ACJ Labs builds products and infrastructure for agentic commerce — focused, inspectable tools for catalog data, tax-aware receipts, and more. Free tier, no card.https://acjlabs.com/en-ushttps://acjlabs.com/blog/abn-checksum-verbatim/https://acjlabs.com/blog/abn-checksum-verbatim/Most extraction tools quietly 'fix' a business number that doesn't check out. We added a fixture specifically to catch that — and confirmed the extractor transcribes what's printed, checksum-invalid or not.Sat, 25 Jul 2026 00:00:00 GMTTaxEngineeringACJ Labshttps://acjlabs.com/blog/build-vs-buy-receipt-extraction/https://acjlabs.com/blog/build-vs-buy-receipt-extraction/A vision-model call gets you 80% of receipt extraction in an afternoon. Here's an honest look at the other 20% — AU GST rules, ABN checksums, schema stability — and when it's worth paying for versus building yourself.Sat, 25 Jul 2026 00:00:00 GMTEngineeringTaxACJ Labshttps://acjlabs.com/blog/llm-taxonomy-accuracy-measured/https://acjlabs.com/blog/llm-taxonomy-accuracy-measured/Zero-shot LLM product classification into the Google taxonomy scored 1–2/12 exact matches on our test set. Grounding the model in the real taxonomy first took it to 22/24. Here's what actually changed, measured against a live API.Sat, 25 Jul 2026 00:00:00 GMTEngineeringACJ Labshttps://acjlabs.com/blog/gst-entertainment-rule/https://acjlabs.com/blog/gst-entertainment-rule/Entertainment expenses have their input tax credit denied by default under Australian GST rules — and nothing printed on the receipt tells you that.Thu, 23 Jul 2026 00:00:00 GMTTaxEngineeringACJ Labshttps://acjlabs.com/blog/parka-category-id/https://acjlabs.com/blog/parka-category-id/A capable vision model labelled a winter parka as 'Shirts & Tops' — confidently. The fix wasn't a better prompt: ground every classification in the real taxonomy data.Thu, 23 Jul 2026 00:00:00 GMTEngineeringACJ Labs