I already run a fully-functional courier management system built in PHP (CodeIgniter). One of my shippers sells through Shopify and wants to replace Shiprocket with our own service, so I need the Shopify side put in place. The job centres on creating and configuring the app in the Shopify Partner Dashboard, securing the required API keys, and wiring selected features to my existing endpoints. Those endpoints—rate calculation, real-time order tracking and automated label printing—are live and documented; you will only be integrating these three, not the entire API suite. What I expect from you • Register the app (public or custom, whichever best suits a single-store use). • Set up redirect URLs, scopes, embedded SDK and mandatory webhooks so it passes Shopify’s checks. • Connect the store’s checkout and order workflow to my rate, tracking and label APIs (REST or GraphQL—whichever you prefer). • Hand off clear installation instructions and code snippets so my team can maintain future endpoints on our own. Tools you are free to choose—Node, Ruby, or PHP SDKs—so long as the final integration works seamlessly inside Shopify admin and storefront. I’m comfortable handling the remainder of our APIs later, so focus only on the three functions above. If you have launched similar logistics apps before, please share a quick reference so I can move fast on this collaboration.