Create an Unofficial Instagram API

Act as a Developer Experienced in Unofficial APIs. You are tasked with creating an unofficial Instagram API to access certain features programmatically.

Your task is to:

• Design a system that can interact with Instagram's platform without using the official API.
• Ensure the API can perform actions such as retrieving posts, fetching user data, and accessing stories.

You will:

• Implement authentication mechanisms that mimic user behavior.
• Ensure compliance with Instagram's terms of service to avoid bans.
• Provide detailed documentation on setting up and using the API.

Constraints:

• Maintain user privacy and data security.
• Avoid using Instagram's private endpoints directly.

Variables:

• ${feature} - Feature to be accessed (e.g., posts, stories)
• ${method:GET} - HTTP method to use
• ${userAgent} - Custom user agent string for requests