fix(cli): make help and output modes predictable

CHANGELOG.md

@@ -7,6 +7,7 @@
 - Photos: add an explicit-opt-in Google Photos Picker workflow for creating selection sessions, waiting for completion, listing chosen media, and downloading selected files. (#754)
 - Docs: add persisted, revision-locked request batches for composing supported mutations locally and submitting them atomically, with explicit split and partial-recovery modes. (#755)
 - CLI: remove the separate `gog agent` and `exit-codes` helpers; expose stable exit codes and effective automation safety state through `gog schema --json`, and summarize the contract in root help. (#677)
+- CLI: add Git-style `gog help <command>`, make explicit output flags override environment defaults, validate color and JSON-only transforms before command execution, report early usage errors on stderr, and reject contradictory schema plain output.
 
 ## 0.24.0 - 2026-06-11
 

docs/automation.md

@@ -12,8 +12,13 @@ Root help summarizes the human-facing contract:
 
 ```bash
 gog --help
+gog help drive ls
 ```
 
+`gog help <command>` and `gog <command> --help` are equivalent. Once a help
+flag is present, trailing arguments are ignored so recovery help remains
+available after a malformed command attempt.
+
 The machine-readable contract is:
 
 ```bash
@@ -34,6 +39,12 @@ gog --json gmail search 'newer_than:7d'
 gog --plain calendar events --today
 ```
 
+`--results-only` and `--select` transform JSON and therefore require
+`--json`. Contradictory output flags fail with usage exit code 2 instead of
+being silently ignored. Explicit output flags override `GOG_JSON` and
+`GOG_PLAIN` environment defaults. `gog schema` always emits JSON and rejects
+`--plain`.
+
 Use `--no-input` in CI and unattended processes. Use `--wrap-untrusted` when
 Google-hosted free text will be consumed by an LLM or another instruction-aware
 system.

docs/commands.generated.md

@@ -174,7 +174,7 @@ Generated from `gog schema --json`.
       - [`gog classroom (class) students (student) add (create,new) <courseId> <userId> [flags]`](commands/gog-classroom-students-add.md) - Add a student
       - [`gog classroom (class) students (student) get (info,show) <courseId> <userId>`](commands/gog-classroom-students-get.md) - Get a student
       - [`gog classroom (class) students (student) list (ls) <courseId> [flags]`](commands/gog-classroom-students-list.md) - List students
-      - [`gog classroom (class) students (student) remove (delete,rm,del,remove) <courseId> <userId>`](commands/gog-classroom-students-remove.md) - Remove a student
+      - [`gog classroom (class) students (student) remove (delete,rm,del) <courseId> <userId>`](commands/gog-classroom-students-remove.md) - Remove a student
     - [`gog classroom (class) submissions (submission) <command>`](commands/gog-classroom-submissions.md) - Student submissions
       - [`gog classroom (class) submissions (submission) get (info,show) <courseId> <courseworkId> <submissionId>`](commands/gog-classroom-submissions-get.md) - Get a student submission
       - [`gog classroom (class) submissions (submission) grade (set,edit) <courseId> <courseworkId> <submissionId> [flags]`](commands/gog-classroom-submissions-grade.md) - Set draft/assigned grades
@@ -186,7 +186,7 @@ Generated from `gog schema --json`.
       - [`gog classroom (class) teachers (teacher) add (create,new) <courseId> <userId>`](commands/gog-classroom-teachers-add.md) - Add a teacher
       - [`gog classroom (class) teachers (teacher) get (info,show) <courseId> <userId>`](commands/gog-classroom-teachers-get.md) - Get a teacher
       - [`gog classroom (class) teachers (teacher) list (ls) <courseId> [flags]`](commands/gog-classroom-teachers-list.md) - List teachers
-      - [`gog classroom (class) teachers (teacher) remove (delete,rm,del,remove) <courseId> <userId>`](commands/gog-classroom-teachers-remove.md) - Remove a teacher
+      - [`gog classroom (class) teachers (teacher) remove (delete,rm,del) <courseId> <userId>`](commands/gog-classroom-teachers-remove.md) - Remove a teacher
     - [`gog classroom (class) topics (topic) <command>`](commands/gog-classroom-topics.md) - Topics
       - [`gog classroom (class) topics (topic) create (add,new) --name=STRING <courseId>`](commands/gog-classroom-topics-create.md) - Create a topic
       - [`gog classroom (class) topics (topic) delete (rm,del,remove) <courseId> <topicId>`](commands/gog-classroom-topics-delete.md) - Delete a topic

docs/commands/gog-classroom-students-remove.md

@@ -7,7 +7,7 @@ Remove a student
 ## Usage
 
 ```bash
-gog classroom (class) students (student) remove (delete,rm,del,remove) <courseId> <userId>
+gog classroom (class) students (student) remove (delete,rm,del) <courseId> <userId>
 ```
 
