How auth is billed
Using Foir for auth is metered on three things: how many of your customers are active, how many people on your team hold an account, and how much auth email you send. This page explains what each one means and how limits behave. For the full billing surface — plans, invoices, payment methods — see Billing & Usage.
The three auth metrics
| Metric | What it counts | Resets |
|---|---|---|
| Monthly Active Users (MAU) | Distinct customers who signed in or held an active session during the billing month | Monthly |
| Admin Seats | People on your team with a live role in the workspace (team members, not customers) | Never (cumulative) |
| Auth Emails | OTP, verification, password-reset, welcome, and invite sends | Monthly |
Monthly active users
An MAU is one of your end users — a customer — who was active in the billing month. A customer who signs in ten times in a month is one MAU; a customer who never returns that month isn’t counted. This is the metric that scales with your app’s success, and it’s the one most auth providers price on.
MAU counts every login path — hosted Login with Foir, the token API, and OAuth — so the number reflects real usage regardless of how you integrated.
Admin seats
A seat is a member of your team — someone you invited into the workspace who holds a live role. It is not a customer. Seats are cumulative: inviting a teammate consumes one, removing them frees it. See Team Members.
Note: “Users” on the billing dashboard means team members (seats), and “Active Users” means your customers (MAU). They are two different populations with two different limits.
Auth emails
Every auth email your project sends — one-time passwords, address verification, password resets, welcome mail, and team invites — counts toward a monthly send allowance. The allowance is a cost and abuse ceiling, not a growth tax: normal auth traffic sits well under it.
How limits behave
Auth limits are designed to gate new growth without ever locking out the users you already have:
- Over your MAU cap? Already-active customers keep signing in. New customer sign-ups at public login pages are what’s gated.
- Over your seat cap? Your existing team is unaffected. Adding a new teammate is what’s gated.
- Over your email allowance? Sends are refused for the rest of the month, but this fails open — a metering problem never takes out your verification email.
When you approach a limit, the Usage tab shows a meter and an upgrade prompt. Higher plans raise every limit, and custom plans can lift them entirely. Browse current limits per plan on the Pricing page without logging in.
Where to see your usage
Open the Usage tab in your workspace for the live picture: your MAU trend over the last 90 days, each metric against its plan cap, and per-project active users. The same numbers drive the caps that are enforced, so what you see is what you’re billed on.