diff --git a/cmd/root_test.go b/cmd/root_test.go
index 83bf770..5fa0d13 100644
--- a/cmd/root_test.go
+++ b/cmd/root_test.go
@@ -50,8 +50,8 @@ func TestRunInit(t *testing.T) {
 		}
 	})
 
-	if got := mustReadFile(t, filepath.Join(root, "miro.toml")); got != "test_dir = \"e2e\"\n" {
-		t.Fatalf("config = %q, want %q", got, "test_dir = \"e2e\"\n")
+	if got := mustReadFile(t, filepath.Join(root, "miro.toml")); got != "[miro]\n  test_dir = \"e2e\"\n" {
+		t.Fatalf("config = %q, want %q", got, "[miro]\n  test_dir = \"e2e\"\n")
 	}
 	info, err := os.Stat(filepath.Join(root, "e2e", "shell.sh"))
 	if err != nil {
@@ -152,7 +152,7 @@ func TestRunRecordRejectsAbsolutePathOutsideTestDir(t *testing.T) {
 	if err := os.MkdirAll(wantDir, 0o755); err != nil {
 		t.Fatalf("MkdirAll() error = %v", err)
 	}
-	writeFile(t, filepath.Join(root, "miro.toml"), "test_dir = \"e2e\"\n")
+	writeFile(t, filepath.Join(root, "miro.toml"), "[miro]\ntest_dir = \"e2e\"\n")
 
 	outside := filepath.Join(root, "outside", "spec")
 	withWorkingDir(t, root, func() {
@@ -206,7 +206,7 @@ func TestRunRecordFailsWhenDependencyMissing(t *testing.T) {
 	if err := os.MkdirAll(wantDir, 0o755); err != nil {
 		t.Fatalf("MkdirAll() error = %v", err)
 	}
-	writeFile(t, filepath.Join(root, "miro.toml"), "test_dir = \"e2e\"\n")
+	writeFile(t, filepath.Join(root, "miro.toml"), "[miro]\ntest_dir = \"e2e\"\n")
 
 	for _, tc := range []struct {
 		name    string
diff --git a/internal/config/config.go b/internal/config/config.go
index 7ecd74f..f595275 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -14,6 +14,10 @@ type Config struct {
 }
 
 type tomlConfig struct {
+	Miro tomlMiroConfig `toml:"miro"`
+}
+
+type tomlMiroConfig struct {
 	TestDir string `toml:"test_dir"`
 }
 
@@ -28,27 +32,32 @@ func ReadConfig(path string) (Config, error) {
 		}
 		return Config{}, fmt.Errorf("failed to read %s: %v", path, err)
 	}
-	if !meta.IsDefined("test_dir") {
-		return Config{}, fmt.Errorf("failed to read %s: missing required test_dir", path)
+	if !meta.IsDefined("miro") {
+		return Config{}, fmt.Errorf("failed to read %s: missing [miro] config", path)
 	}
-	if raw.TestDir == "" {
-		return Config{}, fmt.Errorf("failed to read %s: empty test_dir", path)
+	if !meta.IsDefined("miro", "test_dir") {
+		return Config{}, fmt.Errorf("failed to read %s: missing required miro.test_dir", path)
+	}
+	if raw.Miro.TestDir == "" {
+		return Config{}, fmt.Errorf("failed to read %s: empty miro.test_dir", path)
 	}
 
 	return Config{
-		TestDir: raw.TestDir,
+		TestDir: raw.Miro.TestDir,
 	}, nil
 }
 
 // WriteConfig writes miro.toml.
 func WriteConfig(path string, cfg Config) error {
 	if cfg.TestDir == "" {
-		return errors.New("empty test_dir")
+		return errors.New("empty miro.test_dir")
 	}
 
