5 files changed, 143 insertions, 1 deletions
diff --git a/internal/editor/editor.go b/internal/editor/editor.go
index a1af1be..722e336 100644
--- a/internal/editor/editor.go
+++ b/internal/editor/editor.go
@@ -68,3 +68,23 @@ func OpenTempAndEdit(initial []byte) (string, error) {
 	}
 	return strings.TrimSpace(string(b)), nil
 }
+
+// OpenFile ensures the parent directory exists, then opens path in the editor
+// from Resolve() (HEXAI_EDITOR or EDITOR).
+func OpenFile(path string) error {
+	ed, err := Resolve()
+	if err != nil {
+		return err
+	}
+	path = filepath.Clean(strings.TrimSpace(path))
+	if path == "" || path == "." {
+		return errors.New("config path is empty")
+	}
+	dir := filepath.Dir(path)
+	if dir != "" && dir != "." {
+		if mkErr := os.MkdirAll(dir, 0o700); mkErr != nil {
+			return mkErr
+		}
+	}
+	return RunEditor(ed, path)
+}
diff --git a/internal/editor/editor_test.go b/internal/editor/editor_test.go
index 260fb85..403d165 100644
--- a/internal/editor/editor_test.go
+++ b/internal/editor/editor_test.go
@@ -182,3 +182,45 @@ func TestOpenTempAndEdit_TempFileCleanup(t *testing.T) {
 		t.Fatalf("temp file was not cleaned up: %s", capturedPath)
 	}
 }
+
+func TestOpenFile_CreatesParentAndInvokesEditor(t *testing.T) {
+	old := RunEditor
+	t.Cleanup(func() { RunEditor = old })
+	t.Setenv("HEXAI_EDITOR", "dummy")
+	target := filepath.Join(t.TempDir(), "nested", "config.toml")
+	var gotEditor, gotPath string
+	RunEditor = func(editorCmd, path string) error {
+		gotEditor = editorCmd
+		gotPath = path
+		return nil
+	}
+	if err := OpenFile(target); err != nil {
+		t.Fatalf("OpenFile: %v", err)
+	}
+	if gotEditor != "dummy" {
+		t.Fatalf("editor = %q", gotEditor)
+	}
+	if gotPath != target {
+		t.Fatalf("path = %q, want %q", gotPath, target)
+	}
+	if _, err := os.Stat(filepath.Dir(target)); err != nil {
+		t.Fatalf("parent dir: %v", err)
+	}
+}
+
+func TestOpenFile_NoEditor(t *testing.T) {
+	t.Setenv("HEXAI_EDITOR", "")
+	t.Setenv("EDITOR", "")
+	err := OpenFile(filepath.Join(t.TempDir(), "x.toml"))
+	if err == nil {
+		t.Fatal("expected error when no editor is set")
+	}
+}
+
+func TestOpenFile_EmptyPath(t *testing.T) {
+	t.Setenv("HEXAI_EDITOR", "true")
+	err := OpenFile("  ")
+	if err == nil {
+		t.Fatal("expected error for empty path")
+	}
+}
diff --git a/internal/hexaicli/runner.go b/internal/hexaicli/runner.go
index f372021..eaae1cd 100644
--- a/internal/hexaicli/runner.go
+++ b/internal/hexaicli/runner.go
@@ -67,6 +67,31 @@ func NewRunner() *Runner {
 
