Ephemeral Configuration Database

https://www.juniper.net/documentation/en_US/junos/topics/concept/ephemeral-configuration-database-overview.html

that provides a fast programmatic interface

The ephemeral database enables:
- Juniper Extension Toolkit (JET) applications and
- NETCONF and
- Junos XML management protocol client applications
to concurrently load and commit configuration changes to a device running Junos OS and with significantly greater throughput than when committing data to the candidate configuration database.

In the ephemeral commit model, Junos OS validates the syntax but not the semantics