diff --git a/openspec/changes/archive/2026-09-22-add-run-per-language/.openspec.yaml b/openspec/changes/archive/2026-09-22-add-run-per-language/.openspec.yaml
new file mode 100644
index 0000000..a9eca53
--- /dev/null
+++ b/openspec/changes/archive/2026-09-22-add-run-per-language/.openspec.yaml
@@ -0,0 +1,2 @@
+schema: spec-driven
+created: 2026-09-22
\ No newline at end of file
diff --git a/openspec/changes/archive/2026-09-22-add-run-per-language/design.md b/openspec/changes/archive/2026-09-22-add-run-per-language/design.md
new file mode 100644
index 0000000..1ef1ad7
--- /dev/null
+++ b/openspec/changes/archive/2026-09-22-add-run-per-language/design.md
@@ -0,0 +1,57 @@
+## Context
+
+代码图谱与全文阅读确认：
+- `scripts/run_check.py` 内含 `run()`（subprocess 封装）/ `check_one()`（lint 调用）/ `fix_one()`（format 调用）/ `cli_main()`（CLI 编排 + 报告）。
+- `scripts/fix.py` 内含 `main()`（detect_languages 解析 + LANG_COMMANDS 解包 + subprocess.run 串行 + 失败聚合）。
+- 两脚本对「失败 = exit code != 0」与「command not found」的处置逻辑基本相同但**分散**：run_check 用 `run()` 集中捕获 `FileNotFoundError → return 127`，fix.py 用 try/except 捕获 `FileNotFoundError → continue + failed.append(lang)`。
+
+重复的代价：
+- 同一 lint/format 调用约定的所有演化（subprocess timeout、retry、probe、dry-run、节流）必须双改。
+- MCP 模式占位（`run_check.py::mcp_main`）与 `fix.py` 互相不可见但语义重叠。
+- 未来要支持 `--json` 输出格式、并发执行、retries 时三处同步。
+
+## Decisions
+
+### 共享边界 = 「per-language 串行执行 + 结果聚合」
+
+`scripts/run_per_language.py` 暴露两个对外函数：
+
+```python
+def run_check(languages: list[str], project_root: Path,
+              *, timeout: int = 120, fix: bool = False,
+              dry_run: bool = False) -> list[dict]: ...
+def run_fix(languages: list[str], project_root: Path,
+            *, timeout: int = 120, dry_run: bool = False) -> list[dict]: ...
+```
+
+返回 dict 与现有 `check_one` / `fix_one` 形态兼容（`passed` / `fixed` / `exit_code` / `stderr_tail` / `stdout_tail`），CLI 层零报告格式改动。
+
+### `dry_run` 显式契约
+
+`run_check(dry_run=True)` / `run_fix(dry_run=True)` 仅打印 `would run: <cmd>`，不真跑。`fix.py` 当前就是这种行为（`print(f"  {lang:12s} would run: ...")`），`run_check.py` 无该选项但 change 不引入新 CLI flag；新增的 dry_run 行为仅作为 run_per_language 内部契约。
+
+### fix=True 走 run_check 内部的 retry
+
+`run_check.py` 当前的「lint fail → 自动 fix → 复检」三段式保留在 `run_per_language.run_check` 内部，作为其 fix 参数的实现细节；`run_fix` 不再做这件事——它本身就是 fix。
+
+### subprocess 错误码统一
+
+- 成功：`exit_code == 0`
+- 超时：`exit_code == 124`，`stderr_tail == "timeout after {timeout}s"`
+- 命令缺失：`exit_code == 127`，`stderr_tail == "command not found: ..."`
+
+`run_fix` 在命令缺失时仍把 lang 加入失败列表（与现有 fix.py 行为一致）。
+
+### CLI 文件极简化
+
+`run_check.py` 与 `fix.py` 各自只留：argparse 解析、读调用 `run_per_language` 函数、格式化输出（含人类可读状态行 + 汇总）、设置 sys.exit 码。两份文件均 < 100 行。
+
+### 不引入并发 / 不改调用约定
+
+`run_per_language` 保持串行——并发是 MCP/批量场景的未来 change，不在本 change 范围内。`LANG_COMMANDS` 解包与 `subprocess.run` 调用细节都封装在 runner 内，CLI 只见 dict 结果。
+
+## Risks / Trade-offs
+
+- **fix.py 现有 `--dry-run` 行为**：CLI 层接受 `--dry-run` 时透传给 runner，runner 据此切换打印路径。`fix.py` 当前无 `--dry-run`（注释「只看，不真改」与 argparse `--dry-run` 是同一选项），保持兼容。
+- **新模块导入路径**：`run_check.py` 与 `fix.py` 现都 `sys.path.insert(0, scripts/)`；新模块位于同目录，零额外配置。`run_per_language` 也走相同 import 路径。
+- **MCP 入口**：`run_check.py::mcp_main` 仍是占位，change 不动它；未来 MCP 落地直接调 `run_per_language` 即可。
\ No newline at end of file
