Swift Package Manager makes it easy to split an app into well-defined modules. That structure also helps agents work safely.
Why modules help
A module has a public interface and hidden internals. An agent working in one module can change implementation details without affecting others, and the compiler enforces the boundary.
A typical layout
- A design-system package for shared UI components.
- Feature packages for each area of the app.
- A data or networking package.
- A small app target that composes them.
Keep dependencies one-directional
Features should depend on shared packages but not on each other. Circular or sideways dependencies make changes hard to reason about and tests slow.
Make public APIs small
A narrow public surface reduces what an agent must understand. It also reduces accidental coupling.
Use types as guard rails
Strong typing, enums with associated values for state, and protocols for dependencies let the compiler catch many mistakes. A compile error is quick, objective feedback.
Run targeted builds
Build and test one package at a time. Faster feedback means the agent can iterate more often at lower cost.
Takeaway
A modular codebase is easier for people and agents to change safely, so architecture work is also agent-enablement work.
Continue with the book
Explore the full treatment, worked examples, and exercises in Agentic iOS App Development.
Adapted from Agentic iOS App Development, published by Choral Software. Article text and original examples © 2026 Choral Software. All rights reserved.