PuttBayWhy GSPro only takes one connector (and how to use camera putting with your launch monitor)
Last updated 2026-09-30.
Short answer: GSPro's Open Connect input takes one connected app at a time. If your launch monitor's connector is connected, a separate putting app can't connect too, so putts have to travel through that same connection. And on a launch-monitor maker's GSPro license, there's no Open Connect input to join at all.
Below, kept apart on purpose: what GSPro documents, what golfers have seen, and what PuttBay does.
What GSPro documents
GSPro's Open Connect v1 page is short. The parts that matter here:
- GSPro Connect "opens a socket and listens for an incoming client." It assumes that software runs on the same PC, and it needs no sign-in.
- GSPro sends back player information: which hand, and which club is selected. The page says the club is "typically used for Launch monitors that need to switch between full strike clubs and putting."
- It never says how many apps may connect at once. It says "an incoming client", singular.
The license side is in GSPro's store and knowledge base:
- You buy GSPro with one launch-monitor type (gsprogolf.com). Open API is one of those types, listed as "Other (OpenAPI)".
- Switching types means converting your license with the License Conversion Tool, then clearing GSPro Connect so you can pick the new type.
- Some launch monitors don't putt at all. GSPro's R10 guide says "The Garmin Approach R10 does not support putting", and Rapsodo says "The MLM2PRO does not include a built-in putting feature." Both point you to GSPro's auto putt.
What golfers have seen
- "If you start two connectors only the first one will get connected if I remember correctly." That's alleexx, who wrote the cam-putting-py tracker, in October 2023 (springbok discussion #47).
- "You can't have two connections to gspro." That's springbok, maintainer of the MLM2PRO connector, in March 2024 (discussion #79).
- On a maker's license the Open API window never appears. springbok again, July 2026: "you have to use the gspro openapi license for the window to appear" (discussion #139). That missing window is behind the API window not found error.
- Switching has a cost. Mevo+ owners who moved to Open API for a putting camera report losing the short chips they had on GSPro's FlightScope route (Golf Simulator Forum, 2025 and 2026). More in Mevo+ putting.
One guide reports that GSPro support can add more connection types to a license so you can switch between them in GSPro's connection window (FriendlyGolfer). That's switching, not running two at once.
What that means for you
| Your setup | Putts in GSPro rounds |
|---|---|
| A launch monitor that reads putts, on its maker's license | GSPro handles putting through the device |
| A launch monitor that doesn't putt (Garmin R10, Rapsodo MLM2PRO), on its maker's license | GSPro's auto putt or gimmes; a camera has nowhere to connect |
| A launch monitor with a community connector, on an Open API license | Real putts are possible, if one app carries both full shots and putts |
The relay idea
If only one app can hold GSPro's connection, that app has to carry everything. It sits in the middle: GSPro on one side, the launch monitor and the putting camera on the other. GSPro says which club you have. Putter selected, putts go through. Any other club, full shots go through.
The community already works this way:
- springbok runs its own ball tracker, which hands each putt to the connector on your PC. The connector is still the one app talking to GSPro. (One golfer's putts vanished because a VPN client had taken the tracker's port: issue #117.)
- gsp-r10-adapter, for the Garmin R10, can start cam-putting-py and pass its putts along the same way (gsp-r10-adapter).
- KW Golf's ShotBridge with PuttLinx is one free app that connects to GSPro's Open API and includes webcam putting (kw-golf.com).
The limit is the maker's license. There, GSPro Connect talks to your launch monitor directly, and there's no Open Connect traffic to relay. Nothing in the middle can add putts to that route. Only GSPro could change that.
For the technically curious
- A putt goes to GSPro as an ordinary Open Connect shot: ball speed and horizontal launch angle (the start line), with spin and vertical launch at zero. cam-putting-py's README describes sending "BallSpeed in MPH and HLA of the putt."
- The putter's club code, "PT", isn't on GSPro's page. Community protocol notes list it (libgspro protocol notes).
- Build for one connected app. The official page doesn't promise more.
How PuttBay handles it
PuttBay is the app in the middle. It's how we play our own rounds.
- On an Open API license, PuttBay is the one app connected to GSPro. Your launch monitor's full shots come through
PuttBay, and your putts come from the camera, in the same round.
- Rapsodo MLM2PRO: through springbok, a free community connector you install yourself. PuttBay finds it, points it at PuttBay, starts it minimized and reconnects it with one press. Rapsodo's membership and app approval still apply.
- Garmin R10: in beta with hand-picked testers.
- FlightScope Mevo+ and Mevo Gen2: through flighthook, a free community connector you install yourself and PuttBay supervises. In beta.
- Other launch monitors: not yet.
- It goes by the club. Putter selected: camera putts go to GSPro and launch monitor shots don't. Any other club: the reverse. PuttBay also tells your connector which club GSPro has, so it rests while you putt.
- A second connector that tries to join is turned away, and PuttBay tells you which app it kept.
- On a maker's license (for example GSPro's official Rapsodo or FlightScope routes), GSPro drives the launch monitor and handles putting itself, so PuttBay can't add camera putts to those rounds. The practice green still works with your camera.
Setting up the camera side? Start with webcam putting for GSPro.
PuttBay is an independent product and is not affiliated with GSPro, Rapsodo, Garmin, FlightScope or Square.