docs: update changelog for thread modify

This adds a new `gmail thread modify` subcommand that uses the Gmail API's
Threads.Modify endpoint to apply label changes to all messages in a thread
at once.

Usage:
  gog gmail thread modify <threadId> --add "Label1,Label2" --remove "Label3"

Features:
- Resolves label names to IDs automatically
- Supports both adding and removing labels in a single operation
- JSON output mode for programmatic use

BREAKING CHANGE: The `gmail thread` command is now a parent command with
subcommands. Use `gmail thread get <id>` instead of `gmail thread <id>`.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

CHANGELOG.md

@@ -2,7 +2,7 @@
 
 ## 0.4.2 - Unreleased
 
-- (next)
+- Gmail: `thread modify` subcommand + `thread get` split (#21) — thanks @alexknowshtml.
 
 ## 0.4.1 - 2025-12-28
 

README.md

@@ -174,14 +174,15 @@ gog auth tokens                       # Manage stored refresh tokens
 ```bash
 # Search and read
 gog gmail search 'newer_than:7d' --max 10
-gog gmail thread <threadId>
+gog gmail thread get <threadId>
-gog gmail thread <threadId> --download              # Download attachments to current dir
+gog gmail thread get <threadId> --download              # Download attachments to current dir
-gog gmail thread <threadId> --download --out-dir ./attachments
+gog gmail thread get <threadId> --download --out-dir ./attachments
 gog gmail get <messageId>
 gog gmail get <messageId> --format metadata
 gog gmail attachment <messageId> <attachmentId>
 gog gmail attachment <messageId> <attachmentId> --out ./attachment.bin
 gog gmail url <threadId>              # Print Gmail web URL
+gog gmail thread modify <threadId> --add STARRED --remove INBOX
 
 # Send and compose
 gog gmail send --to a@b.com --subject "Hi" --body "Plain fallback"
@@ -484,7 +485,7 @@ If you use `pnpm`, see the shortcut section for `pnpm -s` (silent) to keep stdou
 gog gmail search 'newer_than:7d has:attachment' --max 10
 
 # Get thread details and download attachments
-gog gmail thread <threadId> --download
+gog gmail thread get <threadId> --download
 ```
 
 ### Create a calendar event with attendees

docs/spec.md

@@ -155,7 +155,8 @@ Environment:
 - `gog calendar freebusy <calendarIds> --from RFC3339 --to RFC3339`
 - `gog calendar respond <calendarId> <eventId> --status accepted|declined|tentative [--send-updates all|none|externalOnly]`
 - `gog gmail search <query> [--max N] [--page TOKEN]`
-- `gog gmail thread <threadId> [--download]`
+- `gog gmail thread get <threadId> [--download]`
+- `gog gmail thread modify <threadId> [--add ...] [--remove ...]`
 - `gog gmail get <messageId> [--format full|metadata|raw] [--headers ...]`
 - `gog gmail attachment <messageId> <attachmentId> [--out PATH] [--name NAME]`
 - `gog gmail url <threadIds...>`

internal/cmd/execute_gmail_more_commands_test.go

@@ -135,7 +135,7 @@ func TestExecute_GmailThreadDraftsSend_JSON(t *testing.T) {
 
 	_ = captureStderr(t, func() {
 		out := captureStdout(t, func() {
-			if err := Execute([]string{"--json", "--account", "a@b.com", "gmail", "thread", "t1", "--download"}); err != nil {
+			if err := Execute([]string{"--json", "--account", "a@b.com", "gmail", "thread", "get", "t1", "--download"}); err != nil {
 				t.Fatalf("thread: %v", err)
 			}
 		})

internal/cmd/execute_gmail_text_test.go

@@ -86,7 +86,7 @@ func TestExecute_GmailThread_Text_Download(t *testing.T) {
 
 	out := captureStdout(t, func() {
 		_ = captureStderr(t, func() {
-			if execErr := Execute([]string{"--account", "a@b.com", "gmail", "thread", "t-thread-1", "--download"}); execErr != nil {
+			if execErr := Execute([]string{"--account", "a@b.com", "gmail", "thread", "get", "t-thread-1", "--download"}); execErr != nil {
 				t.Fatalf("Execute: %v", execErr)
 			}
 		})
@@ -238,7 +238,7 @@ func TestExecute_GmailThread_OutDir_CreatesParents_JSON(t *testing.T) {
 				if execErr := Execute([]string{
 					"--json",
 					"--account", "a@b.com",
-					"gmail", "thread", "t-thread-1",
+					"gmail", "thread", "get", "t-thread-1",
 					"--download",
 					"--out-dir", outDir,
 				}); execErr != nil {