 func (r *Runner) Run(ctx context.Context, args []string, stdin io.Reader, stdout, stderr io.Writer) error {
 	runner := normalizeRunner(r)
+	if len(args) > 0 {
+		sub := args[0]
+		if sub == "config" {
+			if len(args) > 1 {
+				err := fmt.Errorf(`hexai %s: unexpected arguments (use only %q)`, sub, sub)
+				_, _ = fmt.Fprintf(stderr, logging.AnsiBase+"%v"+logging.AnsiReset+"\n", err)
+				return err
+			}
+			cfgPath := strings.TrimSpace(configPathFromContext(ctx))
+			if cfgPath == "" {
+				p, pathErr := appconfig.ConfigPath()
+				if pathErr != nil {
+					err := fmt.Errorf("hexai %s: %w", sub, pathErr)
+					_, _ = fmt.Fprintf(stderr, logging.AnsiBase+"%v"+logging.AnsiReset+"\n", err)
+					return err
+				}
+				cfgPath = p
+			}
+			if err := editor.OpenFile(cfgPath); err != nil {
+				_, _ = fmt.Fprintf(stderr, logging.AnsiBase+"hexai %s: %v"+logging.AnsiReset+"\n", sub, err)
+				return err
+			}
+			return nil
+		}
+	}
 	if spec, ok, err := tpsSimulationFromContext(ctx); err != nil {
 		_, _ = fmt.Fprintln(stderr, logging.AnsiBase+err.Error()+logging.AnsiReset)
 		return err
diff --git a/internal/hexaicli/runner_test.go b/internal/hexaicli/runner_test.go
index 1d438b0..009af54 100644
--- a/internal/hexaicli/runner_test.go
+++ b/internal/hexaicli/runner_test.go
@@ -4,10 +4,12 @@ import (
 	"bytes"
 	"context"
 	"log"
+	"path/filepath"
 	"strings"
 	"testing"
 
 	"codeberg.org/snonux/hexai/internal/appconfig"
+	"codeberg.org/snonux/hexai/internal/editor"
 	"codeberg.org/snonux/hexai/internal/llm"
 	"codeberg.org/snonux/hexai/internal/stats"
 )
@@ -59,3 +61,56 @@ func TestRunner_UsesInjectedDependencies(t *testing.T) {
 		t.Fatalf("expected one global status update, got %d", sink.globalCalls)
 	}
 }
+
+func TestRunner_ConfigSubcommand_OpensConfigFromContext(t *testing.T) {
+	old := editor.RunEditor
+	t.Cleanup(func() { editor.RunEditor = old })
+	t.Setenv("EDITOR", "true")
+	var gotPath string
+	editor.RunEditor = func(_, path string) error {
+		gotPath = path
+		return nil
+	}
+	cfgFile := filepath.Join(t.TempDir(), "hexai", "config.toml")
+	ctx := WithCLIConfigPath(context.Background(), cfgFile)
+	runner := NewRunner()
+	if err := runner.Run(ctx, []string{"config"}, strings.NewReader(""), &bytes.Buffer{}, &bytes.Buffer{}); err != nil {
+		t.Fatalf("Run: %v", err)
+	}
+	if gotPath != cfgFile {
+		t.Fatalf("opened %q, want %q", gotPath, cfgFile)
+	}
+}
+
+func TestRunner_ConfigSubcommand_UsesXDGWhenNoOverride(t *testing.T) {
+	old := editor.RunEditor
+	t.Cleanup(func() { editor.RunEditor = old })
+	t.Setenv("HEXAI_EDITOR", "true")
+	xdg := t.TempDir()
+	t.Setenv("XDG_CONFIG_HOME", xdg)
+	var gotPath string
+	editor.RunEditor = func(_, path string) error {
+		gotPath = path
+		return nil
+	}
+	runner := NewRunner()
+	want := filepath.Join(xdg, "hexai", "config.toml")
+	if err := runner.Run(context.Background(), []string{"config"}, strings.NewReader(""), &bytes.Buffer{}, &bytes.Buffer{}); err != nil {
+		t.Fatalf("Run: %v", err)
+	}
+	if gotPath != want {
+		t.Fatalf("opened %q, want %q", gotPath, want)
+	}
+}
+
+func TestRunner_ConfigSubcommand_RejectsExtraArgs(t *testing.T) {
+	runner := NewRunner()
+	var stderr bytes.Buffer
+	err := runner.Run(context.Background(), []string{"config", "nope"}, strings.NewReader(""), &bytes.Buffer{}, &stderr)
+	if err == nil {
+		t.Fatal("expected error")
+	}
+	if !strings.Contains(err.Error(), "unexpected arguments") {
+		t.Fatalf("err = %v", err)
+	}
+}
diff --git a/internal/version.go b/internal/version.go
index 4fa574f..4305500 100644
--- a/internal/version.go
+++ b/internal/version.go
@@ -1,4 +1,4 @@
 // Package internal provides the Hexai semantic version identifier used by CLI and LSP binaries.
 package internal
 
-const Version = "0.38.3"
+const Version = "0.38.4"