FedorIvanov37 / signal

Current working branch
0 stars 0 forks source link

Signal

Signal user reference guide

This guide describes the Signal basic concept, usage, settings, and library re-usage

The document is currently under construction

Contents

SIGNAL

SIGNAL general overview

The Signal simplifies the sending of banking card e-commerce transactions to banking card processing systems using a useful visual and program interface

The SIGNAL uses ISO-8583 E-pay protocol for transactions sending, instead of PSP. It can be used during the Payment Systems certification test, for checking and setting up the system on the test environment, during the application development process, and so on

Also, the Signal builds like a kit of weakly connected modules like a Parser, Connector, Queue, etc. It allows to reuse or extend the Signal's functionality making emulators, loaders, parsers, converters, application interfaces, and many other things based on Signal modules

UBC SV API is a good example of using SIGNAL modules without any GUI

See more in the chapter About the Signal

In case of any questions about SIGNAL contact the author. Your feedback and suggestions are general drivers of the Signal evolution

Important notes

Release info

What's new is the Signal v0.18

Graphic User Interface

GUI overview

⚠️Only Windows x64 build exists. Use the source code to run SIGNAL on another platform. Tests were done on Windows 10-11 only

SIGNAL GUI is a friendly interface, based on the SIGNAL library. Since v0.15 SIGNAL GUI is released as a binary .exe file. No dependencies need to run the SIGNAL, it is ready to use from the box. No installation or settings are needed to run SIGNAL GUI on a Windows machine. Run the signal.exe executable file to start the SIGNAL

Check the parameters, opened by the "Configuration" button to make your settings

image

Main Window

Main Window overview

Complex fields parser

Reversal

Transactions auto-repeat

Search line

Print data

Fields generators

Secret features

Specification Window

Specification Window overview

Field parameters

Extended field parameters

MTI settings

Set specification

Save specification

Settings Window

Settings Window overview

Triggers

Validations

Windows hotkeys

The list of key sequences and corresponding actions

Key sequence MainWindow SpecWindow
F1 About SIGNAL -
Ctrl + Enter Send transaction -
Ctrl + Shift + Enter Reverse last transaction -
Ctrl + Alt + Enter Send Echo-Test -
Ctrl + N Add new field Add new field
Ctrl + Shift + N Add new subfield Add new subfield
Ctrl + Shift + V Validate current message -
Ctrl + F Search Search
Delete Remove field Remove field
Ctrl + E Edit current field data Edit current field description
Ctrl + W Edit current field number Edit current field number
Ctrl + R Reconnect to host -
Ctrl + L Clear log Clear log
Ctrl + O Open transaction file(s) Open specification file
Ctrl + S Save transaction(s) to file(s) Backup current specification
Ctrl + P Print transaction -
Ctrl + T Open new tab -
Ctrl + PgDn / Ctrl + Tab Next tab -
Ctrl + PgUp / Ctrl + Shift + Tab Previous tab -
Ctrl + F4 Close current tab -
Ctrl + Alt + Q Quit SIGNAL -

Command Line Interface

The SIGNAL can be run in Command Line Interface mode (CLI) by usage of specific flags -c or --console. In CLI mode GUI will not be run, all the output will be placed in the command line instead. CLI mode is useful when some external tool or script needs to send a transaction without the usage of GUI. The CLI mode targets simplified integration for the ISO test system

The console-mode flag -c or --console is required to run CLI mode (see examples). In case of the absence of console-mode flags GUI mode will be run by default

Flags -h or --help --about do not require console-mode flags

CLI Usage

Important: The Windows command line does not support combinations of command line keys. Each key should be added separately

For example, the following incorrect command will return an error, while the correct one will work as expected

Correct Incorrect
signal.exe -c -r -i 2 signal.exe -cri 2

It is recommended to use long keys like --console instead of -c, --repeat instead of -r, and so on. The short keys do the same, but such commands are not easy to read and the scenario is not always transparent

To see usage hint call

signal.exe --help

usage: signal.exe [-h] -c [-f FILE] [-d DIR] [-a ADDRESS] [-p PORT] [-r] [-l LOG_LEVEL] [-i INTERVAL] [--parallel] [-t TIMEOUT] [--about] [-e] [--default] [-v] [--print-config] [--config-file CONFIG_FILE]

SIGNAL v0.18

options:
  -h, --help            show this help message and exit
  -c, --console         Run SIGNAL in Command Line Interface mode
  -f FILE, --file FILE  File or file-mask to parse
  -d DIR, --dir DIR     Directory with files to parse. SIGNAL will try all of the files from the directory
  -a ADDRESS, --address ADDRESS
                        Host TCP/IP address
  -p PORT, --port PORT  TCP/IP port to connect
  -r, --repeat          Repeat transactions after sending
  -l LOG_LEVEL, --log-level LOG_LEVEL
                        Debug level DEBUG, INFO, etc
  -i INTERVAL, --interval INTERVAL
                        Wait (seconds) before send next transaction
  --parallel            Send new transaction with no waiting of answer for previous one
  -t TIMEOUT, --timeout TIMEOUT
                        Timeout of waiting resp
  --about               Show info about the SIGNAL
  -e, --echo-test       Send echo-test
  --default             Send default transaction message
  -v, --version         Print current version of SIGNAL
  --print-config        Print configuration parameters
  --config-file CONFIG_FILE
                        Set configuration file path

CLI examples

Below are a few examples of CLI commands. It is not a complete list of possible combinations. See CLI Usage to get all the commands

Command examples

Command Action
signal.exe --console --default Send default transaction to the host
signal.exe --console --echo-test Send echo-test to the host
signal.exe --console --about Show info about the SIGNAL
signal.exe --console --file /transactions/transaction.json Parse specific file /transactions/transaction.json and send the transaction to the host
signal.exe --console --default --repeat --interval 2 Begin transaction loop, sending new transaction every 2 sec
signal.exe --console --dir /transactions --parallel Immediate send all the transactions from the directory /transactions

CLI output

In CLI mode SIGNAL prints the output at the console and to the log as well. The debug level can be set by --log-level key, see usage

