Send and Cash Checks

This example shows how to:

Send a check to transfer XRP or issued currency to another account.
Get a list of checks you have sent or received.
Cash a check received from another account.
Cancel a check you have sent.

Checks offer another option for transferring funds between accounts. Checks have two particular advantages.

You can use a check to send funds to another account without first creating a trust line - the trust line is created automatically when the receiver chooses to accept the funds.
The receiver can choose to accept less than the full amount of the check. This allows you to authorize a maximum amount when the actual cost is not finalized.

Prerequisites

If you haven't done so already, create a new folder on your local disk and install the Python library using pip.

    pip3 install xrpl-py

Clone or download the Modular Tutorial Samples.

Note

Without the Quickstart Samples, you will not be able to try the examples that follow.

Usage

To get test accounts:

Open and launch lesson10-check.py.
Click Get Standby Account.
Click Get Operational Account.
Click Get Standby Account Info.
Click Get Operational Account Info.
Copy and paste the Standby Seed and Operational Seed fields to a persistent location, such as a Notepad, so that you can reuse the accounts after reloading the form.

You can transfer XRP between your new accounts. Each account has its own fields and buttons.

Send a Check for XRP

To send a check for XRP from the Standby account to the Operational account:

On the Standby (left) side of the form, enter the Amount of XRP to send in drops.
Copy and paste the Operational Account field to the Standby Destination field.
Set the Currency to XRP.
Click Send Check.

Send a Check for an Issued Currency

To send a check for an issued currency token from the Standby account to the Operational account:

On the Standby side of the form, enter the Amount of currency to send.
Copy and paste the Operational Account field to the Standby Destination field.
Copy the Standby Account field and paste the value in the Issuer field.
Enter the Currency code for your token.
Click Send Check.

Get Checks

Click Get Checks to get a list of the current checks you have sent or received. To uniquely identify a check (for existence, when cashing a check), capture the index value for the check.

Cash Check

To cash a check you have received:

Enter the Check ID (index value).
Enter the Amount you want to collect, up to the full amount of the check.
Enter the currency code. a. If you cashing a check for XRP, enter XRP in the Currency field. b. If you are cashing a check for an issued currency token:
1. Enter the Issuer of the token.
2. Enter the Currency code for the token.
Click Cash Check.

Get Balances

Click Get Balances to get a list of obligations and assets for each account.

Cancel Check

To cancel a check you have previously sent to another account.

Enter the Check ID (index value).
Click Cancel Check.

Code Walkthrough

You can download the Quickstart Samples in the source repository for this website.

mod10.py

Import dependencies.

import xrpl
from xrpl.clients import JsonRpcClient
from xrpl.wallet import Wallet
from datetime import datetime
from xrpl.models.transactions import CheckCreate, CheckCash, CheckCancel
from xrpl.models.requests import AccountObjects, AccountTx, GatewayBalances

Set the TestNet URL.

testnet_url = "https://s.altnet.rippletest.net:51234"

send_check

Pass the arguments for the account seed, check amount, and destination account. Set the currency type to XRP, or if it is an issued currency token provide the currency type and issuer.

def send_check(seed, amount, destination, currency, issuer):
		"""send_check"""

Instantiate the account wallet and create a client connection.

    wallet=Wallet.from_seed(seed)
    client=JsonRpcClient(testnet_url)

Create the amount variable. If you are sending XRP, the amount variable is fine as is. If you are sending issued currency, you need to create an amount object that includes the currency and the issuer.

    if currency != "XRP":
        amount = {"value": amount,
                  "currency": currency,
                  "issuer": issuer
                 }

Define the CheckCreate transaction.

    check_tx=xrpl.models.transactions.CheckCreate(
        account=wallet.address,
        send_max=amount,
        destination=destination
    )

Submit the transaction and report the results.

		reply=""
    try:
        response=xrpl.transaction.submit_and_wait(check_tx,client,wallet)
        reply=response.result
    except xrpl.transaction.XRPLReliableSubmissionException as e:
        reply=f"Submit failed: {e}"
    return reply

cash_check

Pass the values for seed, amount, and check_id. Set the currency type to XRP, or include the currency type and issuer.