diff --git a/openspec/changes/archive/2026-09-22-add-run-per-language/proposal.md b/openspec/changes/archive/2026-09-22-add-run-per-language/proposal.md
new file mode 100644
index 0000000..8410aa1
--- /dev/null
+++ b/openspec/changes/archive/2026-09-22-add-run-per-language/proposal.md
@@ -0,0 +1,24 @@
+## Why
+
+`scripts/run_check.py` 与 `scripts/fix.py` 重复编排同一逻辑：枚举 `detect_languages` → 取 `LANG_COMMANDS[lang].lint/format` → `subprocess.run` → 收集结果。两份脚本共 ~198 行，编排代码占约 80%，只有 argparse 与报告格式不同。任何 lint/format 调用约定变更都要两处同步改；任何新加 per-language 行为（pre-flight probe、retries、dry-run）也要改两处。
+
+## What Changes
+
+- 新增 `scripts/run_per_language.py`：暴露 `run_check(languages, project_root, *, timeout, fix=False, dry_run=False) -> list[dict]` 与 `run_fix(languages, project_root, *, timeout, dry_run=False) -> list[dict]` 两个纯函数，封装「per-language 串行执行 + 结果聚合」逻辑。
+- `scripts/run_check.py` 仅保留 CLI 入口（argparse + 报告输出），调用 `run_per_language.run_check`；删除 `check_one` / `fix_one` / `run` 局部实现。
+- `scripts/fix.py` 仅保留 CLI 入口，调用 `run_per_language.run_fix`；删除内联 subprocess 与 LANG_COMMANDS 解包。
+- 不引入新依赖；不改变 CLI 行为（输出格式、`--fix` 语义、退出码 0/2）。
+
+## Capabilities
+
+### New Capabilities
+
+- `idiomatic-runner`: Defines the per-language execution runner shared between `run_check.py` and `fix.py`.
+
+### Modified Capabilities
+
+None.
+
+## Impact
+
+新增 1 个 Python 文件 `scripts/run_per_language.py`（预计 ~120 行）；修改 `scripts/run_check.py`（128 → ~80 行）与 `scripts/fix.py`（70 → ~40 行）；合计 ~110 行净增（注释与日志占大头）。`commands/`、`hooks/`、`tests/`、`skills/`、`openspec/specs/` 全部不变；`scripts/languages.json` 与 `skills.lock.json` 不变。
\ No newline at end of file
diff --git a/openspec/changes/archive/2026-09-22-add-run-per-language/specs/idiomatic-runner/spec.md b/openspec/changes/archive/2026-09-22-add-run-per-language/specs/idiomatic-runner/spec.md
new file mode 100644
index 0000000..faaf78a
--- /dev/null
+++ b/openspec/changes/archive/2026-09-22-add-run-per-language/specs/idiomatic-runner/spec.md
@@ -0,0 +1,47 @@
+## ADDED Requirements
+
+### Requirement: Per-language execution SHALL live in scripts/run_per_language.py
+
+The functions `run_check(languages, project_root, *, timeout=120, fix=False, dry_run=False) -> list[dict]` and `run_fix(languages, project_root, *, timeout=120, dry_run=False) -> list[dict]` SHALL be defined in `scripts/run_per_language.py`. They SHALL encapsulate the per-language subprocess invocation, exit-code normalization, and result aggregation.
+
+#### Scenario: A CLI script delegates to run_per_language
+
+- **WHEN** `scripts/run_check.py` parses args, identifies the project's languages, and needs to execute the lint pass
+- **THEN** it calls `run_per_language.run_check(languages, project_root, timeout=args.timeout, fix=args.fix)` and prints the results
+
+#### Scenario: fix.py delegates the format pass
+
+- **WHEN** `scripts/fix.py` is invoked with a project root and detected languages
+- **THEN** it calls `run_per_language.run_fix(languages, project_root, dry_run=args.dry_run)` and prints the results
+
+### Requirement: run_check.py and fix.py SHALL NOT define subprocess-level runners themselves
+
+After the refactor, `scripts/run_check.py` SHALL NOT define its own `run` / `check_one` / `fix_one` functions or invoke `subprocess.run` directly. Same for `scripts/fix.py`. Any subprocess execution lives in `run_per_language.py`.
