It’s time to Leave Localhost
The agent ready SaaS starter.
A production-ready Next.js + Convex foundation with auth, workspaces, billing, and security already wired into one coherent system.
Built on a focused, modern stack
The foundation your AI agent needs to turn side projects into real SaaS
Agents scaffold screens fast, then stall on the wiring: auth, billing, permissions, data contracts. Leave Localhost gives your agent the written rules, strict types, and all-TypeScript backend it needs to finish the job.
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
Not a checklist of libraries to integrate yourself — a coherent Convex-first foundation where auth, billing, teams, security, and real-time data already talk to each other.
Real-time core
Convex owns the database, typed functions, and reactive queries, so dashboards and workspaces update live — no cache layer or websocket glue to maintain.
Enforced data contracts
Convex schema and runtime validators reject malformed writes and generate typed documents and ids — the database contract lives in your editor, not a migration folder.
Authentication, wired in
Better Auth ships connected to Convex with sessions, 2FA, and fresh-session checks — not a login form you bolt onto a separate database.
Billing to entitlements
Stripe, Polar, and Lemon Squeezy adapters map verified webhooks to capability grants your app can check — you configure one provider.
Teams and workspaces
Personal and team modes, invitations, roles, and RBAC ship together, so collaboration doesn't mean retrofitting authorization later.
Security in the flows
Sensitive actions re-verify identity and emit audit events, with super-admin controls for day-to-day operations.
Transactional email
React Email templates wired to your provider for authentication and product mail, ready to send.
Optional analytics
A typed event catalog behind a provider-neutral boundary that loads PostHog only when you enable it, and no-ops otherwise.
Jobs and file storage
Scheduled functions, background jobs, and file storage live in the same Convex backend — not three more services to provision.
Verification and audit on the actions that carry risk
Security is wired into the workflows, not listed on a checklist. Sensitive actions require a fresh session and a two-factor challenge, and the app records consequential events as an audit trail.
- Two-factor and fresh sessions2FA and fresh-session checks gate sensitive operations before they run.
- Sensitive-action verificationHigh-impact actions re-verify identity instead of trusting an old login.
- Audit events and super adminConsequential changes emit audit events, and super-admin controls handle day-to-day operations.
Workspaces, members, and roles when the product needs them
Personal and team workspace modes ship together, so you add collaboration without retrofitting authorization or billing state later.
- Workspaces and invitationsMembers join workspaces through invitations constrained by role.
- Roles, RBAC, and capabilitiesAccess is gated by roles and named capability grants, not scattered conditionals.
- Personal or team modeStart solo and turn on team features when collaboration arrives.
A super-admin console for running the product day to day
A gated super-admin area ships with the starter, so account lookups, support actions, and audit review don't wait on a custom internal tool you build later.
- Users and workspacesLook up accounts and workspaces, inspect their state, and take supported actions from one console.
- Audit log in viewBrowse consequential events with filters instead of querying the database directly.
- Capability-gated accessThe console is gated by super-admin capability grants, kept separate from normal app roles.
One-time payment
The full Next.js + Convex SaaS starter, lifetime access.
What's included
- Full source for the Convex-first Next.js foundation
- Better Auth with organizations, members, and invitations
- Roles, RBAC, and capability-based authorization
- Security workflows: 2FA, fresh sessions, sensitive actions, audit
- Billing adapters for Stripe, Polar, and Lemon Squeezy
- Verified webhooks mapped to entitlement grants
- Provider-neutral analytics boundary and transactional email
- Shared shadcn UI, typed config, and documentation
Lifetime updates included.
Common questions
Answers on the stack, licensing, and what you get.
More questions? Read the full FAQ