Messages

GRSPay: a free and open-source cryptocurrency payment processor which allows you to receive payments in Groestlcoin with no fees, transaction cost or a middleman.

GRSPay is a non-custodial invoicing system which eliminates the involvement of a third-party. Payments with GRSPay go directly to your wallet, which increases the privacy and security. Your private keys are never uploaded to the server. There is no address re-use, since each invoice generates a new address deriving from your xpubkey or zpubkey.

GRSPay is available at https://grspay.com
https://www.youtube.com/watch?v=c7s3zZnlQ6M

https://www.youtube.com/watch?v=qNMTDEPhWhY

Changelog v1.7.1.0
• Mark MySql and SQLite backend deprecated
• Upgrade Bootstrap to v5.2.3; Design System improvements
• New version of the checkout as opt-in feature
• Request customer data with forms for email and shipping address
• Server settings: Add option to customize the instance logo
• Store settings: Add branding options
• Refactor labels
• Improve PayButton error page

Features
• Direct, P2P Groestlcoin payments
• Lightning Network support
• Complete control over private keys
• Enchanced privacy
• SegWit support
• Process payments for others
• Easy-embeddable Payment buttons
• Point of sale app
• No transaction fees (other than those for the crypto networks)
• No processing fees
• No middleman
• No KYC
• The software is built in C#
• You can run GRSPay as a self-hosted solution on your own server or use our host. The self-hosted solution allows you not only to attach an unlimited number of stores but also become the payment processor for others.
• Open Source - MIT license

This application is licensed under MIT. There is no warranty and no party shall be made liable to you for damages. If you lose coins due to this app, no compensation will be given. Use this app solely at your own risk.

Source code: https://github.com/Groestlcoin/btcpayserver

Core lightning: A specification compliant Lightning Network implementation in C

Core lightning is a lightweight, highly customizable and standard compliant implementation of the Lightning Network protocol.
Core lightning only works on Linux and Mac OS, and requires a locally (or remotely) running groestlcoind (version 2.16.0 or above) that is fully caught up with the network you're testing on.

Changelog 22.11.1
• The new experimental reckless plugin manager can be used to download, install and uninstall plugins on the fly. We have many new features planned for it, so stay tuned.
• When receiving a keysend any extra TLV fields will be stored so they can be retrieved later.
• The --database-update=false flag allows users wanting to test unreleased versions from accidentally upgrading the database, and then be unable to switch to a released version again.
• Several performance issues, particularly for larger nodes, have been addressed.
• Support for the legacy onion encoding has been removed, since the more modern and flexible TLV encoding is now widely deployed.
• We have started preparing for a splicing implementation, but merging the interactive TX creation API.
• We now require all channel_update messages include htlc_maximum_msat (as per latest BOLTs)
• Results from the API can now be filtered using the filter API. This can be used to massively reduce the size of results if only part of it is required.
• The openchannel hook can be used to set a reserve value other than the 1% default value. This also allows not having a reserve in case the peer is (semi-)trusted.
• We reintroduced a number of deprecated features, since some integrations had missed the deprecation window, and asked for some more time to update their apps.
• We delayed the rollout of DNS names in the gossip due to a lack of support in the network.

Features
• Creating channels.
• Closing channels.
• Completely managing all channel states (including the exceptional ones!).
• Performing path finding within the network, passively forwarding incoming payments.
• Sending outgoing onion-encrypted payments through the network.
• Automatic channel management (autopilot).

This application is licensed under MIT. There is no warranty and no party shall be made liable to you for damages. If you lose coins due to this app, no compensation will be given. Use this app solely at your own risk.

Ubuntu: https://github.com/Groestlcoin/lightning/blob/master/doc/INSTALL.md#to-build-on-ubuntu
Fedora: https://github.com/Groestlcoin/lightning/blob/master/doc/INSTALL.md#to-build-on-fedora
OpenBSD: https://github.com/Groestlcoin/lightning/blob/master/doc/INSTALL.md#to-build-on-openbsd
OSX: https://github.com/Groestlcoin/lightning/blob/master/doc/INSTALL.md#to-build-on-macos
Arch Linux: https://github.com/Groestlcoin/lightning/blob/master/doc/INSTALL.md#to-build-on-arch-linux
Raspberry Pi: https://github.com/Groestlcoin/lightning/blob/master/doc/INSTALL.md#to-cross-compile-for-raspberry-pi
Armbian: https://github.com/Groestlcoin/lightning/blob/master/doc/INSTALL.md#to-compile-for-armbian
Alpine: https://github.com/Groestlcoin/lightning/blob/master/doc/INSTALL.md#to-compile-for-alpine

Source code: https://github.com/Groestlcoin/lightning

[What's new in version v24.0.1?This is a major release of Groestlcoin Core, featuring the technical equivalent of Bitcoin Core v24.0.1 but with Groestlcoin specific patches.]

A new major Groestlcoin Core version 24.0.1 is now available for download, so it is recommended to upgrade to it if you are running a full Groestlcoin node or a local Groestlcoin Core wallet.

v24.0.1 is now the official release version of Groestlcoin Core. It is recommended to upgrade to this version as soon as possible.

What's new in version v24.0.1?
This is a major release of Groestlcoin Core, featuring the technical equivalent of Bitcoin Core v24.0.1 but with Groestlcoin specific patches.

Changelog 24.0.1:
https://github.com/Groestlcoin/groestlcoin/blob/24.0.1/doc/release-notes/release-notes-24.0.1.md

Important:
• There is no warranty and no party shall be made liable to you for damages. If you lose coins due to this app, no compensation will be given. Use this app solely at your own risk.
• Encrypt your wallet. This can be done by clicking the settings menu from inside the wallet. Make sure your password is secure and do not forget it.
• Make a copy your wallet.dat file as a backup and move it to a secure location:
Location Windows: Navigate to C:\Users\Username\AppData\Roaming\groestlcoin\wallet.dat (or open windows explorer and enter %appdata%\Groestlcoin\wallet.dat)
Location Mac: Finder -> Go {Hold Option] -> Library -> groestlcoin -> wallet.dat (~/Library/Application Support/groestlcoin/wallet.dat)

WARNING:
While this branch has been extensively tested to be compatible with the existing Groestlcoin v2.11.0, v2.13.3, v2.16.0, v2.16.3, v2.17.2, v2.18.2, v2.19.1, v2.21.0, v2.21.1, 22.0.0 and 23.0.0 network there is the possibility that we missed something. ALWAYS BACKUP YOUR GROESTLCOIN WALLET BEFORE UPGRADING.

How to Upgrade?
Windows: If you are running an older version, shut it down. Wait until it has completely shut down (which might take a few minutes for older versions), then run the installer.
OSX: If you are running an older version, shut it down. Wait until it has completely shut down (which might take a few minutes for older versions), run the dmg and drag Groestlcoin Core to Applications. Users running macOS Catalina need to "right-click" and then choose "Open" to open the Groestlcoin Core .dmg.

