What problem does it solve? Setting up authentication in a Convex app involves choosing a provider, wiring backend config, client providers, environment variables, and access control, and getting any of these steps wrong leaves apps with broken logins or unprotected functions. This Skill guides the full setup so Convex correctly validates authenticated sessions. ## Core Features & Use Cases - Provider Selection and Setup: Supports Convex Auth, Clerk, WorkOS AuthKit, Auth0, and custom JWT providers, with per-provider reference workflows covering installation, convex/auth.config.ts, and client provider wiring. - Protected Backend Functions: Implements server-side identity checks using ctx.auth.getUserIdentity() instead of trusting client-provided user IDs, plus authorization checks for ownership and roles. - Validation and Production Readiness: Verifies login flows, authenticated Convex state, environment variables, and production deployment configuration. - Use Case: A developer adding login to a TanStack Start app backed by Convex can use this Skill to pick Clerk, wire ConvexProviderWithClerk, configure the issuer domain, and confirm protected queries return data only after sign-in. ## Quick Start Set up authentication for my Convex app, help me choose the right auth provider, and wire up protected backend functions.