If your firm routes traffic through a corporate proxy, PAC file, or firewall, a few domains need to be allowed (or bypassed) for Pirros to work. This article is the definitive list, written for the IT team that manages those rules.
Signs Something Is Being Blocked
When a required domain is blocked, the most common symptoms are:
A new user clicks their invite link, enters their email, and gets sent back to the email screen in a loop — they never reach the step to create a password.
Sign-in works on a home network or with the PAC file turned off, but fails on the office network.
The Pirros pane inside Revit stays blank or fails to load.
Turning the proxy or PAC file off will usually confirm the cause, but it isn't a long-term fix. Adding the domains below is.
Domains to Allow
Pirros domains
All of these are required. Note that auth.pirros.com and auth.pirros.io are two different services — both need to be allowed.
Domain | What it's used for |
app.pirros.com | The Pirros web app and the Pirros pane in Revit |
api.pirros.com | The Pirros API that the web app and plugin talk to |
auth.pirros.io | The Pirros login and sign-up page |
auth.pirros.com | Pirros's own sign-in service, used behind the scenes after you log in |
app.pirros.io | Secondary Pirros web app domain |
Bot-detection check
Domain | What it's used for |
newassets.hcaptcha.com | The captcha shown on the login and sign-up page when extra verification is needed |
This one is easy to miss. The captcha only appears some of the time, so it rarely shows up in a normal test — but it's much more likely to appear on a proxied network, because every user shares the same outbound IP address. If the captcha is required but blocked, the sign-in form submits and lands back on the email screen, which produces the invite-link loop described above.
Your identity provider
If your firm signs in to Pirros with single sign-on, your identity provider's domains also need to be reachable. These vary by firm. Common examples:
Microsoft Entra ID (Azure AD): login.microsoftonline.com and device.login.microsoftonline.com
Okta, Duo, or Google: your firm's sign-in domains for that provider
Confirming the Fix
To check whether the captcha is the culprit, have an affected User open the invite link in Chrome or Edge and:
Press F12 to open Developer Tools and select the Network tab.
Type captcha in the filter box.
Go through the sign-in steps. If requests to newassets.hcaptcha.com show as failed or blocked, add it to your allow list.
Once the domains are added, have the User close the browser tab and open the invite link again.
Installing the Revit Plugin
The domains above cover signing in and using Pirros. If your firewall is blocking the plugin installer itself, see Revit Plugin: Download & Installation.
Still Having Trouble?
Reach out to our Support team through the chat in the bottom-right corner. Let us know which domains you've allowed and what the User sees, and we'll help you track down anything that's still blocked.