feat(tui): add fullscreen copy-on-select setting

config.example.json

@@ -102,6 +102,7 @@
     "locale": "auto",
     "theme": "auto",
     "tuiMode": "regular",
+    "copyOnSelect": true,
     "notifications": {
       "method": "auto",
       "condition": "unfocused"

docs/CONFIGURATION.md

@@ -361,6 +361,24 @@ Fullscreen mode is restored on normal exit and on handled `SIGINT`, `SIGTERM`,
 or `SIGHUP` shutdowns. A hard `SIGKILL` cannot be intercepted by any terminal
 application.
 
+### Copy on select
+
+Releasing a mouse selection in fullscreen mode copies the selected text to the
+system clipboard. Set `ui.copyOnSelect` to `false` to keep copying manual:
+drags then only highlight, and the terminal's native selection (hold Shift or
+the modifier your emulator documents while dragging) still works. The setting
+only affects fullscreen mode; regular scrollback mode has no mouse selection.
+The same toggle is available in `/settings` under **Fullscreen copy on
+select**.
+
+```json
+{
+  "ui": {
+    "copyOnSelect": false
+  }
+}
+```
+
 ## Theme
 
 Set `ui.theme` to `"auto"` (terminal detection), `"dark"`, or `"light"` in the

package.json

@@ -68,7 +68,7 @@
     "provenance": true
   },
   "dependencies": {
-    "@earendil-works/pi-tui": "^0.84.3",
+    "@earendil-works/pi-tui": "^0.84.4",
     "playwright-core": "1.59.1"
   },
   "devDependencies": {

packages/zcode-tui/package.json

@@ -7,7 +7,7 @@
     ".": "./dist/index.js"
   },
   "dependencies": {
-    "@earendil-works/pi-tui": "^0.84.3"
+    "@earendil-works/pi-tui": "^0.84.4"
   },
   "license": "MIT",
   "private": true

packages/zcode-tui/src/copy-on-select.ts

@@ -0,0 +1,30 @@
+import { readUserConfig, updateUserConfig } from "../../../src/model-access.ts";
+
+function record(value: unknown): Record<string, unknown> | undefined {
+  return typeof value === "object" && value !== null && !Array.isArray(value)
+    ? value as Record<string, unknown>
+    : undefined;
+}
+
+function configuredCopyOnSelect(config: unknown): boolean | undefined {
+  const value = record(record(config)?.ui)?.copyOnSelect;
+  return typeof value === "boolean" ? value : undefined;
+}
+
+export async function readCopyOnSelect(
+  env: NodeJS.ProcessEnv = process.env
+): Promise<boolean> {
+  const config = await readUserConfig(env);
+  return configuredCopyOnSelect(config) ?? true;
+}
+
+export async function writeCopyOnSelect(
+  enabled: boolean,
+  env: NodeJS.ProcessEnv = process.env
+): Promise<string> {
+  return await updateUserConfig((config) => {
+    const ui = record(config.ui) ?? {};
+    ui.copyOnSelect = enabled;
+    config.ui = ui;
+  }, env);
+}

packages/zcode-tui/src/index.ts

@@ -139,6 +139,10 @@ import {
   resolveTuiMode,
   writeTuiMode
 } from "./tui-mode.ts";
+import {
+  readCopyOnSelect,
+  writeCopyOnSelect
+} from "./copy-on-select.ts";
 import {
   effortPicker,
   explicitModelRequest,
@@ -585,6 +589,7 @@ class ZCodeTui {
   private mode: Mode;
   private model: string;
   private tuiMode: TuiMode;
+  private copyOnSelect = true;
   private thoughtLevel?: string;
   private modelOptions: unknown[];
   private effortOptions: unknown[];
@@ -723,6 +728,13 @@ class ZCodeTui {
     } catch (error) {
       notificationConfigError = error instanceof Error ? error.message : String(error);
     }
+    // The constructor built the TUI before user config was readable; reconcile
+    // copy-on-select here so a tuiMode rebuild below also carries the value.
+    try {
+      this.setCopyOnSelect(await readCopyOnSelect());
+    } catch {
+      // Config unreadable — keep the constructor's default (enabled).
+    }
     // Resolve the effective TUI mode from env > options > config. The vendor
     // runtime does not forward initialTuiMode, so read the persisted config
     // here and rebuild the TUI instance before start() when it differs from
@@ -838,6 +850,16 @@ class ZCodeTui {
     }
   }
 
