ABOUT
Built by one person who ships.
APPEN is built by Dalton Redden, founder of Blind Billing LLC, in St. Louis, Missouri. One person, personal funds, no outside capital. Everything on this site that says “live” runs today: the fourteen-kind rule engine (thirteen local kinds, the fourteenth your own via webhook), the agent-key model, the approval queue, the MCP server, the terminal mission control, and these docs.
The thesis: building software used to take a team; now anyone can do it — and the same should be true of the card that software spends on. Today the state of the art is pasting a raw card number into a prompt or a script, a card that carries no policy at all. An APPEN card is an Open Card: you write the rules — a published Rule Spec every purchase is judged against — and the card carries them. AI agents are the sharpest case for it, but the idea is bigger: if everyone can build, everyone should be able to control how their card spends. Deep enough for a company’s fleet, simple enough to set up before lunch.
THE OPEN CARDS PRINCIPLE
Anyone can now write the rules a card decides by. APPEN publishes the Rule Spec — the declarative language your agent’s spending is judged against — and ships an open API, an open MCP surface, and a CLI on every card, so the policy is yours to author and extend, not ours to grant. Every purchase is declared before it happens; your rules evaluate it before any credential or dollar exists; and every decision is explained and kept, so a decline is a citation, not a shrug. We tell you exactly what is live and exactly what is still designed, because publishing your own limits is where the authority comes from. We do not own the rail underneath, and we are not the bank behind it. We are the layer you program, and the record it answers to.
The names, resolved
Blind Billing LLC is the legal entity (Missouri). APPEN is its card product, at getappen.com. Contact is dalton.redden@blindbilling.com. One company, one product, one person answering the email.
Where things stand
- — Member, Plaid AI Startup Program (2026 cohort).
- — Issuing partnership in progress (bank-sponsored, Mastercard network); cards move real money at the BIN connection.
- — Invite-gated launch. Request access →
THE PRODUCT SPEAKS FOR ITSELF: DRIVE THE SIMULATOR · READ THE DOCS · READ THE SECURITY PAGE