why does mcp server fail | Convex Community | Page 1

barren wave Apr 26, 2025, 11:18 PM

#

says "failed to create client"

ancient geyserBOT Apr 26, 2025, 11:18 PM

#

Hi @barren wave. I'm kapa.ai, your friendly support bot. I will try to answer your question by searching through the knowledge base. :wave:

#

Based on the knowledge sources, there isn't specific information about a "failed to create client" error with the Convex MCP server. However, I can provide some general troubleshooting information about the Convex MCP server based on what's available.

The Convex Model Context Protocol (MCP) server might fail for several reasons:

Command configuration issues: If you're using pnpm, the command configuration might be incorrect. As mentioned in one of the support threads, you should use:

{
  "mcpServers": {
    "convex": {
      "command": "pnpm",
      "args": ["dlx", "convex@latest", "mcp", "start"]
    }
  }
}

Instead of using "pnpm dlx" as the command with the rest as args Discord support thread.

Version compatibility: Make sure you're using a compatible version of your editor. For Cursor, version 0.47 or later is required Using Cursor with Convex.
Server configuration: The MCP server needs to be properly configured in your editor settings. Each editor (Cursor, Windsurf) has specific configuration steps.

If you're still experiencing issues, you might want to:

Try running the command directly in your terminal: npx convex@latest mcp start to see if it works outside your editor
Check if there are any more detailed error messages in your editor's logs
Make sure you have the latest version of Convex installed

For more detailed help, you might want to share the complete error message and your configuration in the Convex Discord community.

#

I hope this helps! If you need more specific assistance, please provide more details about your setup and the complete error message.

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

#

@barren wave Kapa.ai is still learning and improving, please let me know how I did by reacting below.

barren wave Apr 26, 2025, 11:19 PM

#

@ancient geyser this is what i have, is it wrong?

"convex": {
"command": "npx",
"args": ["-y", "convex@latest", "mcp", "start"]
}

ancient geyserBOT Apr 26, 2025, 11:19 PM

#

Let me check the knowledge base for you again. One moment! :books:

#

Based on the knowledge sources, your configuration for the Convex MCP server looks correct. This is exactly the recommended configuration format shown in the documentation:

{
  "mcpServers": {
    "convex": {
      "command": "npx",
      "args": ["-y", "convex@latest", "mcp", "start"]
    }
  }
}

This is the same configuration that's recommended in both the Cursor setup guide and the Windsurf setup guide.

If you're still experiencing the "failed to create client" error, it might be due to other factors:

Make sure your configuration is inside the proper mcpServers object as shown above
Verify you're using a compatible editor version (Cursor 0.47+ is required)
Try running npx convex@latest mcp start directly in your terminal to see if it works outside the editor

If the issue persists, you might want to share the complete error message in the Convex Discord community for more specific help.

Is there anything specific about your setup or the full error message that might provide more context?

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

#

@barren wave Kapa.ai is still learning and improving, please let me know how I did by reacting below.

barren wave Apr 26, 2025, 11:21 PM

#

@ancient geyser when i run npx convex@latest mcp start

const err = new Error(Cannot find module '${request}');
^

Error: Cannot find module

ancient geyserBOT Apr 26, 2025, 11:21 PM

#

Let me check the knowledge base for you again. One moment! :books:

#

Based on the error message you're seeing, it appears you're encountering a module resolution issue when trying to run the Convex MCP server. This is similar to some of the module resolution problems mentioned in the knowledge sources.

Several Discord support threads show similar "Cannot find module" errors with Convex. This could be caused by:

Package installation issues: There might be missing or corrupted dependencies in your node_modules folder.
Version conflicts: You might have multiple versions of Convex installed, causing conflicts.
Node.js environment issues: Your Node.js environment might not be properly set up.

Here are some troubleshooting steps you can try:

Reinstall dependencies: Try removing your node_modules folder and reinstalling all dependencies:
```
rm -rf node_modules
npm install
```
or if you're using another package manager, use the equivalent commands.
Install Convex explicitly: Try installing Convex explicitly before running the MCP server:
```
npm install convex
npx convex mcp start
```
Check Node.js version: Make sure you're using a compatible Node.js version. Some users in the Discord threads mentioned issues with Node.js 23, so you might want to try an earlier stable version.
Check for path issues: If you're in a monorepo or have a complex project structure, there might be path resolution issues.