See examples of output below

️signal.exe --console --about

```text PS C:\signal> signal.exe --console --about 02:57:15 [INFO] 02:57:15 [INFO] :::::::: ::::::::::: :::::::: :::: ::: ::: ::: 02:57:15 [INFO] :+: :+: :+: :+: :+: :+:+: :+: :+: :+: :+: 02:57:15 [INFO] +:+ +:+ +:+ :+:+:+ +:+ +:+ +:+ +:+ 02:57:15 [INFO] +#++:++#++ +#+ :#: +#+ +:+ +#+ +#++:++#++: +#+ 02:57:15 [INFO] +#+ +#+ +#+ +#+# +#+ +#+#+# +#+ +#+ +#+ 02:57:15 [INFO] #+# #+# #+# #+# #+# #+# #+#+# #+# #+# #+# 02:57:15 [INFO] ######## ########### ######## ### #### ### ### ########## 02:57:15 [INFO] 02:57:15 [INFO] Simplified ISO generation algorithm v0.18 02:57:15 [INFO] 02:57:15 [INFO] Use only on test environment 02:57:15 [INFO] 02:57:15 [INFO] Version v0.18 02:57:15 [INFO] 02:57:15 [INFO] Released in May 2024 02:57:15 [INFO] 02:57:15 [INFO] Developed by Fedor Ivanov 02:57:15 [INFO] 02:57:15 [INFO] Contact fedornivanov@gmail.com 02:57:15 [INFO] ```

signal.exe --console --echo-test

```text PS C:\signal> signal.exe --console --echo-test 03:05:12 [INFO] ## Running SIGNAL in Console mode ## 03:05:12 [INFO] Press CTRL+C to exit 03:05:12 [INFO] 03:05:12 [INFO] 03:05:12 [INFO] Processing file echo-test.json 03:05:12 [WARNING] Host disconnected. Trying to establish the connection 03:05:12 [INFO] Connection ESTABLISHED 03:05:12 [INFO] 03:05:12 [INFO] [TRANS_ID][20240414_030512_8695314843] 03:05:12 [INFO] [MSG_TYPE][0800] 03:05:12 [INFO] [BITMAP ][7, 11, 70] 03:05:12 [INFO] [007][010][0414030512] 03:05:12 [INFO] [011][006][615012] 03:05:12 [INFO] [070][003][301] 03:05:12 [INFO] 03:05:12 [INFO] Outgoing transaction ID [20240414_030512_8695314843] sent 03:05:13 [INFO] Incoming transaction ID [20240414_030512_8695314843] received 03:05:13 [INFO] 03:05:13 [INFO] [TRANS_ID][20240414_030512_8695314843] 03:05:13 [INFO] [MSG_TYPE][0810] 03:05:13 [INFO] [BITMAP ][7, 11, 39, 70] 03:05:13 [INFO] [007][010][0414030512] 03:05:13 [INFO] [011][006][615012] 03:05:13 [INFO] [039][002][00] 03:05:13 [INFO] [070][002][30] 03:05:13 [INFO] 03:05:13 [INFO] Transaction ID [20240414_030512_8695314843] matched, response time seconds: 1.082 ```

