Next.js + Convex · Ship product, not plumbing
The agent-ready SaaS starter.
A production-ready Next.js + Convex foundation with auth, workspaces, billing, and security already wired into one coherent system — the parts your AI agent can't one-shot.
Built on a focused, modern stack
Agents scaffold screens fast. Then they stall on the wiring.
Agents can generate screens quickly. They slow down when auth, billing, roles, data rules, and backend workflows all need to agree. Leave Localhost gives them a typed Convex foundation, written repo rules, and an all-TypeScript backend they can extend without inventing the wiring.
Why Convex matters for agent-assisted development
An agent is only as reliable as the contracts it can see. Convex exposes the database as typed functions with runtime validators, live queries, and transactional writes — no separate ORM, migration runner, or websocket layer to keep in sync. That keeps your agent on your product logic instead of SQL glue, cache invalidation, and subscription plumbing.
- Typed schema and validators
- Reactive queries without subscription glue
- Transactional mutations for safer writes
- One backend runtime for data, files, jobs, and webhooks
Rules for every agent
AGENTS.md, CLAUDE.md, and Cursor rules ship in the repo, so Claude Code, Codex, and Cursor all build to the same conventions — not whatever they guess.
50+ skills to build and sell
A version-locked skill library in .agents/skills spans Convex auth, shadcn, and Turborepo through to SEO, pricing, and launch playbooks.
TypeScript all the way down
The UI, Convex functions, validators, permissions, billing, email, analytics, and tests all share one typed language.
Generated backend contracts
Convex schema and validators generate typed documents, ids, and function references that narrow what an agent can invent.
Boundaries the linter enforces
turbo boundaries and sherif keep packages from reaching across seams, and documented verify commands catch drift before it ships.
Docs agents can read
120+ pages of architecture, security, and data-model docs give agents grounded context instead of guesswork.
Everything wired together before your first commit
Start from a working product foundation, not a pile of packages. Auth, billing, teams, email, analytics, and Convex data already share the same contracts.
Real-time data
Convex database, typed functions, and live queries — your UI updates itself.
Type-safe end to end
Schema and validators reject bad writes and generate typed docs and ids.
Authentication
Email, magic links, Google, Microsoft, and 2FA — wired to Convex.
Billing & entitlements
Stripe, Polar, or Lemon Squeezy webhooks mapped to capability grants.
Teams & roles
Workspaces, invitations, and RBAC, scoped to every tenant.
Security built in
Step-up verification, fresh sessions, and audit logs on sensitive actions.
Notifications
In-app bell and email notifications with per-user preferences.
Transactional email
React Email templates wired to your provider, ready to send.
Onboarding
Guided first-run flows for new users and workspaces.
Documentation
A Fumadocs site with 120+ pages, ready to make your own.
Blog & changelog
MDX-powered blog and changelog for launch, SEO, and updates.
Analytics
A typed event catalog; PostHog optional and no-op by default.
Jobs & file storage
Scheduled functions, background jobs, and files in one backend.
Themeable UI
shadcn/ui and Tailwind — swap themes or dark mode with one command.
Mobile-friendly
Responsive layouts across the app, docs, and marketing site.
No vendor lock-in
Your code on your Convex project — swap providers or self-host.
Sign-in, solved on day one
Production auth is already in place: password login, magic links, social sign-in, two-factor security, and fresh-session checks for sensitive actions.
Multi-tenant from the first commit
Personal and team workspaces with invitations, roles, and every record scoped to its own tenant.
Get paid, with real entitlements
Polar, Stripe, or Lemon Squeezy webhooks map to capability grants your app actually checks — not just stored receipts.
Run the platform yourself
Look up users and workspaces and review the audit log from a gated, server-enforced admin console.
Where the first weeks of a build actually go
Build it yourself (even with an agent)
- Data layer
Choose a database, ORM, and real-time layer, then keep them in sync
- Teams and roles
Workspaces and RBAC become an “after launch” ticket
- Billing
A checkout button, then weeks of webhook edge cases
- Security
2FA, audit logs, and sensitive-action checks are on you
- AI assistance
Your agent scaffolds screens, then guesses at the wiring
Leave Localhost
- Data layer
Convex real-time data and typed functions, already wired
- Teams and roles
Workspaces, invitations, roles, and capabilities included
- Billing
Verified webhooks mapped to entitlement grants
- Security
2FA, fresh sessions, sensitive-action verification, audit logs
- AI assistance
Repo rules, 50+ skills, and typed boundaries agents follow
Built by The Localhost Ghost
I’ve started enough side projects to know exactly where they die: not on the idea, but on the auth flows, webhook handlers, and permission checks that stand between a scaffold and a product you can charge for.
Leave Localhost is the foundation I kept rebuilding from scratch, finished properly once. It’s how I build everything I ship now, and every improvement lands back in the repo you get.
The Localhost Ghost
Watch the build in publicon YouTubeSkip the first six weeks
The full Next.js + Convex SaaS starter. One payment, full source, lifetime updates.
- Lifetime updates
- Unlimited projects
- One license covers your whole company
Instant read access to the private GitHub repo, where updates land.
Source code can't be returned, take the live demo for a spin first.Try the live demo
What's included
- Full source code for the Convex-first Next.js foundation
- Auth, done: email, magic links, Google, Microsoft, and 2FA
- Workspaces, invitations, roles, and capability-based permissions
- Stripe, Polar, or Lemon Squeezy webhooks mapped to feature access
- Security workflows: step-up verification, fresh sessions, audit logs
- React Email templates wired to your provider, ready to send
- Typed analytics events, with PostHog optional by default
- 120+ pages of docs, plus a blog and changelog to make your own
Still deciding? Let's clear up the big questions.
Straight answers about fit, proof, licensing, and what happens after purchase.
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Your next session is product work.
$59 one-time, lifetime updates, covers your whole team