SubscribeRequestSchema,
    UnsubscribeRequestSchema,
} from "@modelcontextprotocol/sdk/types.js";
import assert from "assert";
import type { ToolBase } from "./tools/tool.js";
import { validateConnectionString } from "./helpers/connectionOptions.js";
import { packageInfo } from "./common/packageInfo.js";
import { type ConnectionErrorHandler } from "./common/connectionErrorHandler.js";
import type { Elicitation } from "./elicitation.js";

export interface ServerOptions {
    session: Session;
    userConfig: UserConfig;
    mcpServer: McpServer;
    telemetry: Telemetry;
    elicitation: Elicitation;
    connectionErrorHandler: ConnectionErrorHandler;
}

export class Server {
    public readonly session: Session;
    public readonly mcpServer: McpServer;
    private readonly telemetry: Telemetry;
    public readonly userConfig: UserConfig;
    public readonly elicitation: Elicitation;
    public readonly tools: ToolBase[] = [];
    public readonly connectionErrorHandler: ConnectionErrorHandler;

    private _mcpLogLevel: LogLevel = "debug";

    public get mcpLogLevel(): LogLevel {
        return this._mcpLogLevel;
    }

    private readonly startTime: number;
    private readonly subscriptions = new Set<string>();

    constructor({ session, mcpServer, userConfig, telemetry, connectionErrorHandler, elicitation }: ServerOptions) {
        this.startTime = Date.now();
        this.session = session;
        this.telemetry = telemetry;
        this.mcpServer = mcpServer;
        this.userConfig = userConfig;
        this.elicitation = elicitation;
        this.connectionErrorHandler = connectionErrorHandler;
    }

    async connect(transport: Transport): Promise<void> {
        await this.validateConfig();
        // Register resources after the server is initialized so they can listen to events like
        // connection events.
        this.registerResources();
        this.mcpServer.server.registerCapabilities({
            logging: {},
            resources: { listChanged: true, subscribe: true },
            instructions: this.getInstructions(),
        });

        // TODO: Eventually we might want to make tools reactive too instead of relying on custom logic.
        this.registerTools();

        // 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.
        //
        // see: https://github.com/modelcontextprotocol/typescript-sdk/blob/131776764536b5fdca642df51230a3746fb4ade0/src/server/mcp.ts#L705
        // Since paramsSchema here is not undefined, the server will create a non-optional z.object from it.
        const existingHandler = (
            this.mcpServer.server["_requestHandlers"] as Map<
                string,
                (request: unknown, extra: unknown) => Promise<CallToolResult>
            >
        ).get(CallToolRequestSchema.shape.method.value);

        assert(existingHandler, "No existing handler found for CallToolRequestSchema");

        this.mcpServer.server.setRequestHandler(CallToolRequestSchema, (request, extra): Promise<CallToolResult> => {
            if (!request.params.arguments) {
                request.params.arguments = {};
            }

            return existingHandler(request, extra);
        });

        this.mcpServer.server.setRequestHandler(SubscribeRequestSchema, ({ params }) => {
            this.subscriptions.add(params.uri);
            this.session.logger.debug({
                id: LogId.serverInitialized,
                context: "resources",
                message: `Client subscribed to resource: ${params.uri}`,
            });
            return {};
        });

        this.mcpServer.server.setRequestHandler(UnsubscribeRequestSchema, ({ params }) => {
            this.subscriptions.delete(params.uri);
            this.session.logger.debug({
                id: LogId.serverInitialized,
                context: "resources",
                message: `Client unsubscribed from resource: ${params.uri}`,
            });
            return {};
        });

        this.mcpServer.server.setRequestHandler(SetLevelRequestSchema, ({ params }) => {
            if (!McpLogger.LOG_LEVELS.includes(params.level)) {
                throw new Error(`Invalid log level: ${params.level}`);
            }

            this._mcpLogLevel = params.level;
            return {};
        });

        this.mcpServer.server.oninitialized = (): void => {
            this.session.setMcpClient(this.mcpServer.server.getClientVersion());
            // Placed here to start the connection to the config connection string as soon as the server is initialized.
            void this.connectToConfigConnectionString();
            this.session.logger.info({
                id: LogId.serverInitialized,
                context: "server",
                message: `Server with version ${packageInfo.version} started with transport ${transport.constructor.name} and agent runner ${JSON.stringify(this.session.mcpClient)}`,
            });

            this.emitServerTelemetryEvent("start", Date.now() - this.startTime);
        };

        this.mcpServer.server.onclose = (): void => {
            const closeTime = Date.now();
            this.emitServerTelemetryEvent("stop", Date.now() - closeTime);
        };

