diff --git a/.claude-plugin/plugin.json b/.claude-plugin/plugin.json
index 5c75bd7..839168b 100644
--- a/.claude-plugin/plugin.json
+++ b/.claude-plugin/plugin.json
@@ -1,7 +1,7 @@
 {
   "name": "understand-anything",
   "description": "AI-powered codebase understanding — analyze, visualize, and explain any project",
-  "version": "2.7.5",
+  "version": "2.7.6",
   "author": {
     "name": "Lum1104"
   },
diff --git a/.copilot-plugin/plugin.json b/.copilot-plugin/plugin.json
index b18679d..ea367dd 100644
--- a/.copilot-plugin/plugin.json
+++ b/.copilot-plugin/plugin.json
@@ -1,7 +1,7 @@
 {
   "name": "understand-anything",
   "description": "AI-powered codebase understanding — analyze, visualize, and explain any project",
-  "version": "2.7.5",
+  "version": "2.7.6",
   "author": {
     "name": "Lum1104"
   },
diff --git a/.cursor-plugin/plugin.json b/.cursor-plugin/plugin.json
index 075114d..a60b8bc 100644
--- a/.cursor-plugin/plugin.json
+++ b/.cursor-plugin/plugin.json
@@ -2,7 +2,7 @@
   "name": "understand-anything",
   "displayName": "Understand Anything",
   "description": "AI-powered codebase understanding — analyze, visualize, and explain any project",
-  "version": "2.7.5",
+  "version": "2.7.6",
   "author": {
     "name": "Lum1104"
   },
diff --git a/README.md b/README.md
index 3bdb4db..806d4f4 100644
--- a/README.md
+++ b/README.md
@@ -127,6 +127,8 @@ A multi-agent pipeline scans your project, extracts every file, function, class,
 # Supported languages: en (default), zh, zh-TW, ja, ko, ru
 ```
 
+On the **first run** in a project — when you don't pass `--language` and no language is stored yet — `/understand` detects the language you're conversing in. If it isn't English, it asks you to confirm (or override) before generating; English conversations are unaffected. Your choice is saved to `.understand-anything/config.json` and reused on every later run.
+
 The `--language` parameter affects:
 - Node summaries and descriptions in the knowledge graph
 - Dashboard UI labels, buttons, and tooltips
diff --git a/understand-anything-plugin/.claude-plugin/plugin.json b/understand-anything-plugin/.claude-plugin/plugin.json
index 5c75bd7..839168b 100644
--- a/understand-anything-plugin/.claude-plugin/plugin.json
+++ b/understand-anything-plugin/.claude-plugin/plugin.json
@@ -1,7 +1,7 @@
 {
   "name": "understand-anything",
   "description": "AI-powered codebase understanding — analyze, visualize, and explain any project",
-  "version": "2.7.5",
+  "version": "2.7.6",
   "author": {
     "name": "Lum1104"
   },
diff --git a/understand-anything-plugin/package.json b/understand-anything-plugin/package.json
index 303ff98..85f70f0 100644
--- a/understand-anything-plugin/package.json
+++ b/understand-anything-plugin/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@understand-anything/skill",
-  "version": "2.7.5",
+  "version": "2.7.6",
   "type": "module",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",
diff --git a/understand-anything-plugin/skills/understand/SKILL.md b/understand-anything-plugin/skills/understand/SKILL.md
index 610a9dd..35c0b11 100644
--- a/understand-anything-plugin/skills/understand/SKILL.md
+++ b/understand-anything-plugin/skills/understand/SKILL.md
@@ -140,8 +140,10 @@ Determine whether to run a full analysis or incremental update.
       - `chinese` → `zh`, `japanese` → `ja`, `korean` → `ko`, `english` → `en`, `spanish` → `es`, `french` → `fr`, `german` → `de`, `portuguese` → `pt`, `russian` → `ru`, `arabic` → `ar`, etc.
       - Locale variants: `zh-TW`, `zh-HK`, `zh-CN`, `pt-BR`, etc. are preserved as-is.
     - If `--language` is NOT specified:
-      - Check `$PROJECT_ROOT/.understand-anything/config.json` for an existing `outputLanguage` field. If present, use that.
-      - If no stored preference, default to `en` (English).
+      - **Stored preference wins.** If `$PROJECT_ROOT/.understand-anything/config.json` has an `outputLanguage` field, set `$OUTPUT_LANGUAGE` to it and skip the rest.
+      - **Otherwise detect (first run only).** Infer the predominant language of the user's conversation as an ISO 639-1 code (`$DETECTED_LANG`). If it is `en` or cannot be confidently determined, set `$OUTPUT_LANGUAGE=en` and proceed silently — no prompt (English users see no change).
+      - **If `$DETECTED_LANG` ≠ `en`, confirm once before analyzing:** tell the user you detected `<language>` and ask whether to generate all content in it; they press Enter/"yes" to accept, or type another language code/name to override (normalize via the friendly-name map above). If running non-interactively (no reply possible), skip the wait, use `$DETECTED_LANG`, and print a one-line notice instead of blocking.
+      - **Persist** the resolved `$OUTPUT_LANGUAGE` (including `en`) into `config.json` so it never re-prompts for this project.
     - If `--language` IS specified:
       - Update `$PROJECT_ROOT/.understand-anything/config.json` with the new language: merge `{"outputLanguage": "<lang>"}` into existing config.
       - Store as `$OUTPUT_LANGUAGE` for use throughout all phases.