def cash_check(seed, amount, check_id, currency, issuer):
    """cash_check"""

Instantiate the account wallet and create a client connection.

    wallet=Wallet.from_seed(seed)
    client=JsonRpcClient(testnet_url)

If using an issued currency token, create an amount object that includes the currency type and issuer.

    if currency != "XRP":
        amount = {
            "value": amount,
            "currency": currency,
            "issuer": issuer
        }

Define the CheckCash transaction.

    finish_tx=xrpl.models.transactions.CheckCash(
        account=wallet.address,
        amount=amount,
        check_id=check_id
    )

Submit the transaction and report the results.

    reply=""
    try:
        response=xrpl.transaction.submit_and_wait(finish_tx,client,wallet)
        reply=response.result
    except xrpl.transaction.XRPLReliableSubmissionException as e:
        reply=f"Submit failed: {e}"
    return reply

cancel_check

Pass the values for the account seed and the check ID.

def cancel_check(seed, check_id):
    """cancel_check"""

Instantiate the account wallet and create a client connection.

    wallet=Wallet.from_seed(seed)
    client=JsonRpcClient(testnet_url)

Define the CheckCancel transaction.

    cancel_tx=xrpl.models.transactions.CheckCancel(
        account=wallet.address,
        check_id=check_id
    )

Submit the transaction and report the results

    reply=""
    try:
        response=xrpl.transaction.submit_and_wait(cancel_tx,client,wallet)
        reply=response.result
    except xrpl.transaction.XRPLReliableSubmissionException as e:
        reply=f"Submit failed: {e}"
    return reply

get_checks

def get_checks(account):
    """get_checks"""

Create a client connection.

    client=JsonRpcClient(testnet_url)

Define the AccountObjects request, specifying the type check.

    acct_checks=AccountObjects(
        account=account,
        ledger_index="validated",
        type="check"
    )

Send the request and report the results.

    response=client.request(acct_checks)
    return response.result

lesson10-check.py

This example builds on lesson2-send-currency.py. Changes are noted below.

import tkinter as tk
import xrpl
import json

from mod1 import get_account, get_account_info, send_xrp
from mod2 import get_balance

Import check-specific functions.

from mod10 import send_check, cash_check, cancel_check, get_checks

#############################################
## Handlers #################################
#############################################

Add handlers for module 10.

## Mod 10 Handlers

def standby_send_check():
    results=send_check(
        ent_standby_seed.get(),
        ent_standby_amount.get(),
        ent_standby_destination.get(),
        ent_standby_currency.get(),
        ent_standby_issuer.get()
    )
    text_standby_results.delete("1.0", tk.END)
    text_standby_results.insert("1.0", json.dumps(results, indent=4))

def standby_cash_check():
    results=cash_check(
        ent_standby_seed.get(),
        ent_standby_amount.get(),
        ent_standby_check_id.get(),
        ent_standby_currency.get(),
        ent_standby_issuer.get()
    )
    text_standby_results.delete("1.0", tk.END)
    text_standby_results.insert("1.0", json.dumps(results, indent=4))

def standby_cancel_check():
    results=cancel_check(
        ent_standby_seed.get(),
        ent_standby_check_id.get()
    )
    text_standby_results.delete("1.0", tk.END)
    text_standby_results.insert("1.0", json.dumps(results, indent=4))

def standby_get_checks():
    results=get_checks(
        ent_standby_account.get(),
    )
    text_standby_results.delete("1.0", tk.END)
    text_standby_results.insert("1.0", json.dumps(results, indent=4))

def standby_get_balance():
    results=get_balance(
        ent_standby_seed.get(),
        ent_operational_seed.get()
    )
    text_standby_results.delete("1.0", tk.END)
    text_standby_results.insert("1.0", json.dumps(results, indent=4))

def operational_send_check():
    results=send_check(
        ent_operational_seed.get(),
        ent_operational_amount.get(),
        ent_operational_destination.get(),
        ent_operational_currency.get(),
        ent_operational_issuer.get()
    )
    text_operational_results.delete("1.0", tk.END)
    text_operational_results.insert("1.0", json.dumps(results, indent=4))