 	var buf bytes.Buffer
 	if err := toml.NewEncoder(&buf).Encode(tomlConfig{
-		TestDir: cfg.TestDir,
+		Miro: tomlMiroConfig{
+			TestDir: cfg.TestDir,
+		},
 	}); err != nil {
 		return fmt.Errorf("failed to encode %s: %v", path, err)
 	}
diff --git a/internal/config/config_test.go b/internal/config/config_test.go
index 810e1ac..91d3d0f 100644
--- a/internal/config/config_test.go
+++ b/internal/config/config_test.go
@@ -18,27 +18,32 @@ func TestReadConfig(t *testing.T) {
 	}{
 		{
 			name:    "with test dir",
-			content: "test_dir = \"custom/suite\"\n",
+			content: "[miro]\ntest_dir = \"custom/suite\"\n",
 			wantDir: "custom/suite",
 		},
 		{
-			name:    "legacy miro table",
-			content: "[miro]\ntest_dir = \"custom/suite\"\n",
-			wantErr: "missing required test_dir",
+			name:    "legacy top level key",
+			content: "test_dir = \"custom/suite\"\n",
+			wantErr: "missing [miro] config",
+		},
+		{
+			name:    "without miro table",
+			content: "",
+			wantErr: "missing [miro] config",
 		},
 		{
 			name:    "without test dir",
-			content: "",
-			wantErr: "missing required test_dir",
+			content: "[miro]\n",
+			wantErr: "missing required miro.test_dir",
 		},
 		{
 			name:    "empty test dir",
-			content: "test_dir = \"\"\n",
-			wantErr: "empty test_dir",
+			content: "[miro]\ntest_dir = \"\"\n",
+			wantErr: "empty miro.test_dir",
 		},
 		{
 			name:    "invalid toml",
-			content: "test_dir = [\n",
+			content: "[miro]\ntest_dir = [\n",
 			wantErr: "failed to read",
 		},
 		{
@@ -93,8 +98,8 @@ func TestWriteConfig(t *testing.T) {
 	if err != nil {
 		t.Fatalf("ReadFile() error = %v", err)
 	}
-	if string(got) != "test_dir = \"e2e\"\n" {
-		t.Fatalf("config = %q, want %q", string(got), "test_dir = \"e2e\"\n")
+	if string(got) != "[miro]\n  test_dir = \"e2e\"\n" {
+		t.Fatalf("config = %q, want %q", string(got), "[miro]\n  test_dir = \"e2e\"\n")
 	}
 }
 
@@ -105,7 +110,7 @@ func TestWriteConfigEmptyTestDirFails(t *testing.T) {
 	if err == nil {
 		t.Fatal("WriteConfig() error = nil, want error")
 	}
-	if err.Error() != "empty test_dir" {
-		t.Fatalf("WriteConfig() error = %q, want %q", err.Error(), "empty test_dir")
+	if err.Error() != "empty miro.test_dir" {
+		t.Fatalf("WriteConfig() error = %q, want %q", err.Error(), "empty miro.test_dir")
 	}
 }
diff --git a/internal/miro/record_test.go b/internal/miro/record_test.go
index 11ffb37..c6280b7 100644
--- a/internal/miro/record_test.go
+++ b/internal/miro/record_test.go
@@ -15,7 +15,7 @@ func TestRecordCreatesRelativePath(t *testing.T) {
 	root := t.TempDir()
 	testDir := filepath.Join(root, "e2e")
 	mustMkdirAll(t, testDir)
-	writeFile(t, filepath.Join(root, "miro.toml"), "test_dir = \"e2e\"\n")
+	writeFile(t, filepath.Join(root, "miro.toml"), "[miro]\ntest_dir = \"e2e\"\n")
 	mustWriteRecordShell(t, testDir)
 	addFakeRecordDependencies(t, "script")
 
@@ -51,7 +51,7 @@ func TestRecordAcceptsExplicitTestDirPrefix(t *testing.T) {
 	root := t.TempDir()
 	testDir := filepath.Join(root, "e2e")
 	mustMkdirAll(t, testDir)
-	writeFile(t, filepath.Join(root, "miro.toml"), "test_dir = \"e2e\"\n")
+	writeFile(t, filepath.Join(root, "miro.toml"), "[miro]\ntest_dir = \"e2e\"\n")
 	mustWriteRecordShell(t, testDir)
 	addFakeRecordDependencies(t, "script")
 
@@ -83,7 +83,7 @@ func TestRecordAcceptsExplicitTestDirPrefix(t *testing.T) {
 func TestRecordRejectsAbsolutePathOutsideTestDir(t *testing.T) {
 	root := t.TempDir()
 	mustMkdirAll(t, filepath.Join(root, "e2e"))
-	writeFile(t, filepath.Join(root, "miro.toml"), "test_dir = \"e2e\"\n")
+	writeFile(t, filepath.Join(root, "miro.toml"), "[miro]\ntest_dir = \"e2e\"\n")
 	outside := filepath.Join(root, "outside", "a", "b", "c")
 
