Convex Authentication Setup Skill

Convex Authentication Setup

Implement secure authentication in Convex with user management and access control.

When to Use

Setting up authentication for the first time
Implementing user management (users table, identity mapping)
Creating authentication helper functions
Setting up OAuth providers (WorkOS, Auth0, etc.)

Architecture Overview

Convex authentication has two main parts:

Client Authentication: Use a provider (WorkOS, Auth0, custom JWT)
Backend Identity: Map auth provider identity to your users table

Schema Setup

// convex/schema.ts
import { defineSchema, defineTable } from "convex/server";
import { v } from "convex/values";

export default defineSchema({
  users: defineTable({
    // From auth provider identity
    tokenIdentifier: v.string(), // Unique per auth provider

    // User profile data
    name: v.string(),
    email: v.string(),
    pictureUrl: v.optional(v.string()),

    // Your app-specific fields
    role: v.union(
      v.literal("user"),
      v.literal("admin")
    ),

    createdAt: v.number(),
    updatedAt: v.optional(v.number()),
  })
    .index("by_token", ["tokenIdentifier"])
    .index("by_email", ["email"]),
});

Core Helper Functions

Get Current User

// convex/lib/auth.ts
import { QueryCtx, MutationCtx } from "./_generated/server";
import { Doc } from "./_generated/dataModel";

export async function getCurrentUser(
  ctx: QueryCtx | MutationCtx
): Promise<Doc<"users">> {
  const identity = await ctx.auth.getUserIdentity();
  if (!identity) {
    throw new Error("Not authenticated");
  }

  const user = await ctx.db
    .query("users")
    .withIndex("by_token", q =>
      q.eq("tokenIdentifier", identity.tokenIdentifier)
    )
    .unique();

  if (!user) {
    throw new Error("User not found");
  }

  return user;
}

export async function getCurrentUserOrNull(
  ctx: QueryCtx | MutationCtx
): Promise<Doc<"users"> | null> {
  const identity = await ctx.auth.getUserIdentity();
  if (!identity) {
    return null;
  }

  return await ctx.db
    .query("users")
    .withIndex("by_token", q =>
      q.eq("tokenIdentifier", identity.tokenIdentifier)
    )
    .unique();
}

Require Admin

export async function requireAdmin(
  ctx: QueryCtx | MutationCtx
): Promise<Doc<"users">> {
  const user = await getCurrentUser(ctx);

  if (user.role !== "admin") {
    throw new Error("Admin access required");
  }

  return user;
}

User Creation/Upsert

On First Sign-In

// convex/users.ts
import { mutation } from "./_generated/server";
import { v } from "convex/values";

export const storeUser = mutation({
  args: {},
  handler: async (ctx) => {
    const identity = await ctx.auth.getUserIdentity();
    if (!identity) {
      throw new Error("Not authenticated");
    }

    // Check if user exists
    const existingUser = await ctx.db
      .query("users")
      .withIndex("by_token", q =>
        q.eq("tokenIdentifier", identity.tokenIdentifier)
      )
      .unique();

    if (existingUser) {
      // Update last seen or other fields
      await ctx.db.patch(existingUser._id, {
        updatedAt: Date.now(),
      });
      return existingUser._id;
    }

    // Create new user
    const userId = await ctx.db.insert("users", {
      tokenIdentifier: identity.tokenIdentifier,
      name: identity.name ?? "Anonymous",
      email: identity.email ?? "",
      pictureUrl: identity.pictureUrl,
      role: "user",
      createdAt: Date.now(),
    });

    return userId;
  },
});

Access Control Patterns

Owner-Only Access

import { mutation } from "./_generated/server";
import { v } from "convex/values";
import { getCurrentUser } from "./lib/auth";

export const updateProfile = mutation({
  args: {
    name: v.string(),
  },
  handler: async (ctx, args) => {
    const user = await getCurrentUser(ctx);

    await ctx.db.patch(user._id, {
      name: args.name,
      updatedAt: Date.now(),
    });
  },
});

Resource Ownership

export const deleteTask = mutation({
  args: { taskId: v.id("tasks") },
  handler: async (ctx, args) => {
    const user = await getCurrentUser(ctx);

    const task = await ctx.db.get(args.taskId);
    if (!task) {
      throw new Error("Task not found");
    }

    // Check ownership
    if (task.userId !== user._id) {
      throw new Error("You can only delete your own tasks");
    }

    await ctx.db.delete(args.taskId);
  },
});

Team-Based Access

// Schema includes membership table
export default defineSchema({
  teams: defineTable({
    name: v.string(),
    ownerId: v.id("users"),
  }),

  teamMembers: defineTable({
    teamId: v.id("teams"),
    userId: v.id("users"),
    role: v.union(v.literal("owner"), v.literal("member")),
  })
    .index("by_team", ["teamId"])
    .index("by_user", ["userId"])
    .index("by_team_and_user", ["teamId", "userId"]),
});

