I built a hidden AI overlay that's invisible during screen sharing — here's how and why

#showdev #beginners #webdev #productivity

The Problem Nobody Talks About

There's a moment every IT pro, sysadmin and
help desk technician knows intimately.

You're screen sharing. Ten people are watching.
Something breaks unexpectedly. And suddenly you're
on your own — no safety net, no way to quietly
Google the error, no AI tool you can reach for
without your entire audience watching you do it.

Every AI tool in existence assumes you have a
quiet moment to switch context.

Nobody built one for when you're actually in
the fire.

So I built it myself.

What is GhostPilot?

GhostPilot is a Windows desktop overlay that sits
on your screen during any screen sharing session —
completely invisible to Teams, Zoom, Webex and any
other capture tool.

You see it. Nobody else on the call does.

One hotkey toggle. Full AI chat window. Paste an
error, describe the issue, get step by step
guidance — all while your audience sees only your
desktop, your terminal, your RDP session. Never
GhostPilot.

The Technical Core

The entire idea hinges on one capability —
making a window genuinely invisible to screen
capture at the OS level.

Not minimised. Not alt-tabbed away. Actually
invisible while sitting right on your screen.

I won't go into the specific implementation
details here, but Windows exposes native APIs
that allow a window to be excluded from screen
capture entirely — at the OS level, not the
application level. This means it doesn't matter
which screen sharing tool is running. The
exclusion happens before the capture ever reaches
the application.

Once I confirmed that worked, the rest was
execution.

The Stack

Language: C#
UI Framework: WPF (.NET 8)
AI: Third party AI API with full conversation context
Security: Windows DPAPI for local credential encryption
Build: Visual Studio 2022

I chose C# + WPF deliberately. This needed to
be native Windows — performance, OS API access
and reliability mattered more than cross-platform
flexibility. WPF gave me full control over the
window behavior at a level that Electron or
other frameworks simply couldn't match for
this use case.

What I Learned Building Solo

1. Validate the core technical assumption first

Before designing any UI, before thinking about
monetisation, before writing a single line of
application logic — I proved the invisible window
worked. That was the only thing that mattered.
Everything else was just execution once that
was confirmed.

2. Scope ruthlessly

My V1 has exactly what it needs and nothing more.
No cloud sync. No user accounts. No mobile.
No Mac support. Every feature I didn't build in
V1 is a feature I didn't have to debug, test
or maintain while trying to ship.

3. The niche is the moat

GhostPilot isn't for everyone. It's for IT pros
on screen sharing calls. That specificity is a
feature not a bug. A focused tool for a specific
painful moment beats a general tool that does
everything for nobody.

4. Ship before it's perfect

The version I launched has rough edges. The
version I was planning to launch before I
talked myself out of perfecting it would have
taken three more months and shipped to the
same audience.