amzn/selling-partner-api-sdk — reverse-engineered prompt

Build me an official feeling SDK for the Amazon Selling Partner API that makes it really easy for developers to connect and start making calls with just a few lines of code.

I want this to cover Java, PHP, JavaScript, Python, and C#, with clear setup and simple examples for each language so someone can drop it into a new or existing app fast. The core goal is basic API support across all of them. For PHP and Java, also include restricted data token support and rate limiting. For JavaScript, include rate limiting too. Python and C# can stay focused on the basic API flow.

Please make the docs beginner friendly, explain any required Amazon developer setup at a high level, and organize things so future API changes are easy to update. It should feel like one installable package per language, not a random code dump. If anything is unclear, look up the current Amazon Selling Partner API docs online and match what they support now.