We’ve received an email or two asking how to use Zumero sync from Swift code. If you’ve used other Objective-C frameworks in your Swift projects, the steps are just what you’d expect. If you haven’t, don’t worry - it’s not that bad.

Create a Swift-based project, as usual.

Now add the ZumeroSync framework - either directly from the Zumero SDK, or – my preferred way – via Cocoapods.

$ cat >> Podfile 
pod 'ZumeroSync'

$ pod install
Analyzing dependencies
Downloading dependencies
Installing ZumeroSync (
Installing sqlite3 (
Generating Pods project
Integrating client project

[!] Please close any current Xcode sessions and use `swiftnzum.xcworkspace` for this project from now on.

We’ll now open the workspace as instructed, and it looks like we’re all set:

Except that Swift has no idea what we’re talking about:

To let Swift code know about the Zumero classes, we need a bridging header. I followed Mark Petherbridge’s instructions in How to create an Objective-C Bridging header, like so:

Add a new Objective-C file. Call it what you like:

Yes, we do want to create a bridging header:

Add a ZumeroSync import to that header:

//  Use this file to import your target's public headers that you would like to expose to Swift.

#import <ZumeroSync/ZumeroSync.h>

We can delete the “dummy” Objective-C file (optional, but it serves no purpose here):

And voilà, Swift has heard of Zumero:

As for the actual usage, it’s just a Swift-y version of the Objective-C call:

var syncError: NSError?

let ok = ZumeroSync.Sync("foo", cipherKey: nil,
    serverUrl: "http://example.com/", remote: "dbfilename",
    authScheme: nil, user: nil, password: nil,
    error: &syncError)