️signal.exe --console --print-config

```text PS C:\signal> signal.exe --console --print-config 17:01:33 [INFO] ## Configuration parameters ## 17:01:33 [INFO] 17:01:33 [INFO] Path: common/data/settings/config.json 17:01:33 [INFO] 17:01:33 [INFO] Data: 17:01:33 [INFO] { 17:01:33 [INFO] "host": { 17:01:33 [INFO] "host": "172.21.30.5", 17:01:33 [INFO] "port": 16677, 17:01:33 [INFO] "keep_alive_mode": false, 17:01:33 [INFO] "keep_alive_interval": 300, 17:01:33 [INFO] "header_length": 2, 17:01:33 [INFO] "header_length_exists": true 17:01:33 [INFO] }, 17:01:33 [INFO] "terminal": { 17:01:33 [INFO] "process_default_dump": true, 17:01:33 [INFO] "connect_on_startup": true, 17:01:33 [INFO] "load_remote_spec": false 17:01:33 [INFO] }, 17:01:33 [INFO] "debug": { 17:01:33 [INFO] "level": "INFO", 17:01:33 [INFO] "clear_log": true, 17:01:33 [INFO] "parse_subfields": false, 17:01:33 [INFO] "backup_storage_depth": 10 17:01:33 [INFO] }, 17:01:33 [INFO] "validation": { 17:01:33 [INFO] "validation_enabled": true, 17:01:33 [INFO] "validate_window": true, 17:01:33 [INFO] "validate_incoming": true, 17:01:33 [INFO] "validate_outgoing": true, 17:01:33 [INFO] "validation_mode": "WARNING" 17:01:33 [INFO] "rewrite_local_spec": false, 17:01:33 [INFO] "remote_spec_url": "http://172.21.30.20:4242/specification", 17:01:33 [INFO] "backup_storage_depth": 30, 17:01:33 [INFO] "backup_storage": false, 17:01:33 [INFO] "manual_input_mode": false 17:01:33 [INFO] } 17:01:33 [INFO] } 17:01:33 [INFO] 17:01:33 [INFO] ## End of configuration parameters ## 17:01:33 [INFO] 17:01:33 [INFO] ## Running SIGNAL in Console mode ## 17:01:33 [INFO] Press CTRL+C to exit ```

Library re-usage

The Signal is built as a library of weakly connected modules. The modules can be used separately, allowing to develop or improve other solutions by the Signal package

The Signal uses the PyQt6 as a core even if the application does not have any GUI. Before usage, the modules refer to the Resources chapter and make an acquaintance with basic PyQt6 and Pydantic concepts. Otherwise, if you are already familiar with those packages, just go forth

Requirements

Unlike GUI the Signal library requires you to install dependencies, defined in the "requirements.txt" file from the Signal's root directory. See the actual dependencies in the file, here are listed requirements, which are actually for Signal v0.18

The following dependencies are required to install to run the library

Dependency Version Higher version allowed
Python 3.12 Yes
PyQt6 6.6.1 Yes
Pydantic 2.6.3 Yes

Refer to chapter Library installation to figure the dependencies installation process out

Library installation

To install all the dependencies by one command change the directory to the Signal's root, make sure that the "requirements.txt" file exists in the directory, then run the following command.

pip install -r requirements.txt

It is also possible to read the file and install the modules manually

Modules purpose

Logging

Modules usage example

This chapter describes the minimal working code example. It is highly recommended to use Python virtual environment to run the application

Preparation

To prepare for library usage first you have to create and activate the Python virtual environment then install all the dependencies

Create and activate Python virtual environment

C:\signal> python -m venv C:\signal\signal_virtual_env # Create a new virtual environment

C:\signal> C:\signal\signal_virtual_env\Scripts\activate # Activate the virtual environment

Install the dependencies from requirements.txt into the virtual environment

(signal_virtual_env) C:\signal> pip install -r requirements.txt

The preparation is finished, now is possible to run the Code examples

Code examples

The library can be used for its intended purpose, sending the ISO 8583 transactions

️Minimal code example - send the single transaction from the default file ```python from common.lib.data_models.Config import Config from common.lib.enums.TermFilesPath import TermFilesPath from common.lib.core.Terminal import Terminal from common.lib.data_models.Transaction import Transaction from common.lib.core.FieldsGenerator import FieldsGenerator """ The Signal library minimal code example - sends the single transaction from the default file This script does not run QApplication and QEventLoop. Due to that, the script cannot wait for the answer, also the signal-slot model cannot be used The code examples is ready to begin without any changes """ # Create Config object. The Config is a crucial data object, contains basic settings for all the application config: Config = Config.parse_file(TermFilesPath.CONFIG) # After the config is created you can set the parameters as you prefer # e.g.: config.host.port = 16677 and so on # The Terminal - core of the application, which will be used for sending the transaction terminal: Terminal = Terminal(config) # This object will update transaction fields to avoid transaction duplicates data_generator = FieldsGenerator() # Parse default transaction file transaction: Transaction = Transaction.parse_file(TermFilesPath.DEFAULT_FILE) # Update fields dynamic values such as ID, date and so on transaction: Transaction = data_generator.set_generated_fields(transaction) # Send the previously-made transaction to the host terminal.send(transaction) # exit ```
More complex example, with usage PyQt6 features, logging, and so on ```python from PyQt6.QtCore import QCoreApplication, QTimer from common.lib.data_models.Config import Config from common.lib.enums.TermFilesPath import TermFilesPath from common.lib.core.Terminal import Terminal from common.lib.data_models.Transaction import Transaction from common.lib.core.FieldsGenerator import FieldsGenerator from common.lib.core.Logger import Logger """ A bit more complex example, with usage PyQt6 features, logging, and so on This script not runs QApplication and QEventLoop. Due to that, the script will wait for the answer, also the signal-slot model can be used This example illustrates the creation of the PyQt application, which is run and ready for interaction in PyQt style The code examples is ready to begin without any changes """ # The objects preparation # In case when your solution does not use GUI it is required to create QCoreApplication and set in on the Terminal application = QCoreApplication([]) # Create the Signal PyQt application # Create Config object. The Config is a crucial data object, contains basic settings for all the application config: Config = Config.parse_file(TermFilesPath.CONFIG) # After the config is created you can set the parameters as you prefer # e.g.: config.host.port = 16677 and so on # The Terminal - core of the application, which will be used for sending the transaction terminal: Terminal = Terminal(config=config, application=application) # Send previously-made QCoreApplication # Set the default screen logger up Logger().create_logger() # This object will update transaction fields to avoid transaction duplicates data_generator = FieldsGenerator() # Parse default transaction file transaction: Transaction = Transaction.parse_file(TermFilesPath.DEFAULT_FILE) # Update fields dynamic values such as ID, date and so on transaction: Transaction = data_generator.set_generated_fields(transaction) # Create a delayed start timer. This workaround will help to begin the task after the application is started timer = QTimer() # This timer will be processed in QEventloop right after the application is executed timer.setSingleShot(True) # It signals once the application start timer.timeout.connect(lambda: terminal.send(transaction)) # Transaction will be one of the first events timer.start(0) # Signals timeout immediately # Finally run the application, which begin the QEventloop and send the transaction # Due to the part below the application proceed to work, processing PyQt events and signals terminal.run() # Run the QCoreApplication ```

Also, the modules can be valuable in ISO 8583 transaction data processing, without sending the transaction

Generate transaction data-dumps
Convert complicated data-dump files to useful JSON representation
Validate transaction data files

In this chapter, only the basic possibilities of the Signal library were illustrated. There are a huge amount of other options to use the Signal's library as a transactional generator or transactions data processing tool

Compilation of executable binary

Recommendations

Data models

The signal uses Pydantic data models to manipulate the data. The signal uses Pydantic data models to manipulate the data. This chapter described the main data models, their requirements, and validations

Transaction

Config

Specification

Specification settings

Specification Overview

