S3-compatible Storage
Presigned uploads, private prefixes, image processing, and MIME validation.
The AI-native SaaS starter kit.
Auth, billing, teams, transactional email, and analytics are already wired into Next.js 16. Built-in agent skills help your coding agent extend and ship.
- 30-day money-back guarantee
- Lifetime updates
- Pay once, use forever
Built with the best tech on the market
Next.js
TypeScript
Stripe
Better Auth
Docker
Redis
Amazon S3
Cursor
Auth & Multi-Tenancy
Authentication built for B2B.
SyntaxKit combines Better Auth with a database-enforced organization layer for invitations, seat limits, permissions, and ownership safeguards.
- Verified email/password plus Google and GitHub OAuth
- Passkeys, TOTP, backup codes, and Turnstile protection
- Auto-created organizations with owner, admin, and member roles
- Plan-aware seat limits and gated invitations
- Session-scoped organizations and last-owner protection
Billing & Entitlements
From checkout to access.
Stripe handles payment while SyntaxKit keeps subscription state and feature access synchronized across your app.
- Stripe Checkout and customer portal
- Monthly and annual pricing with 7-day trials
- Webhook-backed subscription state
- Server and client entitlement checks
- Plan gates and usage limits
AI & Streaming
Stream answers from any model.
Use one chat interface across OpenAI, Anthropic, and Google while every response streams through the same application layer.
- OpenAI, Anthropic, and Google model providers
- Token-by-token streaming responses
- Typed messages and structured output
- Persistent conversation history
- Abort, retry, and error states
Type-Safe API Layer
Types from database to browser.
oRPC, TanStack Query, and Zod share one contract across every layer, keeping inputs, responses, and errors validated and inferred without hand-written API plumbing.
- oRPC procedures with auth and organization middleware
- Zod validation before every handler runs
- TanStack Query bindings for queries, mutations, and suspense
- Inferred inputs, responses, and structured errors
- Direct access from Server Components and client hooks
Your coding agent already knows the stack.
SyntaxKit ships with scoped skills for auth, billing, email, data, and deployment, so your agent can extend the product without rediscovering its architecture.
Architecture-aware
Scoped skills explain where features belong before your agent changes code.
Domain workflows
Auth, billing, teams, email, and deployment follow the kit’s existing patterns.
Guided verification
Each workflow defines the checks that prove an implementation is complete.
Extensible skills
Add project-specific guidance as your product and conventions evolve.
And the rest
Everything else you didn’t want to build.
A production SaaS needs more than its headline features. SyntaxKit wires the operational and platform work too, so you can stay focused on your product.
Transactional Email
React Email templates with pluggable delivery through Resend, Postmark, SMTP, and more.
Internationalization
next-intl with English, German, and localized URL routing configured from the start.
Analytics & Observability
Typed PostHog events, OpenTelemetry tracing, structured logs, and health probes.
Rate Limiting
Upstash sliding windows per surface, plus Turnstile protection for exposed forms.
Platform Admin
Manage users, roles, bans, and active sessions without building a separate control plane.
Turborepo Workspace
Shared packages, pnpm workspaces, and dependency-aware caching across the monorepo.
CI/CD Pipelines
GitHub Actions for linting, types, tests, browser checks, and container images.
Documentation Included
A Fumadocs-powered documentation application that is ready to make your own.
The creator
I rebuilt this stack 12 times. So you don’t have to.
Hey, I’m Jan. For the past few years, I’ve taught Next.js through SyntaxPath to a community of more than 55,000 developers who want to ship real products.
Across tutorials, client work, and my own SaaS products, I kept rebuilding the same auth, billing, multi-tenancy, and AI foundations. SyntaxKit is the production architecture I wish I had on day one, packaged so you can start with your product instead of months of plumbing.
Jan Marshal
The math
Six months, or one afternoon.
The first demo comes quickly. Making it secure, observable, and ready for paying teams is where the months disappear. SyntaxKit starts where most starter kits stop.
Build it yourself
6 months
≈ 1,000 hours before you return to the product.
Week 1
Email/password authentication
Sessions, required email verification, password reset, and account recovery.