 	err := withWorkingDir(t, root, func() error {
@@ -324,7 +324,7 @@ func TestRecordScenarioUsesDeterministicSandbox(t *testing.T) {
 func TestRecordFailsWhenRecorderShellMissing(t *testing.T) {
 	root := t.TempDir()
 	testDir := filepath.Join(root, "e2e")
-	writeFile(t, filepath.Join(root, "miro.toml"), "test_dir = \"e2e\"\n")
+	writeFile(t, filepath.Join(root, "miro.toml"), "[miro]\ntest_dir = \"e2e\"\n")
 	mustMkdirAll(t, testDir)
 	addFakeRecordDependencies(t, "script")
 
diff --git a/internal/miro/testdir_test.go b/internal/miro/testdir_test.go
index 95e6b6f..cc8e44d 100644
--- a/internal/miro/testdir_test.go
+++ b/internal/miro/testdir_test.go
@@ -19,8 +19,8 @@ func TestInitCreatesConfigAtProjectRoot(t *testing.T) {
 	})
 
 	got := readFile(t, filepath.Join(root, "miro.toml"))
-	if got != "test_dir = \"e2e\"\n" {
-		t.Fatalf("config = %q, want %q", got, "test_dir = \"e2e\"\n")
+	if got != "[miro]\n  test_dir = \"e2e\"\n" {
+		t.Fatalf("config = %q, want %q", got, "[miro]\n  test_dir = \"e2e\"\n")
 	}
 	assertRecordShell(t, filepath.Join(root, "e2e", recordShellName))
 }
@@ -46,7 +46,7 @@ func TestInitUsesGitRoot(t *testing.T) {
 
 func TestInitLeavesExistingValidConfigUntouched(t *testing.T) {
 	root := t.TempDir()
-	writeFile(t, filepath.Join(root, "miro.toml"), "test_dir = \"custom/suite\"\n")
+	writeFile(t, filepath.Join(root, "miro.toml"), "[miro]\ntest_dir = \"custom/suite\"\n")
 	writeFile(t, filepath.Join(root, "custom", "suite", recordShellName), "outdated\n")
 
 	withWorkingDir(t, root, func() struct{} {
@@ -57,15 +57,15 @@ func TestInitLeavesExistingValidConfigUntouched(t *testing.T) {
 	})
 
 	got := readFile(t, filepath.Join(root, "miro.toml"))
-	if got != "test_dir = \"custom/suite\"\n" {
-		t.Fatalf("config = %q, want %q", got, "test_dir = \"custom/suite\"\n")
+	if got != "[miro]\ntest_dir = \"custom/suite\"\n" {
+		t.Fatalf("config = %q, want %q", got, "[miro]\ntest_dir = \"custom/suite\"\n")
 	}
 	assertRecordShell(t, filepath.Join(root, "custom", "suite", recordShellName))
 }
 
 func TestInitCreatesMissingConfiguredTestDir(t *testing.T) {
 	root := t.TempDir()
-	writeFile(t, filepath.Join(root, "miro.toml"), "test_dir = \"custom/suite\"\n")
+	writeFile(t, filepath.Join(root, "miro.toml"), "[miro]\ntest_dir = \"custom/suite\"\n")
 
 	withWorkingDir(t, root, func() struct{} {
 		if err := Init(); err != nil {
@@ -79,7 +79,7 @@ func TestInitCreatesMissingConfiguredTestDir(t *testing.T) {
 
 func TestInitFailsWhenExistingConfigInvalid(t *testing.T) {
 	root := t.TempDir()
-	writeFile(t, filepath.Join(root, "miro.toml"), "[miro]\ntest_dir = \"e2e\"\n")
+	writeFile(t, filepath.Join(root, "miro.toml"), "test_dir = \"e2e\"\n")
 
 	err := withWorkingDir(t, root, func() error {
 		return Init()
@@ -87,8 +87,8 @@ func TestInitFailsWhenExistingConfigInvalid(t *testing.T) {
 	if err == nil {
 		t.Fatal("Init() error = nil, want error")
 	}
-	if !strings.Contains(err.Error(), "missing required test_dir") {
-		t.Fatalf("Init() error = %q, want missing test_dir error", err.Error())
+	if !strings.Contains(err.Error(), "missing [miro] config") {
+		t.Fatalf("Init() error = %q, want missing [miro] config error", err.Error())
 	}
 }
 