If the problem persists, it would be helpful to share the complete error message, including the specific module it's failing to find, as this would provide more context for troubleshooting.

This type of error is common when there are issues with package installation or module resolution, and the specific solutions in the Discord threads suggest that reinstalling dependencies often helps resolve these issues.

#

Would you be able to share the complete error message with the specific module it's failing to find?

I hope this helps! Let me know if you need further assistance.

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

#

@barren wave Kapa.ai is still learning and improving, please let me know how I did by reacting below.

barren wave Apr 28, 2025, 12:32 PM

#

@ancient geyser

const userId = await getAuthUserId(ctx);

why am i unable to get the user id in my convex query?

ancient geyserBOT Apr 28, 2025, 12:32 PM

#

Let me check the knowledge base for you again. One moment! :books:

#

Based on the knowledge sources, there are several common reasons why getAuthUserId(ctx) might return null or undefined in your Convex query:

Authentication not fully propagated: The most common reason is that you're calling the query outside of an Authenticated component, so it runs before authentication has been completely propagated to the backend.

As mentioned in a Discord support thread: "This is usually because you're calling a query outside of a Authenticated component so it is running before the authentication has been completely propagated" Discord support thread.
Static page rendering: If you're using Next.js with export const dynamic = 'force-static', this can cause authentication issues because static pages don't include cookies, which are necessary for authentication.

As explained in another thread: "since that means no cookies, there's no way you could remain logged in" Discord support thread.
Client-side vs. server-side timing: In some frameworks like Remix or TanStack Router, the authentication state might not be available during server-side rendering or in loaders.
Using Convex Auth vs. third-party auth: If you're using Convex Auth, make sure you're using getAuthUserId correctly. If you're using a third-party auth provider like Clerk, the approach is different.

Here are some solutions to try:

Wrap your component with the Authenticated component from Convex:

import { Authenticated } from "convex/react";

// Then in your component:
<Authenticated>
  {/* Your authenticated content here */}
</Authenticated>

#

Use the "skip" pattern with useQuery when the user might not be available yet:

const currentUser = useQuery(api.users.current);
const data = useQuery(
  api.someQuery.getData,
  currentUser ? { userId: currentUser._id } : "skip"
);

If you're using Convex Auth directly, make sure you're properly setting up the auth provider in your client code.

If you're still having issues, it would be helpful to know:

Which authentication provider you're using (Convex Auth, Clerk, Auth0, etc.)
Where exactly you're calling this query (client component, server component, loader, etc.)
The complete code of your query function

This would help provide a more specific solution to your issue.

Hope this helps!

Auth > Authorization
Auth > Api_reference > server

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

#

@barren wave Kapa.ai is still learning and improving, please let me know how I did by reacting below.

barren wave Apr 28, 2025, 12:33 PM

#

@ancient geyser this is inside my convex/test.ts file

ancient geyserBOT Apr 28, 2025, 12:33 PM

#

Let me check the knowledge base for you again. One moment! :books:

#

I understand that you're working with a convex/test.ts file where you're trying to use getAuthUserId(ctx). Based on our previous conversation, you're having trouble getting the user ID in your Convex query.

If your code is inside a Convex function (query, mutation, or action) in your test.ts file, here are some specific things to check:

Make sure you've imported the function correctly:

import { getAuthUserId } from "@convex-dev/auth/server";

Check your function structure:

export const myFunction = query({
  args: {},
  handler: async (ctx) => {
    const userId = await getAuthUserId(ctx);
    if (userId === null) {
      // Handle unauthenticated case
      return null;
    }
    // Continue with authenticated logic
    const user = await ctx.db.get(userId);
    // ...
  },
});

Verify authentication on the client side: As mentioned earlier, make sure you're calling this query from within an Authenticated component in your React code, or handling the case where authentication hasn't propagated yet.
Debug with console logs: You can add a console log to see what's happening:

console.log("server identity", await ctx.auth.getUserIdentity());
const userId = await getAuthUserId(ctx);
console.log("userId", userId);

This will help you see in the Convex dashboard logs what's happening with authentication.

If you're using Convex Auth, remember that getAuthUserId parses the user ID from the subject field of the token, which is formatted as <userId>|<sessionId>.

If you need more specific help, please share your complete function code and how you're calling it from the client.

