Authenticate users

Nimbus verifies JWTs from Auth0, Clerk, Firebase Auth, Keycloak, and other identity providers. The provider must support OIDC or publish a JSON Web Key Set (JWKS). Nimbus exposes the verified identity through ctx.auth. This guide wires a provider into a Convex-style project.

1. Declare the provider

Create exactly one config file: convex/auth.config.ts or convex/auth.config.js. Add a default export that lists your providers.

For an OIDC provider:

// convex/auth.config.ts
export default {
  providers: [
    {
      domain: "https://your-tenant.us.auth0.com",
      applicationID: "your-client-id",
    },
  ],
};

• domain is the token issuer. Nimbus discovers the signing keys from {domain}/.well-known/openid-configuration.
• applicationID must equal the aud claim of the tokens your provider issues. Nimbus rejects tokens with multiple audiences.

For a provider that is not a full OIDC issuer but publishes a JWKS:

// convex/auth.config.ts
export default {
  providers: [
    {
      type: "customJwt",
      issuer: "https://auth.example.com",
      jwks: "https://auth.example.com/.well-known/jwks.json",
      algorithm: "RS256", // or "ES256"
      applicationID: "your-client-id", // optional
    },
  ],
};

Codegen evaluates the config statically. It resolves process.env.* reads against the codegen environment. You can therefore keep issuer URLs out of source:

export default {
  providers: [
    {
      domain: process.env.AUTH_ISSUER!,
      applicationID: process.env.AUTH_CLIENT_ID!,
    },
  ],
};

nimbus dev loads the config on the next codegen pass. A running dev loop starts that pass when you save the file.

2. Send tokens from the client

In React, wrap your app in ConvexProviderWithAuth and supply a useAuth hook that bridges your auth library:

import { ConvexProviderWithAuth, ConvexReactClient } from "convex/react";

const client = new ConvexReactClient("http://localhost:3210/convex/demo");

function useAuthFromMyProvider() {
  // Adapt your auth library to this shape.
  return {
    isLoading: false,
    isAuthenticated: true,
    fetchAccessToken: async ({ forceRefreshToken }) =>
      await myAuthLibrary.getToken({ ignoreCache: forceRefreshToken }),
  };
}

export function App({ children }) {
  return (
    <ConvexProviderWithAuth client={client} useAuth={useAuthFromMyProvider}>
      {children}
    </ConvexProviderWithAuth>
  );
}

useConvexAuth() reports { isLoading, isAuthenticated } from anywhere under the provider. Outside React, set the token directly on the client. Use either a string or an async fetcher that runs again when the token needs a refresh. Clear the token on sign-out:

client.setAuth(async () => await getFreshToken());
// ...later
client.clearAuth();

3. Read the identity in functions

Inside any query, mutation, or action, ctx.auth.getUserIdentity() returns the verified identity, or null when the request carries no valid token:

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

export const send = mutation({
  args: { body: v.string() },
  handler: async (ctx, { body }) => {
    const identity = await ctx.auth.getUserIdentity();
    if (identity === null) {
      throw new Error("Not signed in");
    }
    await ctx.db.insert("messages", {
      author: identity.tokenIdentifier,
      body,
    });
  },
});

tokenIdentifier has the form issuer|subject and is stable for each user and provider. Use it as the foreign key for user records. Your code owns authorization. Check the identity and decide what the caller may do. Nimbus has no separate rules language.

What Nimbus verifies

For each request token, Nimbus checks the signature against the provider's published keys and the issuer against your config. When you set applicationID, Nimbus also checks the audience. A request without a token runs your function, and getUserIdentity() returns null. Nimbus rejects an invalid or expired token before your function runs.

Next steps

• Compatibility reference: the full authentication surface.
• Build with the Convex API: functions, schema, and the dev loop.