An unprofitable account looks exactly like your best one — until the quarter closes.

The provider bills you one big number at the end of the month — forty clients folded into a single line, with no way to pull them apart. The usage meter, yours or theirs, lags by hours. And the price the client pays was set months ago, in a proposal, as a flat retainer or a fixed per-project fee that never moves.

So the account that is quietly bleeding renders identically to the one carrying you. Same green dashboard, same happy client, same tokens flowing out the door. The difference between the two is a number nobody has computed yet, and by the time it is computed it has already been booked. The bleeding is invisible until it is history.

You resell AI. Between the provider's meter and your client's invoice sits every dollar of risk you carry — the spread you priced blind and now have to defend. And today, across that gap, you are flying on instruments that only ever report the past.

An agent does not overspend politely, on a schedule you happen to be watching. It overspends at 3am, in a retry loop, on a prompt that grew a zero. A read-only chart will show you the crater in the morning — accurately, to the cent — and that is exactly no help. What you needed was something standing in the request path with the authority to say no.

So we built the gate we wanted. Not another dashboard — a gate. It sits in front of OpenAI, Anthropic and any OpenAI-compatible endpoint, and on every call it does four things, in order.

It counts every token to the micro-dollar and never rounds on the hot path — a fraction of a cent is still a number, and forty thousand of them is a line item. It attributes that cost to the client who caused it, from the first call, by header or virtual key, with no app rewrite. Before the upstream request goes out, it reserves the estimated cost atomically against every budget that applies; if that reservation would cross the cap, the gate refuses with a real 402 and the provider is never called. The money simply never leaves your account. When the call returns, the reservation commits to the true cost or refunds the difference.

And then the part everyone leaves out: it joins that attributed cost to real revenue. Connect Stripe read-only, and margin stops being a quarterly surprise and becomes a number you can read per account, this week — while you can still renegotiate, cap it tighter, or walk.

We are pre-revenue, and we say so on the page. We have no customer logos because we have no customers yet. No testimonials, no “trusted by” strip, no usage counter spinning up numbers we did not earn. Putting any of that here would be the first small lie — and we are building a product whose entire job is to end the small lies your invoice tells you.

So the most persuasive thing we can put in front of an operator is not proof we borrowed — it is the mechanism itself. The actual 402. The exact arithmetic, carried to the sixth decimal. A cap that holds because it is atomic by construction, not because a marketing page promised it would. If that convinces you, it convinces you for the right reason.

We are not trying to onboard a thousand teams this quarter. We are picking a handful of agencies and studios who carry this exact risk, and building the rest of this with them — against real traffic, real clients, real invoices. If that is you, we would rather have you in the room than on a logo wall.

Built by operators who got tired of finding out in arrears.

— Dani Romero · Founder, SixDecimal