Apps

Make the identifier that lets you into a service without a phone number or a big-platform sign-in.

A PCOC, a self-issued identifier, carries a cost in memory and time, so bots can't make them for free.

These apps make one on your own device. Pick your platform.

Coming soon: an Amethyst integration for Nostr, and a Telegram app.

FlatpakAny distribution · 1.6 MB AppImageComing soon .debComing soon

PCOC Hike 0.1.7 · built 24 Oct 2026 · Source at this version

Install it

Paste each step into a terminal, in order.

OS: Any Linux with Flatpak. The commands are for Debian 13 or Ubuntu 24.04; Ubuntu 24.04 should behave the same, but it was not tested.
You need: Flatpak and the Flathub remote, and about 1.1 GB free for the GNOME runtime
Time: About 5 minutes, mostly the runtime download

Tested on Debian 13, 21 Oct 2026.

1. Install Flatpak

Fedora and Linux Mint come with Flatpak: skip this step.

sudo apt update
sudo apt install -y flatpak

2. Add Flathub

The app gets its GNOME runtime from Flathub.

flatpak remote-add --user --if-not-exists flathub https://dl.flathub.org/repo/flathub.flatpakrepo

3. Download the app

curl -fLO https://pub-54bc1adbb1da45aba1b293480fe7105e.r2.dev/demonstrations/pcoc-desktop-v0.1.7.flatpak

4. Check the download

The number must match exactly. If it does not, delete the download and try again.

sha256sum pcoc-desktop-v0.1.7.flatpak

Expected output

ae1bd64f7ca1a6c5ee066d0256420de66b9a17c977f9f2e880a2bb13595ba5e4  pcoc-desktop-v0.1.7.flatpak

5. Install it

This also downloads the GNOME 50 runtime if you do not have it yet, about 1.1 GB.

flatpak install --user -y ./pcoc-desktop-v0.1.7.flatpak

6. Check the result

flatpak info --user app.pcoc.Hike

Expected output (from the second line)

          ID: app.pcoc.Hike
         Ref: app/app.pcoc.Hike/x86_64/master
        Arch: x86_64
      Branch: master
     Version: 0.1.7
…

7. Run it

It also appears in your applications menu (on some desktops, after you log out and back in). Then follow the desktop guide.

flatpak run --user app.pcoc.Hike

Watch the video in the desktop guide

Release details

Version: 0.1.7, tag desktop-v0.1.7
Size: 1.6 MB (1684464 bytes)
Commit: d4cc86f306a6ab30ba21c8603d5e397216d7daf8
sha256: ae1bd64f7ca1a6c5ee066d0256420de66b9a17c977f9f2e880a2bb13595ba5e4
Rebuild: From the tag, with apps/desktop/flatpak/build-bundle.sh. The rebuild is not bit-for-bit identical across machines; the sha256 checks the published download.

Or build it from source

OS: Debian 13 or Ubuntu 24.04, in a terminal. Ubuntu 24.04 should behave the same; it was not tested. It needs GTK 4.14+ and libadwaita 1.5+.
You need: Rust 1.99.0 (rustup installs it from the repository pin), the GTK 4 and libadwaita development packages, git and curl
Time: About 10 minutes

Tested on Debian 13, 21 Oct 2026.

1. Install the system packages

sudo apt update
sudo apt install -y build-essential pkg-config libgtk-4-dev libadwaita-1-dev git curl

2. Install rustup

The app folder pins Rust 1.99.0, and rustup installs it on the next cargo command.

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y --default-toolchain none
. "$HOME/.cargo/env"

3. Get the code

git clone https://github.com/groundinglab/pcoc.git
cd pcoc/apps/desktop

4. Build

cargo build --release --locked

5. Check the result

cargo test --locked -p pcoc-hike-core

Expected output (each test group ends like this)

test result: ok. …

6. Run it

cargo run --release --locked -p pcoc-hike

Primal (groundinglab fork, demo build)Android APK · debug build · 365 MB Amethyst integrationComing soon Telegram appComing soon

Android app 3.5.50 · built 25 Oct 2026 · Commit 5a1d4f5f3

The phone build is a groundinglab fork of Primal, the open-source Nostr client: a demo build, not an official Primal release.

It is a debug build, so it is large. Side-load only, not the Play Store. This build uses SDK 2.3.1.

Reset flush link and previous signings. Test build ahead of primal-pcoc #54, which is not merged.

Install it

Phone: Android, with installs from your browser or files app allowed
Computer: Optional, to check the download: Debian 13 or Ubuntu 24.04

Download checksum verified 25 Oct 2026.

1. On the phone: download and install

Open this page on the phone and tap the Primal button above. When the download finishes, open it, and allow your browser to install apps if Android asks. It is side-load only, not on the Play Store.

2. Or, on a computer: download it

365 MB.

curl -fLO https://pub-54bc1adbb1da45aba1b293480fe7105e.r2.dev/demonstrations/primal-pcoc-aosp-debug.apk

3. Check the download

sha256sum primal-pcoc-aosp-debug.apk

Expected output

6fd62c90ca78b3905d401b63fbe48dc3dcaf81ef97e3131b03dc7a664abbe69c  primal-pcoc-aosp-debug.apk

4. Install it over USB

Turn on USB debugging on the phone beforehand: Settings, About phone, tap Build number seven times, then Developer options. This step needs a phone attached, so it was not tested here.

sudo apt install -y adb
adb install primal-pcoc-aosp-debug.apk

Expected output (last line)

Success

Then follow the phone guide.

Watch the video in the phone guide

Release details

Version: 3.5.50 (versionCode 2747), commit 5a1d4f5f3
Size: 365 MB (382598590 bytes)
Built: 25 Oct 2026
Commit: 5a1d4f5f3c06cd92cfc1ae758418a47122853d3a
sha256: 6fd62c90ca78b3905d401b63fbe48dc3dcaf81ef97e3131b03dc7a664abbe69c
Signing: Debug key
Changes: Reset flush link and previous signings. Test sideload ahead of primal-pcoc #54 (not merged).
Rebuild: From commit 5a1d4f5f3, following the primal-pcoc README (./gradlew :app:assembleAospDebug). The rebuild is not bit-for-bit identical; the sha256 checks the published download.

Build it into your own app

Both apps are demonstrations of the PCOC SDK. To put the same work in your own app:

SDK setup. Make PCOCs from the language quickstarts.
Admission gate. Accept a PCOC at sign-in.
Agent brief. Hand the wiring to a coding agent. The specification stays the contract.