Invoke-RestMethod - Error when querying session relevance

Customizations
1

This is my first endeavor into utilizing the Rest API. I have created my token and the “API Token Test” (code below) returns fine. BUT .. when I try to perform even a simple session relevance query, I receive the error "…there is no reachable BigFix Explorer and/or BigFix Web Reports instance collecting data from this server."

# --- API Token Test.ps1 ---

# --- DEFENSIVE NETWORKING FIXES ---
[System.Net.ServicePointManager]::SecurityProtocol = [System.Net.SecurityProtocolType]::Tls12 -bor [System.Net.SecurityProtocolType]::Tls13
[System.Net.ServicePointManager]::Expect100Continue = $false

Add-Type @"
    using System.Net;
    using System.Net.Security;
    using System.Security.Cryptography.X509Certificates;
    public class SSLHandler {
        public static void Bypass() {
            ServicePointManager.ServerCertificateValidationCallback = 
                (sender, cert, chain, sslPolicyErrors) => true;
        }
    }
"@
[SSLHandler]::Bypass()

# --- NEW TOKEN AUTHENTICATION ---
$MyToken = "<token>"

# IMPORTANT: In BigFix 11.0.6, the header uses 'Bearer' 
$Headers = @{ 
    "Authorization" = "Bearer $MyToken" 
    "Accept"        = "application/xml"
}

# --- THE COMMAND ---
$BigFixServer = "https://<fqdn>:52311"
$SitesUrl     = "$BigFixServer/api/sites"

try {
    $SitesResponse = Invoke-RestMethod -Uri $SitesUrl -Method Get -Headers $Headers -DisableKeepAlive
    $SitesResponse.BESAPI 
}
catch {
    Write-Error "Token Request Failed: $($_.Exception.Message)"
}

The above works fine. The below returns the error.

# Define Variables
$server = "company.com"
$port = "52311"
$token = "YOUR_BEARER_TOKEN_HERE"
$query = "names of bes computers"

# Construct URI and Headers
$uri = "https://$($server):$($port)/api/query"
$headers = @{
    "Authorization" = "Bearer $token"
    "Accept"        = "application/json"
    "Content-Type"  = "application/json"
}

# Construct the exact JSON Body
$body = @{
    "relevance" = $query
} | ConvertTo-Json

# Execute the REST API Call
try {
    $response = Invoke-RestMethod -Uri $uri -Method Post -Headers $headers -Body $body -SkipCertificateCheck
    $response
} catch {
    Write-Error "Failed to evaluate query: $_"
}

I found this post BigFix API / Web Reports broken? - #4 by itsmpro92 that was similar with the last comment being about an SSL certificate change but seeing that this is my first time using Rest API AND that the test script works, I’m not sure if this is the same issue.

My desired end result is a template that I can “plug n’ pray” session relevance into.

1 Like
2

Given the error, let's start by validating that Web Reports and/or BigFix Explorer are available to the given BigFix instance.

One way to check for the availability of Web Reports is via the BFEnterprise database associated with the BigFix Server:

SELECT * FROM [BFEnterprise].[dbo].[AGGREGATEDBY]

And to verify the availability of a BigFix Explorer instance is via the REST API by performing a GET request against: /api/explorers

https://<BigFixServerFQDN>:52311/api/explorers

At least one of these needs to be available to the BigFix Server in order to process Session Relevance requests to /api/query.

3

Can you try this method and see if it returns anything. This works on my lab but your code failed to (guessing either its the body or the post method vs the get).

$Server = "{fqdn.or.ip.address}"
$Token = "{your_token_string}"
$query = "names of bes computers"
$uri = "https://$($Server):52311/api/query?relevance=$($query)"
$headers = @{
    "Authorization" = "Bearer $Token"
    "Accept" = "application/json"
    "Content-Type" = "application/json"
}

$Responce = Invoke-RestMethod -uri $uri -Method Get -Headers $headers -DisableKeepAlive -skipcertificatecheck
$Responce.BESAPI.Query.Result.Answer
4

Update: Try changing your Content-Type from application/json to application/json+relevance. This allowed your code to run on my lab that has an Explorer instance deployed.

5

This returns the address of Web Reports (lives on same server).

WebReportsURL = https://BigFix-WebReports.MyDomain:8083/webreports LastAggregatedTime: 2026-06-25 18:34:18.047 IsDeleted: 0 SessionToken: SSLCert: Priority: 155 WebReportsSeverID: 1

I have not stood up a BigFix Explorer server. We have a relatively small environment (<1500 systems) so I’m not sure its worth the effort – feel free to contradict this!

6

Error: A parameter cannot be found that matches parameter name “skipcertificatecheck”

7

@SLB

When I use this instead of the -SkipCertificateCheck paramter:

# Globally bypass SSL Certificate Validation [System.Net.ServicePointManager]::ServerCertificateValidationCallback = {$true}

I get an immediate response of:

The underlying connection was closed: An unexpected error occurred on send.
8

@SLB

When I try your exact script using PowerShell 7, I get the original error "…there is no reachable BigFix Explorer and/or BigFix Web Reports instance collecting data from this server."

9

I get that error too if I stop the 1 explorer instance I have. Not sure if my environment knowing there is an explorer instance but it be inaccessible if that is expected behaviour or whether it should just fall over to WebReports, which is up and running. The first code I posted that uses the GET method did work when Explorer isn’t running.

The -SkipCertificateCheck is only available in PowerShell 7 or later and earlier version would require additional methods to bypass an internal or self signed certificate. You can double check by checking the version via $PSVersionTable.PSVersion and by reviewing the available methods via get-help Invoke-RestMethod -ShowWindow

From my lab just for comparative purposes

image
image836×464 31.3 KB

1 Like
10

This from my main server that has the OS default version of PowerShell, same error you see

image
image846×360 130 KB

11

@SLB Yep I caught that (after a moment of frustration) .. and tried on both PowerShell 7 and PowerShell 5 with the correct version specific methods of “skip certificate check”.

v5.2 results:

The underlying connection was closed: An unexpected error occurred on send.

v7 results:

…there is no reachable BigFix Explorer and/or BigFix Web Reports instance collecting data from this server.