FastComments authenticates requests to your account to see that they are coming from your site. This is why we need to know which site, or sites, you want to install FastComments on.

FastComments supports authentication by means of domain, as well as subdomains.

Let's take the site https://example.com. In this case, "example.com" is the domain. example.com supports both example.com, and www.example.com. We'll call the "www" the "subdomain".

For Example:

• To allow only blog.example.com:
  • Add blog.example.com to your domains.
• To allow www.example.com, somesite.example.com, and example.com:
  • Add example.com to your domains.
  • This is billed as having one domain associated with your account.
• You can now add wildcard subdomains, for example *myname.vercel.app.
  • This is billed as having one domain associated with your account.

If you were using a blogging platform, and you were given a subdomain, you would want to add the full domain including the subdomain to your account, for example: cats.blogger.com.

We can add domains to our account by visiting the My Domains page and clicking Add a Domain at the bottom:

The My Domains Page

During the trial period, domains are automatically added to your account when requests come from said domains. However, after this time they must be added explicitly for security. You should receive an email when this automated behavior occurs.

You do not have to add localhost for local development - it is allowed by default.

Via The API

Domains can also be added and configured via the DomainConfigs API.

To found out the limit for the number of domains in your account, visit the Billing Page.

Pricing

The pricing varies based on package:

1. FastComments for Creators
   • Included in package pricing. Limit of three sites.
2. FastComments Flex
   • First site is included. Each additional site is $10/mo.
3. FastComments Pro
   • A large number of sites (can vary based on agreement) is included in package pricing.

Traffic Limits & Domains

In the example where you are on a tier with five million monthly page loads with five domains added to your account, and each domain ends up with one million-page loads, you will have met your monthly quota.

To summarize, traffic limitations are per-account, not per-domain.

Note that we do offer custom packages for different size sites, simply reach out to support.

Sometimes FastComments has to email your users, especially if you are not using Secure SSO.

Examples of this includes verifying their account or activity when commenting for the first time. FastComments will also send them notifications for replies to their comments.

When FastComments emails your users, we will use a default From Name and Email of FastComments Robot and noreply@fastcomments.com.

We'll also use our own logo in the footer of these emails.

If you have FastComments Flex or Pro, this all can be customized on a per-domain basis via the "My Domains page":

Customizing From Name, Email, and Logo

When customizing the logo shown in emails, ensure that the size you are uploading is the same size that you want to show in the footer of the email.

When Customizing The From Domain

If you customize the From Domain, Email providers and clients need to know that FastComments is authorized to send emails on your behalf. Otherwise, defining the From Domain and not following the below steps likely will result in emails going to spam.

1. Setup SPF

To allow FastComments to securely send email as your domain, ensure you add an SPF record that allows us to do so.

Ensure there are SPF records to allow mail.fastcomments.com and sib.fastcomments.com to send mail as your domain.

Some more information on how to do this is here: https://mailtrap.io/blog/multiple-spf-records/

2. Setup DKIM

In addition to SPF, you should set up DKIM. Once your DNS configuration is ready, you can click "Show Advanced" in the domain configurations page to show the DKIM settings per-domain.

You can also invoke the API to set DKIM configuration.

Unsubscribe Links

When using SSO, the unsubscribe features used in emails and notifications can be customized via the DomainConfigs API.

The comment widget can be customized differently for each site.

On the widget customization page, you'll find a dropdown labeled "domain". Selecting All in this field will apply the rule to all sites on your account, you can enter a specific domain which will restrict the settings or custom CSS you wish to apply to only that domain.

This allows you to have FastComments look or function completely different for each site.

Customization Rule Domain

For one site might use bold text and allow anonymous commenting, and another site might have different styling and require the user to leave their email when they comment.

You can use the same FastComments account with multiple WordPress deployments. When you set up the plugin a separate integration token is added each time. You can view your active integrations here.

You can also use the same FastComments account with a WordPress installation that spans multiple domains and has the same content on those domains.