feat(commit): add AI-generated commit message support.

docs-master/Config.md

@@ -359,6 +359,28 @@ git:
     # If autoWrapCommitMessage is true, the width to wrap to
     autoWrapWidth: 72
 
+    # AI commit message generation config
+    ai:
+      # CLI-based generation: runs a command with the staged diff piped to stdin.
+      # Example: "claude -p 'Generate a conventional commit message for this diff:'"
+      cli:
+        # The shell command to run. The staged diff is piped to stdin.
+        command: ""
+
+      # OpenAI-compatible API generation
+      api:
+        # OpenAI-compatible base URL, e.g. "https://api.openai.com/v1"
+        endpoint: ""
+
+        # Model name, e.g. "gpt-4o" or "llama3"
+        model: ""
+
+        # API key value. Use {env:MY_API_KEY} to read from an environment variable.
+        apiKey: ""
+
+        # System prompt. Defaults to a conventional commit prompt if omitted.
+        systemPrompt: ""
+
   # Config relating to merging
   merging:
     # If true, run merges in a subprocess so that if a commit message is required,

docs/Config.md

@@ -16,6 +16,8 @@ If you want to change the config directory:
 
 - MacOS: `export XDG_CONFIG_HOME="$HOME/.config"`
 
+You can place a `.env` file in the same directory as your `config.yml` to define secrets (e.g. API keys) outside of version control. Reference them anywhere in your config using the `{env:VARIABLE_NAME}` syntax — for example, `apiKey: "{env:OPENAI_API_KEY}"`. Variables already set in your shell take precedence over values in `.env`.
+
 In addition to the global config file you can create repo-specific config files in `<repo>/.git/lazygit.yml`. Settings in these files override settings in the global config file. In addition, files called `.lazygit.yml` in any of the parent directories of a repo will also be loaded; this can be useful if you have settings that you want to apply to a group of repositories.
 
 JSON schema is available for `config.yml` so that IntelliSense in Visual Studio Code (completion and error checking) is automatically enabled when the [YAML Red Hat][yaml] extension is installed. However, note that automatic schema detection only works if your config file is in one of the standard paths mentioned above. If you override the path to the file, you can still make IntelliSense work by adding
@@ -359,6 +361,26 @@ git:
     # If autoWrapCommitMessage is true, the width to wrap to
     autoWrapWidth: 72
 
+    # Config for AI-generated commit messages (accessible via the commit menu with <c-o> then 'a')
+    # Use either the 'cli' or 'api' approach, not both.
+    ai:
+      # Use a local CLI tool (e.g. claude, opencode, llm) to generate commit messages.
+      # The staged diff is piped to stdin; the generated message is read from stdout.
+      # Markdown code fences in the output are stripped automatically.
+      # Example: 'claude -p "Generate a conventional commit message:"'
+      cli:
+        command: 'claude -p "Generated a conventional commit message for this diff"'
+
+      # Use an OpenAI-compatible HTTP API to generate commit messages.
+      # Use {env:MY_VAR} to read the API key from an environment variable or
+      # from the .env file next to config.yml (see above).
+      api:
+        endpoint: "https://api.openai.com/v1/chat/completions"
+        model: "gpt-4o-mini"
+        apiKey: "{env:OPENAI_API_KEY}"
+        # Optional system prompt. A sensible default is used when left empty.
+        systemPrompt: ""
+
   # Config relating to merging
   merging:
     # If true, run merges in a subprocess so that if a commit message is required,

pkg/config/app_config.go

@@ -7,6 +7,7 @@ import (
 	"os"
 	"path/filepath"
 	"reflect"
+	"regexp"
 	"strings"
 	"time"
 
@@ -82,6 +83,8 @@ func NewAppConfig(
 		return nil, err
 	}
 
+	loadDotEnv(filepath.Join(configDir, ".env"))
+
 	var configFiles []*ConfigFile
 	customConfigFiles := os.Getenv("LG_CONFIG_FILE")
 	if customConfigFiles != "" {
@@ -135,6 +138,45 @@ func findOrCreateConfigDir() (string, error) {
 	return folder, os.MkdirAll(folder, 0o755)
 }
 
