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jpzip

A static JSON CDN and multi-language SDKs that deliver monthly-updated Japanese postal code data.

A CDN + multi-language SDK project that normalizes the postal code dataset published by Japan Post each month and serves it as static JSON from https://jpzip.nadai.dev.

Highlights

  • Static JSON CDN: served from Cloudflare Pages — no auth, CORS open to all origins, transparent gzip/brotli
  • Multi-language SDKs: TypeScript, Go, Python, Rust, Ruby, Dart, PHP and Swift — 8 languages, all implementing the same protocol
  • Monthly updates: follows the Japan Post release cycle, with version metadata exposed at /meta.json
  • License: MIT for the spec/schema, public-domain-equivalent for the served data

Status

Protocol v1.0 was published in May 2026. The CDN is live; language SDKs are being rolled out in sequence.

Spec: jpzip/spec · CDN: jpzip.nadai.dev

© 2026 nadai · JapanSet in Instrument Serif · Inter