> ## Documentation Index
> Fetch the complete documentation index at: https://docs.syntblaze.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Kotlin Package Declaration
A package declaration in Kotlin establishes the namespace for the contents of a source file, dictating the fully qualified name (FQN) of all classes, interfaces, functions, and properties defined within it.
```kotlin theme={"dark"}
package org.company.project.module
```
## Technical Characteristics
**Placement and Syntax**
The `package` directive must be placed at the top of a Kotlin source file (`.kt`), immediately following any file-level annotations (such as `@file:JvmName(...)` or `@file:OptIn(...)`). It must strictly precede all `import` directives and top-level declarations.
**Visibility and Access Control**
In Kotlin, packages are strictly used for namespacing and code organization; they do not provide encapsulation or access control. Unlike Java, Kotlin does not have "package-private" visibility, and packages do not dictate visibility boundaries. Access control is instead managed via visibility modifiers (`private`, `protected`, `internal`, `public`), where `internal` restricts visibility to the compilation module, completely independent of the package structure.
**File System Decoupling**
Kotlin does not enforce a strict mapping between the declared package name and the underlying directory structure. A file containing `package org.example.network` can technically reside in any directory path (e.g., `src/main/kotlin/utils/`). However, aligning the directory structure with the package name remains the standard convention for Java interoperability and project navigation.
**Default Package**
If a Kotlin source file omits the package declaration, all top-level declarations within that file are automatically assigned to the default, unnamed package.
**Namespace Scope**
The package declaration applies to all top-level constructs in the file, including variables and functions, rather than being limited to classes.
```kotlin theme={"dark"}
@file:JvmName("CoreUtils") // File-level annotations must precede the package
package com.system.core
// FQN: com.system.core.MAX_RETRIES
const val MAX_RETRIES = 3
// FQN: com.system.core.initialize()
fun initialize() { }
// FQN: com.system.core.Engine
class Engine { }
```
**Multiple Files**
A single package can be declared across multiple Kotlin source files. The compiler aggregates all top-level declarations sharing the same package declaration into a single logical namespace, regardless of their physical file distribution.
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