Getting started

Create the project from the Solo SaaS Startup Template:

$ npm create startups leaseline.app -- --template solo-saas --yes

Created Leaseline in testStartup      startup_1Template     Solo SaaSInterfaces   https://api.sb/leaseline.app · MCP · SDK · CLINext: cd leaseline

The Startup runs from the first second, with a Site, an App, an API and an agent in every Role the Startup Template staffs. The project holds only what differs from it:

leaseline/├── startup.ts       the Startup: name, domain, the Startup Template it extends├── startups.lock    the Startup Template Version it pins├── AGENTS.md        how any coding agent works this Startup├── .mcp.json        the MCP servers, scoped to leaseline.app└── package.json

Start the dev server. It watches the project and previews each edit as a Change:

$ cd leaseline$ npx startup-builder dev

Watching leaseline in testPreview   https://preview-4f1c.leaseline.appChange    change_1 (no edits yet)

Add a Noun. Leaseline declares a Lease Noun in one file:

---
properties:
  unit: string
  resident?: Contact
  endsOn: date
  rent?: money
verbs:
  renew: { months: integer, increase?: number }
  notify: {}
---
A Lease is one resident's agreement on one unit.

The dev server compiles it at once and writes its types to .sb/types/. $.Lease is typed, /app/leases lists records, and Lease.renew is a route, a CLI operation and an MCP tool.

Write a first record from code:

import { $ } from 'startup-builder'

const lease = await $.Lease.create({ unit: '4B', endsOn: '2027-01-31', rent: { amount: 1800, currency: 'USD' } })

Add the Offer. Its Price compiles to a Stripe price and a checkout on the preview:

---
price: { amount: 29, currency: USD }
interval: month
---

In a second terminal, stream the Startup's new subscriptions:

$ npx startup-builder listen Offer.subscribed

Open /pricing on the preview, choose the plan and pay with the test card 4242 4242 4242 4242. The listener prints Offer.subscribed with the new Subscription, and the founder's App shows the first $29.

Run the checks on the Change the dev server printed. Every test and Evaluator runs on the preview:

Review my change.

Merge it into a new Version:

$ npx startup-builder do Change.merge --json '{"change":"change_1"}'

Merged change_1Version   version_2

Deploy the Version that merge printed. It asks the founder first, then points the live address at the new build:

$ npx startup-builder do Version.deploy --json '{"version":"version_2"}'

Attach the Domain to the Startup that step 1 printed. Connect prints the DNS records to set at your registrar and verifies them:

$ npx startup-builder do Domain.connect --json '{"hostname":"leaseline.app","startup":"startup_1"}'

Read what you built, own and inherited values side by side:

$ npx startup-builder show /