Download the Windows Installer (64 bit) here: https://github.com/Groestlcoin/groestlcoin/releases/download/v24.0.1/groestlcoin-24.0.1-win64-setup.exe
Download the Windows binaries (64 bit) here: https://github.com/Groestlcoin/groestlcoin/releases/download/v24.0.1/groestlcoin-24.0.1-win64.zip

Download the OSX Intel based Installer here: https://github.com/Groestlcoin/groestlcoin/releases/download/v24.0.1/groestlcoin-24.0.1-x86_64-apple-darwin.dmg
Download the OSX Intel based binaries here: https://github.com/Groestlcoin/groestlcoin/releases/download/v24.0.1/groestlcoin-24.0.1-x86_64-apple-darwin.tar.gz
Download the OSX ARM Installer here: https://github.com/Groestlcoin/groestlcoin/releases/download/v24.0.1/groestlcoin-24.0.1-arm64-apple-darwin.dmg
Download the OSX ARM binaries here: https://github.com/Groestlcoin/groestlcoin/releases/download/v24.0.1/groestlcoin-24.0.1-arm64-apple-darwin.tar.gz

Download the Linux binaries (64 bit) here: https://github.com/Groestlcoin/groestlcoin/releases/download/v24.0.1/groestlcoin-24.0.1-x86_64-linux-gnu.tar.gz
Download the ARM Linux binaries (64 bit) here: https://github.com/Groestlcoin/groestlcoin/releases/download/v24.0.1/groestlcoin-24.0.1-aarch64-linux-gnu.tar.gz
Download the ARM Linux binaries (32 bit) here: https://github.com/Groestlcoin/groestlcoin/releases/download/v24.0.1/groestlcoin-24.0.1-arm-linux-gnueabihf.tar.gz
Download the RISC-V Linux binaries (64 bit) here: https://github.com/Groestlcoin/groestlcoin/releases/download/v24.0.1/groestlcoin-24.0.1-riscv64-linux-gnu.tar.gz
Download PowerPC linux binaries (64 bit) here: https://github.com/Groestlcoin/groestlcoin/releases/download/v24.0.1/groestlcoin-24.0.1-powerpc64-linux-gnu.tar.gz
Download PowerPC LE linux binaries (64 bit) here: https://github.com/Groestlcoin/groestlcoin/releases/download/v24.0.1/groestlcoin-24.0.1-powerpc64le-linux-gnu.tar.gz

Linux Snapcraft: https://snapcraft.io/groestlcoin-core
Linux Flathub: https://flathub.org/apps/details/org.groestlcoin.groestlcoin-qt
Linux Launchpad: https://launchpad.net/~groestlcoin/+archive/ubuntu/groestlcoin
NixOS: https://search.nixos.org/packages?channel=unstable&show=groestlcoin&from=0&size=50&sort=relevance&type=packages&query=groestlcoin
Homebrew Cask: https://formulae.brew.sh/cask/groestlcoin-core
Homebrew: https://formulae.brew.sh/formula/groestlcoin
Arch Linux User Repository: https://aur.archlinux.org/pkgbase/groestlcoin

Source code:
https://github.com/Groestlcoin/groestlcoin

Groestlcoin Eclair (French for Lightning) is a Scala implementation of the Lightning Network. It runs without a GUI and a JSON API is also available.

Groestlcoin Eclair requires Groestlcoin Core 22.0 or higher. If you are upgrading an existing wallet, you need to create a new address and send all your funds to that address.
Groestlcoin Eclair needs a synchronized, segwit-ready, zeromq-enabled, wallet-enabled, non-pruning, tx-indexing Groestlcoin Core node.
Groestlcoin Eclair will use any GRS it finds in the Groestlcoin Core wallet to fund any channels you choose to open. Eclair will return GRS from closed channels to this wallet.
You must configure your Groestlcoin node to use bech32 (segwit) addresses. If your wallet has "non-segwit UTXOs" (outputs that are neither p2sh-segwit or bech32), you must send them to a bech32 address before running eclair.

Changelog 0.7.0
• Eclair now supports cookie authentication for Groestlcoin Core RPC.
• Eclair echoes back the remote peer's IP address in init.
• Eclair now supports circular rebalancing.
• Anchor outputs activated by default.
• Postgres database backend graduates to production-ready.
• Alternate strategy to avoid mass force-close of channels in certain cases.
• Separate log for important notifications.
• Support for onion messages.
• Support for option_payment_metadata.
• Optional safety checks when using Postgres.

Features
• Creating channels.
• Closing channels.
• Completely managing all channel states (including the exceptional ones!).
• Mainnet and testnet support

This application is licensed under Apache. There is no warranty and no party shall be made liable to you for damages. If you lose coins due to this app, no compensation will be given. Use this app solely at your own risk.

Groestlcoin Eclair is developed in Scala, a powerful functional language that runs on the JVM, and is packaged as a ZIP archive.
eclair-node (server daemon): https://github.com/Groestlcoin/eclair/releases/download/v0.7.0/eclair-node_2.13-0.7.0-bin.zip
eclair-front (cluster mode): https://github.com/Groestlcoin/eclair/releases/download/v0.7.0/eclair-front_2.13-0.7.0-bin.zip
eclair-front (awseb bundle): https://github.com/Groestlcoin/eclair/releases/download/v0.7.0/eclair-front_2.13-0.7.0-awseb-bundle.zip

Source code: https://github.com/Groestlcoin/eclair/

A Hierarchical Deterministic Groestlcoin Testnet Wallet

The app allows you to send and receive testnet Groestlcoins on your Android device using QR codes and URI links.
When using this app, please back up your wallet and email them to yourself! This will save your wallet in a password protected file. Then your testnet coins can be retrieved even if you lose your phone.

Changelog 9.03
• Setting for enabling of showing local amounts.
• Use D8 for bytecode desugaring.
• Target Android 11.
• The app now requires Android 7.0 (Nougat) or higher.
• Taproot - Phase I: Send to Bech32m addresses.
• Gro denomination can be selected in the settings.

Features:
• Sweep testnet paper wallets
• Transparant - free and open source
• Testnet blockexplorer support
• Network monitor
• Backup/restore option
• Spending pin
• tpub support
• Ability to reset blockchain
• Ability to change denomination
• Ability to connect to trusted peer
• Connectivity indicator

If the app crashes you can send the report via email or another method if your phone allows it.  Reports of errors can also be posted in this topic.
To close the app, simply press the back button until you reach your home screen.  The app will close itself (there is no need for a disconnect option).
This application is licensed under the GPL version 3. There is no warranty and no party shall be made liable to you for damages. If you lose coins due to this app, no compensation will be given. Use this app solely at your own risk.

Groestlcoin Testnet Wallet is available in the Google play store:
https://play.google.com/store/apps/details?id=hashengineering.groestlcoin.wallet_test

Groestlcoin Testnet Wallet is available on Fdroid:
https://f-droid.org/en/packages/hashengineering.groestlcoin.wallet_test/

Source code:
https://github.com/Groestlcoin/groestlcoin-wallet

A Hierarchical Deterministic Groestlcoin Wallet

The app allows you to send and receive Groestlcoins on your device using QR codes and URI links.
When using this app, please back up your wallet and email them to yourself! This will save your wallet in a password protected file. Then your coins can be retrieved even if you lose your phone.

Changelog 9.03
• Setting for enabling of showing local amounts.
• Use D8 for bytecode desugaring.
• Target Android 11.
• The app now requires Android 7.0 (Nougat) or higher.
• Taproot - Phase I: Send to Bech32m addresses.
• Gro denomination can be selected in the settings.