def operational_cash_check():
    results=cash_check(
        ent_operational_seed.get(),
        ent_operational_amount.get(),
        ent_operational_check_id.get(),
        ent_operational_currency.get(),
        ent_operational_issuer.get()
    )
    text_operational_results.delete("1.0", tk.END)
    text_operational_results.insert("1.0", json.dumps(results, indent=4))

def operational_cancel_check():
    results=cancel_check(
        ent_operational_seed.get(),
        ent_operational_check_id.get()
    )
    text_operational_results.delete("1.0", tk.END)
    text_standby_results.insert("1.0", json.dumps(results, indent=4))

def operational_get_checks():
    results=get_checks(
        ent_operational_account.get(),
    )
    text_operational_results.delete("1.0", tk.END)
    text_operational_results.insert("1.0", json.dumps(results, indent=4))

def operational_get_balance():
    results=get_balance(
        ent_operational_seed.get(),
        ent_standby_seed.get()
    )
    text_operational_results.delete("1.0", tk.END)
    text_operational_results.insert("1.0", json.dumps(results, indent=4))

## Mod 1 Handlers

def get_standby_account():
    new_wallet=get_account(ent_standby_seed.get())
    ent_standby_account.delete(0, tk.END)
    ent_standby_seed.delete(0, tk.END)
    ent_standby_account.insert(0, new_wallet.classic_address)
    ent_standby_seed.insert(0, new_wallet.seed)


def get_standby_account_info():
    accountInfo=get_account_info(ent_standby_account.get())
    ent_standby_balance.delete(0, tk.END)
    ent_standby_balance.insert(0,accountInfo['Balance'])
    text_standby_results.delete("1.0", tk.END)
    text_standby_results.insert("1.0",json.dumps(accountInfo, indent=4))


def standby_send_xrp():
    response=send_xrp(ent_standby_seed.get(),ent_standby_amount.get(),
                       ent_standby_destination.get())
    text_standby_results.delete("1.0", tk.END)
    text_standby_results.insert("1.0",json.dumps(response.result, indent=4))
    get_standby_account_info()
    get_operational_account_info()


def get_operational_account():
    new_wallet=get_account(ent_operational_seed.get())
    ent_operational_account.delete(0, tk.END)
    ent_operational_account.insert(0, new_wallet.classic_address)
    ent_operational_seed.delete(0, tk.END)
    ent_operational_seed.insert(0, new_wallet.seed)


def get_operational_account_info():
    accountInfo=get_account_info(ent_operational_account.get())
    ent_operational_balance.delete(0, tk.END)
    ent_operational_balance.insert(0,accountInfo['Balance'])
    text_operational_results.delete("1.0", tk.END)
    text_operational_results.insert("1.0",json.dumps(accountInfo, indent=4))


def operational_send_xrp():
    response=send_xrp(ent_operational_seed.get(),ent_operational_amount.get(),
                        ent_operational_destination.get())
    text_operational_results.delete("1.0", tk.END)
    text_operational_results.insert("1.0",json.dumps(response.result,indent=4))
    get_standby_account_info()
    get_operational_account_info()


# Create a new window with the title "Check Example"
window=tk.Tk()
window.title("Check Example")

# Form frame
frm_form=tk.Frame(relief=tk.SUNKEN, borderwidth=3)
frm_form.pack()

# Create the Label and Entry widgets for "Standby Account"
lbl_standy_seed=tk.Label(master=frm_form, text="Standby Seed")
ent_standby_seed=tk.Entry(master=frm_form, width=50)
lbl_standby_account=tk.Label(master=frm_form, text="Standby Account")
ent_standby_account=tk.Entry(master=frm_form, width=50)
lbl_standby_balance=tk.Label(master=frm_form, text="XRP Balance")
ent_standby_balance=tk.Entry(master=frm_form, width=50)
lbl_standy_amount=tk.Label(master=frm_form, text="Amount")
ent_standby_amount=tk.Entry(master=frm_form, width=50)
lbl_standby_destination=tk.Label(master=frm_form, text="Destination")
ent_standby_destination=tk.Entry(master=frm_form, width=50)

