Simple Nintex API REST call in PowerShell

Question

I’m trying to make a couple of simple “Hello world” queries with the Nintex RPA REST API.

The documentation examples use Postman, but that’s unavailable in my environment. So I’m trying to use Powershell instead.

My second API call, a graphql query to get the RPA version, is failing with “InvalidOperation”.

Here’s the code:

# Get Access Token:
$response = "XXX"
$uri = "http://MY_NINTEX_HOSTNAME/auth/realms/Kryon/protocol/openid-connect/token"
$contentType = "application/x-www-form-urlencoded"  # Implicitly set to "application/x-www-form-urlencoded" for POST method calls
$formBody= @{
client_id="kryon-public-api"
grant_type="password"
username="MY_NINTEX_USER"
password="NINTEX_USER_PASSWORD"
}
$response = Invoke-RestMethod -Uri $uri -Method POST -ContentType $contentType -Body $formBody
$access_token = $response.access_token
#Write-Host "Get Access Token response: " $response  
#Write-Host "access_token: " $access_token 

# Get RPA Version:
$response = "XXX"
$uri = "http://MY_NINTEX_HOSTNAME/nintex-public-api/graphql"
$contentType = "application/json"
$httpHeaders = @{
  "Authorization"       = "Bearer $access_token"
  "Accept"              = "application/json"
  "kryon-client-id"     = "kryon-public-api"
  "kryon-auth-provider" = "aerobase"
}
$formBody= @'
query {
    getRpaServerVersion
}
'@	
$response = Invoke-RestMethod -Uri $uri -Method POST -Headers $httpHeaders -ContentType $contentType -Body $formBody
Write-Host "Get RPA Version response: " $response

<= The first API call, “Get access token” works OK;
The next call, “Get RPA version” (GraphQL) call fails with this error:

+ $response = Invoke-RestMethod -Uri $uri -Method POST -Headers $httpHe ...
+             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (System.Net.HttpWebRequest:HttpWebRequest) [Invoke-RestMethod], WebException
    + FullyQualifiedErrorId : WebCmdletWebResponseException,Microsoft.PowerShell.Commands.InvokeRestMethodCommand
Get RPA Version response:  XXX

Q: What am I doing wrong???

Best answer by bsikes

Hi @paulsm4 ,

I suspect right now you have two problems:

You do need to have the application/json as the content type (like you originally had)

Your formBody isn’t formatted quite right when it gets passed through. I usually utilize ConvertTo-JSON to get the body into properly formatted JSON:

$Headers = @{
                "Authorization" = "Bearer $token"                
                "kryon-client-id" = "kryon-public-api"
                "kryon-auth-provider" = "aerobase"
            }

            $Body = @{
                "query" = @" 
                {
                   getRpaServerVersion
                  }
"@
                } | ConvertTo-Json -Depth 8

Invoke-RestMethod -Uri $URI -Headers $Headers -Method POST -ContentType "application/json" -Body $Body

I at least know it’s working in 25.11.

bsikes · Accepted Answer

Hi ​@paulsm4,I suspect right now you have two problems:You do need to have the application/json as the content type (like you originally had)Your formBody isn’t formatted quite right when it gets passed through. I usually utilize ConvertTo-JSON to get the body into properly formatted JSON:$Headers = @{                "Authorization" = "Bearer $token"                                "kryon-client-id" = "kryon-public-api"                "kryon-auth-provider" = "aerobase"            }            $Body = @{                "query" = @"                 {                   getRpaServerVersion                  }"@                } | ConvertTo-Json -Depth 8Invoke-RestMethod -Uri $URI -Headers $Headers -Method POST -ContentType "application/json" -Body $BodyI at least know it’s working in 25.11.

paulsm4 · Answer

I modified the Powershell “Invoke-Restmethod” slightly, REMOVING “Accept: application/json” from the headers, and “-ContentType application/json” from the command.

Now I’m getting a different Nintex error: “Forbidden":

Code:

# Get RPA Version:
$response = "XXX"
$uri = "http://VHAPREAPPRPABOT.va.gov/nintex-public-api/graphql"
$contentType = "application/json"
$httpHeaders = @{
  "Authorization"       = "Bearer $access_token"	
  "kryon-client-id"     = "kryon-public-api"
  "kryon-auth-provider" = "aerobase"
}
$formBody= @'
query {
    getRpaServerVersion
}
'@
$httpHeaders | Out-String | Write-Host
$response = Invoke-RestMethod -Uri $uri -Method POST -Headers $httpHeaders -Body $formBody
Write-Host "Get RPA Version response: " $response

Result:

Name                 Value
----                 -----
kryon-auth-provider  aerobase
Authorization        Bearer eyJhbGciOiJSUz...
kryon-client-id      kryon-public-api

Invoke-RestMethod : {"responseMeta":{"trxId":"c8eddd69-e667-4ddb-8fa2-f667f60dfa4c","reqId":"c8eddd69-e667-4ddb-8fa2-f6
  67f60dfa4c","message":"Forbidden"}}
  At E:\Ricoh\psm\invoke-api1.ps1:78 char:13
  + $response = Invoke-RestMethod -Uri $uri -Method POST -Headers $httpHe ...
  +             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      + CategoryInfo          : InvalidOperation: (System.Net.HttpWebRequest:HttpWebRequest) [Invoke-RestMethod], WebExc
     eption
      + FullyQualifiedErrorId : WebCmdletWebResponseException,Microsoft.PowerShell.Commands.InvokeRestMethodCommand
  Get RPA Version response:  XXX
  <= Current Nintex error: "Forbidden"

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