This chapter describes the specification settings and maintenance. Refer to SVFE E-pay specification for more info.

The Specification is a root data structure, describing data processing mechanics, such as fields hierarchy, types, validation, and other things. SIGNAL needs the correct settings in the Specification for regular work. From v0.15 specification settings are required for transaction processing.

The specification can be set using the button "Specification" of MainWindow. Settings through GUI are highly recommended by the author.

Settings description

image

The table below describes the settings window columns from left to right

Field Purpose Used to Type Mandatory
Field The field or subfield number Define main fields structure, describe fields nesting Number Yes
Description Free text field purpose explanation Show field description on MainWindow transaction constructor Text, no min or max length No
Min Len Field value minimum length Fields validation during data processing Number, min value is 1 Yes
Max Len Field value maximum length Fields validation during data processing Number, min value is 1 Yes
Data Len Applicable for variable-length fields. This means count numbers mark the field's own length. Should be taken from the E-pay specification document. In the specification usually marks as LLVAR - 2 digits, LLLVAR - 3 digits, and so on Message construction, Fields validation, Message parsing Number, min value is 0 Yes
Tag Len For complex fields only (field should contain subfields). This means count numbers mark. In the specification usually marked as LLVAR - 2 digits, LLLVAR - 3 digits, and so on. Tag Len of the field should be equal to the field's own Data Len Message construction, Fields validation, Message parsing Number, min value is 0 Yes
Alpha Are the alphabetic letters allowed in this field Fields validation Checkbox Yes
Numeric Are the digits allowed in this field Fields validation Checkbox Yes
Special Are the special characters allowed in this field Fields validation Checkbox Yes
Matching If yes the field will be used for matching requests and responses. It means SIGNAL, sending the transaction expects the same field value in the SV response Message matching Checkbox Yes
Reversal When Yes then the field value will be taken from the original message and put to the reversal in case of reversal Message matching, message construction Checkbox Yes
Generated Can the fields be auto-generated by SIGNAL before sending? If yes then the corresponding checkbox appears in Main Window¹ Message construction Checkbox Yes
Secret If yes field value will be hidden in the log, transaction constructor, and on MainWindow display³ Display data, log writing Checkbox Yes

¹ Currently, SIGNAL supports randomly generated field values only. No date-time and other specific format are supported, except pre-defined fields 7 and 11

² Due to security reasons, it is impossible to set Primary Account Number (Field 2) as non-secret. The field has a non-removable "secret" mark

Specification backup

Remote specification

The local specification JSON file always is at the path common/data/settings/specification.json, however, SIGNAL can get general specification JSON remotely on the startup stage and by the user's request in SpecWindow. The specification URL should be set in the settings. In case when the remote specification is set by settings but the SIGNAL is unable to get remote specification data the local spec data will be taken instead from the "settings" directory

SIGNAL can get general specification JSON remotely on the startup stage and by the user's request in SpecWindow. The specification URL should be set in the settings.

In general, the specification endpoint has to return the Spec JSON by GET request without any additional actions

The conditions for the remote spec endpoint:

Remote specification endpoint setting

The following code illustrates the endpoint example. In this example, endpoint http://127.0.0.1:4242/specification returns specification file data /opt/spec/specification.json

To begin remote specification endpoint

  1. Prepare specification.json file. You can get it from the directory common/data/settings or save a copy using SpecWindow which executes by button Specification on the MainWindow
    1. Prepare file signal_spec.py, containing endpoint script
    2. Set SERVER_ADDRESS, PORT, FILE parameters in the file signal_spec.py
    3. Put both files specification.json and signal_spec.py to remote server
    4. Run the code using command nohup python signal_spec.py &
    5. For checking open specified URL in browser, it should show the specification JSON. In example below the URL is http://127.0.0.1:4242/specification

Test of remote specification endpoint

image

Remote spec endpoint code example

from http import HTTPStatus
from http.server import BaseHTTPRequestHandler, HTTPServer

"""
Basic realization of SIGNAL Specification remote endpoint. This endpoint returns specification.json by GET request

Check and set the required configuration parameters below before run 

Was tested on Python3 only
"""

SERVER_ADDRESS = '127.0.0.1'  # The address of the server machine
PORT = 4242  # Port for incoming connection
PATH = '/specification'  # URL path to get the specification file
FILE = '/opt/spec/specification.json'  # The Specification file path, the file should be returned by GET request

# By these settings we create URL http://127.0.0.1:4242/specification which returns file /opt/spec/specification.json

class HttpSpec(BaseHTTPRequestHandler):
    def do_GET(self):
        if self.path != PATH:
            self.send_response(HTTPStatus.NOT_FOUND)
            self.end_headers()
            return

        self.send_response(HTTPStatus.OK)
        self.send_header("Content-type", "application/json")
        self.end_headers()

        with open(FILE) as json_file:
            self.wfile.write(json_file.read().encode())

server = HTTPServer((SERVER_ADDRESS, PORT), HttpSpec)

try:
    server.serve_forever()
except KeyboardInterrupt:
    pass

server.server_close()

Fields validation

Main validation

Extended validation

Violation mode

Directions

Complex fields representation

Manual entry mode

Configuration

Config overview

Config file

Settings

Remote host

Specification

On startup

Log

Validation

Fields

Transaction data files

Data files overview

The SIGNAL supports multiple representations of transaction data files. The data can be put to the SIGNAL using one of three formats - JSON, INI, and DUMP. The data is stored in text files, which can be read or written by SIGNAL. This chapter describes each format's features and purpose

The data formats description

Format File extension Incoming Outgoing Description
JSON .json Yes Yes Equally well suited for operator reading and machine analysis. The main goal is to make complex fields not so complicated, through structure-readable decomposition. Fields and subfield lengths are left out because they will be calculated later according to the Specification. All the transactions, incoming and outgoing stored in memory in JSON representation. Strictly requires Specification settings for each subfield
INI .ini Yes Yes Flat format, where each field is written in one string. Fields fill in Tag-Length-Value (TLV) style with no separators. All the lengths have to be calculated and set by the operator. The format skips the data validation process. Recommended when you definitely understand what you do. Requires specification for top-level fields only, subfields specification is not required
DUMP .dmp Yes Yes Raw SV-dump format. Used for loading and generating SVFE-compatible dump messages for parsing incoming and generating outgoing SV messages. Low-level data exchange with SVFE makes using this format. The DUMP is the fully ready-read message for the SVFE epayint module. For the sv-dump building recommended setting field data through the transaction constructor using JSON or INI style, then generate the dump by SIGNAL interface. Manual analysis or generation is not recommended

Loading to the SIGNAL

To read the incoming data file in the open SIGNAL window press CTRL + O, or hit the button "Parse file" on the MainWindow bottom, then choose the file using the file-navigation window. SIGNAL recognizes the incoming file format by file extension. When the extension is absent or unknown the SIGNAL will try to parse the file using each format pattern one by one. Better to set the correct extension for each format. Refer to the data formats description to define the correct extension for each file format

Save transaction to file

...

Data storage

Default messages

Dictionaries

License info

Settings storage

Specification backup

