Will there be any code check for Magento 2.0 extensions before approval?

Each submitted extension is going to go through a technical review to ensure the code meets Magento standards. See more info here: http://docs.magento.com/marketplace/user_guide/extensions/review-technical.html).

We have documentation to help you to create a correct package structure. The Quick Start technical guide to the Marketplace includes topics like Intro to Composer and How to Develop/Package components and is accessible at: http://devdocs.magento.com/guides/v2.0/mktpl-quickstart/bk-marketplace-qs.html

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