diff --git a/README.md b/README.md
index 8b08348..7685f15 100644
--- a/README.md
+++ b/README.md
@@ -34,6 +34,10 @@ Marketplace 統一為 `jsc`（https://gitea.jsc.idv.tw/plugins/jsc.git），安
 
 刪除技能：列出全部技能 → 使用者選擇 → sub agent 盤點關聯檔案 → 逐檔判斷是否需修正以維持功能（需要就決策樹問修正細節並依準則檢查）→ 刪除 → PR。
 
+### `ste100-sync`
+
+同步上游 speak-human-tw 的語言規則：比對 `references/ste100.md` 釘住的上游版本，有新版就萃取適用的變更、更新 lint 樣式、全庫重掃，最後開 PR。適合列為本 repo 的維護方式。
+
 <!-- JSC-SKILLS:END -->
 
 ## 參考與工具
diff --git a/references/ste100.md b/references/ste100.md
index 7450219..ee857db 100644
--- a/references/ste100.md
+++ b/references/ste100.md
@@ -2,6 +2,8 @@
 
 jsc 技能組所有交談與文件的語言規則，唯一來源在這裡。基礎紀律沿用 STE100，擬人與在地化層改寫自 [speak-human-tw](https://github.com/Raymondhou0917/speak-human-tw)（MIT），並依技術文件情境剪裁。
 
+上游版本：speak-human-tw v1.4.0（2026-07-18）。上游有新版時用 `jsc-meta:ste100-sync` 同步。
+
 ## 基礎紀律
 
 1. 短句，一句一指令，主動語態。
diff --git a/skills/ste100-sync/SKILL.md b/skills/ste100-sync/SKILL.md
new file mode 100644
index 0000000..82f52f1
--- /dev/null
+++ b/skills/ste100-sync/SKILL.md
@@ -0,0 +1,27 @@
+---
+name: ste100-sync
+description: Sync the STE100 language rules with upstream speak-human-tw. Compare the pinned upstream version in references/ste100.md against the latest release, distill applicable changes, refresh ste100-lint.sh patterns, re-lint all jsc repos, then open a PR via jsc-git pr. Use on periodic maintenance or when upstream releases a new version; not for editing local-only rules.
+---
+
+# ste100-sync
+
+Keep `references/ste100.md` in sync with its upstream source, [speak-human-tw](https://github.com/Raymondhou0917/speak-human-tw) (MIT).
+
+## Steps
+
+1. Read the pinned version from the「上游版本」line in `references/ste100.md`.
+2. Clone the upstream repo (`--depth 1`). Read the `version` and `changelog` fields in its `SKILL.md` frontmatter.
+3. Same version: report「上游沒有新版」and stop.
+4. Newer version — distill the changes. **MUST run as a sub agent**:
+   - Walk the changelog entries newer than the pinned version.
+   - Keep only changes that apply to technical documents and conversation: Taiwan term replacements, punctuation rules, de-AI patterns, humanize targets.
+   - Drop marketing-copy scenes, eval material, and workflow-mode changes.
+   - Apply the distilled changes to `references/ste100.md`. Keep its trimmed structure. Update the「上游版本」line.
+5. If the replacement table or cliché list changed, update the `TERMS` and `CLICHES` patterns in `tools/ste100-lint.sh`.
+6. Run `tools/ste100-lint.sh` over every jsc repo. Fix hits in files this repo owns; report hits elsewhere.
+7. Open a PR via `jsc-git:pr`.
+
+## Notes
+
+- Generated wiki content, commit messages, and PR descriptions stay in Traditional Chinese per the guidelines; only the rule distillation is at stake here.
+- This skill fits the maintenance flow: list it as a maintenance method for the `plugins/meta` repo in `jsc-sdlc:maintain`.