Demo helpers

iso8583sim.demo This module provides convenient functions for:

Pretty-printing ISO 8583 messages
Generating sample messages for different scenarios
Explaining message components

Functions

`pretty_print()`

def pretty_print(message: ISO8583Message | str, show_raw: bool = False) -> None

Pretty print an ISO 8583 message. Parameters

ISO8583Message | str

required

ISO8583Message object or raw message string

bool

default:"False"

Whether to show the raw message bytes

`explain_field()`

def explain_field(field_number: int, value: str | None = None) -> None

Explain a specific field’s definition and optionally its value. Parameters

int

required

The field number to explain

str | None

default:"None"

Optional field value to interpret

`generate_auth_request()`

def generate_auth_request(
    pan: str = '4111111111111111',
    amount: int = 1000,
    stan: str = '123456',
    terminal_id: str = 'TERM0001',
    merchant_id: str = 'MERCHANT123456 ',
    network: CardNetwork | None = None,
) -> ISO8583Message

Generate a sample authorization request. Parameters

str

default:"'4111111111111111'"

Primary Account Number

int

default:"1000"

Transaction amount in cents

str

default:"'123456'"

System Trace Audit Number

str

default:"'TERM0001'"

Terminal ID (8 chars)

str

default:"'MERCHANT123456 '"

Merchant ID (15 chars)

CardNetwork | None

default:"None"

Optional network type

ISO8583Message

ISO8583Message object

`generate_financial_request()`

def generate_financial_request(
    pan: str = '4111111111111111',
    amount: int = 5000,
    stan: str = '654321',
    processing_code: str = '000000',
) -> ISO8583Message

Generate a sample financial request (0200). Parameters

str

default:"'4111111111111111'"

Primary Account Number

int

default:"5000"

Transaction amount in cents

str

default:"'654321'"

System Trace Audit Number

str

default:"'000000'"

Processing code (default: purchase)

ISO8583Message

ISO8583Message object

`generate_reversal()`

def generate_reversal(
    original: ISO8583Message,
    new_stan: str = '999999',
) -> ISO8583Message

Generate a reversal message for an original transaction. Parameters

ISO8583Message

required

The original transaction message

str

default:"'999999'"

New STAN for the reversal

ISO8583Message

ISO8583Message reversal

`generate_network_message()`

def generate_network_message(message_type: str = 'echo') -> ISO8583Message

Generate a network management message. Parameters

str

default:"'echo'"

Type of message - ‘echo’, ‘signon’, ‘signoff’, ‘key_exchange’

ISO8583Message

ISO8583Message object

`generate_emv_auth()`

def generate_emv_auth(
    pan: str = '4111111111111111',
    amount: int = 10000,
    cryptogram: str = 'AABBCCDD11223344',
) -> ISO8583Message

Generate an EMV chip card authorization. Parameters

str

default:"'4111111111111111'"

Primary Account Number

int

default:"10000"

Transaction amount in cents

str

default:"'AABBCCDD11223344'"

Application cryptogram (8 bytes hex)

ISO8583Message

ISO8583Message with EMV data

`build_and_parse()`

def build_and_parse(message: ISO8583Message) -> ISO8583Message

Build a message to raw format and parse it back. Useful for testing roundtrip. Parameters

ISO8583Message

required

ISO8583Message to process

ISO8583Message

Parsed message

`validate()`

def validate(message: ISO8583Message | str) -> None

Validate a message and print results. Parameters

ISO8583Message | str

required

ISO8583Message or raw message string

`explain_emv()`

def explain_emv(emv_hex: str) -> None

Parse and explain EMV data. Parameters

str

required

Hex-encoded EMV TLV data

Core

Security

Wire formats

Networking

LLM

Servers

Demo

Functions

`pretty_print()`

`explain_field()`

`generate_auth_request()`

`generate_financial_request()`

`generate_reversal()`

`generate_network_message()`

`generate_emv_auth()`

`build_and_parse()`

`validate()`

`explain_emv()`

​Functions

​pretty_print()

​explain_field()

​generate_auth_request()

​generate_financial_request()

​generate_reversal()

​generate_network_message()

​generate_emv_auth()

​build_and_parse()

​validate()

​explain_emv()

Functions

`pretty_print()`

`explain_field()`

`generate_auth_request()`

`generate_financial_request()`

`generate_reversal()`

`generate_network_message()`

`generate_emv_auth()`

`build_and_parse()`

`validate()`

`explain_emv()`