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

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31–40 of 94 posts

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

#31
post #23

Surprised how little the B2C and even B2B e-commerce segment is providing API access for automation and agentic coding. One could easily set up rate limits, fraud detection and KYC checks upfront initial access.

Yeah, absolutely. I think internally, everyone is cooking up some gigantic commerce. This is just bringing it to myself a bit earlier.

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

#33

I love the idea of a CLI for groceries. Do you have plans to support 're-order' scripts or meal-plan integration? I can imagine a workflow where a recipes.yaml file gets piped into your CLI to automatically fill the cart with everything needed for the week. Much faster than clicking through a mobile UI.

Absolutely, that could just be a small script or something on top that calls the CLI tool

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

#34

Serious good use of an AI. Just let them do the grey area (like repeated purchase). I'd even let an algo pick better groceries for me. Cools tuff!

Absolutely. For example, I want to ask it: Suggest me some vegetables I haven't ordered in recent weeks or stuff like this, and this is all possible.

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

#36
post #7

Really cool to see things still being built in Haskell! How do you find using it compared to some of the newer languages that have more modern tooling? Did you implement your own OAUTH2 flow in haskell for this?

For me, Haskell is the language of 2026. Having an agent available if you get stuck with some weird type error is a blessing. It also helps with the tooling. Though the modern tooling with cabal is pretty good.

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

#37
post #13

> Finally the best side projects are the ones you actually use and this one will be used for all my future grocery shopping. Until it breaks in a few weeks.

I mean, fixing small issues is not a big deal – during my ordering sessions, if something comes up, I actually just let Claude create an issue for it, and then when I have time, I create a fix.

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

#38
post #28
post #25

Earlier quoted context omitted.

B2B: Look at chefkoch.de They do use the REWE API, and I'm guessing not without their knowledge B2C: Is it really surprising that a busines has no interest in providing more price transparency to their customers?

When Amazon launches an API everyone cries. Same story over and over. Even better example: TakeAway-Group. The perfect MITM.

Think it's context dependent whether it's a good or bad thing.

The owners of German supermarket and car companies are really the richest of the rich in Germany (okay and maybe the SAP guy on top). It would definitely be a net positive if someone manages to scrape and compare their prices.

In the restaurant market it's one player abusing many small players.

And honestly, I think the reason everyone cries when "Amazon launches an API" is because Amazon would not dare to piss off the German supermarket oligopoly.

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

#39
post #12

Cool project, but have mixed feelings about publishing ever easier ways to access this API. They've locked down the API a while ago for a reason. Also there already exists this reverse engineered project: https://github.com/ByteSizedMarius/rewerse-engineering/ I do have a suggestion for your app though: Have it compare your basket of goods across different markets in your region to show you the cheapest option. I'm p…

The existing project was a great inspiration and helped me figure out the mTLS stuff. I totally get your mixed feelings, though. I really like your suggestion. I will put it in an issue and look into that. https://github.com/yannick-cw/korb/issues/4

Just to be clear, my mixed feelings don't come from a moral standpoint. Just hoping they don't lock it down any further heh ;-)

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

#40
post #12

Cool project, but have mixed feelings about publishing ever easier ways to access this API. They've locked down the API a while ago for a reason. Also there already exists this reverse engineered project: https://github.com/ByteSizedMarius/rewerse-engineering/ I do have a suggestion for your app though: Have it compare your basket of goods across different markets in your region to show you the cheapest option. I'm p…

An aggregator like this that could surface the same good for the cheapest price all inclusive of delivery would be something I would pay for!
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