Pepps233 · Aug 16, 2026 · Aug 16, 2026 · Aug 16, 2026 · Aug 16, 2026 · Aug 17, 2026
diff --git a/packages/coding-agent/README.md b/packages/coding-agent/README.md
@@ -147,14 +147,15 @@ The interface from top to bottom:
 
 - **Startup header** - Shows shortcuts (`/hotkeys` for all), loaded AGENTS.md files, prompt templates, skills, and extensions
 - **Messages** - Your messages, assistant responses, tool calls and results, notifications, errors, and extension UI
-- **Editor** - Where you type; border color indicates thinking level
+- **Editor** - Where you type; border color indicates plan mode or shell mode
 - **Footer** - The built-in footer keeps the current model, thinking level, and context usage visible.
 
 The editor can be temporarily replaced by other UI, like built-in `/settings` or custom UI from extensions (e.g., a Q&A tool that lets the user answer model questions in a structured format). [Extensions](#extensions) can also replace the editor, add widgets above/below it, a status line, custom footer, or overlays.
 
 ### Plan Mode
 
-Run `diffex --plan` to start an interactive session in plan mode, or use `/plan [on|off]` while Diffex is idle.
+Run `diffex --plan` to start an interactive session in plan mode, submit `/plan [instructions]`, or press Shift+Tab and type instructions in the editor.
+Shift+Tab toggles plan mode while the editor border and prompt pointer turn green to show that planning is active.
 Plan mode exposes `submit_plan` and the canonical subset of `read`, `grep`, `find`, and `ls` permitted by caller restrictions.
 The agent can inspect the repository, but it cannot run commands, edit files, or call extension and SDK tools.
 `submit_plan` is intrinsic to plan mode and remains available even when caller tool filters disable every inspection tool.
@@ -186,10 +187,10 @@ Type `/` in the editor to trigger commands. [Extensions](#extensions) can regist
 |---------|-------------|
 | `/login`, `/logout` | Manage provider credentials |
 | [`/llama`](docs/llama-cpp.md) | Download, load, and unload llama.cpp router models |
-| `/model` | Switch models |
+| `/model` | Switch models, then select thinking effort |
 | `/scoped-models` | Enable/disable models for Ctrl+P cycling |
-| `/plan [on\|off]` | Toggle plan mode, set it explicitly, or reopen a pending plan |
-| `/settings` | Thinking level, theme, message delivery, transport |
+| `/plan [instructions]` | Activate plan mode and optionally submit planning instructions, or reopen/retry a pending plan |
+| `/settings` | Theme, message delivery, transport |
 | `/resume` | Pick from previous sessions |
 | `/new` | Start a new session |
 | `/name <name>` | Set session display name |
@@ -226,7 +227,7 @@ See `/hotkeys` for the full list. Customize via `~/.diffex/agent/keybindings.jso
 | Escape twice | Open `/tree` |
 | Ctrl+L | Open model selector |
 | Ctrl+P / Shift+Ctrl+P | Cycle scoped models forward/backward |
-| Shift+Tab | Cycle thinking level |
+| Shift+Tab | Toggle plan mode |
 | Ctrl+O | Collapse/expand tool output |
 | Ctrl+T | Collapse/expand thinking blocks |
 | Ctrl+X | Copy the last assistant message |

diff --git a/packages/coding-agent/docs/extensions.md b/packages/coding-agent/docs/extensions.md
@@ -340,7 +340,7 @@ user sends another prompt ◄─────────────────
   ├─► thinking_level_select (if model change changes/clamps thinking level)
   └─► model_select
 
-thinking level changes (settings, keybinding, diffex.setThinkingLevel())
+thinking level changes (/model effort selection, diffex.setThinkingLevel())
   └─► thinking_level_select
 