Add fields for Issuer and Check ID.

lbl_standby_issuer=tk.Label(master=frm_form, text="Issuer")
ent_standby_issuer=tk.Entry(master=frm_form, width=50)
lbl_standby_check_id=tk.Label(master=frm_form, text="Check ID")
ent_standby_check_id=tk.Entry(master=frm_form, width=50)
lbl_standby_currency=tk.Label(master=frm_form, text="Currency")
ent_standby_currency=tk.Entry(master=frm_form, width=50)
lbl_standby_results=tk.Label(master=frm_form, text="Results")
text_standby_results=tk.Text(master=frm_form, height=20, width=65)

# Place fields in a grid.
lbl_standy_seed.grid(row=0, column=0, sticky="e")
ent_standby_seed.grid(row=0, column=1)
lbl_standby_account.grid(row=2, column=0, sticky="e")
ent_standby_account.grid(row=2, column=1)
lbl_standby_balance.grid(row=3, column=0, sticky="e")
ent_standby_balance.grid(row=3, column=1)
lbl_standy_amount.grid(row=4, column=0, sticky="e")
ent_standby_amount.grid(row=4, column=1)
lbl_standby_destination.grid(row=5, column=0, sticky="e")
ent_standby_destination.grid(row=5, column=1)

Place the Issuer and Check ID fields in the grid.

lbl_standby_issuer.grid(row=6, column=0, sticky="e")
ent_standby_issuer.grid(row=6, column=1)
lbl_standby_check_id.grid(row=7, column=0, sticky="e")
ent_standby_check_id.grid(row=7, column=1)
lbl_standby_currency.grid(row=8, column=0, sticky="e")
ent_standby_currency.grid(row=8, column=1)
lbl_standby_results.grid(row=9, column=0, sticky="ne")
text_standby_results.grid(row=9, column=1, sticky="nw")

###############################################
## Operational Account ########################
###############################################

# Create the Label and Entry widgets for "Operational Account"

lbl_operational_seed=tk.Label(master=frm_form, text="Operational Seed")
ent_operational_seed=tk.Entry(master=frm_form, width=50)
lbl_operational_account=tk.Label(master=frm_form, text="Operational Account")
ent_operational_account=tk.Entry(master=frm_form, width=50)
lbl_operational_balance=tk.Label(master=frm_form, text="XRP Balance")
ent_operational_balance=tk.Entry(master=frm_form, width=50)
lbl_operational_amount=tk.Label(master=frm_form, text="Amount")
ent_operational_amount=tk.Entry(master=frm_form, width=50)
lbl_operational_destination=tk.Label(master=frm_form, text="Destination")
ent_operational_destination=tk.Entry(master=frm_form, width=50)

Add fields for the Issuer and Check ID.

lbl_operational_issuer=tk.Label(master=frm_form, text="Issuer")
ent_operational_issuer=tk.Entry(master=frm_form, width=50)
lbl_operational_check_id=tk.Label(master=frm_form, text="Check ID")
ent_operational_check_id=tk.Entry(master=frm_form, width=50)
lbl_operational_currency=tk.Label(master=frm_form, text="Currency")
ent_operational_currency=tk.Entry(master=frm_form, width=50)
lbl_operational_results=tk.Label(master=frm_form,text='Results')
text_operational_results=tk.Text(master=frm_form, height=20, width=65)

#Place the widgets in a grid
lbl_operational_seed.grid(row=0, column=4, sticky="e")
ent_operational_seed.grid(row=0, column=5, sticky="w")
lbl_operational_account.grid(row=2,column=4, sticky="e")
ent_operational_account.grid(row=2,column=5, sticky="w")
lbl_operational_balance.grid(row=3, column=4, sticky="e")
ent_operational_balance.grid(row=3, column=5, sticky="w")
lbl_operational_amount.grid(row=4, column=4, sticky="e")
ent_operational_amount.grid(row=4, column=5, sticky="w")
lbl_operational_destination.grid(row=5, column=4, sticky="e")
ent_operational_destination.grid(row=5, column=5, sticky="w")

