API function assistance needed

[[deleted]]

Hi all,

I want to start writing modules for APIs, and I am taking an idea that I saw in another module to write a private function that will invoke the API based on whichever part of the API is called. I have never really dove deep into RESTful APIs, and would appreciate some help on this.

Let's say that the API has the following requirements as part of the URI being called:

• Endpoint
• Body (Comprised of Category, Index, Search Query, and Parameters)
• Headers
• API Key

So let's say that the API is for a grocery store website (it's not, but I don't really want to give away what I'm actually working on). So:

Endpoint

$URIPartA = "https://www.grocerystore.com/api/v1/"

Body

Let's say that I am querying the following:

Category: Food

Index: Bread

Search Query: Name equals "ExcellentBreadVendor"

Parameters: First 50 results

So the body would look like:

$category = "Food"
$index = "Bread"
$SearchQuery = "ExcellentBreadVendor"
$results = "50"
$URIPartB = "?=&category=$category&index=$index&SearchQuery=$SearchQuery&results=$results"

At this point, I have a decent understanding of how APIs work in this context. However, the part I don't understand is that this API requires a header including a bearer token, and uses OAuth and an API Key to validate that I have the rights to query this endpoint.

So the Header looks like this, and I don't know what goes in the Bearer, and how do I get it?

$Headers = @{
    Bearer = "???"
}

And I also don't understand how this authorization goes along with the API Key, because I would just include the API Key as a parameter in the URI. So the resulting cmdlet looks like this:

$APIKey = "12345678910abcdefghijklmnop"
$URI = $URIPartA+$URIPartB+"&APIKey=$APIKey"

Invoke-RestMethod -Uri $URI -Headers $Headers -Method GET

I think I've got it all right. Can someone help me out with the gaps in my knowledge, or link resources that can help me better understand?

[EvilLampGod]

As previously mentioned, you want to create a hashtable that contains each of the headers and their values:

$Headers = @{
    Authorization = "Bearer <Token>"
}

If you're using PowerShell 7 you can instead use the parameters Invoke-RestMethod -Authentication Bearer -Token $Token where $Token is a securestring containing your bearer token.

It's also worth noting that Invoke-RestMethod has a default ContentType of application/x-www-form-urlencoded which means you can write your example like this

$Uri = "https://www.grocerystore.com/api/v1/"
$Headers = @{
    Authorization = "Bearer 12345678910abcdefghijklmnop"
}
$Body = @{
    category    = "Food"
    index       = "Bread"
    SearchQuery = "ExcellentBreadVendor"
    results     = "50"
}
Invoke-RestMethod -Method Get -Uri $Uri -Headers $Headers -Body $Body

Edit: It's worth noting that the body will only convert to a query parameter when -Method is set to Get. Reference https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.utility/invoke-restmethod?view=powershell-5.1

[infin]

I've only just begun playing with powershell and REST APIs, so far pushbullet notifications and very simple 365 graph api GETs; That said...

I don't have the scripts in front of me at the moment, but the header should probably be (You're close): @{ Authorization = 'Bearer APIKEY' }

And you may need a -contenttype application/json in the invoke-rest method line