@@ -96,7 +96,7 @@ func TestResolveTestDirFromConfig(t *testing.T) {
 	root := t.TempDir()
 	configured := filepath.Join(root, "custom", "suite")
 	mustMkdirAll(t, configured)
-	writeFile(t, filepath.Join(root, "miro.toml"), "test_dir = \"custom/suite\"\n")
+	writeFile(t, filepath.Join(root, "miro.toml"), "[miro]\ntest_dir = \"custom/suite\"\n")
 
 	got := withWorkingDir(t, root, func() string {
 		path, err := ResolveTestDir()
@@ -129,7 +129,7 @@ func TestResolveTestDirMissingConfigFails(t *testing.T) {
 
 func TestResolveTestDirMissingTestDirFails(t *testing.T) {
 	root := t.TempDir()
-	writeFile(t, filepath.Join(root, "miro.toml"), "")
+	writeFile(t, filepath.Join(root, "miro.toml"), "[miro]\n")
 
 	err := withWorkingDir(t, root, func() error {
 		_, err := ResolveTestDir()
@@ -139,14 +139,14 @@ func TestResolveTestDirMissingTestDirFails(t *testing.T) {
 	if err == nil {
 		t.Fatal("ResolveTestDir() error = nil, want error")
 	}
-	if !strings.Contains(err.Error(), "missing required test_dir") {
-		t.Fatalf("ResolveTestDir() error = %q, want missing required test_dir", err.Error())
+	if !strings.Contains(err.Error(), "missing required miro.test_dir") {
+		t.Fatalf("ResolveTestDir() error = %q, want missing required miro.test_dir", err.Error())
 	}
 }
 
 func TestResolveTestDirEmptyTestDirFails(t *testing.T) {
 	root := t.TempDir()
-	writeFile(t, filepath.Join(root, "miro.toml"), "test_dir = \"\"\n")
+	writeFile(t, filepath.Join(root, "miro.toml"), "[miro]\ntest_dir = \"\"\n")
 
 	err := withWorkingDir(t, root, func() error {
 		_, err := ResolveTestDir()
@@ -156,14 +156,14 @@ func TestResolveTestDirEmptyTestDirFails(t *testing.T) {
 	if err == nil {
 		t.Fatal("ResolveTestDir() error = nil, want error")
 	}
-	if !strings.Contains(err.Error(), "empty test_dir") {
-		t.Fatalf("ResolveTestDir() error = %q, want empty test_dir", err.Error())
+	if !strings.Contains(err.Error(), "empty miro.test_dir") {
+		t.Fatalf("ResolveTestDir() error = %q, want empty miro.test_dir", err.Error())
 	}
 }
 
 func TestResolveTestDirMalformedConfigFails(t *testing.T) {
 	root := t.TempDir()
-	writeFile(t, filepath.Join(root, "miro.toml"), "test_dir = [\n")
+	writeFile(t, filepath.Join(root, "miro.toml"), "[miro]\ntest_dir = [\n")
 
 	err := withWorkingDir(t, root, func() error {
 		_, err := ResolveTestDir()
@@ -181,7 +181,7 @@ func TestResolveTestDirMalformedConfigFails(t *testing.T) {
 func TestResolveTestDirConfiguredMissingDirectoryReturnsConfiguredPath(t *testing.T) {
 	root := t.TempDir()
 	want := filepath.Join(root, "missing")
-	writeFile(t, filepath.Join(root, "miro.toml"), "test_dir = \"missing\"\n")
+	writeFile(t, filepath.Join(root, "miro.toml"), "[miro]\ntest_dir = \"missing\"\n")
 
 	got := withWorkingDir(t, root, func() string {
 		path, err := ResolveTestDir()
@@ -199,7 +199,7 @@ func TestResolveTestDirConfiguredMissingDirectoryReturnsConfiguredPath(t *testin
 func TestResolveTestDirConfiguredFileFails(t *testing.T) {
 	root := t.TempDir()
 	writeFile(t, filepath.Join(root, "case.txt"), "hello\n")
-	writeFile(t, filepath.Join(root, "miro.toml"), "test_dir = \"case.txt\"\n")
+	writeFile(t, filepath.Join(root, "miro.toml"), "[miro]\ntest_dir = \"case.txt\"\n")
 
 	err := withWorkingDir(t, root, func() error {
 		_, err := ResolveTestDir()
@@ -218,7 +218,7 @@ func TestResolveTestDirUsesGitRoot(t *testing.T) {
 	root := t.TempDir()
 	mustGitInit(t, root)
 	want := filepath.Join(root, "e2e")
-	writeFile(t, filepath.Join(root, "miro.toml"), "test_dir = \"e2e\"\n")
+	writeFile(t, filepath.Join(root, "miro.toml"), "[miro]\ntest_dir = \"e2e\"\n")
 	subdir := filepath.Join(root, "nested", "dir")
 	mustMkdirAll(t, subdir)