01 ~2 min
npx create-saas-harness-new Scaffold
Pick your modules — payments, storage, email, package manager. The CLI copies the template, wires your choices, prunes the rest, installs and makes the first commit.
Open source · MIT ·
npx create-saas-harness-new Ship a SaaS with an agent harness built in.
A Next.js 15 + Supabase monorepo that comes with the machinery to plan and build your product — specialized subagents, slash commands, an executable roadmap, and deterministic guards. You don't get a boilerplate. You get a boilerplate that builds itself from 0 to 100.
- Next.js 15 · React 19
- Supabase + RLS
- Mock-first — zero keys to run
- Claude Code native
$
How it works Three commands between an idea
Three commands between an idea
and a shipping loop.
02 ~15 min
/project-setup Define your product
A 7-round interview inside your agent. It writes FOUNDATIONS/* (your source of truth), commits a concrete design system, and generates a fully executable roadmap.
03 0 → 100
/session-start Build, session by session
Each session opens with a decision gate: answer everything up front, then the orchestrator delegates tasks to dev agents, verifies with tests and reviews the diff — autonomously.
Configurator
Compose your stack. Copy one command.
The CLI assembles the template deterministically: chosen adapters get wired, everything else is pruned — code, SDK dependencies and env vars. What you pick here is exactly what lands in your repo.
Fully unattended — -y skips every prompt. Drop the flags to answer
interactively instead.
your choice always included
Unchosen providers are pruned, not flagged off — their adapters, SDK deps and env vars never touch your repo.
The harness
Not a boilerplate. A build system for your product.
harness/ ships agents, slash commands, machine-readable state and guards — the
operating manual an AI coding agent needs to take your roadmap from task to shipped,
without you babysitting it.
Orchestrator–workers loop
The main session orchestrates; dev-agent (Sonnet) and dev-agent-pro (Opus) implement, a verifier runs the task's tests, a reviewer audits the diff in fresh context. A task is done only with verify green AND review approval.
Front-loaded decision gate
Every session starts by asking you all of the MVP's open questions at once — pricing, wiring, design calls. Answer them, walk away, and the loop runs autonomously. It never blocks mid-run.
Executable roadmap
/project-setup writes mvp-*.json with sprints, tasks and per-task verification specs — plus a local dashboard (pnpm roadmap) to watch progress. Agents pick up tasks; percentages compute themselves.
Committed design system
Setup commits .impeccable/design.json + DESIGN.md + real tokens in globals.css. UI tasks read it as a contract, so generated screens share one deliberate look — no placeholder aesthetic.
Deterministic guards
Hooks the agent cannot bypass: a Stop hook type-checks after every response; a PreToolUse guard blocks force-pushes, dangerous rm -rf, .env edits and touching applied migrations.
Mock-first integrations
Payments, email and storage sit behind interfaces with mock defaults — the app runs with zero third-party keys from commit one. Real providers activate the moment their keys land in .env.local.