        this.mcpServer.server.onerror = (error: Error): void => {
            const closeTime = Date.now();
            this.emitServerTelemetryEvent("stop", Date.now() - closeTime, error);
        };

        await this.mcpServer.connect(transport);
    }

    async close(): Promise<void> {
        await this.telemetry.close();
        await this.session.close();
        await this.mcpServer.close();
    }

    public sendResourceListChanged(): void {
        this.mcpServer.sendResourceListChanged();
    }

    public sendResourceUpdated(uri: string): void {
        this.session.logger.info({
            id: LogId.serverInitialized,
            context: "resources",
            message: `Resource updated: ${uri}`,
        });

        if (this.subscriptions.has(uri)) {
            void this.mcpServer.server.sendResourceUpdated({ uri });
        }
    }

    private emitServerTelemetryEvent(command: ServerCommand, commandDuration: number, error?: Error): void {
        const event: ServerEvent = {
            timestamp: new Date().toISOString(),
            source: "mdbmcp",
            properties: {
                result: "success",
                duration_ms: commandDuration,
                component: "server",
                category: "other",
                command: command,
            },
        };

        if (command === "start") {
            event.properties.startup_time_ms = commandDuration;
            event.properties.read_only_mode = this.userConfig.readOnly || false;
            event.properties.disabled_tools = this.userConfig.disabledTools || [];
            event.properties.confirmation_required_tools = this.userConfig.confirmationRequiredTools || [];
        }
        if (command === "stop") {
            event.properties.runtime_duration_ms = Date.now() - this.startTime;
            if (error) {
                event.properties.result = "failure";
                event.properties.reason = error.message;
            }
        }

        this.telemetry.emitEvents([event]);
    }

    private registerTools(): void {
        for (const toolConstructor of [...AtlasTools, ...MongoDbTools]) {
            const tool = new toolConstructor({
                session: this.session,
                config: this.userConfig,
                telemetry: this.telemetry,
                elicitation: this.elicitation,
            });
            if (tool.register(this)) {
                this.tools.push(tool);
            }
        }
    }

    private registerResources(): void {
        for (const resourceConstructor of Resources) {
            const resource = new resourceConstructor(this.session, this.userConfig, this.telemetry);
            resource.register(this);
        }
    }

    private async validateConfig(): Promise<void> {
        // Validate connection string
        if (this.userConfig.connectionString) {
            try {
                validateConnectionString(this.userConfig.connectionString, false);
            } catch (error) {
                console.error("Connection string validation failed with error: ", error);
                throw new Error(
                    "Connection string validation failed with error: " +
                        (error instanceof Error ? error.message : String(error))
                );
            }
        }

        // Validate API client credentials
        if (this.userConfig.apiClientId && this.userConfig.apiClientSecret) {
            try {
                if (!this.userConfig.apiBaseUrl.startsWith("https://")) {
                    const message =
                        "Failed to validate MongoDB Atlas the credentials from config: apiBaseUrl must start with https://";
                    console.error(message);
                    throw new Error(message);
                }

                await this.session.apiClient.validateAccessToken();
            } catch (error) {
                if (this.userConfig.connectionString === undefined) {
                    console.error("Failed to validate MongoDB Atlas the credentials from the config: ", error);

                    throw new Error(
                        "Failed to connect to MongoDB Atlas instance using the credentials from the config"
                    );
                }
                console.error(
                    "Failed to validate MongoDB Atlas the credentials from the config, but validated the connection string."
                );
            }
        }
    }

    private getInstructions(): string {
        let instructions = `
            This is the MongoDB MCP server.
        `;
        if (this.userConfig.connectionString) {
            instructions = `
            This MCP server was configured with a MongoDB connection string, and you can assume that you are connected to a MongoDB cluster.
            `;
        }

        if (this.userConfig.apiClientId && this.userConfig.apiClientSecret) {
            instructions = `
            This MCP server was configured with MongoDB Atlas API credentials.`;
        }

        return instructions;
    }

    private async connectToConfigConnectionString(): Promise<void> {
        if (this.userConfig.connectionString) {
            try {
                this.session.logger.info({
                    id: LogId.mongodbConnectTry,
                    context: "server",
                    message: `Detected a MongoDB connection string in the configuration, trying to connect...`,
                });
                await this.session.connectToMongoDB({
                    connectionString: this.userConfig.connectionString,
                });
            } catch (error) {
                // We don't throw an error here because we want to allow the server to start even if the connection string is invalid.
                this.session.logger.error({
                    id: LogId.mongodbConnectFailure,
                    context: "server",
                    message: `Failed to connect to MongoDB instance using the connection string from the config: ${error instanceof Error ? error.message : String(error)}`,
                });
            }
        }
    }
}