 ## Parent

docs/commands/gog-classroom-teachers-remove.md

@@ -7,7 +7,7 @@ Remove a teacher
 ## Usage
 
 ```bash
-gog classroom (class) teachers (teacher) remove (delete,rm,del,remove) <courseId> <userId>
+gog classroom (class) teachers (teacher) remove (delete,rm,del) <courseId> <userId>
 ```
 
 ## Parent

internal/cmd/classroom_rosters.go

@@ -16,7 +16,7 @@ type ClassroomStudentsCmd struct {
 	List   ClassroomStudentsListCmd   `cmd:"" default:"withargs" aliases:"ls" help:"List students"`
 	Get    ClassroomStudentsGetCmd    `cmd:"" aliases:"info,show" help:"Get a student"`
 	Add    ClassroomStudentsAddCmd    `cmd:"" aliases:"create,new" help:"Add a student"`
-	Remove ClassroomStudentsRemoveCmd `cmd:"" aliases:"delete,rm,del,remove" help:"Remove a student"`
+	Remove ClassroomStudentsRemoveCmd `cmd:"" aliases:"delete,rm,del" help:"Remove a student"`
 }
 
 type ClassroomStudentsListCmd struct {
@@ -244,7 +244,7 @@ type ClassroomTeachersCmd struct {
 	List   ClassroomTeachersListCmd   `cmd:"" default:"withargs" aliases:"ls" help:"List teachers"`
 	Get    ClassroomTeachersGetCmd    `cmd:"" aliases:"info,show" help:"Get a teacher"`
 	Add    ClassroomTeachersAddCmd    `cmd:"" aliases:"create,new" help:"Add a teacher"`
-	Remove ClassroomTeachersRemoveCmd `cmd:"" aliases:"delete,rm,del,remove" help:"Remove a teacher"`
+	Remove ClassroomTeachersRemoveCmd `cmd:"" aliases:"delete,rm,del" help:"Remove a teacher"`
 }
 
 type ClassroomTeachersListCmd struct {

internal/cmd/desire_paths_test.go

@@ -59,6 +59,28 @@ func TestDesirePaths_GlobalFlagAliases(t *testing.T) {
 	}
 }
 
+func TestDesirePaths_RewriteHelp(t *testing.T) {
+	tests := []struct {
+		name string
+		in   []string
+		want []string
+	}{
+		{name: "root", in: []string{"help"}, want: []string{"--help"}},
+		{name: "command", in: []string{"help", "drive", "ls"}, want: []string{"drive", "ls", "--help"}},
+		{name: "global flag", in: []string{"--color", "never", "help", "gmail"}, want: []string{"--color", "never", "gmail", "--help"}},
+		{name: "help ignores trailing args", in: []string{"drive", "--help", "nonsense"}, want: []string{"drive", "--help"}},
+		{name: "help after delimiter is data", in: []string{"open", "--", "--help"}, want: []string{"open", "--", "--help"}},
+		{name: "global value named help", in: []string{"--account", "help", "version"}, want: []string{"--account", "help", "version"}},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := rewriteHelpArgs(tt.in); !reflect.DeepEqual(got, tt.want) {
+				t.Fatalf("rewriteHelpArgs(%v) = %v, want %v", tt.in, got, tt.want)
+			}
+		})
+	}
+}
+
 func TestDesirePaths_DryRunAlias_ExitsBeforeAuth(t *testing.T) {
 	out := captureStdout(t, func() {
 		_ = captureStderr(t, func() {

internal/cmd/help_printer.go

@@ -105,6 +105,7 @@ func injectAutomationHelp(out string, selected *kong.Node) string {
 
 	const section = `Automation:
   Use --json or --plain for stable output; --no-input disables prompts.
+  Use "gog help <command>" or "gog <command> --help" for command help.
   Exit codes: 0 success, 1 error, 2 usage, 3 empty, 4 auth, 5 not found,
     6 denied, 7 rate limited, 8 retryable, 10 config, 11 orphaned,
     130 interrupted.

internal/cmd/help_snapshot_test.go

@@ -91,6 +91,7 @@ func TestHelpSnapshot_RootAutomationContract(t *testing.T) {
 	requireHelpContains(t, out,
 		"\nAutomation:\n",
 		"Use --json or --plain for stable output",
+		`Use "gog help <command>"`,
 		"Exit codes: 0 success",
 		`Run "gog schema --json"`,
 	)

internal/cmd/root.go

@@ -108,22 +108,23 @@ func Execute(args []string) (err error) {
 	if len(args) == 0 {
 		args = []string{"--help"}
 	}
+	args = rewriteHelpArgs(args)
 	args = rewriteDesirePathArgs(args)
 	args = rewriteDocsCellUpdateContentArgs(args)
 
 	preHomeApplied := false
 	if home, ok := preScanHomeArg(args); ok {
 		restoreHome, homeErr := config.SetHomeOverride(home)
 		if homeErr != nil {
-			return newUsageError(homeErr)
+			return reportEarlyError(newUsageError(homeErr))
 		}
 		preHomeApplied = true
 		defer restoreHome()
 	}
 
 	parser, cli, err := newParser(helpDescription())
 	if err != nil {
-		return err
+		return reportEarlyError(err)
 	}
 
