https://jpzip.nadai.dev/en/blog/ Notes on jpzip — Cloudflare Pages design, MCP servers, AI-assisted development, and indie OSS. en Mon, 25 May 2026 00:00:00 GMT https://jpzip.nadai.dev/en/blog/0011-migrate-from-jpostal-ruby/ https://jpzip.nadai.dev/en/blog/0011-migrate-from-jpostal-ruby/ Mon, 25 May 2026 00:00:00 GMT Migrate off ken_all (KEN_ALL.csv in a database) and jpostcode (submodule-bundled data) to jpzip-ruby's CDN lookup: field mapping, no monthly imports, and the one feature you lose. Migration Ruby Rails CDN https://jpzip.nadai.dev/en/blog/0010-cloudflare-workers-edge/ https://jpzip.nadai.dev/en/blog/0010-cloudflare-workers-edge/ Sun, 24 May 2026 00:00:00 GMT Run jpzip-js inside a Cloudflare Worker for Japanese postcode lookups, and choose between Cache API, Workers KV, and Durable Objects by cost and measured p50/p99 latency. The short answer is usually "none of them." Use Case Cloudflare Workers TypeScript Edge https://jpzip.nadai.dev/en/blog/0009-migrate-from-zipcoda-js/ https://jpzip.nadai.dev/en/blog/0009-migrate-from-zipcoda-js/ Fri, 22 May 2026 00:00:00 GMT Move from the zipcoda.net runtime postcode API to jpzip-js's static CDN model — response field mapping, JSONP and CSP cleanup, dropping rate-limit workarounds, and measured latency and cache wins. Migration JavaScript TypeScript CDN https://jpzip.nadai.dev/en/blog/0008-nextjs-server-actions/ https://jpzip.nadai.dev/en/blog/0008-nextjs-server-actions/ Thu, 21 May 2026 00:00:00 GMT Build a postcode-to-address autofill form with Next.js 16 App Router Server Actions and jpzip-js — progressive enhancement that works without JavaScript, the Edge runtime, and server-side caching via the use cache directive. Framework Integration Next.js TypeScript Forms Edge https://jpzip.nadai.dev/en/blog/0007-rails-hotwire-form/ https://jpzip.nadai.dev/en/blog/0007-rails-hotwire-form/ Thu, 21 May 2026 00:00:00 GMT Autofill a Japanese address from a postal code in Rails with Turbo Frame or a Stimulus fetch controller, plus an L2 cache that stops Puma workers from re-fetching the same CDN bucket. Framework Integration Ruby Rails Hotwire Forms https://jpzip.nadai.dev/en/blog/0006-react-hook-form-zod/ https://jpzip.nadai.dev/en/blog/0006-react-hook-form-zod/ Tue, 19 May 2026 00:00:00 GMT How to wire jpzip-js into a React Hook Form with a Zod schema. Covers postcode validation, onBlur lookup, setValue auto-fill, double-fetch suppression, and aria-busy for accessibility. Framework Integration React TypeScript Forms Zod https://jpzip.nadai.dev/en/blog/0005-migrate-from-yubinbango-js/ https://jpzip.nadai.dev/en/blog/0005-migrate-from-yubinbango-js/ Tue, 19 May 2026 00:00:00 GMT A step-by-step migration from JSONP-based Yubinbango to jpzip-js. Keep your microformats h-adr forms intact, switch to fetch-only data loading, and tighten your CSP. Migration JavaScript TypeScript Forms https://jpzip.nadai.dev/en/blog/0004-claude-code-8-sdks-6-hours/ https://jpzip.nadai.dev/en/blog/0004-claude-code-8-sdks-6-hours/ Sun, 17 May 2026 00:00:00 GMT How I shipped Go / TypeScript / Python / Rust / Ruby / Dart / PHP / Swift SDKs for jpzip in 6 hours using Claude Code — spec-first design, Go as the reference implementation, translation-not-transpilation prompting, and per-language gotchas. Claude Code AI SDK multi-language OSS https://jpzip.nadai.dev/en/blog/0002-cloudflare-pages-static-zipcode-delivery/ https://jpzip.nadai.dev/en/blog/0002-cloudflare-pages-static-zipcode-delivery/ Sun, 17 May 2026 00:00:00 GMT The data-delivery design behind jpzip — shard layout, ETL pipeline, and why I deliberately use no Worker, no R2, no KV. Cloudflare CDN ETL Go https://jpzip.nadai.dev/en/blog/0003-mcp-server-japanese-postcode/ https://jpzip.nadai.dev/en/blog/0003-mcp-server-japanese-postcode/ Sun, 17 May 2026 00:00:00 GMT A tiny stateless MCP server that lets Claude resolve Japanese postcodes — tool design, cache lifetimes, cross-script (kanji/katakana/romaji) search. MCP Claude TypeScript AI https://jpzip.nadai.dev/en/blog/0001-cloudflare-pages-micro-saas/ https://jpzip.nadai.dev/en/blog/0001-cloudflare-pages-micro-saas/ Sun, 17 May 2026 00:00:00 GMT The story behind jpzip, a one-person side project, and why it stays free forever — not by luck, but by design. 120,677 Japanese postcodes served from Cloudflare Pages alone. Cloudflare OSS indie micro-SaaS