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Frequently asked questions

9 questions

Do you connect to QuickBooks?

No. There is nothing to authorize in your client's QuickBooks. You export three standard QuickBooks Online reports (Sales by Product/Service Detail, Transaction List by Customer with shipping and billing addresses, and the customer contact list) or fill in our one-file template, and upload them.

Why does the address matter so much?

A sale generally belongs to the state where the customer receives it, usually the ship-to address; the billing address is only a fallback when no delivery address is known. QuickBooks Online reports can show a customer's default address, or a blank, instead of the ship-to typed on the invoice, so Nexus Auditor records where each sale's address came from and flags results where more than 10% of sales rest on default addresses. Addresses that cannot be placed in a state are listed so you can fix them.

Which taxes and places does it cover?

State sales and use tax: economic nexus for every state with a sales tax plus DC, physical nexus in the client's home state (recording other offices, employees and inventory is coming), and the Alaska Remote Seller Sales Tax Commission threshold for the local taxes of its member cities and boroughs. New Mexico's gross receipts tax and Hawaii's general excise tax are treated as those states' sales taxes. States where localities administer their own sales tax, such as Colorado's self-collecting home-rule cities, are marked but not evaluated. Five separate business taxes (Washington B&O, Ohio CAT, Texas franchise, Delaware and Oregon gross receipts) are listed as not evaluated, and income taxes are not covered.

How current is the law?

Each state's economic nexus rule shows its source and the date it was last checked; all were rechecked in September 2026. Changes are added as new versions with effective dates: sales are counted under the rules in force on their dates, the threshold in force on the measurement date decides, and a threshold met only under an earlier version is marked for review. Rules where sources disagree or are silent carry a lower confidence rating, which lowers the finding's confidence.

What does a finding show?

The status for the state; each test the state applies (sales, and transactions where it still counts them) against its threshold with the rule's comparator; every measurement window; what counted, including the state's sales basis, marketplace and resale treatment, and exempt or resale claims without a valid certificate; the rule versions applied with their sources; and the reasons behind the confidence level.

Is this a filed return or a legal opinion?

No. Nexus Auditor is decision support for your professional judgment. It does not register, file or remit anything, and its results are not legal advice.

Who can see a client's data?

Each firm has its own workspace, and firms are isolated from each other in the database. Everyone in a firm, including guests, can see its clients; roles decide who can change data, and only owners and admins can undo an import.

What files can we upload?

CSV, XLSX or XLS files up to 25 MB and 250,000 rows each. Files are stored when you upload them, but no sales are recorded until you review the check and confirm, and an owner or admin can undo a confirmed import.

What does it cost?

Early access is by invitation while we work with a small group of firms. Pricing will be published before general availability.

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Web / Getting started

Introduction

Get to know the foundation, then make it yours.

Build from a shared foundation

supastack is a modular foundation for AI SaaS on web and mobile. The web surface uses Next.js for the interface and backend-for-frontend. Shared TypeScript packages handle identity, workspaces, billing, AI, jobs, email, and observability.

Start with the local reference flow to understand how the modules fit together. Configure production providers only after that flow works in your environment.

Find your way around

Applications compose the shared packages. Product-specific features belong in the consuming product codebase rather than in the reusable core.

apps/
  web/       Next.js interface and API routes
  mobile/    Expo application
packages/
  auth/      Identity and sessions
  db/        Schema and workspace persistence
  billing/   Billing and entitlements
  ai/        Providers, routing, and usage
  jobs/      Background job contract
  email/     Transactional delivery

Choose your starting point

Follow Local setup to prepare the workspace and run the deterministic checks. Use the Mobile tab for Expo configuration, or Modules to explore the contracts underneath both applications.

The local golden path has passed in the project’s development environment. Timed clean-clone setup, real-provider smoke, deployment, and physical-device acceptance remain separate verification steps.