Features:
• Sweep paper wallets
• Transparant - free and open source
• Blockexplorer support
• Network monitor
• Backup/restore option
• Spending pin
• xpub support
• Ability to reset blockchain
• Ability to change denomination
• Ability to connect to trusted peer
• Connectivity indicator

If the app crashes you can send the report via email or another method if your phone allows it.
To close the app, simply press the back button until you reach your home screen.  The app will close itself (there is no need for a disconnect option).
This application is licensed under the GPL version 3. There is no warranty and no party shall be made liable to you for damages. If you lose coins due to this app, no compensation will be given. Use this app solely at your own risk.

Groestlcoin Wallet is available in the Google play store:
https://play.google.com/store/apps/details?id=hashengineering.groestlcoin.wallet

Groestlcoin Wallet is available on Fdroid:
https://f-droid.org/en/packages/hashengineering.groestlcoin.wallet

Source code:
https://github.com/Groestlcoin/groestlcoin-wallet

GRS BlueWallet is a thin client for Groestlcoin.

GRS BlueWallet is built with React Native and Electrum-GRS.

Changelog 6.3.1
• Passphrase support for wallets.
• Korean language.
• Derivation path for watch only wallets.
• Remove error-prone placeholder scroll calculation.
• Don't use hardcoded label.
• Backup QR doesn't have a "@server" suffix.
• UI for import electrum-grs wallet with passphrase.
• Better handling large transactions from electrum-grs.
• Faster native navigation.
• Enhanced offline mode UI.
• Borders to Dynamic QR Code.
• Support for truncated BIP39 wordlist (3-4 chars per word).
• Wallet accounts search & discovery.
• Offline wallet import.
• Custom derivation paths.
• Passphrases in advanced mode.
• Toggle for disabling Tor.
• Sinhala language.
• View QRCode button on 'is it my address'.
• Support for electrum -grswith groestlcoin core 22+.
• Handoff in-app rather than browser.
• Screenshot prevented in onchain receive.
• Choose next electrum-grs server if current one is dead.
• Dark mode in new import screens.
• Copy QRCode to Clipboard.
• ISK Fiat added.
• Add unique ID in Settings.
• Rate last updated date added.
• Danish currency added.
• Send support for Taproot address type.
• Support truncated words during slip39 wallet import.
• Show selected coins summary on CoinControl screen.
• Passphrase support on Multisig.
• Import BIP39 multi language.
• LNurl-Auth (Login with Lightning).

Features
• Multi-currency- GRS Bluewallet supports more than 20 currencies, including USD, AUD, BRL, CAD, CHF, CZK, CNY, EUR, GDP, HRK, INR, JPY, MXN, MYR, or RUB.
• Multi-language - GRS Bluewallet supports more than 20 languages, including Chinese, Japanese, Portuguese, Spanish, Indonesian, Russian, Ukranian, Italian, German, Swedish, Norwegian, French, Danish or Turkish.
• Export TXHEX - You can get your transaction HEX (TXHEX) without broadcasting it, and only do it with the relay of your choice.
• Be in control - On your Groestlcoin wallet your private keys never leave your device. You are in full control of your private keys. You can at any moment generate backups and export/import your wallets, with full control of what to do with your private keys.
• Multiple wallets support - GRS Bluewallet aims to support the maximum wallet standards. Currently supported: BIP44 (HD), BIP49 (HD SegWit), BIP84 (HD bech32, native SegWit), BIP39 Groestlwallet-compatible (m/0'/0/0), Legacy single-address, SegWit single-address (P2SH). You can have many wallets in a single app at the same time.
• HD wallets - The Hierarchical Deterministic (HD) key creation and transfer protocol (BIP32), which allows creating child keys from parent keys in a hierarchy. The HD Wallets will generate you different public keys for each transactions.
• SegWit - SegWit supported in P2SH-compatibility mode and bech32 Native mode. Segwit was a massive upgrade to the Groestlcoin Protocol released in 2017. You will find all wallets with SegWit enabled by default.
• Full encryption - On top of the phone multi-layer encryption, GRS Bluewallet can encrypt everything with an added password. Biometric security (touch ID, Face ID) is not safe, so you will have an additional password to encrypt your wallet instead.
• Plausible deniability - A custom made feature thinking about your personal security. GRS Bluewallet allows you to define a different password which will decrypt a fake wallet set up. For any situation you are forced to disclose your access or when you don't want or you can't show your real wallet.
• Open Source - GRS Bluewallet is built on a public repo, up-to-date and available on the Groestlcoin GitHub. This means that any user can build it and run it on his own, without any custodial dependencies. Verify the code and contribute to the wallet development. GRS BlueWallet is made with ReactNative and Distributed under a MIT licensed.
• Watch-only wallets - Watch-only wallets allows you to keep an eye on your cold storage without touching your private key. Easily import your address or xpub and watch it from your app without ever touching it.
• Lightning Wallets - Wallets with support for the Lightning Network Protocol. Unfairly cheap and fast transactions. You can send, receive and refill your wallets.
• Bump and Cancel transactions - Ability to bump and cancel sent transactions with "Replace-by-fee" (RBF) and ability to Bump received transactions with "Child-pays-for-parent" (CPFP) on Native Segwit wallets (bech32/BIP84).
• Plug-in your Groestlcoin Full node new - Ability to plug-in your own Groestlcoin Full node through Electrum Personal Server (EPS), ElectrumX or Electrs. Don't trust, verify for a maximum sovereignty.

This application is under MIT license. There is no warranty and no party shall be made liable to you for damages. If you lose coins due to this app, no compensation will be given. Use this app solely at your own risk.

GRS BlueWallet is available in the Google play store:
https://play.google.com/store/apps/details?id=org.groestlcoin.bluewallet

Source code:
https://github.com/Groestlcoin/bluewallet

GRS BlueWallet is a thin client for Groestlcoin.

GRS BlueWallet is built with React Native and Electrum-GRS.

Changelog 6.3.1
• Passphrase support for wallets.
• Korean language.
• Derivation path for watch only wallets.
• Remove error-prone placeholder scroll calculation.
• Don't use hardcoded label.
• Backup QR doesn't have a "@server" suffix.
• UI for import electrum-grs wallet with passphrase.
• Better handling large transactions from electrum-grs.
• Faster native navigation.
• Enhanced offline mode UI.
• Borders to Dynamic QR Code.
• Support for truncated BIP39 wordlist (3-4 chars per word).
• Wallet accounts search & discovery.
• Offline wallet import.
• Custom derivation paths.
• Passphrases in advanced mode.
• Toggle for disabling Tor.
• Sinhala language.
• View QRCode button on 'is it my address'.
• Support for electrum -grswith groestlcoin core 22+.
• Handoff in-app rather than browser.
• Screenshot prevented in onchain receive.
• Choose next electrum-grs server if current one is dead.
• Dark mode in new import screens.
• Copy QRCode to Clipboard.
• ISK Fiat added.
• Add unique ID in Settings.
• Rate last updated date added.
• Danish currency added.
• Send support for Taproot address type.
• Support truncated words during slip39 wallet import.
• Show selected coins summary on CoinControl screen.
• Passphrase support on Multisig.
• Import BIP39 multi language.
• LNurl-Auth (Login with Lightning).

