I recently discovered that Enterprise customers can create free “service accounts” for API access to Airtable.
These are not “user accounts” that can log into Airtable’s website, but they are “API-only accounts” that can only access Airtable’s API via a personal access token or by authorizing an OAuth integration.
The advantage is that this service account does not count towards the user count for billing purposes. So, for all intents and purposes, this is a “free account”.
More details here:
https://support.airtable.com/docs/service-accounts-overview
p.s. Note that for now, 3rd-party apps like Make & Zapier don’t support personal access tokens nor OAuth integrations, but they will before February 2024.