The virtual fence collar
you can build.
- 2.2 m
- First-fix accuracyPrototype 01, open sky
- ≤ 2.5 m
- Accuracy targetV1, open pasture
- 60+ d
- Without sunV1 target, solar top unit
- < 2 min
- Setup per collarV1 target: scan, strap, done
Most collars are leased. This one is yours.
| Question | Leased | OpenCollar |
|---|---|---|
| How you get it | Yearly subscription | Buy it, or build it |
| If you stop paying | The fence stops | Nothing to stop paying |
| Software | Theirs only | Any software |
| Designs | Closed | Published |
| Repair | Not yours to open | A screwdriver and a parts list |
Opening the designs.
- Parts listpublished
- Collar protocoldrafted
- Firmwarein progress
- Enclosure and CADV1 in design
- Repair guidesplanned
Get the designs first.
You're on the list. Cody will write when designs go up.
That didn't send. Try again in a moment, or email cody@openpasture.dev.
Sun on top, sky at the crown.
Everything electronic lives in one sealed top unit, held with gaskets and screws instead of potting, so every part can be replaced.
The weight at the bottom does work. It's a bay for ballast, a Battery Extension, or a camera module.
The fence runs on the collar, so it holds with no signal.
The full design and targetsRuns with any software.
The collar speaks a documented protocol, with open-source code to speak it back.
- yoursYour own scripts and tools
- researchData pipelines for trials and studies
- farm appsAny app that implements the protocol
- openpastureFirst-party software that draws the fence and decides each day's move. Download it.
A new boundary, down to every collar
{
"version": 42,
"effective_at": "2026-09-25T12:30:00Z",
"boundary": [[-92.41, 38.12], …],
"warn_m": 10
}
Each collar answers
{ "version": 42, "status": "applied" }
From the draft collar protocol.
Assembled
target$2491
Built and tested by openpasture. A $50 reservation per collar holds your place in the first batch, targeted for Q1 2027. You confirm your order, and the price, before it ships.
- Top unit, strap, and ballast module
- Battery Extension and camera module as add-ons
- Fully refundable until you confirm3
Build it yourself
~$260in parts
The same collar from breakout boards, a bought strap, and printed parts, at retail on today's list.
- Every part, vendor, and price
- What to print it in
- A battery setup with nothing to configure
Where it stands
- Prototype 01
- first GPS fix
- Firmware
- boots, loads a boundary
- Collar protocol
- drafted
- Field test
- not started
- Parts list
- published
- mid-OctoberPrototype complete
- end of 2026V1 design final
- Q1 2027First batch to early adopters
Targets, not promises. Walk tests first, then on sheep, alongside a farm's existing fence. Sound first.
You're on the list. You'll hear at each milestone.
That didn't go through. Try again in a moment, or email cody@openpasture.dev.
-
Firmware
nRF Connect SDK, low power, a geofence that never leaves an animal without a line.
-
Power and radio
Solar, LiFePO4, GNSS on a moving neck, and LTE-M with no signal.
-
Board and enclosure
A sealed top unit you can still open and repair.
Built hardware before?
Questions, answered.
OpenCollar
Who is behind OpenCollar?
openpasture started it, contributes to it, and sells it assembled. It's an open initiative: any contributor or team can build on it, and anyone can build one.
Do I need openpasture's software?
No. Any software that speaks the protocol can run the collars. openpasture's software is one option.
Can I buy one today?
You can reserve an assembled one. A $50 reservation fee per collar holds your place in the first batch, is applied to your order when you confirm it, and is fully refundable until then. Reserve now.
When does it ship?
The targets: the prototype complete by mid-October 2026, the V1 design final by the end of 2026, and the first batch delivered to early adopters in Q1 2027. They may move; progress goes on the build log.
Does it need cell signal?
Not to hold the fence. Boundary logic runs on the collar, which keeps its last good boundary. Signal is for new boundaries and position reports.
Which animals?
Sheep first, then cattle. The first live test will be on sheep, alongside a farm's existing fence.
What license do the designs use?
The firmware and protocol are Apache-2.0, so you can use them in anything. The boards and enclosure are CERN-OHL-W-2.0: build and sell them, and if you ship a changed version, publish your changes to those files. The docs are CC BY 4.0. Details are in the opencollar repo.
1$249 is a back-of-the-envelope target for the assembled OpenCollar (top unit, strap, and ballast module) in US dollars, not a quote. Reaching it likely depends on designing our own custom board, which we plan to sell on its own as well, alongside the other components and the 3D-printed designs. It is our target, and we may not hit it. It excludes add-ons, shipping, taxes, and fees, and the actual price is confirmed before you order.
2The OpenCollar is a prototype. Specifications are V1 design targets, not measurements, unless marked as measured. Our targets are the prototype complete by mid-October 2026, the V1 design final by the end of 2026, and the first batch delivered to early adopters in Q1 2027. They are targets, not commitments, and may change.
3The reservation fee is $50 per collar, paid through Stripe. It is fully refundable at any time before you confirm an order, and applied to the purchase price when you do. A reservation is not an order and does not guarantee a price or a delivery date. See the terms.
4openpasture software features such as proposed and scheduled moves describe the design in progress. What works today is in the release notes and on the build log.