Features
• Multi-currency- GRS Bluewallet supports more than 20 currencies, including USD, AUD, BRL, CAD, CHF, CZK, CNY, EUR, GDP, HRK, INR, JPY, MXN, MYR, or RUB.
• Multi-language - GRS Bluewallet supports more than 20 languages, including Chinese, Japanese, Portuguese, Spanish, Indonesian, Russian, Ukranian, Italian, German, Swedish, Norwegian, French, Danish or Turkish.
• Export TXHEX - You can get your transaction HEX (TXHEX) without broadcasting it, and only do it with the relay of your choice.
• Be in control - On your Groestlcoin wallet your private keys never leave your device. You are in full control of your private keys. You can at any moment generate backups and export/import your wallets, with full control of what to do with your private keys.
• Multiple wallets support - GRS Bluewallet aims to support the maximum wallet standards. Currently supported: BIP44 (HD), BIP49 (HD SegWit), BIP84 (HD bech32, native SegWit), BIP39 Groestlwallet-compatible (m/0'/0/0), Legacy single-address, SegWit single-address (P2SH). You can have many wallets in a single app at the same time.
• HD wallets - The Hierarchical Deterministic (HD) key creation and transfer protocol (BIP32), which allows creating child keys from parent keys in a hierarchy. The HD Wallets will generate you different public keys for each transactions.
• SegWit - SegWit supported in P2SH-compatibility mode and bech32 Native mode. Segwit was a massive upgrade to the Groestlcoin Protocol released in 2017. You will find all wallets with SegWit enabled by default.
• Full encryption - On top of the phone multi-layer encryption, GRS Bluewallet can encrypt everything with an added password. Biometric security (touch ID, Face ID) is not safe, so you will have an additional password to encrypt your wallet instead.
• Plausible deniability - A custom made feature thinking about your personal security. GRS Bluewallet allows you to define a different password which will decrypt a fake wallet set up. For any situation you are forced to disclose your access or when you don't want or you can't show your real wallet.
• Open Source - GRS Bluewallet is built on a public repo, up-to-date and available on the Groestlcoin GitHub. This means that any user can build it and run it on his own, without any custodial dependencies. Verify the code and contribute to the wallet development. GRS BlueWallet is made with ReactNative and Distributed under a MIT licensed.
• Watch-only wallets - Watch-only wallets allows you to keep an eye on your cold storage without touching your private key. Easily import your address or xpub and watch it from your app without ever touching it.
• Lightning Wallets - Wallets with support for the Lightning Network Protocol. Unfairly cheap and fast transactions. You can send, receive and refill your wallets.
• Bump and Cancel transactions - Ability to bump and cancel sent transactions with "Replace-by-fee" (RBF) and ability to Bump received transactions with "Child-pays-for-parent" (CPFP) on Native Segwit wallets (bech32/BIP84).
• Plug-in your Groestlcoin Full node new - Ability to plug-in your own Groestlcoin Full node through Electrum Personal Server (EPS), ElectrumX or Electrs. Don't trust, verify for a maximum sovereignty.

This application is under MIT license. There is no warranty and no party shall be made liable to you for damages. If you lose coins due to this app, no compensation will be given. Use this app solely at your own risk.

GRS BlueWallet is available in the App store:
https://apps.apple.com/us/app/grs-bluewallet/id1518766083

Source code:
https://github.com/Groestlcoin/bluewallet

GRSPay Testnet: a free and open-source cryptocurrency payment processor which allows you to receive payments in Groestlcoin Testnet with no fees, transaction cost or a middleman.

GRSPay Testnet is a non-custodial invoicing system which eliminates the involvement of a third-party. Payments with GRSPay Testnet go directly to your wallet, which increases the privacy and security. Your private keys are never uploaded to the server. There is no address re-use, since each invoice generates a new address deriving from your tpubkey or vpubkey.

GRSPay Testnet is available at https://testnet.grspay.com/
https://www.youtube.com/watch?v=c7s3zZnlQ6M

https://www.youtube.com/watch?v=qNMTDEPhWhY

Changelog v1.6.9.0
• New features:
   - Dashboard: Add Lightning balances and easy access to lightning services.
   - Dashboard: Add Point Of Sale data.
   - Greenfield: Basic API Get and Delete operations for apps.
   - Greenfield: Add Lightning balance endpoint.
   - Greenfield: Allow excluding unconfirmed UTXOs when creating a new transaction.
   - Checkout: Public invoice's receipt.
   - Can disable TLS certificate check for email servers.
   - Can add sender's name to any field accepting an email destination, for example Satoshi Nakamoto <[email protected]> rather than just [email protected].
   - Support LNURL Withdraw in payouts.
   - Can send parametized emails based on invoice events.
   - Dashboard: Added toggle button to switch to store default currency.
   - Support Lightning node connection string with onion addresses.
   - Add Refunds list to Invoice details page.
   - Point of Sale: Add discount option for Keypad view.
   - Edit Pull Payment UI.
   - Custodian Account Deposit UI.
• Bug fixes:
   - UI: Fix cancel plugin command.
   - Crowdfunding: Fix the links for the default Quake sounds.
   - UI: Fix nav height issue on mobile devices.
   - UI: Fix mark all notifications as seen return URL.
   - UI: When disabling a user, then it as an admin, attempting to remove or enable the user would fail while showing success in the UI.
   - Deleting an admin gives a 500 error, and cannot disable the same user.
   - Dashboard: Do not display archived invoices in recent invoices.
   - Error happening when broadcasting transactions weren't shown in the UI.
   - If LNURL for standard invoice was disabled, and PoS print view used, the QR code would throw error 404.
   - Fix: Cannot withdraw refund (payouts) with LNURL.
   - Fix: Cannot withdraw refund (payouts) with LN Address.
   - Fix: Missing pager in the wallet transaction list.
   - Fix: webhook "Send specific events" display issue.
   - When a payjoin label was applied, coin selection filter would not work.
   - When a payjoin happened with a receive address wallet, the payjoin label was not applied.
   - Crowdfund: Show free when invoice is fixed and 0 amount in apps.
   - Crowdfund: Animations on crowdfund not enabled broke JS.
   - Crowdfund: Perk expansion in crowdfund was broken.
   - Redirect instead of show 404 on 0 amount invoices.
   - Minor checkout UI fix.
   - Greenfield: Update webhook would reset the secret.
   - Make InvoicePaymentSettled return correct afterExpiration value.
   - Greenfield: Allow tagging a transaction even if it hasn't been yet broadcasted.
   - Ensure payout processors update state.
   - Fix edge cases around LNURL not providing invoice.
   - Fix store creation button distortion.
   - Fix payout labels.
   - Handle hold invoices in ln payouts.
   - Save preimage of ln payouts when possible.
   - Fix crash on stores that had configured a payment method that is no longer supported.
   - Fix Wallet Transactions screen not loading in case of older payout labels.
   - Fix missing route hints for LNURL.
   - Fix API Docs url.
   - Fix Pay button logo and url.
• Improvements:
   - Don't show "Set up a Lightning node" when LN is not supported.
   - Redirect to invoice details instead of list upon creation.
   - Better UI/UX for on-chain send and receive.
   - Add refund badge to invoice lists.
   - Creating and editing a payment request now redirect to the payment request list.
   - Crowdfunding: Several UI/UX improvement for the settings.
   - Improve the refund flow.
   - Improve email settings validation and UX.
   - Add spam rate limits for public invoice endpoints.
   - Greenfield doc: Adding description to speedPolicy parameter.
   - UI: Improvement of Crowdfund & PoS Modal.
   - Server Settings: Consolidate Storage and Files.
   - Move View action to the Name column in Payouts & Payment Requests.
   - UI: Properly report Shopify errors when testing new settings.
   - Mobile header improvements.
   - Notification modal improvements.
   - Improve payouts UI.
   - Update language to explicitly request view-only wallet files.
   - Open public app views in new tab/window.
   - Added HRF and Strike to the list of supporters.
   - Invoice summary: Fix indentation and heading levels.
   - A few design brush up.
   - Coin Selection: Fix responsive display.
   - Point of Sale: In the receipt, the Order Id is now a link pointing to the point of sale.
   - The invoice filter dropdown list labels should be "Settled invoice" rather than "Paid invoice".
   - If a webhook is the loopback address, skip SSL verification.
   - Add no rate found error message in Invoices.
   - Greenfield API docs improvements.

