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

40•wazHFsRy•2d ago

I just had the best time learning about the REWE (German supermarket chain) API, how they use mTLS and what the workflows are. Also `mitmproxy2swagger`[1] is a great tool to create OpenAPI spec automatically.

And then 2026 feels like the perfect time writing Haskell. The code is handwritten, but whenever I got stuck with the build system or was just not getting the types right, I could fall back to ask AI to unblock me. It was never that smooth before.

Finally the best side projects are the ones you actually use and this one will be used for all my future grocery shopping.

[1]https://github.com/alufers/mitmproxy2swagger

Comments

wklm•1h ago

Nice! Do you know if the Austrian billa (REWE's subsidiary) is using the same api?

fractallyte•44m ago

My friend works at Billa AT; I could ask her – but that would be cheating ;-)

Dominik1001•1h ago

Very cool! Thanks for sharing, I’ll try it out.

Haskell is indeed an interesting choice. ;)

kls0e•20m ago

this feels a bit like Sandra Bullock ordering pizza in „The Net“, impressive

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