spacetimedb-auth

name	spacetimedb-auth
description	Use when implementing SpacetimeDB authentication or authorization, including SpacetimeAuth, Auth0, Clerk, OIDC, auth claims, subject/issuer checks, custom claims, roles, row-level security, and rejecting client connections. Triggers on: auth, authentication, authorization, SpacetimeAuth, Auth0, Clerk, OIDC, claims, RLS, row-level security.
license	MIT

Use this skill for identity, claims, access control, and authorization policy.

Core auth patterns

• SpacetimeDB derives an Identity from the JWT sub and iss claims. Use identity for stable ownership; use JWT claims for provider, audience, role, and policy decisions.
• Authenticated modules should reject unauthenticated clients in client_connected/clientConnected before they can subscribe or call reducers.
• Always validate issuer and audience before trusting subject or custom claims. Claim names and expected values are deployment-specific.
• Treat senderAuth/SenderAuth/sender_auth() as the source of JWT details, not the client-provided identity alone.
• Use role or custom-claim helpers inside reducers for authorization checks; return sender-facing errors for expected denials.
• RLS is experimental. Its rules are SQL filters, use :sender for the caller identity, return full rows from one table, and multiple rules for a table are ORed together. Module owners bypass RLS.

TypeScript connection rejection pattern:

import { SenderError } from "spacetimedb/server";

const OIDC_CLIENT_IDS = ["client_..."];

export const onConnect = spacetimedb.clientConnected((ctx) => {
  const jwt = ctx.senderAuth.jwt;
  if (jwt == null) throw new SenderError("Unauthorized: JWT is required");
  if (jwt.issuer !== "https://auth.spacetimedb.com/oidc") {
    throw new SenderError("Unauthorized: invalid issuer");
  }
  if (!jwt.audience.some((aud) => OIDC_CLIENT_IDS.includes(aud))) {
    throw new SenderError("Unauthorized: invalid audience");
  }
});

Reference map

Need	Open
Auth overview	references/core-concepts-authentication.md
SpacetimeAuth	references/core-concepts-authentication-spacetimeauth*.md
Third-party providers	references/core-concepts-authentication-auth0.md, references/core-concepts-authentication-clerk.md
Claims in module code	references/core-concepts-authentication-usage.md
Row-level security and connection rejection	references/how-to-rls.md, references/how-to-reject-client-connections.md

Guidance

• Keep authentication identity checks separate from table visibility and row-level authorization choices.
• Treat claim names, issuers, and audiences as deployment-specific; do not hard-code sample values unless they are already in the user's project.
• Route HTTP token mechanics to spacetimedb-http when the task is endpoint-level.