Hi,
We’re building an ad system that uses safecracker to upload all the ads and associated data, but then must aggregate all of the ads together and send them as one JSON call to a mobile app. But while the user is inputting the ads, he/she must be able to get through the administration section without seeing what would look like gobbledygook to them. Can SC handle both?

You can’t have a redirect and output json at the same time. I’d recommend using a normal redirect and creating a separate template to create your aggregated JSON.