Place the Issuer and Check ID fields in the grid.

lbl_operational_issuer.grid(row=6, column=4, sticky="e")
ent_operational_issuer.grid(row=6, column=5, sticky="w")
lbl_operational_check_id.grid(row=7, column=4, sticky="e")
ent_operational_check_id.grid(row=7, column=5, sticky="w")
lbl_operational_currency.grid(row=8, column=4, sticky="e")
ent_operational_currency.grid(row=8, column=5)
lbl_operational_results.grid(row=9, column=4, sticky="ne")
text_operational_results.grid(row=9, column=5, sticky="nw")

#############################################
## Buttons ##################################
#############################################

# Create the Get Standby Account Buttons
btn_get_standby_account=tk.Button(master=frm_form, text="Get Standby Account",
                                    command=get_standby_account)
btn_get_standby_account.grid(row=0, column=2, sticky="nsew")
btn_get_standby_account_info=tk.Button(master=frm_form,
                                         text="Get Standby Account Info",
                                         command=get_standby_account_info)
btn_get_standby_account_info.grid(row=1, column=2, sticky="nsew")
btn_standby_send_xrp=tk.Button(master=frm_form, text="Send XRP >",
                                 command=standby_send_xrp)
btn_standby_send_xrp.grid(row=2, column=2, sticky="nsew")

Add standby buttons for Send Check, Get Checks, Cash Check, Cancel Check, and Get Balances.

btn_standby_send_check=tk.Button(master=frm_form, text="Send  Check",
                                 command=standby_send_check)
btn_standby_send_check.grid(row=4, column=2, sticky="nsew")
btn_standby_get_checks=tk.Button(master=frm_form, text="Get Checks",
                                 command=standby_get_checks)
btn_standby_get_checks.grid(row=5, column=2, sticky="nsew")
btn_standby_cash_check=tk.Button(master=frm_form, text="Cash  Check",
                                 command=standby_cash_check)
btn_standby_cash_check.grid(row=6, column=2, sticky="nsew")
btn_standby_cancel_check=tk.Button(master=frm_form, text="Cancel  Check",
                                 command=standby_cancel_check)
btn_standby_cancel_check.grid(row=7, column=2, sticky="nsew")
btn_standby_get_balances=tk.Button(master=frm_form, text="Get Balances",
                            command=standby_get_balance)
btn_standby_get_balances.grid(row=8, column=2, sticky="nsew")

# Create the Operational Account Buttons
btn_get_operational_account=tk.Button(master=frm_form,
                                        text="Get Operational Account",
                                        command=get_operational_account)
btn_get_operational_account.grid(row=0, column=3, sticky="nsew")
btn_get_op_account_info=tk.Button(master=frm_form, text="Get Op Account Info",
                                    command=get_operational_account_info)
btn_get_op_account_info.grid(row=1, column=3, sticky="nsew")
btn_op_send_xrp=tk.Button(master=frm_form, text="< Send XRP",
                            command=operational_send_xrp)
btn_op_send_xrp.grid(row=2, column=3, sticky="nsew")

Add operational buttons for Send Check, Get Checks, Cash Check, Cancel Check, and Get Balances.

btn_op_send_check=tk.Button(master=frm_form, text="Send Check",
                            command=operational_send_check)
btn_op_send_check.grid(row=4, column=3, sticky="nsew")
btn_op_get_checks=tk.Button(master=frm_form, text="Get Checks",
                            command=operational_get_checks)
btn_op_get_checks.grid(row=5, column=3, sticky="nsew")
btn_op_cash_check=tk.Button(master=frm_form, text="Cash Check",
                            command=operational_cash_check)
btn_op_cash_check.grid(row=6, column=3, sticky="nsew")
btn_op_cancel_check=tk.Button(master=frm_form, text="Cancel Check",
                            command=operational_cancel_check)
btn_op_cancel_check.grid(row=7, column=3, sticky="nsew")
btn_op_get_balances=tk.Button(master=frm_form, text="Get Balances",
                            command=operational_get_balance)
btn_op_get_balances.grid(row=8, column=3, sticky="nsew")

# Start the application
window.mainloop()