ISO's external code sets, current by tomorrow morning
ISO 20022 messages lean on external code sets: purpose codes, category purposes, clearing systems, return reasons, status reasons and about 160 more lists. ISO publishes them as one downloadable file and revises it several times a year. Most software copies those lists once and never updates them, so they slowly drift out of date. We built a small service so ours don’t. Every night it downloads ISO’s published file and compares it with the copy we hold. If nothing changed, that is the end of it. If something did, it prepares a pull request that shows exactly which codes were added, removed or reworded. A person reads it and approves it. Once approved, the new lists are live on the web, as plain JSON, one address per code set.