diff --git a/cmd/pad/chatgpt_projection_test.go b/cmd/pad/chatgpt_projection_test.go
index d478017a9..e8e5f118a 100644
--- a/cmd/pad/chatgpt_projection_test.go
+++ b/cmd/pad/chatgpt_projection_test.go
@@ -37,12 +37,19 @@ type projectionFixture struct {
 }
 
 func newProjectionFixture(t *testing.T) projectionFixture {
+	t.Helper()
+	return newProjectionFixtureNamed(t, "Olivia Owner")
+}
+
+// newProjectionFixtureNamed is the fixture with the owner's display name set
+// to ownerName (an email-shaped one exercises the name mask).
+func newProjectionFixtureNamed(t *testing.T, ownerName string) projectionFixture {
 	t.Helper()
 	s := storetest.NewSQLite(t)
 	api := padserver.New(s)
 	t.Cleanup(api.Stop)
 
-	owner, err := s.CreateUser(models.UserCreate{Email: "owner@example.com", Name: "Olivia Owner", Password: "correct-horse-battery-staple"})
+	owner, err := s.CreateUser(models.UserCreate{Email: "owner@example.com", Name: ownerName, Password: "correct-horse-battery-staple"})
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -93,11 +100,11 @@ func newProjectionFixture(t *testing.T) projectionFixture {
 	if _, err := s.CreateItemLink(ws.ID, models.ItemLinkCreate{TargetID: t2.ID, LinkType: "blocks"}, t1.ID); err != nil {
 		t.Fatal(err)
 	}
-	c, err := s.CreateComment(ws.ID, t1.ID, owner.ID, models.CommentCreate{Body: "Seen in prod.", Author: "Olivia Owner"})
+	c, err := s.CreateComment(ws.ID, t1.ID, owner.ID, models.CommentCreate{Body: "Seen in prod.", Author: ownerName})
 	if err != nil {
 		t.Fatal(err)
 	}
-	if _, err := s.CreateComment(ws.ID, t1.ID, owner.ID, models.CommentCreate{Body: "Fix incoming.", Author: "Olivia Owner", ParentID: c.ID}); err != nil {
+	if _, err := s.CreateComment(ws.ID, t1.ID, owner.ID, models.CommentCreate{Body: "Fix incoming.", Author: ownerName, ParentID: c.ID}); err != nil {
 		t.Fatal(err)
 	}
 
@@ -171,7 +178,14 @@ func leaks(path string, v any, allowedIDKeys map[string]bool) []string {
 }
 
 func TestChatGPTProjection_NoIdentifiersOrEmailsLeak(t *testing.T) {
-	f := newProjectionFixture(t)
+	// Twice: with an ordinary display name, and with one that IS an email
+	// address (a user can set that), which every person field must mask.
+	for _, name := range []string{"Olivia Owner", "olivia.owner@example.com"} {
+		t.Run(name, func(t *testing.T) { sweepAllTools(t, newProjectionFixtureNamed(t, name)) })
+	}
+}
+
+func sweepAllTools(t *testing.T, f projectionFixture) {
 	ws := f.ws
 	calls := []struct {
 		tool string
@@ -321,3 +335,20 @@ func TestChatGPTProjection_ErrorPathsDoNotLeak(t *testing.T) {
 }
 