Features
• Direct, P2P Groestlcoin Testnet payments
• Lightning Network Testnet support
• Complete control over private keys
• Enchanced privacy
• SegWit Testnet support
• Process payments for others
• Payment buttons
• Point of sale
• No transaction fees (other than those for the crypto networks)
• No processing fees
• No middleman
• No KYC
• The software is built in C#
• You can run GRSPay Testnet as a self-hosted solution on your own server or use our host. The self-hosted solution allows you not only to attach an unlimited number of stores but also become the payment processor for others.
• Open Source - MIT license

This application is licensed under MIT. There is no warranty and no party shall be made liable to you for damages. If you lose coins due to this app, no compensation will be given. Use this app solely at your own risk.

Source code: https://github.com/Groestlcoin/btcpayserver

GRSPay: a free and open-source cryptocurrency payment processor which allows you to receive payments in Groestlcoin with no fees, transaction cost or a middleman.

GRSPay is a non-custodial invoicing system which eliminates the involvement of a third-party. Payments with GRSPay go directly to your wallet, which increases the privacy and security. Your private keys are never uploaded to the server. There is no address re-use, since each invoice generates a new address deriving from your xpubkey or zpubkey.

GRSPay is available at https://grspay.com
https://www.youtube.com/watch?v=c7s3zZnlQ6M

https://www.youtube.com/watch?v=qNMTDEPhWhY

Changelog v1.6.9.0
• New features:
   - Dashboard: Add Lightning balances and easy access to lightning services.
   - Dashboard: Add Point Of Sale data.
   - Greenfield: Basic API Get and Delete operations for apps.
   - Greenfield: Add Lightning balance endpoint.
   - Greenfield: Allow excluding unconfirmed UTXOs when creating a new transaction.
   - Checkout: Public invoice's receipt.
   - Can disable TLS certificate check for email servers.
   - Can add sender's name to any field accepting an email destination, for example Satoshi Nakamoto <[email protected]> rather than just [email protected].
   - Support LNURL Withdraw in payouts.
   - Can send parametized emails based on invoice events.
   - Dashboard: Added toggle button to switch to store default currency.
   - Support Lightning node connection string with onion addresses.
   - Add Refunds list to Invoice details page.
   - Point of Sale: Add discount option for Keypad view.
   - Edit Pull Payment UI.
   - Custodian Account Deposit UI.
• Bug fixes:
   - UI: Fix cancel plugin command.
   - Crowdfunding: Fix the links for the default Quake sounds.
   - UI: Fix nav height issue on mobile devices.
   - UI: Fix mark all notifications as seen return URL.
   - UI: When disabling a user, then it as an admin, attempting to remove or enable the user would fail while showing success in the UI.
   - Deleting an admin gives a 500 error, and cannot disable the same user.
   - Dashboard: Do not display archived invoices in recent invoices.
   - Error happening when broadcasting transactions weren't shown in the UI.
   - If LNURL for standard invoice was disabled, and PoS print view used, the QR code would throw error 404.
   - Fix: Cannot withdraw refund (payouts) with LNURL.
   - Fix: Cannot withdraw refund (payouts) with LN Address.
   - Fix: Missing pager in the wallet transaction list.
   - Fix: webhook "Send specific events" display issue.
   - When a payjoin label was applied, coin selection filter would not work.
   - When a payjoin happened with a receive address wallet, the payjoin label was not applied.
   - Crowdfund: Show free when invoice is fixed and 0 amount in apps.
   - Crowdfund: Animations on crowdfund not enabled broke JS.
   - Crowdfund: Perk expansion in crowdfund was broken.
   - Redirect instead of show 404 on 0 amount invoices.
   - Minor checkout UI fix.
   - Greenfield: Update webhook would reset the secret.
   - Make InvoicePaymentSettled return correct afterExpiration value.
   - Greenfield: Allow tagging a transaction even if it hasn't been yet broadcasted.
   - Ensure payout processors update state.
   - Fix edge cases around LNURL not providing invoice.
   - Fix store creation button distortion.
   - Fix payout labels.
   - Handle hold invoices in ln payouts.
   - Save preimage of ln payouts when possible.
   - Fix crash on stores that had configured a payment method that is no longer supported.
   - Fix Wallet Transactions screen not loading in case of older payout labels.
   - Fix missing route hints for LNURL.
   - Fix API Docs url.
   - Fix Pay button logo and url.
• Improvements:
   - Don't show "Set up a Lightning node" when LN is not supported.
   - Redirect to invoice details instead of list upon creation.
   - Better UI/UX for on-chain send and receive.
   - Add refund badge to invoice lists.
   - Creating and editing a payment request now redirect to the payment request list.
   - Crowdfunding: Several UI/UX improvement for the settings.
   - Improve the refund flow.
   - Improve email settings validation and UX.
   - Add spam rate limits for public invoice endpoints.
   - Greenfield doc: Adding description to speedPolicy parameter.
   - UI: Improvement of Crowdfund & PoS Modal.
   - Server Settings: Consolidate Storage and Files.
   - Move View action to the Name column in Payouts & Payment Requests.
   - UI: Properly report Shopify errors when testing new settings.
   - Mobile header improvements.
   - Notification modal improvements.
   - Improve payouts UI.
   - Update language to explicitly request view-only wallet files.
   - Open public app views in new tab/window.
   - Added HRF and Strike to the list of supporters.
   - Invoice summary: Fix indentation and heading levels.
   - A few design brush up.
   - Coin Selection: Fix responsive display.
   - Point of Sale: In the receipt, the Order Id is now a link pointing to the point of sale.
   - The invoice filter dropdown list labels should be "Settled invoice" rather than "Paid invoice".
   - If a webhook is the loopback address, skip SSL verification.
   - Add no rate found error message in Invoices.
   - Greenfield API docs improvements.

Features
• Direct, P2P Groestlcoin payments
• Lightning Network support
• Complete control over private keys
• Enchanced privacy
• SegWit support
• Process payments for others
• Easy-embeddable Payment buttons
• Point of sale app
• No transaction fees (other than those for the crypto networks)
• No processing fees
• No middleman
• No KYC
• The software is built in C#
• You can run GRSPay as a self-hosted solution on your own server or use our host. The self-hosted solution allows you not only to attach an unlimited number of stores but also become the payment processor for others.
• Open Source - MIT license

This application is licensed under MIT. There is no warranty and no party shall be made liable to you for damages. If you lose coins due to this app, no compensation will be given. Use this app solely at your own risk.