#

Auth > Debugging Authentication

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

#

@barren wave Kapa.ai is still learning and improving, please let me know how I did by reacting below.

barren wave Apr 28, 2025, 12:35 PM

#

@ancient geyser
Server [CONVEX Q(pages:getAllPages)] [LOG] 'server identity' null
page.ts:37 Server [CONVEX Q(pages:getAllPages)] [LOG] 'userId' null

why is it null

ancient geyserBOT Apr 28, 2025, 12:35 PM

#

Let me check the knowledge base for you again. One moment! :books:

#

Based on your logs showing 'server identity' null and 'userId' null, there are several common reasons why authentication is returning null in your Convex query:

Authentication not fully propagated: The most common reason is that your query is being called before authentication has been fully propagated to the Convex backend.

As mentioned in the documentation: "Even if the user has been logged-in previously, it takes some time for the client to authenticate with the Convex backend. Therefore on page load, ctx.auth.getUserIdentity() called within a query returns null." Auth > Debugging Authentication
Missing Authenticated component: If you're using React, you might be calling the query outside of an Authenticated component:

"This is usually because you're calling a query outside of a Authenticated component so it is running before the authentication has been completely propagated" Discord support thread
Server-side rendering issues: If you're using fetchQuery with Next.js Server Components or similar, you need to explicitly pass the auth token:

"If you are using fetchQuery for Next.js Server Rendering, make sure you are explicitly passing in a JWT token" Auth > Debugging Authentication
Scheduled functions: If this is happening in a scheduled function, auth is not propagated to scheduled functions:

"The auth is not propagated from the scheduling to the scheduled function. If you want to authenticate or check authorization, you'll have to pass the requisite user information in as a parameter." Discord support thread

To fix this issue:

#

Wrap your component with the Authenticated component from Convex:

import { Authenticated } from "convex/react";

<Authenticated>
  {/* Your component that calls the query */}
</Authenticated>

Handle the null case gracefully in your query:

export const getAllPages = query({
  handler: async (ctx) => {
    const identity = await ctx.auth.getUserIdentity();
    if (!identity) {
      // Return a sentinel value instead of throwing
      return null; // or [] if returning a collection
    }
    // Continue with authenticated logic
  }
});

If using server-side rendering, make sure to pass the token explicitly.

This should help resolve the authentication issue in your Convex query.

Hope this helps!

Auth > Debugging Authentication

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

#

@barren wave Kapa.ai is still learning and improving, please let me know how I did by reacting below.

barren wave Apr 28, 2025, 12:37 PM

#

@ancient geyser i am logged in and calling this query, so it should never be reeturning null, yet it is...

ancient geyserBOT Apr 28, 2025, 12:37 PM

#

Let me check the knowledge base for you again. One moment! :books:

#

Based on the knowledge sources and your situation, there are several reasons why ctx.auth.getUserIdentity() might return null even when you're logged in:

Race condition during authentication: Even when you're logged in, there's a timing issue where the authentication token might not have been fully propagated to the Convex backend when your query runs.

As one Discord thread explains: "Even if the user has been logged-in previously, it takes some time for the client to authenticate with the Convex backend. Therefore on page load, ctx.auth.getUserIdentity() called within a query returns null." Auth > Debugging Authentication
Component rendering order: If you're using React, the query might be executing before authentication is complete:

"This is usually because you're calling a query outside of an Authenticated component so it is running before the authentication has been completely propagated" Discord support thread
Token verification issues: There could be issues with token verification on the production environment:

One user reported: "Having issues with auth on prod where I log in with google and the user gets stored in db but get this error on the client. Almost all of my queries require a user so when I query for a user I get null" Discord support thread

To troubleshoot this issue:

Make sure you're using the Authenticated component from convex/react to wrap components that call queries requiring authentication.

#

Try refreshing the page - some users reported that refreshing fixes authentication state issues:
"The client can get into a state where it believes it's not authenticated, and is sending requests with an old token... When this happens, refreshing the browser fixes the client auth state." Discord support thread
Check if you're using static page rendering in Next.js (export const dynamic = 'force-static'), which can cause authentication issues.
If you're using Convex Auth directly, verify your token configuration is correct.

This appears to be a known issue that several users have encountered, often related to timing and state synchronization between the client and server.

Hope this helps identify the issue!

