Show HN: CLI to order groceries via reverse-engineered REWE API (Haskell)

First up: Read and follow the rules. No need to insult me. Especially considering what you said shows that you both misunderstood AND misrepresented what I've said.

And frankly, my reasoning was simply saying "Company won't publicize internal info if they don't get an advantage from doing so". It's literally the same reason Google doesn't publish all of their source code. I'm struggling to see what part you are misunderstanding but it has to be something extremely basic to conclude I'm a conspiracy nut for basically stating "Company acts in their interest".

Opening an API to the public allows third parties to develop apps that can then be consumed by end-consumers. Not trying to be offensive here, but do you know what an API is? To conclude I meant every single end-consumers building their own app is at best disingenuously twisting my words.

Opening the API would allow new players like you and me to enter the market and take a piece of the pie. Why would a market, dominated and controlled by a few big players, opt for that? You don't even need to know that the German grocery market is incredibly price competitive, to understand that.

> If you think about it, imagine if REWE officially exposed an API B2C. This would mean they are obligated to provide support. Can you provide a source for that requirement? I'm pretty sure you just made that up.

> Businesses and services differentiating between B2C and B2B is nothing new, that is why the two different terminologies exist ! At this point I'm entirely lost what you read in my comment. Yes I know. I specifically made that distinction.

> What next, you don't want to fill up your car at the petrol station (B2C) but you want to be permitted to buy a barrel crude oil direct from the drill and refine it yourself (B2B) ? Yeah you definitely misunderstood something... What I said/meant:

The question: Why isn't the API open?

My answer: For B2B I gave an example where the API is used by another German firm, providing an example that the API is indeed consumed B2B.

For B2C: They have no reason to do so. They have a well functioning app where you can order stuff. They have one of the bigger recipe pages (at least it does very well SEO-wise) in Germany where you can immediately order ingredients from a recipe. The biggest recipe page in Germany (chefkoch) offers a direct link from recipes to their order page. Maybe you're missing this info? Thinking it's an internal API to data that isn't exposed anywhere at all would somehow explain whatever you tried to say here. But again, if you're that uninformed, don't insult people.

What I suspect though: They mainly show current discounts. The REWE API exposes those as a separate list for each market. There's around 3.5k markets and each can set their own discounts and has their own product catalogue with their own pricing.

So it would be 3.5k API calls to fetch all offers for all markets. Which is doable.

But fetching all products takes like 100 calls per market. It's quite a bit of data. And I think most supermarket don't publish their catalogue at all since they don't have delivery options.

This is the future of doing groceries. Let us login with our credentials and let us do the search/filling the cart with agents.

Totally fine to do the payment only on the web, so everyone can be sure they only order what was wished, and not 300 avocados.

I'm a huge fan of Haskell and I'm really exploring it as my primary language now that AI has gotten so huge, not just because it makes it easier but also because I can really lock down what I allow code to do (through pure functions, type checking etc) and so I feel a lot more confident in AI generated code