Source code: https://github.com/Groestlcoin/btcpayserver

Core lightning: A specification compliant Lightning Network implementation in C

Core lightning is a lightweight, highly customizable and standard compliant implementation of the Lightning Network protocol.
Core lightning only works on Linux and Mac OS, and requires a locally (or remotely) running groestlcoind (version 2.16.0 or above) that is fully caught up with the network you're testing on.

Changelog 0.12.0
• NEW Built-in bookkeeper plugin! This plugin tracks all movements of msats for your node, gives you a better idea of your costs and revenues, prints out CSVs that are uploadable to Koinly and CoinTracker, lets you inspect the on-chain footprint of a channel (useful when it goes to chain). Check out the new bkpr- prefixed commands.
• NEW Built-in commando plugin! This lets you create runes to allow access to your node from a commando client, which will let you send and receive RPC commands over the lightning network.
• NEW Emergency channel backup ("static backup")! Keep track of what peers you have channels with, and in case of node failure ask those peers to close the channel.
• NEW zeroconf channels are possible for whitelisted peers.
• hsmtool has a new command, checkhsm, which will let you check a BIP30 passphrase against the hsm_secret.
• Multiple log-file options will open multiple files for logging.
• Various crashes and issues fixed in connectd including crash on peer reconnect and large memory usage when many concurrent peers.
• PSBT: fixes signature encoding to comply with BIP-0174.
• We added dynamically detected public IP addresses to getinfo.
• Due to dependency issues on some platforms, a tarball of pre-generated manual pages is included with this release.

Features
• Creating channels.
• Closing channels.
• Completely managing all channel states (including the exceptional ones!).
• Performing path finding within the network, passively forwarding incoming payments.
• Sending outgoing onion-encrypted payments through the network.
• Automatic channel management (autopilot).

This application is licensed under MIT. There is no warranty and no party shall be made liable to you for damages. If you lose coins due to this app, no compensation will be given. Use this app solely at your own risk.

Ubuntu: https://github.com/Groestlcoin/lightning/blob/master/doc/INSTALL.md#to-build-on-ubuntu
Fedora: https://github.com/Groestlcoin/lightning/blob/master/doc/INSTALL.md#to-build-on-fedora
OpenBSD: https://github.com/Groestlcoin/lightning/blob/master/doc/INSTALL.md#to-build-on-openbsd
OSX: https://github.com/Groestlcoin/lightning/blob/master/doc/INSTALL.md#to-build-on-macos
Arch Linux: https://github.com/Groestlcoin/lightning/blob/master/doc/INSTALL.md#to-build-on-arch-linux
Raspberry Pi: https://github.com/Groestlcoin/lightning/blob/master/doc/INSTALL.md#to-cross-compile-for-raspberry-pi
Armbian: https://github.com/Groestlcoin/lightning/blob/master/doc/INSTALL.md#to-compile-for-armbian
Alpine: https://github.com/Groestlcoin/lightning/blob/master/doc/INSTALL.md#to-compile-for-alpine

Source code: https://github.com/Groestlcoin/lightning

Electrum-grs is a lightweight "thin client" groestlcoin wallet Android based on a client-server protocol. Its main advantages over the original Groestlcoin client include support for multi-signature wallets and not requiring the download of the entire block chain.

If you are an ordinary user of Groestlcoin and simply want the convenience of a web wallet with the security of a real application and support for multi-signature, then Electrum-GRS is the right choice for you.

Changelog 4.3.1
• Kivy GUI:
   - fix "Child Pays For Parent" not working on Android.
   - revert to defaulting the UI language to English.
   - bring kivy request dialog more in-line with Qt.
   - kivy: fix deleting "local" tx from history.
   - kivy: fix paying amountless LN invoice.
   - kivy: dust-valued requests could not be created for LN.

Features
• Encrypted wallet - the file that contains your groestlcoins is protected with a password. You are protected from thieves.
• Deterministic key generation - If you lose your wallet, you can recover it from its seed. You are protected from your own mistakes.
• Instant on - the client does not download the blockchain, it requests that information from a server. No delays, always up-to-date.
• Freedom and Privacy - The server does not store user accounts. You are not tied to a particular server, and the server does not need to know you.
• No scripts - Electrum-GRS does not download any script. A compromised server cannot send you arbitrary code and steal your groestlcoins.
• No single point of failure - The server code is open source, anyone can run a server.
• Transactions are signed locally - Your private keys are not shared with the server. You do not have to trust the server with your money.
• Firewall friendly - The client does not need to open a port, it simply polls the server for updates.
• Free software - Gnu GPL v3. Anyone can audit the code.
• Written in Python - The code is short, and easy to review.
• User Friendly - Support for Groestlcoin URIs, signed URIs and Groestlcoin aliases
• No Lock-In - You can export your private keys and use them in other groestlcoin clients.
• No Downtimes - Electrum-GRS servers are decentralized and redundant. Your wallet is never down.
• Proof Checking - Electrum-GRS Wallet verifies all the transactions in your history using SPV.
• Cold Storage - Keep your private keys offline, and go online with a watching-only wallet. Sign transactions from a computer that is always offline. Broadcast them from a machine that does not have your keys.
• Multisign - Split the permission to spend your coins between several wallets using parallel BIP32 derivations and P2SH addresses ("2 of 2", "2 of 3"). Compact serialization format for unsigned or partially signed transactions, that includes the BIP32 master public key and derivation needed to sign inputs. Serialized transactions can be sent to cosigners or to cold storage using QR codes

This application is licensed under the GPL version 3. There is no warranty and no party shall be made liable to you for damages. If you lose coins due to this app, no compensation will be given. Use this app solely at your own risk.

Important:
Store your secret phrase somewhere safe!
The multi-signature and non native segwit addresses starts with a "3" and not with a "F".

Electrum-GRS is available in the Google play store:
https://play.google.com/store/apps/details?id=org.groestlcoin.electrumgrs

Source code:
GitHub Source server: https://github.com/spesmilo/electrumx
Github Source server installer: https://github.com/Groestlcoin/electrumx-grs-installer
Github Source client: https://github.com/Groestlcoin/electrum-grs

Electrum-grs is a lightweight "thin client" groestlcoin wallet Windows, MacOS and Linux based on a client-server protocol. Its main advantages over the original Groestlcoin client include support for multi-signature wallets and not requiring the download of the entire block chain.

If you are an ordinary user of Groestlcoin and simply want the convenience of a web wallet with the security of a real application and support for multi-signature, then Electrum-GRS is the right choice for you.

