PowerShell

Egyptian eReceipt OAuth2 Client Credentials

See more Egypt eReceipt Examples

Get an OAuth2 access token for the Egyptian eReceipt REST API using client credentials (no interactivity with a web browser required). PowerShell

Add-Type -Path "C:\chilkat\ChilkatDotNet47-x64\ChilkatDotNet47.dll"

$success = $false

# This example assumes the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

$http = New-Object Chilkat.Http

# Note: Any provider of a REST API, such as the Egyptian government in this case, can make life 
# much easier for developers by providing one or more of the following in the API documentation:
# 
# 1) A sample CURL statement for each API call.
# 2) A Postman collection, or Swagger/OpenAPI specification file.
# 3) A sample of a raw HTTP request and response for each API call.
# 
# The sample CURL statements or raw HTTP request/responses do not need to comprehensively show all 
# possible options.  Providing a sample allows one to quickly make a successful API call.
# It also allows for code generation directly from the CURL, Postman collection, or raw request/response,
# and it tends to answer all questions about the format/structure of a request that, suprisingly,
# remain ambiguous or not obvious in other forms of documentation.

$req = New-Object Chilkat.HttpRequest
$req.AddParam("grant_type","client_credentials")
# Use your actual client ID and client secret...
$req.AddParam("client_id","d0394a9f-0607-40de-a978-2d3eb8375b04")
$req.AddParam("client_secret","6d62315e-d65a-4e41-9112-4195ea834edf")

$req.AddHeader("posserial","1234567899")
$req.AddHeader("pososversion","os")
$req.AddHeader("posmodelframework","1")
$req.AddHeader("presharedkey","03ac674216f3e1...")

# When writing this example, the documentation at https://sdk.invoicing.eta.gov.eg/ereceiptapi/01-authenticate-pos/
# shows us the HTTP verb and path (POST /connect/token), however,
# we don't see the actual domain where the request is to be sent.
# What are the endpoints???
# It took some searching, but we found some endpoints here:  https://sdk.invoicing.eta.gov.eg/faq/
# It's not immediately apparent which endpoint is to be used with a given API call.
# Why not just include the endpoint in the documentation for each REST API call?
# Endpoints are literally the #1 thing that needs to be known.
# They can't just be buried in a FAQ.  They should be up-front and obvious.
# 
# So.. we're guessing the endpoint is likely "https://invoicing.eta.gov.eg/connect/token"
$req.HttpVerb = "POST"
$req.ContentType = "application/x-www-form-urlencoded"

$resp = New-Object Chilkat.HttpResponse
$success = $http.HttpReq("https://invoicing.eta.gov.eg/connect/token",$req,$resp)
if ($success -eq $false) {
    $($http.LastErrorText)
    exit
}

$sbResponseBody = New-Object Chilkat.StringBuilder
$resp.GetBodySb($sbResponseBody)

$jResp = New-Object Chilkat.JsonObject
$jResp.LoadSb($sbResponseBody)
$jResp.EmitCompact = $false

$("Response Body:")
$($jResp.Emit())

$respStatusCode = $resp.StatusCode
$("Response Status Code = " + $respStatusCode)
if ($respStatusCode -ge 400) {
    $("Response Header:")
    $($resp.Header)
    $("Failed.")
    exit
}

# If successful, the OAuth2 access token JSON looks like this:

# {
#   "token_type": "Bearer",
#   "access_token": "eyJraW......R2sbqrY",
#   "expires_in": "3600",
#   "scope": "..."
# }

$token_type = $jResp.StringOf("token_type")
$access_token = $jResp.StringOf("access_token")
$expires_in = $jResp.StringOf("expires_in")
$scope = $jResp.StringOf("scope")