NORTHSTAR

Independent digital-product studio

Practical systems for agent‑powered work.

NORTHSTAR builds focused digital tools and AI-agent workflows that turn messy professional processes into clear, repeatable outputs. Our products ship as downloadable AI-agent workflow skills and digital productivity tools, designed around explicit human approval points.

Explore our first product Contact NORTHSTAR

First product

Milestone Billing Evidence Gate

Verify each proposed agency or service-business charge against the supplied agreement, billing trigger, approval, and delivery evidence before the invoice is sent.

Built for agencies and service businesses using:

  • Milestone billing
  • Retainers
  • Time & materials
  • Approved change orders

A normal invoice linter

Checks fields and arithmetic: line items add up, required fields are present, formats are valid.

Milestone Billing Evidence Gate

Examines whether the supplied source documents support each proposed charge, and whether the documented billing trigger appears satisfied.

Evidence review expected outputs
  • Charge-by-charge evidence mapping
  • Classification of every charge Supported Unsupported Unresolved
  • Missing billing-trigger evidence, flagged
  • Exact source-document locators
  • Bounded recommendation SEND REVISE STOP

Availability

Milestone Billing Evidence Gate is sold as a downloadable AI-agent workflow skill — a one-time digital product. Checkout and delivery occur through the Agensi marketplace.

The marketplace listing is pending review.

How it works

From purchase to reviewed invoice

  1. Purchase and download

    Buy the skill through the marketplace and download the product files.

  2. Install the skill

    Add it to a compatible AI agent. It is designed for compatible SKILL.md-based AI agents.

  3. Supply your documents

    Provide the proposed invoice together with the relevant agreement, approvals, and delivery evidence.

  4. Review the output

    Receive a structured evidence review, ready for your human approval before anything is sent.

Boundaries

What our products do — and what they don't

NORTHSTAR products assist with structured document review. They are decision support, not a professional service.

  • They do not provide legal advice.
  • They do not provide tax advice.
  • They do not provide accounting or audit services.
  • They do not guarantee invoice accuracy, contractual enforceability, or payment.

You review every output and make the final decision.

About

A small studio with a narrow focus

NORTHSTAR is an independent digital-product studio focused on small, software-led systems and agent workflows. Products are designed to operate with low infrastructure overhead and clear human approval points.

Policies

Delivery, refunds, and the fine print

Digital delivery

All current NORTHSTAR products are digital downloads — no physical item is shipped. Purchases are processed and delivered through the third-party marketplace shown at checkout, and access is normally provided electronically after successful payment. Marketplace availability and delivery remain subject to the marketplace's terms.

Read the digital delivery policy

Refunds

NORTHSTAR does not currently process customer purchases directly through this website. Purchases made through Agensi are governed by the refund terms Agensi presents at checkout and in its current terms, and refund requests should be submitted through Agensi. You can contact NORTHSTAR for product-support issues at any time.

Read the refund policy

Also see the Privacy Policy and Terms of Use.

Contact

Support is provided by email

Questions about a product, an order, or anything on this site — write to us and a real person will read it.

northstarappstudio@gmail.com