Changelog 4.3.1
• This version introduces a set of UI modifications that simplify the use of Lightning. The idea is to abstract payments from the payment layer, and to suggest solutions when a lightning payment is hindered by liquidity issues:
    - Invoice unification: on-chain and lightning invoices have been merged into a unique type of invoice, and the GUI has a single 'create request' button. Unified invoices contain both a lightning invoice and an onchain fallback address.
    - The receive tab of the GUI can display, for each payment request, a lightning invoice, a BIP21 URI, or an onchain address. If the request is paid off-chain, the associated on-chain address will be recycled in subsequent requests.
    - The receive tab displays whether a payment can be received using Lightning, given the current channel liquidity. If a payment cannot be received, but may be received after a channel rebalance or a submarine swap, the GUI will propose such an operation.
    - Similarly, if channels do not have enough liquidity to pay a lightning invoice, the GUI will suggest available alternatives: rebalance existing channels, open a new channel, perform a submarine swap, or pay to the provided onchain fallback address.
    - A single balance is shown in the GUI. A pie chart reflects how that balance is distributed (on-chain, lightning, unconfirmed, frozen, etc).
    - The semantics of the wallet balance has been modified: only incoming transactions are considered in the 'unconfirmed' part of the balance. Indeed, if an outgoing transaction does not get mined, that is not going to decrease the wallet balance. Thus, change outputs of outgoing transactions are not subtracted from the confirmed balance. (Before this change, the arithmetic values of both incoming and outgoing transactions were added to the unconfirmed balance, and could potentially cancel each other.)
• Exchange
   - Added Coinbase exchange
   - Removed Binance exchange
• Binaries:
   - Windows: we are dropping support for Windows 7. Version 4.2.0 already unintentionally broke compatibility with Win7 and there is no easy way to restore and maintain support. Existing users can keep using version 4.1.5 for now, but should consider upgrading or changing their OS. Win8.1 still works but only Win10 is regularly tested.
   - bump bundled Python version (win, mac, appimage) to 3.9.11, (android) to 3.8.13. (note these include a fix to an openssl DOS-vector CVE-2022-0778)
   - windows: bump pyinstaller to 4.10 and wine to 7.0.
   - Appimage: fix the "--portable" flag for AppImage, and for pip installs.
   - Appimage: fix AppImage failing to run on certain systems.
   - Source-only: we now also distribute a "source-only" Linux-packager-friendly tarball, in addition to the current "normal" tarball. The "source-only" tarball excludes compiled locale files, generated protobuf files, and does not vendor our runtime python dependencies (the packages/ folder).
   - Linux: fix os.chmod when running in tmpfs on Linux.
• Qt GUI:
   - macOS: fix opening "Preferences" segfaulting for some.
   - more resilient startup: better error-handling and fallback.
   - some improvements for high-DPI monitors.
   - fix duplication of some OS notifications on onchain txs.
   - better handle unparseable URIs.
• Library:
   - fix LN error/warning message-handling, and fix regression that errors during channel-open were not properly shown in GUI.
   - during LN chan open, do not backup wallet automatically.
   - Imported wallets: fix delete_address removing too many txs.
   - fix potential deadlock in wallet.py.
   - fix "Automated BIP39 recovery" not scanning change paths.
   - labels of payment requests were not propagated to history/addresses.
   - better default labels of outgoing txs.
   - bypass network proxy for localhost electrum server.
   - security fix: remove support of "file://" URIs from BIP70 payment requests, which could be used to trigger "open()" on arbitrary files (see https://github.com/spesmilo/electrum/security/advisories/GHSA-4fh4-hx35-r355)
• Hardware wallets:
   - ledger: add progress indicator to sign_transaction.
   - smarter pairing during sign_transaction.
   - keepkey: fix pairing with device using a workaround.
• Lightning:
   - watching onchain outputs: significant perf. improvements.
   - enforce relative order of some msgs during chan reestablishment, lack of which can lead to unwanted force-closures.
   - fix: in case of a force-close containing incoming HTLCs, we were redeeming all HTLCs that we know the preimage for. This might publish the preimage of an incomplete MPP.
   - support for LNURL-pay (LUD-06)
   - updated trampoline feature bit in invoices.
   - the claim transactions of reverse swaps are not broadcast until the parent transaction is confirmed. This can be overridden by manually broadcasting the local transaction.
   - the fee of submarine swap transactions can be bumped.
   - better error handling for trampoline payments, which should improve payment success rate.
   - channel backups are removed automatically when the corresponding channel is redeemed.
   - remove support of "legacy" (without static_remotekey) LN channels. Opening these channels were never supported in a release version, only during development prior to the first lightning-capable release. Wallets with such channels will have to close them.
   - handle NotEnoughFunds when trying to pay LN invoice.
   - handle NotEnoughFuds when trying to open LN channel.
   - when closing LN channels, future (timelocked) txs were not shown in history.

Features
• Encrypted wallet - the file that contains your groestlcoins is protected with a password. You are protected from thieves.
• Deterministic key generation - If you lose your wallet, you can recover it from its seed. You are protected from your own mistakes.
• Instant on - the client does not download the blockchain, it requests that information from a server. No delays, always up-to-date.
• Freedom and Privacy - The server does not store user accounts. You are not tied to a particular server, and the server does not need to know you.
• No scripts - Electrum-GRS does not download any script. A compromised server cannot send you arbitrary code and steal your groestlcoins.
• No single point of failure - The server code is open source, anyone can run a server.
• Transactions are signed locally - Your private keys are not shared with the server. You do not have to trust the server with your money.
• Firewall friendly - The client does not need to open a port, it simply polls the server for updates.
• Free software - Gnu GPL v3. Anyone can audit the code.
• Written in Python - The code is short, and easy to review.
• User Friendly - Support for Groestlcoin URIs, signed URIs and Groestlcoin aliases
• No Lock-In - You can export your private keys and use them in other groestlcoin clients.
• No Downtimes - Electrum-GRS servers are decentralized and redundant. Your wallet is never down.
• Proof Checking - Electrum-GRS Wallet verifies all the transactions in your history using SPV.
• Cold Storage - Keep your private keys offline, and go online with a watching-only wallet. Sign transactions from a computer that is always offline. Broadcast them from a machine that does not have your keys.
• Multisign - Split the permission to spend your coins between several wallets using parallel BIP32 derivations and P2SH addresses ("2 of 2", "2 of 3"). Compact serialization format for unsigned or partially signed transactions, that includes the BIP32 master public key and derivation needed to sign inputs. Serialized transactions can be sent to cosigners or to cold storage using QR codes

This application is licensed under the GPL version 3. There is no warranty and no party shall be made liable to you for damages. If you lose coins due to this app, no compensation will be given. Use this app solely at your own risk.

Important:
Store your secret phrase somewhere safe!
The multi-signature and non native segwit addresses starts with a "3" and not with a "F".
Electrum-GRS creates an encrypted filename default_wallet instead of wallet.dat (like in Groestlcoin Core)
• Location Windows: Navigate to C:\Users\USER NAME\AppData\Roaming\Electrum-grs\wallets (or open windows explorer and enter %appdata%\Electrum-grs\wallets) and back up your default_wallet file by making a copy of it and moving it to a secure location.
• Location Mac: Navigate to ~/Library/Application Support/Electrum-grs/wallets and back up your default_wallet file by making a copy of it and moving it to a secure location.

You can download it using the links below and be up and running with Groestlcoin in 5 minutes.

