First Steps

In this chapter, you will learn how to build a basic Nika application from scratch. We'll create a simple application that returns a list of users.

Installation

First, initialize a new Go module and install Nika:

go install github.com/nika-framework/nika-cli@latest

nika new <app-name>

cd <app-name>

go mod tidy

go run .

Creating a Module

Modules are the building blocks of a Nika application. Each module encapsulates a specific domain or feature.

package src

import (
    "github.com/gin-gonic/gin"
    "github.com/nika-framework/nika"
)

// AppModule is the root module of the application
type AppModule struct{}

func NewAppModule() *AppModule {
    return &AppModule{}
}

func (m *AppModule) Controllers() []interface{} {
    return []interface{}{
        NewUserController,
    }
}

func (m *AppModule) Providers() []interface{} {
    return []interface{}{
        NewUserService,
    }
}

func (m *AppModule) Imports() []nika.Module {
    return []nika.Module{}
}

Creating a Service (Provider)

Providers are the core building blocks that contain business logic. They are automatically injected via Nika's DI container.

package src

type UserService struct{}

func NewUserService() *UserService {
    return &UserService{}
}

func (s *UserService) FindAll() []string {
    return []string{"Alice", "Bob", "Charlie"}
}

Creating a Controller

Controllers handle incoming HTTP requests and return responses. In Nika, routes are defined using struct tags.

package src

import (
    "net/http"
    "github.com/gin-gonic/gin"
)

type UserController struct {
    service *UserService
}

func NewUserController(service *UserService) *UserController {
    return &UserController{service: service}
}

var ListUsers = func(c *gin.Context) {
    // Your handler logic here
    c.JSON(http.StatusOK, gin.H{"users": []string{"Alice", "Bob"}})
}

Bootstrap the Application

Finally, create the main.go file to bootstrap your Nika application:

package main

import (
    "fmt"
    "my-nika-app/src"
    "github.com/nika-framework/nika"
)

func main() {
    app := nika.NewApp()

    rootModule := src.NewAppModule()
    app.LoadModule(rootModule)

    fmt.Printf("🚀 Nika is running on http://localhost:3001\n")
    app.Listen(":3001")
}

Run the Application

go run main.go

You should see output similar to:

✅ Registered: GET /users -> List
🚀 Nika is running on http://localhost:3001

Summary

In this chapter you built a basic Nika application with:

• A Module that organizes controllers and providers
• A Provider (Service) that contains business logic
• A Controller that handles HTTP requests
• A Main entry point that bootstraps everything

Next Steps

Learn more about Controllers and Modules in the next chapters.