diff --git a/AGENTS.md b/AGENTS.md
index 0e507e2c9d8caae3e6ca603d7df97311e869d9a3..e5ff25e8a7ff4233ed40c80c73fcc988eab81f7b 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -109,10 +109,11 @@ Assisted-by: This is a very long value, with spaces and
 - `-B` / `--breaking`: Boolean flag for breaking changes (adds `!` to subject)
 - `-b` / `--body`: String flag for commit body text (can use heredoc for multiline)
 - `-T` / `--trailer`: Repeatable flag accepting full trailer strings in `Key: value` format (not separate key/value args)
-- `-a` / `--amend`: Boolean flag to amend the previous commit instead of creating a new one
+- `-a` / `--add`: Boolean flag to stage all modified files before committing (optional)
+- `--amend`: Boolean flag to amend the previous commit instead of creating a new one (optional)
 
 Trailer format detail: Each `-T` flag takes a complete trailer string like `-T "Assisted-by: GLM 4.6 via Crush"`, NOT separate key and value arguments.
 
 ### Final Output
 
-The formatted commit message must be piped to `git commit -F -` to read from stdin. When the `-a`/`--amend` flag is used, it pipes to `git commit --amend -F -` instead.
+The formatted commit message must be piped to `git commit -F -` to read from stdin. When the `--amend` flag is used, it pipes to `git commit --amend -F -` instead.
diff --git a/README.md b/README.md
index 00b7d9b2a1ba76abbb82ec762acb324e977031a3..b45aeb7a837cb87667401bc3dde836f69aedeed0 100644
--- a/README.md
+++ b/README.md
@@ -65,7 +65,8 @@ Create/amend commits exclusively using `formatted-commit`. Try to use it normall
 -m --message Commit message (required)
 -b --body Commit body (optional)
 -T --trailer Trailer in 'Sentence-case-key: value' format (optional, repeatable)
--a --amend Amend the previous commit (optional)
+-a --add Stage all modified files before committing (optional)
+--amend Amend the previous commit (optional)
 -h --help
 </formatted-commit_flags>
 <formatted-commit_example>
@@ -154,7 +155,8 @@ $ formatted-commit -h
 
   FLAGS
 
-    -a --amend         Amend the previous commit (optional)
+    -a --add           Stage all modified files before committing (optional)
+       --amend         Amend the previous commit (optional)
     -b --body          Commit body (optional)
     -B --breaking      Mark as breaking change (optional)
     -h --help          Help for formatted-commit
diff --git a/main.go b/main.go
index cf34bcdbd815aef8673554272666a54afec596b8..8e4b62f3dbb3daddfdeac1200c70f789483f9e39 100644
--- a/main.go
+++ b/main.go
@@ -23,6 +23,7 @@ var (
 	body           string
 	scope          string
 	breakingChange bool
+	add            bool
 	amend          bool
 )
 
@@ -84,6 +85,9 @@ formatted-commit upgrade -a
 		}
 
 		gitArgs := []string{"commit"}
+		if add {
+			gitArgs = append(gitArgs, "-a")
+		}
 		if amend {
 			gitArgs = append(gitArgs, "--amend")
 		}
@@ -124,7 +128,8 @@ func init() {
 	rootCmd.Flags().StringVarP(&body, "body", "b", "", "commit body (optional)")
 	rootCmd.Flags().StringVarP(&scope, "scope", "s", "", "commit scope (optional)")
 	rootCmd.Flags().BoolVarP(&breakingChange, "breaking", "B", false, "mark as breaking change (optional)")
-	rootCmd.Flags().BoolVarP(&amend, "amend", "a", false, "amend the previous commit (optional)")
+	rootCmd.Flags().BoolVarP(&add, "add", "a", false, "stage all modified files before committing (optional)")
+	rootCmd.Flags().BoolVar(&amend, "amend", false, "amend the previous commit (optional)")
 
 	if err := rootCmd.MarkFlagRequired("type"); err != nil {
 		panic(err)