Download the OSX wallet here: https://github.com/Groestlcoin/electrum-grs/releases/download/v4.3.1/electrum-grs-4.3.1.dmg

Download Windows installer here: https://github.com/Groestlcoin/electrum-grs/releases/download/v4.3.1/electrum-grs-4.3.1-setup.exe
Download Windows standalone wallet here: https://github.com/Groestlcoin/electrum-grs/releases/download/v4.3.1/electrum-grs-4.3.1.exe
Download Windows portable version here: https://github.com/Groestlcoin/electrum-grs/releases/download/v4.3.1/electrum-grs-4.3.1-portable.exe
                                       
Download Linux installer here: https://github.com/Groestlcoin/electrum-grs/releases/download/v4.3.1/electrum-grs-4.3.1-x86_64.AppImage

Source code:
GitHub Source server: https://github.com/spesmilo/electrumx
Github Source server installer: https://github.com/Groestlcoin/electrumx-grs-installer
Github Source client: https://github.com/Groestlcoin/electrum-grs

Groestlcoin Electrum Personal Server: Maximally lightweight electrum-grs server for a single user

Groestlcoin Electrum Personal Server aims to make using Electrum groestlcoin wallet more secure and more private. It makes it easy to connect your Electrum-GRS wallet to your own full node.
It is an implementation of the Electrum-grs server protocol which fulfills the specific need of using the Electrum-grs wallet backed by a full node, but without the heavyweight server backend, for a single user. It allows the user to benefit from all of Groestlcoin Core's resource-saving features like pruning, blocksonly and disabled txindex. All of Electrum-GRS's feature-richness like hardware wallet integration, multisignature wallets, offline signing, seed recovery phrases, coin control and so on can still be used, but connected only to the user's own full node.
Full node wallets are important in groestlcoin because they are an big part of what makes the system be trustless. No longer do people have to trust a financial institution like a bank or paypal, they can run software on their own computers. If groestlcoin is digital gold, then a full node wallet is your own personal goldsmith who checks for you that received payments are genuine.
Full node wallets are also important for privacy. Using Electrum-GRS under default configuration requires it to send (hashes of) all your groestlcoin addresses to some server. That server can then easily spy on your transactions. Full node wallets like Groestlcoin Electrum Personal Server would download the entire blockchain and scan it for the user's own addresses, and therefore don't reveal to anyone else which groestlcoin addresses they are interested in. Groestlcoin Electrum Personal Server can also broadcast transactions through Tor which improves privacy by resisting traffic analysis for broadcasted transactions which can link the IP address of the user to the transaction. If enabled this would happen transparently whenever the user simply clicks "Send" on a transaction in Electrum-grs wallet.

Changelog 0.2.4
• Fixed crash caused by deprecated RPC in Groestlcoin Core 23.0
• Added signet support

Features:
• Use your own node
• Tor support
• Uses less CPU and RAM than electrumx
• Used intermittently rather than needing to be always-on
• Doesn't require an index of every groestlcoin address ever used like on electrumx

How To
• If you dont already have them, download and install Groestlcoin Core version 2.17.2 or higher. The Groestlcoin node must have wallet enabled, and must have the RPC server switched on (server=1 in groestlcoin.conf). On first run, it is recommended to create a wallet dedicated to Groestlcoin Electrum Personal Server using the command line argument groestlcoin-cli createwallet electrumpersonalserver true.
• If you dont already have it, download and install Electrum-grs wallet, and set up your Electrum-grs wallet (for example by linking your hardware wallet). To avoid damaging privacy by connecting to public Electrum-GRS servers, disconnect from the internet first or run Electrum-grs with the command line argument --server localhost:50002:s.
• Download the latest release of Groestlcoin Electrum Personal Server. If using Windows OS take the packaged binary release build electrum-grs-personalserver-windows-release-XXX.zip.
• Extract and enter the directory, and copy the file config.ini_sample to config.ini. Edit the file config.ini to configure everything about the server. Add your wallet master public keys or watch-only addresses to the [master-public-keys] and [watch-only-addresses] sections. Master public keys for an Electrum-grs wallet (which start with xpub/ypub/zpub/etc) can be found in the Electrum-grs client menu Wallet -> Information. You can add multiple master public keys or watch-only addresses by adding separate lines for the different keys/addresses:
wallet1 = xpub661MyMwAqRbcF...
wallet2 = xpub7712KLsfsg46G...
• If you created a wallet dedicated to Groestlcoin Electrum Personal Server in Groestlcoin Core, you have to modify the line wallet_filename in the [groestlcoin-rpc] section with the name of the wallet, for example electrumpersonalserver.
• If using the windows packaged binary release, drag the file config.ini onto the file electrum-personal-server.exe to run the server, or on the command line run electrum-personal-server config.ini.
• If installing from the source release, install Groestlcoin Electrum Personal Server in your home directory with pip3 install --user .. On Linux the script electrum-personal-server will be installed in ~/.local/bin. Please note, if for some reason, you want to make a system-wide install, simply run pip3 install . as root (e.g. if you have sudo setup, you could use: sudo pip3 install .). Run electrum-personal-server /path/to/config.ini to start Groestlcoin Electrum Personal Server.
• The first time the server is run it will import all configured addresses as watch-only into the Groestlcoin node, and then exit. If the wallets contain historical transactions you can use the rescan script (electrum-personal-server --rescan /path/to/config.ini) to make them appear. If using the windows packaged binary release build then drag the file config.ini onto the file electrum-personal-server-rescan.bat.
• Run the server again which will start Groestlcoin Electrum Personal Server. Wait until the message Listening for Electrum-grs Wallet ... appears and then tell Electrum-grs to connect to the server in Tools -> Server. By default the server details are localhost if running on the same machine. Make sure the port number matches what is written in config.ini (port 50002 by default).

This application is licensed under the MIT license. There is no warranty and no party shall be made liable to you for damages. If you lose coins due to this app, no compensation will be given. Use this app solely at your own risk.

Windows: https://github.com/Groestlcoin/electrum-personal-server/releases/download/eps-v0.2.4-grs/electrum-grs-personal-server-windows-release-v0.2.4.zip
Linux: https://github.com/Groestlcoin/electrum-personal-server#quick-start-on-a-debianubuntu-machine-with-a-running-groestlcoin-full-node
OSX: https://github.com/Groestlcoin/electrum-personal-server#quick-start-on-a-debianubuntu-machine-with-a-running-groestlcoin-full-node

Note: Right now Groestlcoin Electrum Personal Server can only accept one connection at a time.

Source code: https://github.com/Groestlcoin/electrum-personal-server

GRSPay Testnet: a free and open-source cryptocurrency payment processor which allows you to receive payments in Groestlcoin Testnet with no fees, transaction cost or a middleman.

GRSPay Testnet is a non-custodial invoicing system which eliminates the involvement of a third-party. Payments with GRSPay Testnet go directly to your wallet, which increases the privacy and security. Your private keys are never uploaded to the server. There is no address re-use, since each invoice generates a new address deriving from your tpubkey or vpubkey.

GRSPay Testnet is available at https://testnet.grspay.com/
https://www.youtube.com/watch?v=c7s3zZnlQ6M

https://www.youtube.com/watch?v=qNMTDEPhWhY

Changelog v1.5.4.0
• New dashboard
• Wallet transactions export
• Allow resending verification email for users
• Allow Users to be disabled/enabled
• Add additional rate providers as supported from CoinGecko

Features
• Direct, P2P Groestlcoin Testnet payments
• Lightning Network Testnet support
• Complete control over private keys
• Enchanced privacy
• SegWit Testnet support
• Process payments for others
• Payment buttons
• Point of sale
• No transaction fees (other than those for the crypto networks)
• No processing fees
• No middleman
• No KYC
• The software is built in C#
• You can run GRSPay Testnet as a self-hosted solution on your own server or use our host. The self-hosted solution allows you not only to attach an unlimited number of stores but also become the payment processor for others.
• Open Source - MIT license

This application is licensed under MIT. There is no warranty and no party shall be made liable to you for damages. If you lose coins due to this app, no compensation will be given. Use this app solely at your own risk.

Source code: https://github.com/Groestlcoin/btcpayserver