diff --git a/README.md b/README.md
index 9952543..cbed687 100644
--- a/README.md
+++ b/README.md
@@ -114,28 +114,7 @@ This package bundles a pinned `gomc-rest` binary (currently **v1.4.0**, set in
 that raises its minimum server version can't be installed without also bumping
 the bundled binary.
 
-## Releasing / bundled binaries
-
-The bundled server version is pinned in `GOMC_REST_VERSION`. Binaries are not
-committed to git; they are fetched from the matching gomc-rest GitHub release.
-
-- Locally: `python scripts/vendor_binaries.py` downloads all three binaries
-  into `src/gomc_rest/binaries/`, verifying each against the trusted SHA-256
-  values committed in `checksums/<version>.sha256`.
-- On a `v*` tag, `.github/workflows/release.yml` builds one platform-specific
-  wheel per OS (each bundling only its matching binary) and publishes to PyPI
-  via trusted publishing. The release job verifies the tag equals
-  `project.version`; `workflow_dispatch` builds wheels for verification only and
-  never publishes.
-
-To cut a release:
-
-1. To change the bundled server, edit `GOMC_REST_VERSION` (keep it within the
-   range accepted by the pinned `gomc-rest-client`) and add a matching
-   `checksums/<version>.sha256` with the trusted SHA-256 of each asset. If the
-   new binaries change their glibc requirement, update the `plat` tags in
-   `release.yml` accordingly.
-2. Bump the package version in **both** `pyproject.toml` (`project.version`)
-   and `src/gomc_rest/__init__.py` (`__version__`) — they must match.
-3. Tag that exact version, e.g. `git tag v0.2.0 && git push origin v0.2.0`
-   (the tag must equal `project.version` or the release job fails).
+## Development
+
+Release procedure and bundled-binary maintenance are documented in
+[RELEASING.md](https://github.com/Moge800/gomc_rest_python/blob/main/RELEASING.md).
diff --git a/README_JP.md b/README_JP.md
index ac8cab6..7285af5 100644
--- a/README_JP.md
+++ b/README_JP.md
@@ -125,28 +125,8 @@ finally:
 これにより、より新しいサーバーを必要とするクライアントが意図せず
 インストールされることを防ぎます。
 
-## リリースと同梱バイナリ
+## 開発者向け
 
-バイナリはGitリポジトリへコミットせず、対応するgomc-restのGitHub Releaseから
-取得します。
-
-- ローカルでは `python scripts/vendor_binaries.py` を実行すると、3種類の
-  バイナリが `src/gomc_rest/binaries/` にダウンロードされます。各ファイルは
-  `checksums/<version>.sha256` に記録されたSHA-256ハッシュと照合されます。
-- `v*` タグをpushすると、`.github/workflows/release.yml` がOS別の `wheel` と
-  クライアント専用の `sdist` をビルドし、PyPIのTrusted Publishingを使用して
-  公開します。`workflow_dispatch` では検証用のビルドのみを行い、公開しません。
-
-### リリース手順
-
-1. 同梱サーバーを変更する場合は `GOMC_REST_VERSION` を更新し、各バイナリの
-   SHA-256ハッシュを記載した `checksums/<version>.sha256` を追加します。
-   必要なglibcバージョンが変わる場合は、`release.yml` の `plat` タグも更新します。
-2. `pyproject.toml` の `project.version` と
-   `src/gomc_rest/__init__.py` の `__version__` を同じバージョンへ更新します。
-3. パッケージバージョンと同じタグを作成してpushします。
-
-```bash
-git tag v0.2.0
-git push origin v0.2.0
-```
+リリース手順と同梱バイナリの管理方法は
+[RELEASING.md](https://github.com/Moge800/gomc_rest_python/blob/main/RELEASING.md)
+を参照してください。
diff --git a/RELEASING.md b/RELEASING.md
new file mode 100644
index 0000000..2073510
--- /dev/null
+++ b/RELEASING.md
@@ -0,0 +1,72 @@
+# Releasing
+
+Maintainer notes. Users don't need anything here — see [README.md](README.md).
+
+## What a tag push does
+
+Pushing a `v*` tag runs `.github/workflows/release.yml`:
+
+1. **Guard** — the tag must equal `project.version` in `pyproject.toml`,
+   or every job fails immediately.
+2. **Build wheels** (one per platform, each bundling only its matching
+   server binary, downloaded and SHA-256-verified at build time):
+   - `win_amd64` — `gomc-rest.exe`
+   - `manylinux_2_34_x86_64` — `gomc-rest-linux-amd64` (dynamically linked,
+     needs glibc ≥ 2.34; hence the 2_34 tag)
+   - `manylinux2014_aarch64` — `gomc-rest-linux-arm64` (statically linked)
+3. **Build sdist** — no binary; the client-only fallback for platforms
+   without a wheel (macOS, Windows arm64, older glibc).
+4. **Publish to PyPI** — trusted publishing (OIDC) via the `pypi`
+   environment. `skip-existing` makes re-running a tag safe.
+5. **GitHub Release** — created only after PyPI publish succeeds, with
+   generated notes and all dist files attached as assets.
+
+`workflow_dispatch` runs the builds for verification but never publishes.
+
+## Cutting a release
+
+1. Bump the package version in **both** places (they must match the tag):
+   - `pyproject.toml` → `project.version`
+   - `src/gomc_rest/__init__.py` → `__version__`
+2. Merge to `main`, then tag that exact version:
+
+   ```bash
+   git tag v0.2.0
+   git push origin v0.2.0
+   ```
+
+If publish fails transiently, re-run the failed jobs for that tag's run
+from the GitHub Actions UI — PyPI skips files it already has, and the
+release job then attaches the assets. Only delete and recreate the tag if
+the fix requires new commits (which means a new version anyway).
+
+## Bumping the bundled gomc-rest server
+
+Only needed when changing the bundled server version:
+
+1. Edit `GOMC_REST_VERSION`. Keep it within the range accepted by the
+   pinned `gomc-rest-client` (its `MINIMUM_SUPPORTED_GOMC_REST_VERSION`);
+   bump the client pin in `pyproject.toml` together if needed.
+2. Add `checksums/<version>.sha256` with the trusted SHA-256 of each
+   release asset (`gomc-rest.exe`, `gomc-rest-linux-amd64`,
+   `gomc-rest-linux-arm64`). These are committed so a swapped release
+   asset is detected; vendoring fails closed without them.
+3. If the new binaries change their glibc requirement (check with
+   `readelf -V <binary> | grep GLIBC`), update the `plat` tags in
+   `release.yml` and the CI floor test image in `ci.yml`.
+
+## Local builds (testing without PyPI)
+
+```bash
+python scripts/vendor_binaries.py            # fetch + verify all binaries
+python -m build --wheel
+python -m wheel tags --platform-tag manylinux_2_34_x86_64 --remove dist/*.whl
+rm src/gomc_rest/binaries/gomc-rest*         # drop vendored binaries for a clean sdist
+python -m build --sdist
+```
+
+## One-time infrastructure (already done)
+
+- PyPI trusted publisher: repo `Moge800/gomc_rest_python`, workflow
+  `release.yml`, environment `pypi`.
+- GitHub environment `pypi` on the repository.