Week 2
OAuth and account linking
GitHub, Google, callbacks, and duplicate-account protection.
Week 3
2FA and passkeys
TOTP, backup codes, WebAuthn, and secure recovery flows.
Week 4
Organizations and RBAC
Tenant scoping, role hierarchy, and permission checks across every request.
Week 5
Invitations and seat safety
Invites, plan limits, role changes, and last-owner protection.
Week 6
Stripe Checkout and portal
Products, prices, trials, tax, and customer self-service.
Week 7
Webhook idempotency
Event deduplication, side-effect keys, retries, and ordering.
Week 8
Billing state and entitlements
Trials, grace periods, upgrades, downgrades, and feature gates.
Week 9
Type-safe API layer
Validated procedures, middleware, typed errors, and client inference.
Weeks 10–11
AI chat and streaming
Model gateway, persisted messages, attachments, and web search.
Week 12
AI usage and abuse controls
Usage ledgers, plan caps, and limits per user and organization.
Month 3
The demo works.
It feels 80% complete. It isn’t. Everything users never see is still missing.
Weeks 13–14
Security hardening
Authorization audits, CSRF, secrets, headers, and dependency review.
Week 15
Abuse protection
Rate limits, bot protection, payload bounds, and input validation.
Weeks 16–17
CI/CD and safe releases
Automated checks, migrations, container builds, and rollbacks.
Week 18
Staging and previews
Environment isolation, preview deployments, and representative test data.
Weeks 19–20
Observability and operations
Structured logs, traces, alerts, health probes, and on-call context.
Week 21
Transactional email
Templates, provider fallbacks, deduplication, and deliverability.
Week 22
File storage
Signed uploads, private prefixes, MIME checks, and image processing.
Week 23
Platform operations
Admin tooling, internationalization, session revocation, and bans.
Weeks 24–26
The compliance long tail
Audit logs, privacy workflows, documentation, runbooks, and cleanup.
Six months later
You shipped infrastructure instead of learning from users.
With SyntaxKit
Recommended1 afternoon
≈ 4 hours to a production-ready foundation.
Hour 1
Clone and install
Hour 2
Connect your services
Hour 3
Make it yours
Hour 4
Deploy your product
Day one, live
Six months ahead.
Use the time to build what customers actually pay for.
Pricing
One purchase. Lifetime updates.
Choose the license that matches your team and the products you ship. Every plan is a one-time purchase with the full source code and a 30-day refund.
See everything shipped so farSolo
One developer. Unlimited products you own.
$199one-time
$299Save $100
- 1 developer seat
- Unlimited personal and commercial products you own
- The complete starter kit and every current module
- Lifetime updates
- Discord community and email support
Studio
Most popularA small product team building under one organization.
$299one-time
$399Save $100
- Everything in Solo, plus:
- 5 developer seats, about $60 per seat
- Team collaboration on organization-owned products
- Unlimited personal, commercial, and team products you own
- 30-minute architecture call with Jan
- Priority Discord support
- Vote on the public roadmap
Agency
For studios and agencies delivering products to clients.
$599one-time
$799Save $200
- Everything in Studio, plus:
- 10 developer seats instead of 5
- Unlimited client projects
- Client-delivery rights for shipped client products
- 1-hour architecture call instead of 30 minutes
- Private Discord channel with Jan
No plan requires attribution. Agency adds client-delivery rights; Solo and Studio cover products you or your organization own.
FAQ
Answers before you hit checkout.
Licensing, updates, support, and what happens after you buy.
Can’t find what you’re looking for? Contact our support team.
Purchase & licensing
Using SyntaxKit
Can’t find what you’re looking for? Contact our support team.
Start with SyntaxKit
Start your next SaaS six months ahead.
Skip the auth, billing, multi-tenancy, AI, and operational plumbing. Own the production foundation and spend your time on the product only you can build.
Licenses from $199 · one-time payment
30 days to decide
A full money-back guarantee if it is not the right fit.
Lifetime updates
New modules and compatibility releases are included.
The source is yours
No subscription, remote lock-in, or required attribution.