Logging

Log levels

Storage and rotation

Hide secrets

Bugs

List of known bugs

Bug Status Workaround Comment
Console window appears when I run GUI Active Set Terminal app to default to "Windows Console Host" instead of "Windows Terminal" Solution
No data in Connector when no such field in the specification Active - -
Sending Field 62 I get Format Error (RC=30) in response Active Fill the field data manually in flat mode -

About SIGNAL

The text version of Signal's logo

  ::::::::  :::::::::::  ::::::::   ::::    :::      :::      :::        
 :+:    :+:     :+:     :+:    :+:  :+:+:   :+:    :+: :+:    :+:        
 +:+            +:+     +:+         :+:+:+  +:+   +:+   +:+   +:+        
 +#++:++#++     +#+     :#:         +#+ +:+ +#+  +#++:++#++:  +#+        
        +#+     +#+     +#+   +#+#  +#+  +#+#+#  +#+     +#+  +#+        
 #+#    #+#     #+#     #+#    #+#  #+#   #+#+#  #+#     #+#  #+#        
  ########  ###########  ########   ###    ####  ###     ###  ########## 

  Simplified ISO generation algorithm v0.18 | Released in May 2024

Concept

The main idea behind Signal is to make simple things easy to do. It targets to simplification of complicated everyday tasks when a part of your job is ISO 8583 OLTP service

SIGNAL is not an emulator of PSP or SmartVista. It doesn't try to be similar to these systems. It is more positioned as a simplified version card payment terminal, developed with respect for the everyday needs of the Card Processing Support Team

Written on Python 3.12 with the use of PyQt6 and Pydantic packages

License

SIGNAL is distributed under the GNU/GPL license as free software. Using SIGNAL you have to accept the license agreement

See more on GNU licence page and free software Wiki article in the resources chapter

Long story short: the SIGNAL is free for any purpose, excluding selling it. Sales are strictly prohibited. Contact the author in case of any copyright questions

️GNU/GPL license agreement

GNU GENERAL PUBLIC LICENSE Version 3, 29 June 2007 Copyright (C) 2007 Free Software Foundation, Inc. Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. Preamble The GNU General Public License is a free, copyleft license for software and other kinds of works. The licenses for most software and other practical works are designed to take away your freedom to share and change the works. By contrast, the GNU General Public License is intended to guarantee your freedom to share and change all versions of a program--to make sure it remains free software for all its users. We, the Free Software Foundation, use the GNU General Public License for most of our software; it applies also to any other work released this way by its authors. You can apply it to your programs, too. When we speak of free software, we are referring to freedom, not price. Our General Public Licenses are designed to make sure that you have the freedom to distribute copies of free software (and charge for them if you wish), that you receive source code or can get it if you want it, that you can change the software or use pieces of it in new free programs, and that you know you can do these things. To protect your rights, we need to prevent others from denying you these rights or asking you to surrender the rights. Therefore, you have certain responsibilities if you distribute copies of the software, or if you modify it: responsibilities to respect the freedom of others. For example, if you distribute copies of such a program, whether gratis or for a fee, you must pass on to the recipients the same freedoms that you received. You must make sure that they, too, receive or can get the source code. And you must show them these terms so they know their rights. Developers that use the GNU GPL protect your rights with two steps: (1) assert copyright on the software, and (2) offer you this License giving you legal permission to copy, distribute and/or modify it. For the developers' and authors' protection, the GPL clearly explains that there is no warranty for this free software. For both users' and authors' sake, the GPL requires that modified versions be marked as changed, so that their problems will not be attributed erroneously to authors of previous versions. Some devices are designed to deny users access to install or run modified versions of the software inside them, although the manufacturer can do so. This is fundamentally incompatible with the aim of protecting users' freedom to change the software. The systematic pattern of such abuse occurs in the area of products for individuals to use, which is precisely where it is most unacceptable. Therefore, we have designed this version of the GPL to prohibit the practice for those products. If such problems arise substantially in other domains, we stand ready to extend this provision to those domains in future versions of the GPL, as needed to protect the freedom of users. Finally, every program is threatened constantly by software patents. States should not allow patents to restrict development and use of software on general-purpose computers, but in those that do, we wish to avoid the special danger that patents applied to a free program could make it effectively proprietary. To prevent this, the GPL assures that patents cannot be used to render the program non-free. The precise terms and conditions for copying, distribution and modification follow. TERMS AND CONDITIONS 0. Definitions. "This License" refers to version 3 of the GNU General Public License. "Copyright" also means copyright-like laws that apply to other kinds of works, such as semiconductor masks. "The Program" refers to any copyrightable work licensed under this License. Each licensee is addressed as "you". "Licensees" and "recipients" may be individuals or organizations. To "modify" a work means to copy from or adapt all or part of the work in a fashion requiring copyright permission, other than the making of an exact copy. The resulting work is called a "modified version" of the earlier work or a work "based on" the earlier work. A "covered work" means either the unmodified Program or a work based on the Program. To "propagate" a work means to do anything with it that, without permission, would make you directly or secondarily liable for infringement under applicable copyright law, except executing it on a computer or modifying a private copy. Propagation includes copying, distribution (with or without modification), making available to the public, and in some countries other activities as well. To "convey" a work means any kind of propagation that enables other parties to make or receive copies. Mere interaction with a user through a computer network, with no transfer of a copy, is not conveying. An interactive user interface displays "Appropriate Legal Notices" to the extent that it includes a convenient and prominently visible feature that (1) displays an appropriate copyright notice, and (2) tells the user that there is no warranty for the work (except to the extent that warranties are provided), that licensees may convey the work under this License, and how to view a copy of this License. If the interface presents a list of user commands or options, such as a menu, a prominent item in the list meets this criterion. 1. Source Code. The "source code" for a work means the preferred form of the work for making modifications to it. "Object code" means any non-source form of a work. A "Standard Interface" means an interface that either is an official standard defined by a recognized standards body, or, in the case of interfaces specified for a particular programming language, one that is widely used among developers working in that language. The "System Libraries" of an executable work include anything, other than the work as a whole, that (a) is included in the normal form of packaging a Major Component, but which is not part of that Major Component, and (b) serves only to enable use of the work with that Major Component, or to implement a Standard Interface for which an implementation is available to the public in source code form. A "Major Component", in this context, means a major essential component (kernel, window system, and so on) of the specific operating system (if any) on which the executable work runs, or a compiler used to produce the work, or an object code interpreter used to run it. The "Corresponding Source" for a work in object code form means all the source code needed to generate, install, and (for an executable work) run the object code and to modify the work, including scripts to control those activities. However, it does not include the work's System Libraries, or general-purpose tools or generally available free programs which are used unmodified