+
+#### Scenario: A new CLI flag is added to run_check.py
+
+- **WHEN** a new flag (e.g. `--json`) requires reusing the lint pass
+- **THEN** the implementer calls `run_per_language.run_check(...)` and converts the list of dicts to JSON, without re-implementing the subprocess loop
+
+### Requirement: subprocess exit codes SHALL be normalized
+
+`run_per_language` SHALL map subprocess outcomes to:
+- 0 for success
+- 124 for `subprocess.TimeoutExpired`
+- 127 for `FileNotFoundError`
+
+When a command is not found, the result SHALL include `stderr_tail == "command not found: <cmd>"`.
+
+#### Scenario: linter binary is missing
+
+- **WHEN** the project's linter binary is not installed
+- **THEN** `run_per_language.run_check` returns a dict with `exit_code == 127` and `passed == False`
+
+### Requirement: dry_run SHALL only print would-run lines
+
+When `dry_run=True`, neither `run_check` nor `run_fix` SHALL spawn a subprocess; they SHALL emit one line per language showing the command that would have been executed.
+
+#### Scenario: fix.py invoked with --dry-run on a mixed-language project
+
+- **WHEN** the user passes `--dry-run` to `scripts/fix.py`
+- **THEN** the output contains one `would run: ...` line per detected language and no subprocess is launched
\ No newline at end of file
diff --git a/openspec/changes/archive/2026-09-22-add-run-per-language/tasks.md b/openspec/changes/archive/2026-09-22-add-run-per-language/tasks.md
new file mode 100644
index 0000000..2fced74
--- /dev/null
+++ b/openspec/changes/archive/2026-09-22-add-run-per-language/tasks.md
@@ -0,0 +1,33 @@
+## 1. New file
+
+- [ ] 1.1 Create `scripts/run_per_language.py` with `run_check` and `run_fix` per the design; export `__all__` listing them.
+
+## 2. run_check.py slim down
+
+- [ ] 2.1 Remove local `run` / `check_one` / `fix_one` from `scripts/run_check.py`.
+- [ ] 2.2 Replace the per-language loop body in `cli_main()` with `results = run_per_language.run_check(languages, project_root, timeout=args.timeout, fix=args.fix)`.
+- [ ] 2.3 Keep the argparse, the `mcp_main` placeholder, and the human-readable summary lines untouched.
+
+## 3. fix.py slim down
+
+- [ ] 3.1 Remove the in-line subprocess loop from `scripts/fix.py`.
+- [ ] 3.2 Replace it with `results = run_per_language.run_fix(languages, project_root, dry_run=args.dry_run)` and the existing summary lines.
+
+## 4. Validation
+
+- [ ] 4.1 `python3 -m unittest discover -s tests -p 'test_*.py' -v` — both `test_plugin_manifests.py` and `test_skill_vendor.py` must pass.
+- [ ] 4.2 `python3 tests/run_all.py` — full 141 / 0 / 0 must hold (hooks/manifests/vendored skills).
+- [ ] 4.3 Smoke `python3 scripts/run_check.py --help` and `python3 scripts/fix.py --help` — exit 0, argparse output unchanged from `v0.6.1`.
+- [ ] 4.4 Smoke `python3 scripts/fix.py --dry-run .` on this repo — each detected language prints `would run: ...` and no subprocess is launched.
+- [ ] 4.5 `ruff check scripts/run_per_language.py scripts/run_check.py scripts/fix.py` — zero new errors attributable to this change.
+- [ ] 4.6 `git diff --check` — clean.
+- [ ] 4.7 `openspec validate --all --strict` — pass (3 pre-existing + new `idiomatic-runner`).
+
+## 5. Release
+
+- [ ] 5.1 `node scripts/bump-plugin.mjs codeguard patch` — bump 0.6.1 → 0.6.2.
+- [ ] 5.2 Fix in-repo `.agents/plugins/marketplace.json` ref/icon to `v0.6.2`.
+- [ ] 5.3 Open PR, wait for vendor-check, merge.
+- [ ] 5.4 Push tag `v0.6.2`.
+- [ ] 5.5 Sync market repo catalog + README codeguard row to `0.6.2` and push.
+- [ ] 5.6 `openspec archive add-run-per-language` after all tasks above are checked.
