databutler.dev · /facts · Verified Facts protocol · publish your own

Verified Facts publishers

Every site here publishes official figures under verified-facts/0.3: one figure per key, with its official source, the day a person verified it and a hash; at L3 a signature. Each is re-checked every Monday with the public conformance checker (npx verified-facts check <site>, offline, 25 keys sampled), and the badge shows the level that check reached, not the level the site declares.

publisherlevellast checkcheckeddiscovery
Data Butler
Reference implementation: UK, US, German, EU and Japanese official figures.		 verified facts: L3 verified-facts/0.3; declares L3, reached L3; 749 facts2026-11-02facts.json
auto-maengel
German HU intervals, overdue-HU fines and Kfz-Steuer components from the statutes on gesetze-im-internet.de.		 verified facts: L1 verified-facts/0.3; declares L1, reached L1; 13 facts
failing: item 8 (L2), item 9 (L2), item 10 (L2), item 11 (L2), item 12 (L2), item 13 (L2), item 14 (L2), item 15 (L3), item 16 (L3)		2026-11-02facts.json
controle-technique-fiabilite
French contrôle technique rules from service-public.fr and Légifrance.		 verified facts: L1 verified-facts/0.3; declares L1, reached L1; 9 facts
failing: item 8 (L2), item 9 (L2), item 10 (L2), item 11 (L2), item 12 (L2), item 13 (L2), item 14 (L2), item 15 (L3), item 16 (L3)		2026-11-02facts.json
lowriskquotes
England permitted-development and Building Regulations limits, and the Gas Safe rule, from legislation.gov.uk and HSE.		 verified facts: L1 verified-facts/0.3; declares L1, reached L1; 4 facts
failing: item 8 (L2), item 9 (L2), item 10 (L2), item 11 (L2), item 12 (L2), item 13 (L2), item 14 (L2), item 15 (L3), item 16 (L3)		2026-11-02facts.json
shakendata
Japanese vehicle statutory costs and living-cost figures from MLIT, MHLW and ANRE.		 verified facts: L1 verified-facts/0.3; declares L1, reached L1; 23 facts
failing: item 8 (L2), item 9 (L2), item 10 (L2), item 11 (L2), item 12 (L2), item 13 (L2), item 14 (L2), item 15 (L3), item 16 (L3)		2026-11-02facts.json
whatbreaks
UK MOT rules the site's cost model uses, from gov.uk.		 verified facts: L1 verified-facts/0.3; declares L1, reached L1; 3 facts
failing: item 8 (L2), item 9 (L2), item 10 (L2), item 11 (L2), item 12 (L2), item 13 (L2), item 14 (L2), item 15 (L3), item 16 (L3)		2026-11-02facts.json

To be listed: publish at L1 or above (the recipe), then open an issue at github.com/physics-star-cat/databutler with your facts.json URL. Badges for your own README: https://databutler.dev/badge/facts-L1.svg, facts-L2.svg, facts-L3.svg.