in performing those activities but which are not part of the work. For example, Corresponding Source includes interface definition files associated with source files for the work, and the source code for shared libraries and dynamically linked subprograms that the work is specifically designed to require, such as by intimate data communication or control flow between those subprograms and other parts of the work. The Corresponding Source need not include anything that users can regenerate automatically from other parts of the Corresponding Source. The Corresponding Source for a work in source code form is that same work. 2. Basic Permissions. All rights granted under this License are granted for the term of copyright on the Program, and are irrevocable provided the stated conditions are met. This License explicitly affirms your unlimited permission to run the unmodified Program. The output from running a covered work is covered by this License only if the output, given its content, constitutes a covered work. This License acknowledges your rights of fair use or other equivalent, as provided by copyright law. You may make, run and propagate covered works that you do not convey, without conditions so long as your license otherwise remains in force. You may convey covered works to others for the sole purpose of having them make modifications exclusively for you, or provide you with facilities for running those works, provided that you comply with the terms of this License in conveying all material for which you do not control copyright. Those thus making or running the covered works for you must do so exclusively on your behalf, under your direction and control, on terms that prohibit them from making any copies of your copyrighted material outside their relationship with you. Conveying under any other circumstances is permitted solely under the conditions stated below. Sublicensing is not allowed; section 10 makes it unnecessary. 3. Protecting Users' Legal Rights From Anti-Circumvention Law. No covered work shall be deemed part of an effective technological measure under any applicable law fulfilling obligations under article 11 of the WIPO copyright treaty adopted on 20 December 1996, or similar laws prohibiting or restricting circumvention of such measures. When you convey a covered work, you waive any legal power to forbid circumvention of technological measures to the extent such circumvention is effected by exercising rights under this License with respect to the covered work, and you disclaim any intention to limit operation or modification of the work as a means of enforcing, against the work's users, your or third parties' legal rights to forbid circumvention of technological measures. 4. Conveying Verbatim Copies. You may convey verbatim copies of the Program's source code as you receive it, in any medium, provided that you conspicuously and appropriately publish on each copy an appropriate copyright notice; keep intact all notices stating that this License and any non-permissive terms added in accord with section 7 apply to the code; keep intact all notices of the absence of any warranty; and give all recipients a copy of this License along with the Program. You may charge any price or no price for each copy that you convey, and you may offer support or warranty protection for a fee. 5. Conveying Modified Source Versions. You may convey a work based on the Program, or the modifications to produce it from the Program, in the form of source code under the terms of section 4, provided that you also meet all of these conditions: a) The work must carry prominent notices stating that you modified it, and giving a relevant date. b) The work must carry prominent notices stating that it is released under this License and any conditions added under section 7. This requirement modifies the requirement in section 4 to "keep intact all notices". c) You must license the entire work, as a whole, under this License to anyone who comes into possession of a copy. This License will therefore apply, along with any applicable section 7 additional terms, to the whole of the work, and all its parts, regardless of how they are packaged. This License gives no permission to license the work in any other way, but it does not invalidate such permission if you have separately received it. d) If the work has interactive user interfaces, each must display Appropriate Legal Notices; however, if the Program has interactive interfaces that do not display Appropriate Legal Notices, your work need not make them do so. A compilation of a covered work with other separate and independent works, which are not by their nature extensions of the covered work, and which are not combined with it such as to form a larger program, in or on a volume of a storage or distribution medium, is called an "aggregate" if the compilation and its resulting copyright are not used to limit the access or legal rights of the compilation's users beyond what the individual works permit. Inclusion of a covered work in an aggregate does not cause this License to apply to the other parts of the aggregate. 6. Conveying Non-Source Forms. You may convey a covered work in object code form under the terms of sections 4 and 5, provided that you also convey the machine-readable Corresponding Source under the terms of this License, in one of these ways: a) Convey the object code in, or embodied in, a physical product (including a physical distribution medium), accompanied by the Corresponding Source fixed on a durable physical medium customarily used for software interchange. b) Convey the object code in, or embodied in, a physical product (including a physical distribution medium), accompanied by a written offer, valid for at least three years and valid for as long as you offer spare parts or customer support for that product model, to give anyone who possesses the object code either (1) a copy of the Corresponding Source for all the software in the product that is covered by this License, on a durable physical medium customarily used for software interchange, for a price no more than your reasonable cost of physically performing this conveying of source, or (2) access to copy the Corresponding Source from a network server at no charge. c) Convey individual copies of the object code with a copy of the written offer to provide the Corresponding Source. This alternative is allowed only occasionally and noncommercially, and only if you received the object code with such an offer, in accord with subsection 6b. d) Convey the object code by offering access from a designated place (gratis or for a charge), and offer equivalent access to the Corresponding Source in the same way through the same place at no further charge. You need not require recipients to copy the Corresponding Source along with the object code. If the place to copy the object code is a network server, the Corresponding Source may be on a different server (operated by you or a third party) that supports equivalent copying facilities, provided you maintain clear directions next to the object code saying where to find the Corresponding Source. Regardless of what server hosts the Corresponding Source, you remain obligated to ensure that it is available for as long as needed to satisfy these requirements. e) Convey the object code using peer-to-peer transmission, provided you inform other peers where the object code and Corresponding Source of the work are being offered to the general public at no charge under subsection 6d. A separable portion of the object code, whose source code is excluded from the Corresponding Source as a System Library, need not be included in conveying the object code work. A "User Product" is either (1) a "consumer product", which means any tangible personal property which is normally used for personal, family, or household purposes, or (2) anything designed or sold for incorporation into a dwelling. In determining whether a product is a consumer product, doubtful cases shall be resolved in favor of coverage. For a particular product received by a particular user, "normally used" refers to a typical or common use of that class of product, regardless of the status of the particular user or of the way in which the particular user actually uses, or expects or is expected to use, the product. A product is a consumer product regardless of whether the product has substantial commercial, industrial or non-consumer uses, unless such uses represent the only significant mode of use of the product. "Installation Information" for a User Product means any methods, procedures, authorization keys, or other information required to install and execute modified versions of a covered