\ No newline at end of file
diff --git a/openspec/specs/idiomatic-runner/spec.md b/openspec/specs/idiomatic-runner/spec.md
new file mode 100644
index 0000000..9745864
--- /dev/null
+++ b/openspec/specs/idiomatic-runner/spec.md
@@ -0,0 +1,51 @@
+# idiomatic-runner Specification
+
+## Purpose
+TBD - created by archiving change add-run-per-language. Update Purpose after archive.
+## Requirements
+### Requirement: Per-language execution SHALL live in scripts/run_per_language.py
+
+The functions `run_check(languages, project_root, *, timeout=120, fix=False, dry_run=False) -> list[dict]` and `run_fix(languages, project_root, *, timeout=120, dry_run=False) -> list[dict]` SHALL be defined in `scripts/run_per_language.py`. They SHALL encapsulate the per-language subprocess invocation, exit-code normalization, and result aggregation.
+
+#### Scenario: A CLI script delegates to run_per_language
+
+- **WHEN** `scripts/run_check.py` parses args, identifies the project's languages, and needs to execute the lint pass
+- **THEN** it calls `run_per_language.run_check(languages, project_root, timeout=args.timeout, fix=args.fix)` and prints the results
+
+#### Scenario: fix.py delegates the format pass
+
+- **WHEN** `scripts/fix.py` is invoked with a project root and detected languages
+- **THEN** it calls `run_per_language.run_fix(languages, project_root, dry_run=args.dry_run)` and prints the results
+
+### Requirement: run_check.py and fix.py SHALL NOT define subprocess-level runners themselves
+
+After the refactor, `scripts/run_check.py` SHALL NOT define its own `run` / `check_one` / `fix_one` functions or invoke `subprocess.run` directly. Same for `scripts/fix.py`. Any subprocess execution lives in `run_per_language.py`.
+
+#### Scenario: A new CLI flag is added to run_check.py
+
+- **WHEN** a new flag (e.g. `--json`) requires reusing the lint pass
+- **THEN** the implementer calls `run_per_language.run_check(...)` and converts the list of dicts to JSON, without re-implementing the subprocess loop
+
+### Requirement: subprocess exit codes SHALL be normalized
+
+`run_per_language` SHALL map subprocess outcomes to:
+- 0 for success
+- 124 for `subprocess.TimeoutExpired`
+- 127 for `FileNotFoundError`
+
+When a command is not found, the result SHALL include `stderr_tail == "command not found: <cmd>"`.
+
+#### Scenario: linter binary is missing
+
+- **WHEN** the project's linter binary is not installed
+- **THEN** `run_per_language.run_check` returns a dict with `exit_code == 127` and `passed == False`
+
+### Requirement: dry_run SHALL only print would-run lines
+
+When `dry_run=True`, neither `run_check` nor `run_fix` SHALL spawn a subprocess; they SHALL emit one line per language showing the command that would have been executed.
+
+#### Scenario: fix.py invoked with --dry-run on a mixed-language project
+
+- **WHEN** the user passes `--dry-run` to `scripts/fix.py`
+- **THEN** the output contains one `would run: ...` line per detected language and no subprocess is launched
+
diff --git a/scripts/fix.py b/scripts/fix.py
index 381529b..7ea6525 100755
--- a/scripts/fix.py
+++ b/scripts/fix.py
@@ -3,17 +3,20 @@
 CLI：
     python3 fix.py              # 自动检测并修复所有语言
     python3 fix.py --lang java  # 只修 java
+    python3 fix.py --dry-run    # 只看，不真改
+
+按语言执行细节委托给 `scripts/run_per_language.py`；本文件仅负责
+argparse、目标语言过滤、报告输出。
 """
 from __future__ import annotations
 
 import argparse
-import subprocess
 import sys
 from pathlib import Path
 
 sys.path.insert(0, str(Path(__file__).resolve().parent))
+import run_per_language
 from detect_lang import (
-    LANG_COMMANDS,
     detect_languages,
     find_project_root,
 )
@@ -39,32 +42,26 @@ def main() -> int:
     print(f"[codeguard] languages: {languages}  dry-run={args.dry_run}")
     print()
 
-    failed = []
-    for lang in languages:
-        cmd_def = LANG_COMMANDS.get(lang)
-        if not cmd_def:
-            continue
-        if args.dry_run:
-            print(f"  {lang:12s} would run: {' '.join(cmd_def['format'])}")
-            continue
-        try:
-            proc = subprocess.run(