 var uuidAnywhere = regexp.MustCompile(`[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}`)
+
+// item_history names who made each change (the display name #1714 added),
+// and masks a name that is an email address.
+func TestChatGPTProjection_HistoryNamesTheEditor(t *testing.T) {
+	for name, want := range map[string]string{"Olivia Owner": "Olivia Owner", "olivia.owner@example.com": "a Pad user"} {
+		f := newProjectionFixtureNamed(t, name)
+		f.call(t, "update_item", map[string]any{"workspace": f.ws, "ref": f.task1, "content": "Edited through ChatGPT."})
+		_, v := f.call(t, "item_history", map[string]any{"workspace": f.ws, "ref": f.task1})
+		rows, _ := v.(map[string]any)["items"].([]any)
+		if len(rows) == 0 {
+			t.Fatalf("%s: no history rows", name)
+		}
+		if got := rows[0].(map[string]any)["actor_name"]; got != want {
+			t.Errorf("owner %q: newest row actor_name = %v, want %q", name, got, want)
+		}
+	}
+}
diff --git a/cmd/pad/testdata/mcp_wire/chatgpt_tools_list.json b/cmd/pad/testdata/mcp_wire/chatgpt_tools_list.json
index 5a0460889..750353269 100644
--- a/cmd/pad/testdata/mcp_wire/chatgpt_tools_list.json
+++ b/cmd/pad/testdata/mcp_wire/chatgpt_tools_list.json
@@ -237,7 +237,7 @@
         "idempotentHint": true,
         "openWorldHint": false
       },
-      "description": "List an item's saved versions, newest first: when each was saved, and whether a person, an agent or ChatGPT made it.",
+      "description": "List an item's saved versions, newest first: when each was saved and who made it, with whether that was a person, an agent or ChatGPT.",
       "inputSchema": {
         "properties": {
           "limit": {
diff --git a/internal/mcp/chatgpt_catalog.go b/internal/mcp/chatgpt_catalog.go
index fea2bb2e5..fe85649b5 100644
--- a/internal/mcp/chatgpt_catalog.go
+++ b/internal/mcp/chatgpt_catalog.go
@@ -225,7 +225,7 @@ var ChatGPTCatalog = []ChatGPTTool{
 	},
 	{
 		Name:        "item_history",
-		Description: "List an item's saved versions, newest first: when each was saved, and whether a person, an agent or ChatGPT made it.",
+		Description: "List an item's saved versions, newest first: when each was saved and who made it, with whether that was a person, an agent or ChatGPT.",
 		Source:      ChatGPTSource{"pad_item", "history"},
 		Params:      []string{chatGPTWorkspaceParam, "ref", "limit"},
 		Required:    []string{chatGPTWorkspaceParam, "ref"},
diff --git a/internal/mcp/chatgpt_project.go b/internal/mcp/chatgpt_project.go
index e956357d2..79c45242f 100644
--- a/internal/mcp/chatgpt_project.go
+++ b/internal/mcp/chatgpt_project.go
@@ -189,7 +189,7 @@ var chatGPTResponseShapes = map[string]shape{
 	"restore_item":      itemShape,
 	"add_comment":       commentShape,
 	"list_comments":     shapeList(commentShape),
-	"item_history":      shapeList(shapeKeys("created_at", "created_by", "source", "change_summary")),
+	"item_history":      shapeList(shapeKeys("created_at", "created_by", "source", "change_summary", "actor_name")),
 	"item_dependencies": shapeList(linkShape),
 	"link_items":        linkShape,
 	"project_dashboard": dashboardShape,
@@ -239,6 +239,7 @@ func projectChatGPTResult(t ChatGPTTool, in map[string]any, res *CallToolResult)
 	}
 	projected := s.apply(value)
 	rewriteRelationValues(projected, value)
+	maskEmailShapedNames(projected, "")
 	b, err := json.Marshal(projected)
 	if err != nil {
 		return NewErrorResult(ErrorPayload{Code: ErrServerError, Message: "could not encode the response"})
@@ -457,3 +458,51 @@ func projectChatGPTError(res *CallToolResult) *CallToolResult {
 	out.IsError = true
 	return out
 }
+
+// personNameKeys are the keys whose values are a person's display name.
+// "name" counts only inside a "user" object; elsewhere it names a
+// workspace, collection or role.
+var personNameKeys = map[string]bool{
+	"author": true, "agent_name": true, "actor_name": true, "assigned_user": true,
+	"assigned_user_name": true, "owner_username": true, "assigned_users": true,
+}
+
+// emailLike matches a value containing an email address.
+var emailLike = regexp.MustCompile(`[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,}`)
+
+// maskedPersonName replaces a display name that is (or contains) an email
+// address. A user can set their display name to their email, and a name is
+// shown wherever a person is; OpenAI's review forbids emails in responses.
+// It is not replaced by the local part, which would be a new identifier
+// (lead's ruling on TASK-3321).
+const maskedPersonName = "a Pad user"
+
+// maskEmailShapedNames replaces email-shaped person names in place.
+func maskEmailShapedNames(v any, parent string) {
+	switch t := v.(type) {
+	case map[string]any:
+		for k, e := range t {
+			isName := personNameKeys[k] || (k == "name" && parent == "user")
+			if isName {
+				switch x := e.(type) {
+				case string:
+					if emailLike.MatchString(x) {
+						t[k] = maskedPersonName
+					}
+				case []any:
+					for i, el := range x {
+						if s, ok := el.(string); ok && emailLike.MatchString(s) {
+							x[i] = maskedPersonName
+						}
+					}
+				}
+				continue
+			}
+			maskEmailShapedNames(e, k)
+		}
+	case []any:
+		for _, e := range t {
+			maskEmailShapedNames(e, parent)
+		}
+	}
+}
diff --git a/internal/mcp/chatgpt_project_test.go b/internal/mcp/chatgpt_project_test.go
index 36b5534a0..a96b3c9e4 100644
--- a/internal/mcp/chatgpt_project_test.go
+++ b/internal/mcp/chatgpt_project_test.go
@@ -112,3 +112,25 @@ func TestChatGPTProjection_TextFallbackIsProjected(t *testing.T) {
 		t.Errorf("text fallback not projected: %s", text)
 	}
 }
+
+// A display name that is an email address reaches ChatGPT as "a Pad user"
+// in every person field, and nowhere else is a name touched (TASK-3321).
+func TestChatGPTProjection_EmailShapedNamesAreMasked(t *testing.T) {
+	v := map[string]any{
+		"user":       map[string]any{"name": "jane@example.com"},
+		"workspace":  map[string]any{"name": "Acme Launch"},
+		"author":     "jane@example.com",
+		"actor_name": "Jane Doe",
+		"by_role":    []any{map[string]any{"role_name": "Dev", "assigned_users": []any{"jane@example.com", "Sam"}}},
+	}
+	maskEmailShapedNames(v, "")
+	b, _ := json.Marshal(v)
+	if strings.Contains(string(b), "@") {
+		t.Errorf("an email-shaped name survived: %s", b)
+	}
+	for _, keep := range []string{"Acme Launch", "Jane Doe", `"Sam"`} {
+		if !strings.Contains(string(b), keep) {
+			t.Errorf("an ordinary name %s was masked: %s", keep, b)
+		}
+	}
+}