work in that User Product from a modified version of its Corresponding Source. The information must suffice to ensure that the continued functioning of the modified object code is in no case prevented or interfered with solely because modification has been made. If you convey an object code work under this section in, or with, or specifically for use in, a User Product, and the conveying occurs as part of a transaction in which the right of possession and use of the User Product is transferred to the recipient in perpetuity or for a fixed term (regardless of how the transaction is characterized), the Corresponding Source conveyed under this section must be accompanied by the Installation Information. But this requirement does not apply if neither you nor any third party retains the ability to install modified object code on the User Product (for example, the work has been installed in ROM). The requirement to provide Installation Information does not include a requirement to continue to provide support service, warranty, or updates for a work that has been modified or installed by the recipient, or for the User Product in which it has been modified or installed. Access to a network may be denied when the modification itself materially and adversely affects the operation of the network or violates the rules and protocols for communication across the network. Corresponding Source conveyed, and Installation Information provided, in accord with this section must be in a format that is publicly documented (and with an implementation available to the public in source code form), and must require no special password or key for unpacking, reading or copying. 7. Additional Terms. "Additional permissions" are terms that supplement the terms of this License by making exceptions from one or more of its conditions. Additional permissions that are applicable to the entire Program shall be treated as though they were included in this License, to the extent that they are valid under applicable law. If additional permissions apply only to part of the Program, that part may be used separately under those permissions, but the entire Program remains governed by this License without regard to the additional permissions. When you convey a copy of a covered work, you may at your option remove any additional permissions from that copy, or from any part of it. (Additional permissions may be written to require their own removal in certain cases when you modify the work.) You may place additional permissions on material, added by you to a covered work, for which you have or can give appropriate copyright permission. Notwithstanding any other provision of this License, for material you add to a covered work, you may (if authorized by the copyright holders of that material) supplement the terms of this License with terms: a) Disclaiming warranty or limiting liability differently from the terms of sections 15 and 16 of this License; or b) Requiring preservation of specified reasonable legal notices or author attributions in that material or in the Appropriate Legal Notices displayed by works containing it; or c) Prohibiting misrepresentation of the origin of that material, or requiring that modified versions of such material be marked in reasonable ways as different from the original version; or d) Limiting the use for publicity purposes of names of licensors or authors of the material; or e) Declining to grant rights under trademark law for use of some trade names, trademarks, or service marks; or f) Requiring indemnification of licensors and authors of that material by anyone who conveys the material (or modified versions of it) with contractual assumptions of liability to the recipient, for any liability that these contractual assumptions directly impose on those licensors and authors. All other non-permissive additional terms are considered "further restrictions" within the meaning of section 10. If the Program as you received it, or any part of it, contains a notice stating that it is governed by this License along with a term that is a further restriction, you may remove that term. If a license document contains a further restriction but permits relicensing or conveying under this License, you may add to a covered work material governed by the terms of that license document, provided that the further restriction does not survive such relicensing or conveying. If you add terms to a covered work in accord with this section, you must place, in the relevant source files, a statement of the additional terms that apply to those files, or a notice indicating where to find the applicable terms. Additional terms, permissive or non-permissive, may be stated in the form of a separately written license, or stated as exceptions; the above requirements apply either way. 8. Termination. You may not propagate or modify a covered work except as expressly provided under this License. Any attempt otherwise to propagate or modify it is void, and will automatically terminate your rights under this License (including any patent licenses granted under the third paragraph of section 11). However, if you cease all violation of this License, then your license from a particular copyright holder is reinstated (a) provisionally, unless and until the copyright holder explicitly and finally terminates your license, and (b) permanently, if the copyright holder fails to notify you of the violation by some reasonable means prior to 60 days after the cessation. Moreover, your license from a particular copyright holder is reinstated permanently if the copyright holder notifies you of the violation by some reasonable means, this is the first time you have received notice of violation of this License (for any work) from that copyright holder, and you cure the violation prior to 30 days after your receipt of the notice. Termination of your rights under this section does not terminate the licenses of parties who have received copies or rights from you under this License. If your rights have been terminated and not permanently reinstated, you do not qualify to receive new licenses for the same material under section 10. 9. Acceptance Not Required for Having Copies. You are not required to accept this License in order to receive or run a copy of the Program. Ancillary propagation of a covered work occurring solely as a consequence of using peer-to-peer transmission to receive a copy likewise does not require acceptance. However, nothing other than this License grants you permission to propagate or modify any covered work. These actions infringe copyright if you do not accept this License. Therefore, by modifying or propagating a covered work, you indicate your acceptance of this License to do so. 10. Automatic Licensing of Downstream Recipients. Each time you convey a covered work, the recipient automatically receives a license from the original licensors, to run, modify and propagate that work, subject to this License. You are not responsible for enforcing compliance by third parties with this License. An "entity transaction" is a transaction transferring control of an organization, or substantially all assets of one, or subdividing an organization, or merging organizations. If propagation of a covered work results from an entity transaction, each party to that transaction who receives a copy of the work also receives whatever licenses to the work the party's predecessor in interest had or could give under the previous paragraph, plus a right to possession of the Corresponding Source of the work from the predecessor in interest, if the predecessor has it or can get it with reasonable efforts. You may not impose any further restrictions on the exercise of the rights granted or affirmed under this License. For example, you may not impose a license fee, royalty, or other charge for exercise of rights granted under this License, and you may not initiate litigation (including a cross-claim or counterclaim in a lawsuit) alleging that any patent claim is infringed by making, using, selling, offering for sale, or importing the Program or any portion of it. 11. Patents. A "contributor" is a copyright holder who authorizes use under this License of the Program or a work on which the Program is based. The work thus licensed is called the contributor's "contributor version". A contributor's "essential patent claims" are all patent claims owned or controlled by the contributor, whether already acquired or hereafter acquired, that would be infringed by some manner, permitted by this License, of making, using, or selling its contributor version, but do not include claims that would be infringed only as a consequence of further modification of the contributor