Skip to content
All articles
Product10 August 2026·3 min read

Add native AuthKit sign-in to your iOS app with the Paycux iOS SDK

The best signal that a feature is right is not that people ask for it.

Paycux engineering

The best signal that a feature is right is not that people ask for it. It is that people describe their problem in the shape of it before you have built anything.

This piece walks through how we think about it at Paycux, what we have changed our minds about, and where the sharp edges are.

What you'll build

What you'll build deserves its own treatment. Defaults are the product. Most people will never open the settings screen, which means the behaviour you chose for them is the behaviour they will experience forever.

Ship the smallest version that is honest about its limits. A feature that does one thing completely beats one that does five things with an asterisk on each.

Prerequisites

Prerequisites is where this gets concrete. Ship the smallest version that is honest about its limits. A feature that does one thing completely beats one that does five things with an asterisk on each.

Defaults are the product. Most people will never open the settings screen, which means the behaviour you chose for them is the behaviour they will experience forever.

  • Choose defaults as carefully as features
  • Settle the name before you ship the thing
  • Ship the smallest honest version
  • Say plainly what the feature does not do

Configure your app in the Paycux dashboard

Configure your app in the Paycux dashboard deserves its own treatment. Naming is design work. If the team argues about what to call something, the disagreement is usually about what it is, and shipping before that is settled means shipping the confusion to customers.

Ship the smallest version that is honest about its limits. A feature that does one thing completely beats one that does five things with an asterisk on each.

Add the SDK

Consider add the sdk. Ship the smallest version that is honest about its limits. A feature that does one thing completely beats one that does five things with an asterisk on each.

Defaults are the product. Most people will never open the settings screen, which means the behaviour you chose for them is the behaviour they will experience forever.

Naming is design work.

Kick off the PKCE flow

That brings us to kick off the pkce flow. Naming is design work. If the team argues about what to call something, the disagreement is usually about what it is, and shipping before that is settled means shipping the confusion to customers.

Defaults are the product. Most people will never open the settings screen, which means the behaviour you chose for them is the behaviour they will experience forever.

Present the sign-in screen

That brings us to present the sign-in screen. Ship the smallest version that is honest about its limits. A feature that does one thing completely beats one that does five things with an asterisk on each.

Defaults are the product. Most people will never open the settings screen, which means the behaviour you chose for them is the behaviour they will experience forever.

Validate state and exchange the code

That brings us to validate state and exchange the code. Ship the smallest version that is honest about its limits. A feature that does one thing completely beats one that does five things with an asterisk on each.

Ship the smallest version that is honest about its limits. A feature that does one thing completely beats one that does five things with an asterisk on each.

Where this leaves us

If there is one thing worth taking away, it is that the expensive decisions are the ones made implicitly. Making them on purpose costs an afternoon.

If you are working through the same problem and want to compare notes, the docs cover the mechanics and the console shows the behaviour on your own data.

Everything here, already built

Sign-in, enterprise SSO, directory provisioning, roles and an audit trail behind one API. Start with the quickstart and have a working sign-in this afternoon.

Start selling to enterprise customers

Create an account, point sign-in at Paycux, and get back to the part of the product that is actually yours.