PowerShell JSON Headers not Converting correctly - json

Question

I am using an API REST call, but the problem is that it for some reason is not passing the header value correctly. I am getting an error about it not converting from "System.String" to "System.Collections.IDictionary".
The code is:
$Headers = New-Object 'System.Collections.Generic.Dictionary[[String],[String]]'
$Headers.Add('X-CENTRIFY-NATIVE-CLIENT', 'true')
$Headers.Add('Content-Type', 'application/json')
$Body = #{
TenantId = 'ID'
User = 'cloudadmin#andrew1.com'
Version = '1.0'
}
#$wr = Invoke-WebRequest -Method Post -Uri $url -Headers $Headers -Body $Body -Verbose
Invoke-RestMethod -Uri "https://uri/Security/StartAuthentication" -Method Post -Headers ($Headers | ConvertTo-Json -Compress) -UseBasicParsing -Body $Body
But when I execute I get this error (FQID):
Invoke-RestMethod : Cannot bind parameter 'Headers'. Cannot convert the "{
"X-CENTRIFY-NATIVE-CLIENT": "true",
"Content-Type": "application/json"
}" value of type "System.String" to type "System.Collections.IDictionary".
At line:31 char:109
+ ... tication" -Method Post -Headers ($Headers1 | ConvertTo-Json) -UseBas ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidArgument: (:) [Invoke-RestMethod], ParameterBindingException
+ FullyQualifiedErrorId : CannotConvertArgumentNoMessage,Microsoft.PowerShell.Commands.InvokeRestMethodCommand
I have tried my headers being like this as well:
$headers = #{
'Content-Type'= 'application/json'
'X-CENTRIFY-NATIVE-CLIENT'= 'true'
}
But I still get that same error. It is odd that it keeps complaining about this reference; This library is not native to PoSH. Is there a DLL I should load or is there a better way to go about this?

Answer 1

The -Headers parameter expects a dictionary, not a json object.
Pass $Headers directly:
$uri = "https://uri/Security/StartAuthentication"
Invoke-RestMethod -Uri $uri -Method Post -Headers $Headers -UseBasicParsing -Body $Body
You can inspect parameter details with Get-Help:
PS > Get-Help Invoke-WebRequest -Parameter Headers
-Headers <IDictionary>
Required? false
Position? Named
Accept pipeline input? false
Parameter set name (All)
Aliases None
Dynamic? false

Answer 2

I took the json conversion out of the header on your invoke restmethod. That part will need to be done on your payload $Body. Give this a try.
$Headers = #{}
$Headers.Add('X-CENTRIFY-NATIVE-CLIENT', 'true')
$Headers.Add('Content-Type', 'application/json')
$Body = #{
TenantId = 'ID'
User = 'cloudadmin#andrew1.com'
Version = '1.0'
}
$Body = ($Body | ConvertTo-Json)
#$wr = Invoke-WebRequest -Method Post -Uri $url -Headers $Headers -Body $Body -Verbose
Invoke-RestMethod -Uri "https://uri/Security/StartAuthentication" -Method Post -Headers $Headers -UseBasicParsing -Body $Body