version. For purposes of this definition, "control" includes the right to grant patent sublicenses in a manner consistent with the requirements of this License. Each contributor grants you a non-exclusive, worldwide, royalty-free patent license under the contributor's essential patent claims, to make, use, sell, offer for sale, import and otherwise run, modify and propagate the contents of its contributor version. In the following three paragraphs, a "patent license" is any express agreement or commitment, however denominated, not to enforce a patent (such as an express permission to practice a patent or covenant not to sue for patent infringement). To "grant" such a patent license to a party means to make such an agreement or commitment not to enforce a patent against the party. If you convey a covered work, knowingly relying on a patent license, and the Corresponding Source of the work is not available for anyone to copy, free of charge and under the terms of this License, through a publicly available network server or other readily accessible means, then you must either (1) cause the Corresponding Source to be so available, or (2) arrange to deprive yourself of the benefit of the patent license for this particular work, or (3) arrange, in a manner consistent with the requirements of this License, to extend the patent license to downstream recipients. "Knowingly relying" means you have actual knowledge that, but for the patent license, your conveying the covered work in a country, or your recipient's use of the covered work in a country, would infringe one or more identifiable patents in that country that you have reason to believe are valid. If, pursuant to or in connection with a single transaction or arrangement, you convey, or propagate by procuring conveyance of, a covered work, and grant a patent license to some of the parties receiving the covered work authorizing them to use, propagate, modify or convey a specific copy of the covered work, then the patent license you grant is automatically extended to all recipients of the covered work and works based on it. A patent license is "discriminatory" if it does not include within the scope of its coverage, prohibits the exercise of, or is conditioned on the non-exercise of one or more of the rights that are specifically granted under this License. You may not convey a covered work if you are a party to an arrangement with a third party that is in the business of distributing software, under which you make payment to the third party based on the extent of your activity of conveying the work, and under which the third party grants, to any of the parties who would receive the covered work from you, a discriminatory patent license (a) in connection with copies of the covered work conveyed by you (or copies made from those copies), or (b) primarily for and in connection with specific products or compilations that contain the covered work, unless you entered into that arrangement, or that patent license was granted, prior to 28 March 2007. Nothing in this License shall be construed as excluding or limiting any implied license or other defenses to infringement that may otherwise be available to you under applicable patent law. 12. No Surrender of Others' Freedom. If conditions are imposed on you (whether by court order, agreement or otherwise) that contradict the conditions of this License, they do not excuse you from the conditions of this License. If you cannot convey a covered work so as to satisfy simultaneously your obligations under this License and any other pertinent obligations, then as a consequence you may not convey it at all. For example, if you agree to terms that obligate you to collect a royalty for further conveying from those to whom you convey the Program, the only way you could satisfy both those terms and this License would be to refrain entirely from conveying the Program. 13. Use with the GNU Affero General Public License. Notwithstanding any other provision of this License, you have permission to link or combine any covered work with a work licensed under version 3 of the GNU Affero General Public License into a single combined work, and to convey the resulting work. The terms of this License will continue to apply to the part which is the covered work, but the special requirements of the GNU Affero General Public License, section 13, concerning interaction through a network will apply to the combination as such. 14. Revised Versions of this License. The Free Software Foundation may publish revised and/or new versions of the GNU General Public License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. Each version is given a distinguishing version number. If the Program specifies that a certain numbered version of the GNU General Public License "or any later version" applies to it, you have the option of following the terms and conditions either of that numbered version or of any later version published by the Free Software Foundation. If the Program does not specify a version number of the GNU General Public License, you may choose any version ever published by the Free Software Foundation. If the Program specifies that a proxy can decide which future versions of the GNU General Public License can be used, that proxy's public statement of acceptance of a version permanently authorizes you to choose that version for the Program. Later license versions may give you additional or different permissions. However, no additional obligations are imposed on any author or copyright holder as a result of your choosing to follow a later version. 15. Disclaimer of Warranty. THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION. 16. Limitation of Liability. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. 17. Interpretation of Sections 15 and 16. If the disclaimer of warranty and limitation of liability provided above cannot be given local legal effect according to their terms, reviewing courts shall apply local law that most closely approximates an absolute waiver of all civil liability in connection with the Program, unless a warranty or assumption of liability accompanies a copy of the Program in return for a fee. END OF TERMS AND CONDITIONS How to Apply These Terms to Your New Programs If you develop a new program, and you want it to be of the greatest possible use to the public, the best way to achieve this is to make it free software which everyone can redistribute and change under these terms. To do so, attach the following notices to the program. It is safest to attach them to the start of each source file to most effectively state the exclusion of warranty; and each file should have at least the "copyright" line and a pointer to where the full notice is found. Copyright (C) This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . Also add information on how to contact you by electronic and paper mail. If the program does terminal interaction, make it output a short notice like this when it starts in an interactive mode: Copyright (C) This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'. This is free software, and you are welcome to redistribute it under certain conditions; type `show c' for details. The hypothetical commands `show w' and `show c' should show the appropriate parts of the General Public License. Of course, your program's commands might be different; for a GUI interface, you would use an "about box". You should also get your employer (if you work as a programmer) or school, if any, to sign a "copyright disclaimer" for the program, if necessary. For more information on this, and how to apply and follow the GNU GPL, see . The GNU General Public License does not permit incorporating your program into proprietary programs. If your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you want to do, use the GNU Lesser General Public License instead of this License. But first, please read

Resources

Support

The project was designed and developed concerning the everyday needs of banking systems support engineers. It helped to save thousands of working hours and meet hundreds of deadlines. The basic monetization concept is that SIGNAL is free, always, and for everyone, not depending on usage. All the licensing and copyright targeting firstly to protect usage for free

However, the project needs your support. If you want to support the project you can spend your time, working on it or make a voluntary donation directly to the author. ⚠️ Any donation can be voluntary only

The project needs help

️❤️Support the project

BTC wallet ``` bc1qs2jaqpnse9qgzz9y9wyns50km0f5x4wxe8cggs ```

Author

Designed and developed by Fedor Ivanov

In case of any question feel free to contract author directly