Auth > Debugging Authentication

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

#

@barren wave Kapa.ai is still learning and improving, please let me know how I did by reacting below.

barren wave Apr 28, 2025, 12:44 PM

#

@ancient geyser i think its cos
const userId = await getAuthUserId(ctx);
can only be called on the client, is that right?

ancient geyserBOT Apr 28, 2025, 12:44 PM

#

Let me check the knowledge base for you again. One moment! :books:

#

No, that's not correct. getAuthUserId(ctx) is specifically designed to be called on the server side within Convex functions (queries, mutations, or actions), not on the client.

According to the documentation:

import { getAuthUserId } from "@convex-dev/auth/server";
import { query } from "./_generated/server";
 
export const currentUser = query({
  args: {},
  handler: async (ctx) => {
    const userId = await getAuthUserId(ctx);
    if (userId === null) {
      return null;
    }
    return await ctx.db.get(userId);
  },
});

The function is imported from @convex-dev/auth/server and is meant to be used within server-side Convex functions to get the ID of the currently authenticated user Auth > Authorization.

The issue you're experiencing is likely related to one of these common problems:

Authentication hasn't fully propagated to the server when your query runs
The query is being called outside of an <Authenticated> component in your React code
There might be token verification issues in your environment

This is a timing/synchronization issue rather than a client vs. server issue. The function itself is definitely meant for server-side use within Convex functions.

Auth > Api_reference > server

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

#

@barren wave Kapa.ai is still learning and improving, please let me know how I did by reacting below.

barren wave Apr 28, 2025, 12:45 PM

#

@ancient geyser why the hell is it null then

ancient geyserBOT Apr 28, 2025, 12:45 PM

#

Let me check the knowledge base for you again. One moment! :books:

#

I understand your frustration with this issue. Based on the knowledge sources, there are several specific reasons why getAuthUserId(ctx) might return null even when you believe you're properly authenticated:

Race condition in authentication flow: The most common reason is that authentication takes time to propagate to the Convex backend. When your query runs, the authentication might not be fully established yet.

As one Discord thread explains: "This is usually because you're calling a query outside of an Authenticated component so it is running before the authentication has been completely propagated" Discord support thread.
Missing Authenticated wrapper: If you're not wrapping your component with the <Authenticated> component from Convex, this is likely the issue:
```
<Authenticated>
  {/* Component that calls your query */}
</Authenticated>
```
Server-side rendering issues: If you're using Next.js or another SSR framework, the authentication state might not be available during server rendering.
Token verification problems: There could be issues with how your token is being verified on the server side.
Session expiration: Your session might have expired or been invalidated.

To troubleshoot this specific issue:

Add more detailed logging in your function:

console.log("Full identity object:", await ctx.auth.getUserIdentity());

Check if refreshing the page resolves the issue (indicating a race condition).
Verify you're not using static rendering features like export const dynamic = 'force-static' in Next.js.
Try using the direct ctx.auth.getUserIdentity() method and inspect its full output to see if there's any partial authentication data.

#

This is a common issue that many Convex users encounter, and it's typically related to timing and state synchronization rather than a fundamental problem with your code.

Auth > Debugging Authentication

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

#

@barren wave Kapa.ai is still learning and improving, please let me know how I did by reacting below.

barren wave Apr 29, 2025, 7:17 PM

#

@ancient geyser how to create role based permissions

ancient geyserBOT Apr 29, 2025, 7:17 PM

#

Let me check the knowledge base for you again. One moment! :books:

#

Based on the knowledge sources, there are several approaches to implementing role-based permissions in Convex. Here are the main methods:

Using Convex Auth with Roles

You can implement role-based permissions by adding roles to your user objects when using Convex Auth:

export const { auth, signIn, signOut, store, isAuthenticated } = convexAuth({
  providers: [
    Password({
      verify: ResendVerify,
      reset: ResendOTPPasswordReset,
    }),
  ],
  callbacks: {
    async createOrUpdateUser(ctx, args) {
      const existingUser = await ctx.db
        .query("users")
        .withIndex("email", (q) => q.eq("email", args.profile.email))
        .first();

      if (existingUser) {
        return existingUser._id;
      }

      return await ctx.db.insert("users", {
        email: args.profile.email,
        emailVerificationTime: Date.now(),
        roles: ["user"], // Assign default role
        permissions: {
          view_dashboard: true,
          upload_files: true,
        },
      });
    },
  },
});