internal/cmd/gmail_thread.go

@@ -16,11 +16,21 @@ import (
 )
 
 func newGmailThreadCmd(flags *rootFlags) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "thread",
+		Short: "Thread operations (get, modify)",
+	}
+	cmd.AddCommand(newGmailThreadGetCmd(flags))
+	cmd.AddCommand(newGmailThreadModifyCmd(flags))
+	return cmd
+}
+
+func newGmailThreadGetCmd(flags *rootFlags) *cobra.Command {
 	var download bool
 	var outDir string
 
 	cmd := &cobra.Command{
-		Use:   "thread <threadId>",
+		Use:   "get <threadId>",
 		Short: "Get a thread with all messages (optionally download attachments)",
 		Args:  cobra.ExactArgs(1),
 		RunE: func(cmd *cobra.Command, args []string) error {
@@ -147,6 +157,77 @@ func newGmailThreadCmd(flags *rootFlags) *cobra.Command {
 	return cmd
 }
 
+func newGmailThreadModifyCmd(flags *rootFlags) *cobra.Command {
+	var add string
+	var remove string
+
+	cmd := &cobra.Command{
+		Use:   "modify <threadId>",
+		Short: "Modify labels on all messages in a thread",
+		Long: `Modify labels on all messages within a thread. This applies the label changes
+to every message in the conversation, which is useful for archiving or categorizing
+entire email threads at once.
+
+Examples:
+  gog gmail thread modify abc123 --add "Work,Important"
+  gog gmail thread modify abc123 --remove INBOX --add "Archive"
+  gog gmail thread modify abc123 --add STARRED`,
+		Args: cobra.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			u := ui.FromContext(cmd.Context())
+			account, err := requireAccount(flags)
+			if err != nil {
+				return err
+			}
+			threadID := args[0]
+
+			addLabels := splitCSV(add)
+			removeLabels := splitCSV(remove)
+			if len(addLabels) == 0 && len(removeLabels) == 0 {
+				return usage("must specify --add and/or --remove")
+			}
+
+			svc, err := newGmailService(cmd.Context(), account)
+			if err != nil {
+				return err
+			}
+
+			// Resolve label names to IDs
+			idMap, err := fetchLabelNameToID(svc)
+			if err != nil {
+				return err
+			}
+
+			addIDs := resolveLabelIDs(addLabels, idMap)
+			removeIDs := resolveLabelIDs(removeLabels, idMap)
+
+			// Use Gmail's Threads.Modify API
+			_, err = svc.Users.Threads.Modify("me", threadID, &gmail.ModifyThreadRequest{
+				AddLabelIds:    addIDs,
+				RemoveLabelIds: removeIDs,
+			}).Context(cmd.Context()).Do()
+			if err != nil {
+				return err
+			}
+
+			if outfmt.IsJSON(cmd.Context()) {
+				return outfmt.WriteJSON(os.Stdout, map[string]any{
+					"modified":      threadID,
+					"addedLabels":   addIDs,
+					"removedLabels": removeIDs,
+				})
+			}
+
+			u.Out().Printf("Modified thread %s", threadID)
+			return nil
+		},
+	}
+
+	cmd.Flags().StringVar(&add, "add", "", "Labels to add (comma-separated, name or ID)")
+	cmd.Flags().StringVar(&remove, "remove", "", "Labels to remove (comma-separated, name or ID)")
+	return cmd
+}
+
 func newGmailURLCmd(flags *rootFlags) *cobra.Command {
 	return &cobra.Command{
 		Use:   "url <threadIds...>",

