> ## Documentation Index
> Fetch the complete documentation index at: https://www.plain.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# importCustomers

> Upsert up to 25 customers from an external system using their externalId for idempotency. Each customer can include an optional list of tenants to associate with. Returns an ImportResult with added, updated, and skipped counts.