+var envInterpolatePattern = regexp.MustCompile(`\{env:([^}]+)\}`)
+
+// envInterpolate replaces {env:KEY} placeholders in config content with the
+// corresponding environment variable values.
+func envInterpolate(content []byte) []byte {
+	return envInterpolatePattern.ReplaceAllFunc(content, func(match []byte) []byte {
+		key := string(match[5 : len(match)-1]) // strip "{env:" and "}"
+		return []byte(os.Getenv(key))
+	})
+}
+
+// loadDotEnv reads a .env file and sets any key=value pairs as environment
+// variables, skipping keys that are already set. Lines starting with '#' and
+// blank lines are ignored. Quoted values have their quotes stripped.
+func loadDotEnv(path string) {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return // file is optional
+	}
+	for _, line := range strings.Split(string(data), "\n") {
+		line = strings.TrimSpace(line)
+		if line == "" || strings.HasPrefix(line, "#") {
+			continue
+		}
+		key, value, ok := strings.Cut(line, "=")
+		if !ok {
+			continue
+		}
+		key = strings.TrimSpace(key)
+		value = strings.TrimSpace(value)
+		if len(value) >= 2 && (value[0] == '"' || value[0] == '\'') && value[len(value)-1] == value[0] {
+			value = value[1 : len(value)-1]
+		}
+		if os.Getenv(key) == "" {
+			_ = os.Setenv(key, value)
+		}
+	}
+}
+
 func loadUserConfigWithDefaults(configFiles []*ConfigFile, isGuiInitialized bool) (*UserConfig, error) {
 	return loadUserConfig(configFiles, GetDefaultConfig(), isGuiInitialized)
 }
@@ -191,6 +233,7 @@ func loadUserConfig(configFiles []*ConfigFile, base *UserConfig, isGuiInitialize
 
 		existingCustomCommands := base.CustomCommands
 
+		content = envInterpolate(content)
 		if err := yaml.Unmarshal(content, base); err != nil {
 			return nil, fmt.Errorf("The config at `%s` couldn't be parsed, please inspect it before opening up an issue.\n%w", path, err)
 		}

pkg/config/app_config_test.go

@@ -6,6 +6,44 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+func TestEnvInterpolate(t *testing.T) {
+	t.Setenv("MY_KEY", "hello")
+	t.Setenv("ANOTHER", "world")
+
+	scenarios := []struct {
+		name     string
+		input    string
+		expected string
+	}{
+		{
+			name:     "no placeholders unchanged",
+			input:    "apiKey: hardcoded",
+			expected: "apiKey: hardcoded",
+		},
+		{
+			name:     "single placeholder replaced",
+			input:    "apiKey: {env:MY_KEY}",
+			expected: "apiKey: hello",
+		},
+		{
+			name:     "multiple placeholders replaced",
+			input:    "{env:MY_KEY} and {env:ANOTHER}",
+			expected: "hello and world",
+		},
+		{
+			name:     "unset variable replaced with empty string",
+			input:    "apiKey: {env:UNSET_VAR_XYZ}",
+			expected: "apiKey: ",
+		},
+	}
+	for _, s := range scenarios {
+		t.Run(s.name, func(t *testing.T) {
+			result := envInterpolate([]byte(s.input))
+			assert.Equal(t, s.expected, string(result))
+		})
+	}
+}
+
 func TestMigrationOfRenamedKeys(t *testing.T) {
 	scenarios := []struct {
 		name              string

pkg/config/user_config.go

@@ -355,6 +355,32 @@ type CommitConfig struct {
 	AutoWrapCommitMessage bool `yaml:"autoWrapCommitMessage"`
 	// If autoWrapCommitMessage is true, the width to wrap to
 	AutoWrapWidth int `yaml:"autoWrapWidth"`
+	// AI commit message generation config
+	AI AIConfig `yaml:"ai"`
+}
+
+type AIConfig struct {
+	// CLI-based generation: runs a command with the staged diff piped to stdin.
+	// Example: "claude -p 'Generate a conventional commit message for this diff:'"
+	CLI AICliConfig `yaml:"cli"`
+	// OpenAI-compatible API generation
+	API AIAPIConfig `yaml:"api"`
+}
+
+type AICliConfig struct {
+	// The shell command to run. The staged diff is piped to stdin.
+	Command string `yaml:"command"`
+}
+
+type AIAPIConfig struct {
+	// OpenAI-compatible base URL, e.g. "https://api.openai.com/v1"
+	Endpoint string `yaml:"endpoint"`
+	// Model name, e.g. "gpt-4o" or "llama3"
+	Model string `yaml:"model"`
+	// API key value. Use {env:MY_API_KEY} to read from an environment variable.
+	APIKey string `yaml:"apiKey"`
+	// System prompt. Defaults to a conventional commit prompt if omitted.
+	SystemPrompt string `yaml:"systemPrompt"`
 }
 
 type MergingConfig struct {

pkg/gui/controllers/commit_message_controller.go

@@ -167,6 +167,10 @@ func (self *CommitMessageController) setCommitMessageAtIndex(index int) (bool, e
 }
 
 func (self *CommitMessageController) confirm() error {
+	if self.c.Helpers().Commits.IsGenerating() {
+		return nil
+	}
+
 	// The default keybinding for this action is "<enter>", which means that we
 	// also get here when pasting multi-line text that contains newlines. In
 	// that case we don't want to confirm the commit, but switch to the
@@ -185,6 +189,10 @@ func (self *CommitMessageController) confirm() error {
 }
 
 func (self *CommitMessageController) close() error {
+	if self.c.Helpers().Commits.IsGenerating() {
+		return nil
+	}
+
 	self.c.Helpers().Commits.CloseCommitMessagePanel()
 	return nil
 }