-                cmd_def["format"], cwd=project_root, capture_output=True, text=True, timeout=180
-            )
-        except FileNotFoundError as e:
-            print(f"  {lang:12s} \u274c command not found: {e}")
-            failed.append(lang)
+    results = run_per_language.run_fix(
+        languages, project_root, dry_run=args.dry_run,
+    )
+    failed: list[str] = []
+    for r, lang in zip(results, languages):
+        if r.get("dry_run"):
+            print(f"  {lang:12s} would run: {' '.join(r.get('command') or [])}")
             continue
-        if proc.returncode == 0:
+        if r.get("fixed"):
             print(f"  {lang:12s} \u2705 fixed")
         else:
-            print(f"  {lang:12s} \u274c failed: exit={proc.returncode}")
-            if proc.stderr:
-                print(f"     \u2514\u2500 {proc.stderr.strip().splitlines()[-1][:120]}")
+            print(f"  {lang:12s} \u274c failed: exit={r.get('exit_code')}")
+            if r.get("stderr_tail"):
+                last = r["stderr_tail"].strip().splitlines()
+                tail = last[-1] if last else ""
+                print(f"     \u2514\u2500 {tail[:120]}")
             failed.append(lang)
 
     return 1 if failed else 0
 
 
 if __name__ == "__main__":
-    sys.exit(main())
+    sys.exit(main())
\ No newline at end of file
diff --git a/scripts/run_check.py b/scripts/run_check.py
index 6c9d9c8..281a80c 100755
--- a/scripts/run_check.py
+++ b/scripts/run_check.py
@@ -5,60 +5,25 @@
     python3 run_check.py --lang java       # 只跑 java
     python3 run_check.py --fix             # 失败时自动修复
     python3 run_check.py --mcp             # MCP server 模式
+
+按语言执行细节（subprocess 调用、退出码归一化、fix 复检）全部委托给
+`scripts/run_per_language.py`；本文件仅负责 argparse + 报告输出。
 """
 from __future__ import annotations
 
 import argparse
-import subprocess
 import sys
 from pathlib import Path
 
 sys.path.insert(0, str(Path(__file__).resolve().parent))
+import run_per_language
 from detect_lang import (
-    LANG_COMMANDS,
     detect_languages,
     find_project_root,
     load_user_config,
 )
 
 
-def run(cmd: list[str], cwd: Path, timeout: int = 120) -> tuple[int, str, str]:
-    try:
-        proc = subprocess.run(cmd, cwd=cwd, capture_output=True, text=True, timeout=timeout)
-        return proc.returncode, proc.stdout, proc.stderr
-    except subprocess.TimeoutExpired:
-        return 124, "", f"timeout after {timeout}s"
-    except FileNotFoundError as e:
-        return 127, "", f"command not found: {e}"
-
-
-def check_one(lang: str, project_root: Path, timeout: int) -> dict:
-    cmd_def = LANG_COMMANDS.get(lang)
-    if not cmd_def:
-        return {"language": lang, "passed": False, "error": "no command defined"}
-    rc, out, err = run(cmd_def["lint"], cwd=project_root, timeout=timeout)
-    return {
-        "language": lang,
-        "passed": rc == 0,
-        "exit_code": rc,
-        "stderr_tail": err[-2000:] if err else "",
-        "stdout_tail": out[-1000:] if out else "",
-    }
-
-
-def fix_one(lang: str, project_root: Path, timeout: int) -> dict:
-    cmd_def = LANG_COMMANDS.get(lang)
-    if not cmd_def:
-        return {"language": lang, "fixed": False, "error": "no command defined"}
-    rc, out, err = run(cmd_def["format"], cwd=project_root, timeout=timeout + 60)
-    return {
-        "language": lang,
-        "fixed": rc == 0,
-        "exit_code": rc,
-        "stderr_tail": err[-2000:] if err else "",
-    }
-
-
 def cli_main():
     parser = argparse.ArgumentParser()
     parser.add_argument("--lang", help="只跑指定语言（逗号分隔）")
@@ -89,15 +54,15 @@ def cli_main():
     print(f"[codeguard] languages: {languages}")
     print()
 
-    results = []
-    for lang in languages:
-        r = check_one(lang, project_root, args.timeout)
+    results = run_per_language.run_check(
+        languages, project_root,
+        timeout=args.timeout, fix=args.fix,
+    )
+    for r, lang in zip(results, languages):
+        if r.get("dry_run"):
+            continue
         if not r["passed"] and args.fix:
             print(f"[codeguard] \u26a0\ufe0f  {lang} lint failed, attempting auto-fix...")
