The answer is…a bit complicated.
700s are, by design, not manageable with traditional Check Point management.
They were sold as SMB appliances with this capability explicitly removed.
Their 1400 equivalents can be managed by traditional Check Point management as can the newer 1500/1800/1900 series.
Regular Check Point management has REST APIs, of course, but the actual SMB gateway object must be created manually in SmartConsole (ie that does not have REST API support yet).
This support is limited to Access and Threat Prevention policy, not actual device management (e.g. interfaces, routing).
As for accessing a REST API on the device itself, the 700 does not offer this and there are no plans to add one there.
We recently added support for a REST API on the 1500 (in R80.20.25 firmware), though I can’t immediately find the relevant documentation.
I assume it will be similar to what is noted in the release notes: limited to clish commands.
Which would imply some ability to manage the device/access policy/threat prevention using this.