OpenHaystack – Track Your Items on Apple’s Find My Network

Who hasn’t dreamed of being able to find their lost keys, bag, or laptop anywhere in the world? Personally, it’s not that dramatic, although… I do constantly misplace my keys around the house, so I’m grateful that Apple offers its AirTag system.

However, the AirTag comes with two major downsides: its relatively high licensing fee for manufacturers and its closed ecosystem. The good news is that there is a free, open-source alternative that allows you to harness the power of Apple’s Find My network to create your own Bluetooth trackers.

OpenHaystack cleverly utilizes Apple’s Find My network based on this principle:

1. A pair of cryptographic keys (public/private) is generated on your Mac – the private key remains securely stored in the system keychain.
2. Your OpenHaystack beacon regularly emits a Bluetooth signal containing the public key.
3. Nearby iPhones capture this signal, obtain their GPS location, encrypt it with the public key, and send it to Apple’s servers.
4. The OpenHaystack application on your Mac retrieves and decrypts these locations using the corresponding private key.

The coolest part is that all this works without an internet connection for your tracker! It only requires that an iPhone running iOS 13 or later passes nearby for its location to be updated. And iPhones cannot distinguish between your OpenHaystack accessories and official Apple devices.

Note that OpenHaystack is capable of:

• Multi-device support: manage as many trackers as you want.
• Map interface: visualize all your devices on a single map.
• Position history: view the last known locations.
• Data export: save your settings and histories.
• Mobile version: a smartphone app is available, requiring a proxy server on a Mac.

To set up your personal tracking system, here’s what you will need:

• A Mac running macOS 11 (Big Sur) or later.
• A Bluetooth Low Energy compatible device such as a BBC micro:bit (approx. €15), an ESP32 board (approx. €5), or a Raspberry Pi or another Linux device.

Installation of the application

The first step is to configure your system to allow OpenHaystack to run. Open a terminal and temporarily disable Gatekeeper by running the following command:

1sudo spctl --master-disable

This command is necessary because OpenHaystack uses a custom plugin for Apple Mail that requires special permissions.

Configuring the Mail plugin

Once the application is installed, you need to configure the Mail plugin that allows OpenHaystack to access the necessary Apple services. Here’s how:

1. Launch Apple Mail and go to Preferences from the menu. In the “General” tab, click on the “Manage Extensions…” button. If this button doesn’t appear, you first need to run the following command in the terminal: 1sudo defaults write "/Library/Preferences/com.apple.mail" EnableBundles 1
2. In the extensions management window, look for and enable “OpenHaystackMail.mailbundle”. The system will prompt you to confirm this activation. Once confirmed, restart Apple Mail for the changes to take effect.

Creating an accessory

Now that the installation is complete, you can create your first tracking accessory. Launch the OpenHaystack application from your Applications folder.

In the main interface, use the “+” button to add a new accessory. A configuration window will open where you can customize your accessory. Give it a clear name that will help you identify it easily and choose an appropriate icon from the provided list.

OpenHaystack will automatically generate a pair of encryption keys. The private key will be securely stored in your Mac’s keychain, while the public key will be used for Bluetooth communications.

Deploying on your device

The final step is to deploy the configuration onto your compatible physical device. Connect your device (such as a micro:bit or ESP32) to your Mac via USB. In the OpenHaystack interface, click the “Deploy” button next to the accessory you just configured.

A window will open allowing you to select the type of device corresponding to your hardware. Choose the appropriate model and follow the specific instructions for your device.

Daily usage

Once configured, your accessory will start emitting Bluetooth signals that will be captured by Apple’s Find My network. The first location reports may take up to 30 minutes to appear on the map. The frequency of updates will depend on the presence of nearby iOS devices that can relay the position.

You can check the last known location of your accessories directly from the OpenHaystack interface. The map will display all your devices, and you can click on each to see the details of their last update.

Securing your system

Once the installation is complete, it is highly recommended to reactivate Gatekeeper to maintain the security of your system. Run the following command in the terminal:

1sudo spctl --master-enable

However, keep in mind that OpenHaystack is an experimental project and the current firmware broadcasts a fixed public key. This means your accessories can be tracked by other nearby devices.

By combining affordable hardware, open-source software, and existing infrastructure, this project offers an accessible solution for locating objects. So, if you’re excited to create your first tracker, head over to the OpenHaystack GitHub repository!