Role Checking Functions

You can create helper functions to check roles in your Convex functions:

export async function checkRole(
  ctx: QueryCtx | MutationCtx,
  requiredRole: Role
): Promise<boolean> {
  const user = await ctx.auth.getUserIdentity();

  // If the user doesn't exist or doesn't have a role, return false
  if (!user || !user.roles) return false;

  // Check if the user has the required role
  return user.roles === requiredRole;
}

export async function requireRole(
  ctx: QueryCtx | MutationCtx,
  requiredRole: Role
): Promise<void> {
  const hasRole = await checkRole(ctx, requiredRole);
  if (!hasRole) {
    throw new Error(`Access denied. Required role: ${requiredRole}`);
  }
}

Row-Level Security (RLS)

#

For more sophisticated role-based access control, you can use the Row-Level Security pattern from convex-helpers:

import { customCtx, customMutation, customQuery } from "convex-helpers/server/customFunctions";
import { Rules, wrapDatabaseReader, wrapDatabaseWriter } from "convex-helpers/server/rowLevelSecurity";

async function rlsRules(ctx: QueryCtx) {
  const identity = await ctx.auth.getUserIdentity();
  const viewer = await getCurrentUser(ctx);
  
  return {
    messages: {
      read: async ({ auth }, message) => {
        if (!viewer) return false;
        // Check if user has admin role
        return viewer.role === "admin" || message.author === viewer._id;
      },
      modify: async ({ auth }, message) => {
        if (!viewer) return false;
        // Only admins or the author can modify
        return viewer.role === "admin" || message.author === viewer._id;
      },
    },
  };
}

export const queryWithRLS = customQuery(
  query,
  customCtx(async (ctx) => ({
    db: wrapDatabaseReader(ctx, ctx.db, await rlsRules(ctx)),
  })),
);

Customizing RLS with Roles

You can customize the RLS context to include roles:

const rules = {
  users: {
    read: async ({ viewer, roles }, user) => {
      if (!viewer) return false;
      return true;
    },
    modify: async ({ viewer, roles }, user) => {
      if (!viewer) throw new Error("Must be authenticated");
      if (roles.includes("admin")) return true;
      return viewer._id === user._id;
    },
  },
};

const myCustomQuery = customQuery(
  query,
  customCtx(async (ctx) => {
    const viewer = await getCurrentUser(ctx);
    const roles = await getRoles(ctx, viewer);
    return {
      db: wrapDatabaseReader({ viewer, roles }, ctx.db, rules),
    };
  }),
);

Best Practices

#

Always check authorization in every public function
Use helper functions to avoid duplicating authorization logic
Consider separating functions by permission level (e.g., setTeamOwner vs setTeamName)
Use ctx.auth.getUserIdentity() rather than function arguments for authentication checks

#why does mcp server fail

I hope this helps! If you need more specific assistance, please provide more details about your setup and the complete error message.

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

Is there anything specific about your setup or the full error message that might provide more context?

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

I hope this helps! Let me know if you need further assistance.

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

Auth > Authorization
Auth > Api_reference > server

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

Auth > Debugging Authentication

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

Auth > Debugging Authentication

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

Auth > Debugging Authentication

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

Auth > Api_reference > server

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

Auth > Debugging Authentication

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

Using Convex Auth with Roles

Role Checking Functions

Row-Level Security (RLS)

Customizing RLS with Roles

Best Practices

For more detailed information, check out the Row Level Security article and Authorization documentation.

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

#why does mcp server fail

I hope this helps! If you need more specific assistance, please provide more details about your setup and the complete error message.

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

Is there anything specific about your setup or the full error message that might provide more context?

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

I hope this helps! Let me know if you need further assistance.

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

Auth > Authorization Auth > Api_reference > server

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

Auth > Debugging Authentication

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

Auth > Debugging Authentication

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

Auth > Debugging Authentication

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

Auth > Api_reference > server

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

Auth > Debugging Authentication

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

Using Convex Auth with Roles

Role Checking Functions

Row-Level Security (RLS)

Customizing RLS with Roles

Best Practices

For more detailed information, check out the Row Level Security article and Authorization documentation.

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

Auth > Authorization
Auth > Api_reference > server