1	import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
2	import type { Session } from "./common/session.js";
3	import type { Transport } from "@modelcontextprotocol/sdk/shared/transport.js";
4	import { AtlasTools } from "./tools/atlas/tools.js";	2✔
5	import { MongoDbTools } from "./tools/mongodb/tools.js";	2✔
6	import { Resources } from "./resources/resources.js";	2✔
7	import type { LogLevel } from "./common/logger.js";
8	import { LogId, McpLogger } from "./common/logger.js";	2✔
9	import type { Telemetry } from "./telemetry/telemetry.js";
10	import type { UserConfig } from "./common/config.js";
11	import { type ServerEvent } from "./telemetry/types.js";
12	import { type ServerCommand } from "./telemetry/types.js";
13	import type { CallToolResult } from "@modelcontextprotocol/sdk/types.js";
14	import {	2✔
15	CallToolRequestSchema,
16	SetLevelRequestSchema,
17	SubscribeRequestSchema,
18	UnsubscribeRequestSchema,
19	} from "@modelcontextprotocol/sdk/types.js";
20	import assert from "assert";	2✔
21	import type { ToolBase } from "./tools/tool.js";
22	import { validateConnectionString } from "./helpers/connectionOptions.js";	2✔
23	import { packageInfo } from "./common/packageInfo.js";	2✔
24	import { type ConnectionErrorHandler } from "./common/connectionErrorHandler.js";
25	import type { Elicitation } from "./elicitation.js";
26
27	export interface ServerOptions {
28	session: Session;
29	userConfig: UserConfig;
30	mcpServer: McpServer;
31	telemetry: Telemetry;
32	elicitation: Elicitation;
33	connectionErrorHandler: ConnectionErrorHandler;
34	}
35
36	export class Server {	2✔
37	public readonly session: Session;
38	public readonly mcpServer: McpServer;
39	private readonly telemetry: Telemetry;
40	public readonly userConfig: UserConfig;
41	public readonly elicitation: Elicitation;
42	public readonly tools: ToolBase[] = [];	2✔
43	public readonly connectionErrorHandler: ConnectionErrorHandler;
44
45	private _mcpLogLevel: LogLevel = "debug";	2✔
46
47	public get mcpLogLevel(): LogLevel {	2✔
48	return this._mcpLogLevel;	2✔
49	}	2✔
50
51	private readonly startTime: number;
52	private readonly subscriptions = new Set<string>();	2✔
53
54	constructor({ session, mcpServer, userConfig, telemetry, connectionErrorHandler, elicitation }: ServerOptions) {	2✔
55	this.startTime = Date.now();	77✔
56	this.session = session;	77✔
57	this.telemetry = telemetry;	77✔
58	this.mcpServer = mcpServer;	77✔
59	this.userConfig = userConfig;	77✔
60	this.elicitation = elicitation;	77✔
61	this.connectionErrorHandler = connectionErrorHandler;	77✔
62	}	77✔
63
64	async connect(transport: Transport): Promise<void> {	2✔
65	await this.validateConfig();	76✔
66	// Register resources after the server is initialized so they can listen to events like
67	// connection events.
68	this.registerResources();	76✔
69	this.mcpServer.server.registerCapabilities({	76✔
70	logging: {},	76✔
71	resources: { listChanged: true, subscribe: true },	76✔
72	instructions: this.getInstructions(),	76✔
73	});	76✔
74
75	// TODO: Eventually we might want to make tools reactive too instead of relying on custom logic.
76	this.registerTools();	76✔
77
78	// This is a workaround for an issue we've seen with some models, where they'll see that everything in the `arguments`
79	// object is optional, and then not pass it at all. However, the MCP server expects the `arguments` object to be if
80	// the tool accepts any arguments, even if they're all optional.
81	//
82	// see: https://github.com/modelcontextprotocol/typescript-sdk/blob/131776764536b5fdca642df51230a3746fb4ade0/src/server/mcp.ts#L705
83	// Since paramsSchema here is not undefined, the server will create a non-optional z.object from it.
84	const existingHandler = (	76✔
85	this.mcpServer.server["_requestHandlers"] as Map<	76✔
86	string,
87	(request: unknown, extra: unknown) => Promise<CallToolResult>
88	>
89	).get(CallToolRequestSchema.shape.method.value);	76✔
90
