Built by a host.
For hosts.

It started with one property

I'm Mike. I transformed a large 8/5 in Twin Lakes, Wisconsin into a compelling vacation rental: EnglishPrairieBnB. It sleeps 20+ adults. I'm a long-time Airbnb Superhost, and I love hosting large groups — bachelorette parties, family reunions, corporate retreats.

But hosting 20+ people under one roof comes with a unique set of problems. Problems that none of the existing tools were built to solve.

Three strikes and you're out

Twin Lakes has a strict local ordinance: three police calls to your property in a year and you lose your rental license. Not three violations. Three calls. Doesn't matter if the noise complaint is legitimate or a neighbor having a bad day.

On top of that, Wisconsin rule ATCP 72.16 requires all tourist rooming houses to record contact information for every adult guest (18+) staying at the property. Not just the booker — every adult. This isn't optional. It's the law. And I was doing it by hand, if at all.

I want to support large groups responsibly and be a respectful neighbor. But the tools I had weren't built for that.

The duct-tape era

Before GuestKey, I was running multiple disconnected systems that each did one thing:

• StayFi for guest information collection (WiFi-gating)
• Minut for noise monitoring (7 devices throughout the property)
• A separate portal for security deposits
• Another separate portal for the digital guest guidebook
• Manual guest registration for local compliance

Five different systems. None of them talked to each other. And guests were being sent to multiple different portals — one for the deposit, one for registration, one for the guidebook. A bad experience for them and a nightmare for me.

What actually broke

The core failure was simple: I couldn't reliably reach the people in my property when noise got out of hand.

Minut would detect noise and send an alert to the primary booker — one person out of 20. That booker could claim their phone died. The other 19 adults? Never contacted. They had no idea the house was too loud.

I needed phone numbers for everyone. StayFi was supposed to collect guest info through WiFi-gating, but the data was unreliable. Guests entered fake emails, reused contacts, or just skipped WiFi entirely — mobile data bypasses the whole thing. Besides, not everyone even connects to WiFi — and on a Friday night at check-in, people are thinking more about that first drink than connecting to my local WiFi. On a good day, I'd get contact info for maybe 4-5 out of 20 adults. Usually less.

I hired a guy on Fiverr to wire up a custom Zapier integration to connect StayFi and Minut. It worked for a while. Then it broke. I didn't know how to fix it. And I was back to manually asking guests for phone numbers, one by one, and entering them into Minut myself.

The AI moment

When AI-assisted coding became viable, something clicked. I'm not a traditional software developer. But I understood the problem deeply — I lived it every weekend. And now I had a tool that could help me build the solution.

So I started building. No Zapier. No duct tape. A single system that does everything automatically.

One link. Everything unified.

The breakthrough was realizing that guests were being sent to too many places. The registration step was the anchor — every adult has to do it. So I built everything around that moment.

One link gives every guest:

• Registration — OTP-verified phone number. Can't be faked.
• Security deposit — gated. No deposit, no door code.
• Smart home controls — lock and unlock doors right from the portal.
• Digital guidebook — with real controls, not a static PDF nobody reads.
• Noise monitoring dashboard — all 7 sensors, near real-time. Guests can see their own noise levels before they even get an alert.

No app download. No separate logins. One link, sent in the pre-arrival message.

The noise dashboard no one else builds

Here's something I noticed: noise monitoring platforms don't show noise data to guests. They alert the host. The host texts the guest. The guest argues. It's adversarial. Some platforms do alert the guest directly — but only the one who booked. And it's still adversarial. A robot telling you you're too loud, with no context, no dashboard, no way to see where you stand? That's a notification, not a solution.

I used Minut's API to build a real-time dashboard showing all 7 sensors. Then I bought a low-cost Android tablet, locked it down, and mounted it on the wall in the main common area. It's always on, always showing the noise dashboard.

When every guest registers with their real name, verified phone number, and home address — and has serious skin in the game with a Host Safety Deposit that isn't just a damage deposit but a behavior deposit — the dynamic shifts completely. Add noise visibility on top of that, and it's not the host policing the guests. It's the group self-regulating.

The results

It's not perfect. Guests still underreport the number of adults sometimes, or make last-minute changes to who's coming. But the improvement is dramatic.

• All registered adults get noise alerts — not just the booker
• Guests actually use the guidebook because it has real controls, not just information
• Fewer "how do I work the TV" messages at 11 PM
• Guest marketing opt-in data that's actually usable — 90%+ verified contacts vs. a handful of maybe-real emails

What's next

Solo founder. Bootstrapped.

GuestKey is built and funded by me — a solo founder who's also the host, the developer, and the first customer. No VC. No team of 50. No pitch decks or Series A rounds.

Just a host who got frustrated enough to build the solution himself, and realized other hosts have the exact same problems.

I'm not building this from a Silicon Valley office. I'm building it from the same desk where I respond to guest messages, check noise dashboards, and manage turnovers. That's not a limitation — it's the whole point.