+  /** The live fullscreen alt screen, when the active TUI is the fullscreen one. */
+  private get fullscreenAltScreen(): ZCodeAltScreen | undefined {
+    return this.ui instanceof ZCodeAltScreen ? this.ui : undefined;
+  }
+
+  private setCopyOnSelect(enabled: boolean): void {
+    this.copyOnSelect = enabled;
+    this.fullscreenAltScreen?.setCopyOnSelect(enabled);
+  }
+
   private createTui(mode: TuiMode): TUI {
     let fullscreenTui: ZCodeAltScreen | undefined;
     const terminal = new NotifyingProcessTerminal((data) => {
@@ -857,6 +879,10 @@ class ZCodeTui {
           return false;
         }
       },
+      // pi-tui copies the selection on mouse release by default; ui.copyOnSelect
+      // opts out so a drag only highlights and copying stays manual (/copy,
+      // native terminal selection).
+      copyOnSelect: this.copyOnSelect,
       mouse: true,
       wheelScrollLines: 3
     });
@@ -1216,7 +1242,7 @@ class ZCodeTui {
     }
     for (const command of [
       { name: "cls", description: "Clear the visible transcript (the runtime's /clear starts a new session)" },
-      { name: "copy", description: "Copy the latest assistant response" },
+      { name: "copy", description: "Copy the active fullscreen selection or latest assistant response" },
       { name: "paste-image", description: "Attach an image from the system clipboard" },
       { name: "attachments", description: "Manage or clear pending attachments", argumentHint: "[clear]" },
       { name: "activity", description: "Inspect every active tool and open task" },
@@ -1429,7 +1455,7 @@ class ZCodeTui {
       return;
     }
     if (input === "/copy") {
-      await this.copyLastResponse();
+      await this.copySelectionOrLastResponse();
       return;
     }
     if (input === "/paste-image") {
@@ -3715,6 +3741,11 @@ class ZCodeTui {
             description: tuiModeOverride === "fullscreen" || tuiModeOverride === "regular"
               ? `Current: ${this.tuiMode === "fullscreen" ? "Fullscreen" : "Regular"} (environment override)`
               : `Current: ${this.tuiMode === "fullscreen" ? "Fullscreen" : "Regular"}`
+          },
+          {
+            value: "copy-on-select",
+            label: "Fullscreen copy on select",
+            description: `Current: ${this.copyOnSelect ? "Enabled" : "Disabled"}`
           }
         ],
         selectedIndex: selectedSettingIndex
@@ -3765,6 +3796,46 @@ class ZCodeTui {
         continue;
       }
 
+      if (setting.value === "copy-on-select") {
+        selectedSettingIndex = 4;
+        const selected = await this.showChoice({
+          title: "Fullscreen copy on select",
+          prompt: "Only applies to fullscreen mode. Releasing a mouse selection copies it to the clipboard.",
+          help: "Up/Down choose · Enter save · Esc back",
+          items: [
+            {
+              value: "enabled",
+              label: "Enabled",
+              description: "Release copies the selection (default)"
+            },
+            {
+              value: "disabled",
+              label: "Disabled",
+              description: "Selection only highlights; copy manually via /copy or the terminal"
+            }
+          ],
+          selectedIndex: this.copyOnSelect ? 0 : 1
+        });
+        if (!selected) {
+          feedback = "No changes · Esc closes settings";
+          continue;
+        }
+        const next = selected.value === "enabled";
+        if (next === this.copyOnSelect) {
+          feedback = "Copy on select unchanged";
+          continue;
+        }
+        try {
+          await writeCopyOnSelect(next);
+          this.setCopyOnSelect(next);
+          feedback = `Copy on select ${next ? "enabled" : "disabled"} · saved`;
+        } catch (error) {
+          this.addNotice(error instanceof Error ? error.message : String(error), "error");
+          feedback = "Could not save the setting · select it to retry";
+        }
+        continue;
+      }
+
       selectedSettingIndex = setting.value === "notification-condition" ? 2 : setting.value === "notification-method" ? 1 : 0;
       let next = stored;
       let changedLabel: string;
@@ -4844,7 +4915,13 @@ class ZCodeTui {
     }
   }
 
-  private async copyLastResponse(): Promise<void> {
+  private async copySelectionOrLastResponse(): Promise<void> {
+    const fullscreen = this.fullscreenAltScreen;
+    if (fullscreen?.hasActiveSelection()) {
+      await fullscreen.copyActiveSelectionToClipboard();
+      return;
+    }
+
     const text = this.transcript.selectedText() ?? this.lastAssistantText;
     if (!text) {
       this.addNotice("There is no assistant response to copy.", "muted");