Structuring a Multi-File Project
Organize modules cleanly.
Structuring a Multi-File Project is a free Zig Academy lesson on CoddyKit — lesson 2 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Zig Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
One File Gets Crowded
As a program grows, a single main file turns into a wall of code. Splitting it into focused files keeps each part readable. 🗂️
main.zig Is the Entry
Your executable starts in main.zig, where the main function lives. It imports the other files and wires the program together.
const greet = @import("greet.zig");Group by Responsibility
Put related code in one file: parsing in parser.zig, output in render.zig. Each file owns a clear responsibility and a small surface.
A File Is a Module
Since a file is a struct, importing it gives you a tidy module. Its pub functions and types form that module's public API.
const parser = @import("parser.zig");
const ast = parser.parse(input);Use Folders for Scale
Group files into folders like src/net or src/cli. Import them with a relative path that includes the folder name.
const http = @import("net/http.zig");Re-export from One Place
A small root file can re-expose pieces from several files, giving callers a single import that gathers the whole module.
pub const http = @import("http.zig");
pub const dns = @import("dns.zig");Keep the API Small
Mark only what callers truly need as pub. Everything else stays private, so you can refactor internals without breaking other files.
Types Travel Too
Files export types, not just functions. A pub struct or enum in shapes.zig becomes shapes.Circle anywhere it is imported.
const shapes = @import("shapes.zig");
var c: shapes.Circle = undefined;Watch for Cycles
Two files that import each other can form a cycle. Zig tolerates many cases, but a cleaner layout puts shared types in a third file.
Tests Live Beside Code
Each file can hold its own test blocks next to the code they check. Splitting files keeps related tests close to what they verify.
test "add works" {
try std.testing.expect(add(2, 2) == 4);
}Name Files Predictably
Use clear, lowercase file names that hint at the contents, like token.zig or config.zig. Good names make imports read almost like prose.
const config = @import("config.zig");Quick Check
Recall how one file exposes its features to another.
Recap
You saw how to split code into focused files and folders, expose a small pub API, and even re-export through one root module. 🎯
Frequently asked questions
Is the “Structuring a Multi-File Project” lesson free?
Yes — the full text of “Structuring a Multi-File Project” is free to read here on the web, and the Zig Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Zig Academy course, upgrade to CoddyKit PRO.
What will I learn in “Structuring a Multi-File Project”?
Organize modules cleanly. You practise Zig Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Zig Academy?
No prior experience is required. Zig Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 2 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “Structuring a Multi-File Project” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Zig Academy lesson?
Yes. Every Zig Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- Importing Files with @import
- Structuring a Multi-File Project
- build.zig.zon and the Package Manager
- Adding a Third-Party Module