91	assert(existingHandler, "No existing handler found for CallToolRequestSchema");	76✔
92
93	this.mcpServer.server.setRequestHandler(CallToolRequestSchema, (request, extra): Promise<CallToolResult> => {	76✔
94	if (!request.params.arguments) {	573✔
95	request.params.arguments = {};	1✔
96	}	1✔
97
98	return existingHandler(request, extra);	573✔
99	});	76✔
100
101	this.mcpServer.server.setRequestHandler(SubscribeRequestSchema, ({ params }) => {	76✔
102	this.subscriptions.add(params.uri);	20✔
103	this.session.logger.debug({	20✔
104	id: LogId.serverInitialized,	20✔
105	context: "resources",	20✔
106	message: `Client subscribed to resource: ${params.uri}`,	20✔
107	});	20✔
108	return {};	20✔
109	});	76✔
110
111	this.mcpServer.server.setRequestHandler(UnsubscribeRequestSchema, ({ params }) => {	76✔
112	this.subscriptions.delete(params.uri);	×
113	this.session.logger.debug({	×
114	id: LogId.serverInitialized,	×
115	context: "resources",	×
116	message: `Client unsubscribed from resource: ${params.uri}`,	×
117	});	×
118	return {};	×
119	});	76✔
120
121	this.mcpServer.server.setRequestHandler(SetLevelRequestSchema, ({ params }) => {	76✔
122	if (!McpLogger.LOG_LEVELS.includes(params.level)) {	×
123	throw new Error(`Invalid log level: ${params.level}`);	×
124	}	×
125
126	this._mcpLogLevel = params.level;	×
127	return {};	×
128	});	76✔
129
130	this.mcpServer.server.oninitialized = (): void => {	76✔
131	this.session.setMcpClient(this.mcpServer.server.getClientVersion());	76✔
132	// Placed here to start the connection to the config connection string as soon as the server is initialized.
133	void this.connectToConfigConnectionString();	76✔
134	this.session.logger.info({	76✔
135	id: LogId.serverInitialized,	76✔
136	context: "server",	76✔
137	message: `Server with version ${packageInfo.version} started with transport ${transport.constructor.name} and agent runner ${JSON.stringify(this.session.mcpClient)}`,	76✔
138	});	76✔
139
140	this.emitServerTelemetryEvent("start", Date.now() - this.startTime);	76✔
141	};	76✔
142
143	this.mcpServer.server.onclose = (): void => {	76✔
144	const closeTime = Date.now();	76✔
145	this.emitServerTelemetryEvent("stop", Date.now() - closeTime);	76✔
146	};	76✔
147
148	this.mcpServer.server.onerror = (error: Error): void => {	76✔
149	const closeTime = Date.now();	×
NEW 150	this.emitServerTelemetryEvent("stop", Date.now() - closeTime, error);	×
151	};	×
152
153	await this.mcpServer.connect(transport);	76✔
154	}	76✔
155
156	async close(): Promise<void> {	2✔
157	await this.telemetry.close();	76✔
158	await this.session.close();	76✔
159	await this.mcpServer.close();	76✔
160	}	76✔
161
162	public sendResourceListChanged(): void {	2✔
163	this.mcpServer.sendResourceListChanged();	628✔
164	}	628✔
165
166	public sendResourceUpdated(uri: string): void {	2✔
167	this.session.logger.info({	628✔
168	id: LogId.serverInitialized,	628✔
169	context: "resources",	628✔
170	message: `Resource updated: ${uri}`,	628✔
171	});	628✔
172
173	if (this.subscriptions.has(uri)) {	628!
174	void this.mcpServer.server.sendResourceUpdated({ uri });	20✔
175	}	20✔
176	}	628✔
177
178	private emitServerTelemetryEvent(command: ServerCommand, commandDuration: number, error?: Error): void {	2✔
179	const event: ServerEvent = {	152✔
180	timestamp: new Date().toISOString(),	152✔
181	source: "mdbmcp",	152✔
182	properties: {	152✔
183	result: "success",	152✔
184	duration_ms: commandDuration,	152✔
185	component: "server",	152✔
186	category: "other",	152✔
187	command: command,	152✔
188	},	152✔
189	};	152✔
190
191	if (command === "start") {	152✔
192	event.properties.startup_time_ms = commandDuration;	76✔
193	event.properties.read_only_mode = this.userConfig.readOnly \|\| false;	76✔
194	event.properties.disabled_tools = this.userConfig.disabledTools \|\| [];	76!
195	event.properties.confirmation_required_tools = this.userConfig.confirmationRequiredTools \|\| [];	76!
196	}	76✔
197	if (command === "stop") {	152✔
198	event.properties.runtime_duration_ms = Date.now() - this.startTime;	76✔
