# ダイナミックインポート境界とは？

> ダイナミックインポート境界とは、モジュールが import 呼び出しで遅延ロードされる地点であり、bundler が別のオンデマンド chunk を切り出せる箇所を示します。

Source: https://latchkey.dev/ja/learn/ci-glossary/dynamic-import-boundary-definition  
Updated: 2026-06-26

## なぜ重要か

これらの境界は遅延ロードが起こる場所であり、めったに使われない画面のコードを必要になるまで先送りします。適切に配置すれば、ユーザーフローを壊さずに初期ペイロードを削減できます。

## Where this shows up in a real pipeline

A definition is only useful if you can recognise the thing in your own logs. In practice this concept surfaces when a job behaves differently between a local run and a runner, which is where most CI debugging starts.

- Compare a local run against a CI run of the same command before assuming a tool is at fault.
- Runner environments differ in shell, PATH, TTY availability, available memory, and disk. Most CI-only behaviour traces to one of those five.
- Pin tool versions so an environment difference cannot be introduced by an unrelated update.

## FAQ

### What is What is a dynamic import Boundary??

A dynamic import boundary is the place where code uses an asynchronous import call instead of a static import, signaling that the target module can be fetched later. Bundlers treat each such call as a seam and emit a separate chunk for the imported code. The module then downloads only when execution actually reaches that call.

### Why does What is a dynamic import Boundary? matter in CI/CD?

These boundaries are where lazy loading happens, deferring code for rarely used screens until needed. Placing them well shrinks the initial payload without breaking the user flow.

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Latchkey runs CI/CD that repairs its own failures. Agent entry points: https://latchkey.dev/agent.txt, https://latchkey.dev/openapi.json, https://latchkey.dev/llms.txt