internal/cmd/gmail_thread_cmd_test.go

@@ -0,0 +1,104 @@
+package cmd
+
+import (
+	"context"
+	"encoding/json"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/steipete/gogcli/internal/outfmt"
+	"github.com/steipete/gogcli/internal/ui"
+	"google.golang.org/api/gmail/v1"
+	"google.golang.org/api/option"
+)
+
+func TestGmailThreadModifyCmd_JSON(t *testing.T) {
+	origNew := newGmailService
+	t.Cleanup(func() { newGmailService = origNew })
+
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch {
+		case r.Method == http.MethodGet && (strings.HasSuffix(r.URL.Path, "/users/me/labels") || strings.HasSuffix(r.URL.Path, "/gmail/v1/users/me/labels")):
+			w.Header().Set("Content-Type", "application/json")
+			_ = json.NewEncoder(w).Encode(map[string]any{
+				"labels": []map[string]any{
+					{"id": "INBOX", "name": "INBOX", "type": "system"},
+					{"id": "Label_1", "name": "Custom", "type": "user"},
+				},
+			})
+			return
+		case r.Method == http.MethodPost && (strings.Contains(r.URL.Path, "/users/me/threads/") || strings.Contains(r.URL.Path, "/gmail/v1/users/me/threads/")) && strings.HasSuffix(r.URL.Path, "/modify"):
+			var body struct {
+				AddLabelIds    []string `json:"addLabelIds"`
+				RemoveLabelIds []string `json:"removeLabelIds"`
+			}
+			_ = json.NewDecoder(r.Body).Decode(&body)
+			if len(body.AddLabelIds) != 1 || body.AddLabelIds[0] != "INBOX" {
+				http.Error(w, "bad addLabelIds", http.StatusBadRequest)
+				return
+			}
+			if len(body.RemoveLabelIds) != 1 || body.RemoveLabelIds[0] != "Label_1" {
+				http.Error(w, "bad removeLabelIds", http.StatusBadRequest)
+				return
+			}
+			w.Header().Set("Content-Type", "application/json")
+			_ = json.NewEncoder(w).Encode(map[string]any{})
+			return
+		default:
+			http.NotFound(w, r)
+			return
+		}
+	}))
+	defer srv.Close()
+
+	svc, err := gmail.NewService(context.Background(),
+		option.WithoutAuthentication(),
+		option.WithHTTPClient(srv.Client()),
+		option.WithEndpoint(srv.URL+"/"),
+	)
+	if err != nil {
+		t.Fatalf("NewService: %v", err)
+	}
+	newGmailService = func(context.Context, string) (*gmail.Service, error) { return svc, nil }
+
+	flags := &rootFlags{Account: "a@b.com"}
+
+	out := captureStdout(t, func() {
+		u, uiErr := ui.New(ui.Options{Stdout: io.Discard, Stderr: io.Discard, Color: "never"})
+		if uiErr != nil {
+			t.Fatalf("ui.New: %v", uiErr)
+		}
+		ctx := ui.WithUI(context.Background(), u)
+		ctx = outfmt.WithMode(ctx, outfmt.Mode{JSON: true})
+
+		cmd := newGmailThreadModifyCmd(flags)
+		cmd.SetContext(ctx)
+		cmd.SetArgs([]string{"t1"})
+		cmd.Flags().Set("add", "INBOX")
+		cmd.Flags().Set("remove", "Custom")
+		if err := cmd.Execute(); err != nil {
+			t.Fatalf("execute: %v", err)
+		}
+	})
+
+	var parsed struct {
+		Modified      string   `json:"modified"`
+		AddedLabels   []string `json:"addedLabels"`
+		RemovedLabels []string `json:"removedLabels"`
+	}
+	if err := json.Unmarshal([]byte(out), &parsed); err != nil {
+		t.Fatalf("json parse: %v\nout=%q", err, out)
+	}
+	if parsed.Modified != "t1" {
+		t.Fatalf("unexpected modified: %q", parsed.Modified)
+	}
+	if len(parsed.AddedLabels) != 1 || parsed.AddedLabels[0] != "INBOX" {
+		t.Fatalf("unexpected added labels: %#v", parsed.AddedLabels)
+	}
+	if len(parsed.RemovedLabels) != 1 || parsed.RemovedLabels[0] != "Label_1" {
+		t.Fatalf("unexpected removed labels: %#v", parsed.RemovedLabels)
+	}
+}

internal/cmd/root.go

@@ -56,7 +56,7 @@ func Execute(args []string) error {
 
 	  # Gmail
 	  gog gmail search 'newer_than:7d' --max 10
-	  gog gmail thread <threadId>
+	  gog gmail thread get <threadId>
 	  gog gmail get <messageId> --format metadata
 	  gog gmail attachment <messageId> <attachmentId> --out ./attachment.bin
 	  gog gmail labels get INBOX --json