199	if (error) {	76!
200	event.properties.result = "failure";	×
201	event.properties.reason = error.message;	×
202	}	×
203	}	76✔
204
205	this.telemetry.emitEvents([event]);	152✔
206	}	152✔
207
208	private registerTools(): void {	2✔
209	for (const toolConstructor of [...AtlasTools, ...MongoDbTools]) {	76✔
210	const tool = new toolConstructor({	2,508✔
211	session: this.session,	2,508✔
212	config: this.userConfig,	2,508✔
213	telemetry: this.telemetry,	2,508✔
214	elicitation: this.elicitation,	2,508✔
215	});	2,508✔
216	if (tool.register(this)) {	2,508✔
217	this.tools.push(tool);	1,739✔
218	}	1,739✔
219	}	2,508✔
220	}	76✔
221
222	private registerResources(): void {	2✔
223	for (const resourceConstructor of Resources) {	76✔
224	const resource = new resourceConstructor(this.session, this.userConfig, this.telemetry);	228✔
225	resource.register(this);	228✔
226	}	228✔
227	}	76✔
228
229	private async validateConfig(): Promise<void> {	2✔
230	// Validate connection string
231	if (this.userConfig.connectionString) {	76!
232	try {	5✔
233	validateConnectionString(this.userConfig.connectionString, false);	5✔
234	} catch (error) {	5!
235	console.error("Connection string validation failed with error: ", error);	×
236	throw new Error(	×
237	"Connection string validation failed with error: " +	×
238	(error instanceof Error ? error.message : String(error))	×
239	);	×
240	}	×
241	}	5✔
242
243	// Validate API client credentials
244	if (this.userConfig.apiClientId && this.userConfig.apiClientSecret) {	76✔
245	try {	13✔
246	if (!this.userConfig.apiBaseUrl.startsWith("https://")) {	13!
NEW 247	const message =	×
NEW 248	"Failed to validate MongoDB Atlas the credentials from config: apiBaseUrl must start with https://";	×
NEW 249	console.error(message);	×
NEW 250	throw new Error(message);	×
NEW 251	}	×
252
253	await this.session.apiClient.validateAccessToken();	13✔
254	} catch (error) {	13!
255	if (this.userConfig.connectionString === undefined) {	×
256	console.error("Failed to validate MongoDB Atlas the credentials from the config: ", error);	×
257
258	throw new Error(	×
259	"Failed to connect to MongoDB Atlas instance using the credentials from the config"	×
260	);	×
261	}	×
262	console.error(	×
263	"Failed to validate MongoDB Atlas the credentials from the config, but validated the connection string."	×
264	);	×
265	}	×
266	}	13✔
267	}	76✔
268
269	private getInstructions(): string {	2✔
270	let instructions = `	76✔
271	This is the MongoDB MCP server.
272	`;
273	if (this.userConfig.connectionString) {	76!
274	instructions = `	5✔
275	This MCP server was configured with a MongoDB connection string, and you can assume that you are connected to a MongoDB cluster.
276	`;
277	}	5✔
278
279	if (this.userConfig.apiClientId && this.userConfig.apiClientSecret) {	76✔
280	instructions = `	13✔
281	This MCP server was configured with MongoDB Atlas API credentials.`;
282	}	13✔
283
284	return instructions;	76✔
285	}	76✔
286
287	private async connectToConfigConnectionString(): Promise<void> {	2✔
288	if (this.userConfig.connectionString) {	76!
289	try {	5✔
290	this.session.logger.info({	5✔
291	id: LogId.mongodbConnectTry,	5✔
292	context: "server",	5✔
293	message: `Detected a MongoDB connection string in the configuration, trying to connect...`,	5✔
294	});	5✔
295	await this.session.connectToMongoDB({	5✔
296	connectionString: this.userConfig.connectionString,	5✔
297	});	5✔
298	} catch (error) {	3✔
299	// We don't throw an error here because we want to allow the server to start even if the connection string is invalid.
300	this.session.logger.error({	2✔
301	id: LogId.mongodbConnectFailure,	2✔
302	context: "server",	2✔
303	message: `Failed to connect to MongoDB instance using the connection string from the config: ${error instanceof Error ? error.message : String(error)}`,	2!
304	});	2✔
305	}	2✔
306	}	5✔
307	}	76✔
308	}	2✔

mongodb-js / mongodb-mcp-server / 18007165187

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