PSKindleWatch is a PowerShell module that keeps a Kindle book watchlist and can alert you when a price drop occurs.

Install-Module -Name PSKindleWatch -Scope CurrentUser

Clone the repository and run .\build.ps1 deploy.

This will install several modules if you do not already have them, see build.ps1 for details. These are only required for the build process and are not otherwise used by PSKindleWatch.

Copy the files from src to C:\Program Files\WindowsPowerShell\Modules\PSKindleWatch and rename the .ps1 file to .psm1.

PSKindleWatch only has 4 cmdlets

CommandType     Name                                               Version    Source
-----------     ----                                               -------    ------
Function        Add-KindleBook                                     1.0        PSKindleWatch
Function        Get-KindleBooks                                    1.0        PSKindleWatch
Function        Remove-KindleBook                                  1.0        PSKindleWatch
Function        Update-KindleBookPrices                            1.0        PSKindleWatch

Add-KindleBook -BookURL <String> [-DataFile <String>]

Please ensure the URL is of the Kindle edition of the book, others may not work due to differences in Amazon's APIs.

The module stores book data in a JSON file, the -DataFile parameter specifies the path to this file. It is an optional parameter, by default it will be placed in the user's Documents folder and named KindleBooks.json.

Example

Add-KindleBook -BookURL "https://www.amazon.com.au/dp/B07YX3B5G9/"

Get-KindleBooks [-DataFile <String>]

Returns a list of currently monitored books.

Example

PS C:\> Get-KindleBooks | Format-Table -AutoSize

Title                                                                                            Authors                               OriginalPrice
-----                                                                                            -------                               -------------
The Age of Surveillance Capitalism: The Fight for a Human Future at the New Frontier of Power    Shoshana Zuboff                                9.80
Superforecasting: The Art and Science of Prediction                                              Philip Tetlock,Dan Gardner                    14.99
Naked Economics: Undressing the Dismal Science (Fully Revised and Updated)                       Charles J. Wheelan, Burton G. Malkiel         23.06

Remove-KindleBook -BookTitle <String>

The title lookup uses -match, a partial string match will suffice.

Example

PS C:\> Remove-KindleBook -BookTitle narco
Removing:
 -Narconomics: How To Run a Drug Cartel

Update-KindleBookPrices [-DataFile <String>] [-AlertScriptBlock <ScriptBlock>]

Checks the current price of all books in the data file and prints any price drop to the console.

It is recommended a wrapper be created to run this in a loop in a PowerShell window, or as a scheduled task, or as a Windows Service. I've written up a quick guide on how it can be made to run as a service to avoid needing to manually restart the process after reboots. Check it out here.

Example

while($true) {
    Get-Date
    Update-KindleBookPrices
    Start-Sleep -Seconds 43200
}

Example Output

PS C:\> Update-KindleBookPrices
Checking price of Windows PowerShell Cookbook: The Complete Guide to Scripting Microsoft's Command Shell
+Found discount for Windows PowerShell Cookbook: The Complete Guide to Scripting Microsoft's Command Shell, new price is $41.98 (original: $67.91)

As there are many options for alerting (email, SMS, push, API, ...) and each one with a myriad of providers this functionality has been left to the user to implement.

The Update-KindleBookPrices accepts a ScriptBlock parameter called -AlertScriptBlock. The ScriptBlock is executed if there is a change in price, and gets passed the $Book object (see JSON representation below) as the first parameter, and a descriptive message (a string, see example above in green) as the second parameter.

{
    "ASIN":  "B00ARN9MEK",
    "Title":  "Windows PowerShell Cookbook: The Complete Guide to Scripting Microsoft's Command Shell",
    "Authors":  [
                    "Lee Holmes"
                ],
    "URL":  "https://www.amazon.com.au/Windows-PowerShel...<truncated>",
    "ImageURL":  "https://images-na.ssl-images-amazon.com/images/I/51MtlVpXnvL.jpg",
    "IsOnSale":  true,
    "OriginalPrice":  67.91,
    "SalePrice":  41.98
}

Example

[ScriptBlock]$SendEmail = { 
    Param(
        $Book,
        $Msg
    )

    $Body = "<h1><a href=$($Book.URL)>Get it!</a></h1>"

    Send-MailMessage `
        -From "[email protected]" `
        -To "[email protected]" `
        -Subject $Msg `
        -Body $Body `
        -BodyAsHtml `
        -SmtpServer "mail.mydomain.com"

    Write-Host "Sending email!"
}

Update-KindleBookPrices -AlertScriptBlock $SendEmail

Checking price of Windows PowerShell Cookbook: The Complete Guide to Scripting Microsoft's Command Shell
Found discount for Windows PowerShell Cookbook: The Complete Guide to Scripting Microsoft's Command Shell, new price is $41.98 (original: $61.99)
Sending email!