{"data":{"slug":"fusionauth","name":"FusionAuth","tagline":"Source-available CIAM; Community self-host free unlimited users","category":"nextjs","categoryName":"Next.js","url":"https://fusionauth.io","github":null,"pricing":"freemium","hook":"FusionAuth is the downloadable auth server when Keycloak is the OSS Java IAM and Auth0 is the per-MAU SaaS bill.","whatsGood":"Community Edition: free forever self-host, unlimited users/MAU — OIDC/OAuth/SAML, MFA basics, themes, APIs, Lambdas, multi-tenancy. Flat paid tiers (not per-MAU) for advanced MFA, breached-password, SCIM, theming extras, support. Cloud hosting optional.","theCatch":"LOUD: NOT open source — source-available proprietary CE. Vs Keycloak/ZITADEL/Ory: easier admin UX + flat pricing, but you cannot fork freely like Apache/AGPL IdPs. Premium features and FusionAuth Cloud are paid. Ops burden is yours on CE.","verdict":"Free unlimited self-host CIAM. Not OSS; paid for premium/Cloud.","addedAt":"2026-09-04","featured":false,"domain":"Auth","subSpecialty":"Auth","capabilities":["auth","oidc","ciam"],"surfaces":["Self-host","Hosted"],"ecosystem":["Multi-platform"],"licenseModel":"Freemium","githubStars":null},"related":[{"slug":"vercel","name":"Vercel","tagline":"The platform that made Next.js deployment trivial"},{"slug":"prisma","name":"Prisma","tagline":"Type-safe database access with killer DX"},{"slug":"drizzle","name":"Drizzle ORM","tagline":"TypeScript ORM that feels like SQL"},{"slug":"trpc","name":"tRPC","tagline":"End-to-end typesafe APIs without codegen"},{"slug":"clerk","name":"Clerk","tagline":"Auth that actually ships with your UI"}],"links":{"self":"/api/gems/fusionauth","html":"/gems/fusionauth","markdown":"/gems/fusionauth.md","category":"/api/gems?category=nextjs","categoryPage":"/stacks/nextjs"}}