 	defer func() {
@@ -142,33 +143,28 @@ func Execute(args []string) (err error) {
 
 	kctx, err := parser.Parse(args)
 	if err != nil {
-		parsedErr := wrapParseError(err)
-		_, _ = fmt.Fprintln(os.Stderr, errfmt.Format(parsedErr))
-		return parsedErr
+		return reportEarlyError(wrapParseError(err))
 	}
+	applyExplicitOutputModePrecedence(kctx, &cli.RootFlags)
 	if !preHomeApplied && strings.TrimSpace(cli.Home) != "" {
 		restoreHome, homeErr := config.SetHomeOverride(cli.Home)
 		if homeErr != nil {
-			return newUsageError(homeErr)
+			return reportEarlyError(newUsageError(homeErr))
 		}
 		defer restoreHome()
 	}
 
 	if err = enforceBakedSafetyProfile(kctx); err != nil {
-		_, _ = fmt.Fprintln(os.Stderr, errfmt.Format(err))
-		return err
+		return reportEarlyError(err)
 	}
 	if err = enforceEnabledCommands(kctx, cli.EnableCommands, cli.EnableCommandsExact); err != nil {
-		_, _ = fmt.Fprintln(os.Stderr, errfmt.Format(err))
-		return err
+		return reportEarlyError(err)
 	}
 	if err = enforceDisabledCommands(kctx, cli.DisableCommands); err != nil {
-		_, _ = fmt.Fprintln(os.Stderr, errfmt.Format(err))
-		return err
+		return reportEarlyError(err)
 	}
 	if err = enforceGmailNoSend(kctx, &cli.RootFlags); err != nil {
-		_, _ = fmt.Fprintln(os.Stderr, errfmt.Format(err))
-		return err
+		return reportEarlyError(err)
 	}
 
 	logLevel := slog.LevelWarn
@@ -187,7 +183,11 @@ func Execute(args []string) (err error) {
 
 	mode, err := outfmt.FromFlags(cli.JSON, cli.Plain)
 	if err != nil {
-		return newUsageError(err)
+		return reportEarlyError(newUsageError(err))
+	}
+	err = validateJSONTransformFlags(mode, &cli.RootFlags)
+	if err != nil {
+		return reportEarlyError(err)
 	}
 
 	ctx := context.Background()
@@ -216,7 +216,7 @@ func Execute(args []string) (err error) {
 		Color:  uiColor,
 	})
 	if err != nil {
-		return err
+		return reportEarlyError(newUsageError(err))
 	}
 	ctx = ui.WithUI(ctx, u)
 
@@ -247,6 +247,85 @@ func Execute(args []string) (err error) {
 	return err
 }
 
+func rewriteHelpArgs(args []string) []string {
+	for i, arg := range args {
+		if arg == "--" {
+			break
+		}
+		if arg == "--help" || arg == "-h" {
+			return append([]string(nil), args[:i+1]...)
+		}
+	}
+
+	for i := 0; i < len(args); i++ {
+		arg := args[i]
+		if arg == "--" {
+			return args
+		}
+		if strings.HasPrefix(arg, "-") {
+			if globalFlagTakesValue(arg) && i+1 < len(args) {
+				i++
+			}
+			continue
+		}
+		if arg != "help" {
+			return args
+		}
+
+		out := make([]string, 0, len(args))
+		out = append(out, args[:i]...)
+		out = append(out, args[i+1:]...)
+		out = append(out, "--help")
+		return out
+	}
+	return args
+}
+
+func validateJSONTransformFlags(mode outfmt.Mode, flags *RootFlags) error {
+	if flags == nil || mode.JSON {
+		return nil
+	}
+
+	hasResultsOnly := flags.ResultsOnly
+	hasSelect := strings.TrimSpace(flags.Select) != ""
+	switch {
+	case hasResultsOnly && hasSelect:
+		return usage("--results-only and --select require --json")
+	case hasResultsOnly:
+		return usage("--results-only requires --json")
+	case hasSelect:
+		return usage("--select requires --json")
+	default:
+		return nil
+	}
+}
+
+func applyExplicitOutputModePrecedence(kctx *kong.Context, flags *RootFlags) {
+	if flags == nil {
+		return
+	}
+
+	jsonSet := flagProvided(kctx, "json")
+	plainSet := flagProvided(kctx, "plain")
+	switch {
+	case jsonSet && !plainSet:
+		flags.Plain = false
+	case plainSet && !jsonSet:
+		flags.JSON = false
+	}
+}
+
+func reportEarlyError(err error) error {
+	if err == nil {
+		return nil
+	}
+	msg := strings.TrimSpace(errfmt.Format(err))
+	if msg != "" {
+		_, _ = fmt.Fprintln(os.Stderr, msg)
+	}
+	return err
+}
+
 func rewriteDesirePathArgs(args []string) []string {
 	// Some commands use `--fields` for API field masks. Agents also frequently
 	// guess `--fields` to mean "select output fields", so we squat it everywhere