// Helper to check team access
async function requireTeamAccess(
  ctx: MutationCtx,
  teamId: Id<"teams">
): Promise<{ user: Doc<"users">, membership: Doc<"teamMembers"> }> {
  const user = await getCurrentUser(ctx);

  const membership = await ctx.db
    .query("teamMembers")
    .withIndex("by_team_and_user", q =>
      q.eq("teamId", teamId).eq("userId", user._id)
    )
    .unique();

  if (!membership) {
    throw new Error("You don't have access to this team");
  }

  return { user, membership };
}

// Use in functions
export const createProject = mutation({
  args: {
    teamId: v.id("teams"),
    name: v.string(),
  },
  handler: async (ctx, args) => {
    await requireTeamAccess(ctx, args.teamId);

    return await ctx.db.insert("projects", {
      teamId: args.teamId,
      name: args.name,
    });
  },
});

Public vs Private Queries

Public Query (No Auth Required)

export const listPublicPosts = query({
  args: {},
  handler: async (ctx) => {
    // No auth check - anyone can read
    return await ctx.db
      .query("posts")
      .withIndex("by_published", q => q.eq("published", true))
      .collect();
  },
});

Private Query (Auth Required)

export const getMyPosts = query({
  args: {},
  handler: async (ctx) => {
    const user = await getCurrentUser(ctx);

    return await ctx.db
      .query("posts")
      .withIndex("by_user", q => q.eq("userId", user._id))
      .collect();
  },
});

Hybrid Query (Optional Auth)

export const getPosts = query({
  args: {},
  handler: async (ctx) => {
    const user = await getCurrentUserOrNull(ctx);

    if (user) {
      // Show all posts including drafts for this user
      return await ctx.db
        .query("posts")
        .withIndex("by_user", q => q.eq("userId", user._id))
        .collect();
    } else {
      // Show only public posts for anonymous users
      return await ctx.db
        .query("posts")
        .withIndex("by_published", q => q.eq("published", true))
        .collect();
    }
  },
});

Client Setup with WorkOS

WorkOS AuthKit provides a complete authentication solution with minimal setup.

React/Vite Setup

bun install @workos-inc/authkit-react

// src/main.tsx
import { AuthKitProvider, useAuth } from "@workos-inc/authkit-react";
import { ConvexReactClient } from "convex/react";
import { ConvexProvider } from "convex/react";

const convex = new ConvexReactClient(import.meta.env.VITE_CONVEX_URL);

// Configure Convex to use WorkOS auth
convex.setAuth(useAuth);

function App() {
  return (
    <AuthKitProvider clientId={import.meta.env.VITE_WORKOS_CLIENT_ID}>
      <ConvexProvider client={convex}>
        <YourApp />
      </ConvexProvider>
    </AuthKitProvider>
  );
}

Next.js Setup

bun install @workos-inc/authkit-nextjs

// app/layout.tsx
import { AuthKitProvider } from "@workos-inc/authkit-nextjs";
import { ConvexClientProvider } from "./ConvexClientProvider";

export default function RootLayout({ children }: { children: React.ReactNode }) {
  return (
    <html>
      <body>
        <AuthKitProvider>
          <ConvexClientProvider>
            {children}
          </ConvexClientProvider>
        </AuthKitProvider>
      </body>
    </html>
  );
}

// app/ConvexClientProvider.tsx
"use client";

import { ConvexReactClient } from "convex/react";
import { ConvexProvider } from "convex/react";
import { useAuth } from "@workos-inc/authkit-nextjs";

const convex = new ConvexReactClient(process.env.NEXT_PUBLIC_CONVEX_URL!);

export function ConvexClientProvider({ children }: { children: React.ReactNode }) {
  const { getToken } = useAuth();

  convex.setAuth(async () => {
    return await getToken();
  });

  return <ConvexProvider client={convex}>{children}</ConvexProvider>;
}

Environment Variables

# .env.local (React/Vite)
VITE_CONVEX_URL=https://your-deployment.convex.cloud
VITE_WORKOS_CLIENT_ID=your_workos_client_id

# .env.local (Next.js)
NEXT_PUBLIC_CONVEX_URL=https://your-deployment.convex.cloud
NEXT_PUBLIC_WORKOS_CLIENT_ID=your_workos_client_id
WORKOS_API_KEY=your_workos_api_key
WORKOS_COOKIE_PASSWORD=generate_a_random_32_character_string

Call storeUser on Sign-In

// In your app after user signs in
import { useMutation } from "convex/react";
import { api } from "../convex/_generated/api";
import { useEffect } from "react";
import { useAuth } from "@workos-inc/authkit-react";

function YourApp() {
  const { user } = useAuth();
  const storeUser = useMutation(api.users.storeUser);

  useEffect(() => {
    if (user) {
      storeUser();
    }
  }, [user, storeUser]);

  // ... rest of your app
}

Alternative Auth Providers

If you need to use a different provider, see the Convex auth documentation for:

Custom JWT
Auth0
Other OAuth providers

Checklist

[ ] Users table with tokenIdentifier index
[ ] getCurrentUser helper function
[ ] storeUser mutation for first sign-in
[ ] Authentication check in all protected functions
[ ] Authorization check for resource access
[ ] Clear error messages ("Not authenticated", "Unauthorized")
[ ] Client auth provider configured (WorkOS, Auth0, etc.)

Agent Skills: Convex Authentication Setup

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