-            fix = fix_one(lang, project_root, args.timeout)
-            if fix["fixed"]:
-                r = check_one(lang, project_root, args.timeout)
-        results.append(r)
         status = "\u2705 passed" if r["passed"] else f"\u274c FAILED (exit={r.get('exit_code')})"
         print(f"  {lang:12s} {status}")
         if not r["passed"] and r.get("stderr_tail"):
diff --git a/scripts/run_per_language.py b/scripts/run_per_language.py
new file mode 100644
index 0000000..4c1c472
--- /dev/null
+++ b/scripts/run_per_language.py
@@ -0,0 +1,87 @@
+"""scripts/run_per_language.py：按语言串行执行 + 结果聚合的共享入口。
+
+暴露两个纯函数供 CLI 复用：
+- `run_check(languages, project_root, *, timeout, fix, dry_run)` — 跑 lint。
+- `run_fix(languages, project_root, *, timeout, dry_run)` — 跑 format。
+
+CLI（run_check.py / fix.py）只负责 argparse + 报告格式；任何 subprocess
+调用约定、退出码归一化、超时与命令缺失的处置都集中在本文件。
+
+`run_check(fix=True)` 走「lint 失败 → 自动 fix → 复检」三段式。
+"""
+from __future__ import annotations
+
+import subprocess
+from pathlib import Path
+
+from detect_lang import LANG_COMMANDS
+
+__all__ = ["run_check", "run_fix"]
+
+
+def _run(cmd: list[str], cwd: Path, timeout: int) -> tuple[int, str, str]:
+    """subprocess 调用统一封装：归一化超时(124) / 命令缺失(127) / 其它返回原码。"""
+    try:
+        proc = subprocess.run(cmd, cwd=cwd, capture_output=True, text=True, timeout=timeout)
+    except subprocess.TimeoutExpired:
+        return 124, "", f"timeout after {timeout}s"
+    except FileNotFoundError as e:
+        return 127, "", f"command not found: {e}"
+    return proc.returncode, proc.stdout, proc.stderr
+
+
+def run_check(languages: list[str], project_root: Path,
+              *, timeout: int = 120, fix: bool = False,
+              dry_run: bool = False) -> list[dict]:
+    """对每个语言跑 lint；fix=True 时失败后自动跑 format 复检一次。"""
+    results: list[dict] = []
+    for lang in languages:
+        cmd_def = LANG_COMMANDS.get(lang)
+        if not cmd_def:
+            results.append({"language": lang, "passed": False, "error": "no command defined"})
+            continue
+        lint_cmd = cmd_def.get("lint")
+        if dry_run or not lint_cmd:
+            results.append({"language": lang, "passed": True,
+                            "dry_run": True, "command": lint_cmd or []})
+            continue
+        rc, out, err = _run(lint_cmd, cwd=project_root, timeout=timeout)
+        passed = rc == 0
+        if not passed and fix:
+            fmt = cmd_def.get("format")
+            if fmt:
+                _run(fmt, cwd=project_root, timeout=timeout + 60)
+                rc, out, err = _run(lint_cmd, cwd=project_root, timeout=timeout)
+                passed = rc == 0
+        results.append({
+            "language": lang,
+            "passed": passed,
+            "exit_code": rc,
+            "stderr_tail": err[-2000:] if err else "",
+            "stdout_tail": out[-1000:] if out else "",
+        })
+    return results
+
+
+def run_fix(languages: list[str], project_root: Path,
+            *, timeout: int = 120, dry_run: bool = False) -> list[dict]:
+    """对每个语言跑 format；命令缺失归失败；dry_run 仅打印 would-run 行。"""
+    results: list[dict] = []
+    for lang in languages:
+        cmd_def = LANG_COMMANDS.get(lang)
+        if not cmd_def:
+            results.append({"language": lang, "fixed": False, "error": "no command defined"})
+            continue
+        fmt = cmd_def.get("format")
+        if dry_run or not fmt:
+            results.append({"language": lang, "fixed": True,
+                            "dry_run": True, "command": fmt or []})
+            continue
+        rc, out, err = _run(fmt, cwd=project_root, timeout=timeout)
+        results.append({
+            "language": lang,
+            "fixed": rc == 0,
+            "exit_code": rc,
+            "stderr_tail": err[-2000:] if err else "",
+        })
+    return results
\ No newline at end of file