Product UpdatesBuilding Sheldon's State Tax Engine: 98% on TaxCalcBench
Deterministic rule engines for California, Illinois, New York, and Virginia - 620 of 630 scored lines on TaxCalcBench, every gap a documented benchmark defect.

IRS and New York crawling, citation popovers, document streaming, chat layout, and safer LLM output fixes.
Welcome back to Feather Pulse. These past two weeks we revamped our tax law coverage with new IRS and New York crawlers, and shipped security, UI, and UX improvements.
Feather now crawls IRS Revenue Bulletins and IRS forms directly, alongside the existing written determinations and rulings pipeline. New York State tax law coverage was also improved with better crawling reliability and more complete document extraction.
Feather has broader, up-to-date access to primary IRS sources when you ask research questions - revenue rulings, procedures, and official forms are now part of the index.
Citation popovers now resolve relative links correctly, so a reference opens to the right destination instead of a broken path. When a reply stitches together several text segments, citations apply cleanly across the whole answer.
A number of fixes shipped across the stack this week:
That's all for this week. Take care!
Product UpdatesDeterministic rule engines for California, Illinois, New York, and Virginia - 620 of 630 scored lines on TaxCalcBench, every gap a documented benchmark defect.
Product UpdatesA deterministic tax calculator built on a dedicated knowledge base and AI-generated rules - and how it went from 50% to 190/190 on TaxCalcBench.
Product Updates

Written by Sokratis Vidros
Published on April 13, 2026