 exit (Ctrl+C, Ctrl+D, SIGHUP, SIGTERM)
@@ -744,7 +744,7 @@ diffex.on("thinking_level_select", async (event, ctx) => {
 });
 ```
 
-Use this to update extension UI when `diffex.setThinkingLevel()`, model changes, or built-in thinking-level controls change the active thinking level.
+Use this to update extension UI when `diffex.setThinkingLevel()`, model changes, or `/model` effort selection changes the active thinking level.
 
 ### Tool Events
 

diff --git a/packages/coding-agent/docs/keybindings.md b/packages/coding-agent/docs/keybindings.md
@@ -136,14 +136,14 @@ This routing remains configurable through the ordinary action bindings. For exam
 | `app.session.delete` | `ctrl+d` | Delete session |
 | `app.session.deleteNoninvasive` | `ctrl+backspace` | Delete session when query is empty |
 
-### Models and Thinking
+### Models, Planning, and Thinking
 
 | Keybinding id | Default | Description |
 |--------|---------|-------------|
-| `app.model.select` | `ctrl+l` | Open model selector |
+| `app.model.select` | `ctrl+l` | Open model selector, followed by thinking effort selection |
 | `app.model.cycleForward` | `ctrl+p` | Cycle to next model |
 | `app.model.cycleBackward` | `shift+ctrl+p` | Cycle to previous model |
-| `app.thinking.cycle` | `shift+tab` | Cycle thinking level |
+| `app.plan.toggle` | `shift+tab` | Toggle plan mode |
 | `app.thinking.toggle` | `ctrl+t` | Collapse or expand thinking blocks |
 
 ### Display and Message Queue

diff --git a/packages/coding-agent/docs/quickstart.md b/packages/coding-agent/docs/quickstart.md
@@ -130,7 +130,7 @@ The command output is sent to the model. Use `!!command` to run a command withou
 
 ### Switch models
 
-Use `/model` or Ctrl+L to choose a model. Use Shift+Tab to cycle thinking level. Use Ctrl+P / Shift+Ctrl+P to cycle through scoped models.
+Use `/model` or Ctrl+L to choose a model, then select its thinking effort. Use Ctrl+P / Shift+Ctrl+P to cycle through scoped models. Shift+Tab toggles plan mode.
 
 ### Continue later
 

diff --git a/packages/coding-agent/docs/settings.md b/packages/coding-agent/docs/settings.md
@@ -25,6 +25,8 @@ Use `/trust` in interactive mode to save a project trust decision for future ses
 
 ### Model & Thinking
 
+In interactive mode, `/model` selects both the model and its thinking effort.
+
 | Setting | Type | Default | Description |
 |---------|------|---------|-------------|
 | `defaultProvider` | string | - | Default provider (e.g., `"anthropic"`, `"openai"`) |

diff --git a/packages/coding-agent/docs/themes.md b/packages/coding-agent/docs/themes.md
@@ -56,7 +56,8 @@ vim ~/.diffex/agent/themes/my-theme.json
   "name": "my-theme",
   "vars": {
     "primary": "#00aaff",
-    "secondary": 242
+    "secondary": 242,
+    "green": "#00ff00"
   },
   "colors": {
     "accent": "primary",
@@ -114,7 +115,8 @@ vim ~/.diffex/agent/themes/my-theme.json
     "thinkingHigh": "#ff00ff",
     "thinkingXhigh": "#ff0000",
     "thinkingMax": "#ff0088",
-    "bashMode": "#ffaa00"
+    "bashMode": "#ffaa00",
+    "planMode": "green"
   }
 }
 ```
@@ -145,15 +147,15 @@ vim ~/.diffex/agent/themes/my-theme.json
 - `name` is required, must be unique, and must not contain `/`.
 - `vars` is optional. Define reusable colors here, then reference them in `colors`.
 - `colors` must define all 51 required tokens.
-  `thinkingMax`, `scrollbarThumb`, `startupIntroText`, `startupIntroAccent`, `selectionAccent`, and `autocompleteSelected` are optional compatibility tokens with fallbacks.
+  `planMode`, `thinkingMax`, `scrollbarThumb`, `startupIntroText`, `startupIntroAccent`, `selectionAccent`, and `autocompleteSelected` are optional compatibility tokens with fallbacks.
 
 The `$schema` field enables editor auto-completion and validation.
 
 ## Color Tokens
 
 Every theme must define all 51 required color tokens.
-`thinkingMax`, `scrollbarThumb`, `startupIntroText`, `startupIntroAccent`, `selectionAccent`, and `autocompleteSelected` are optional for compatibility with existing themes.
-When omitted, they use `thinkingXhigh`, `selectedBg`, `text`, `mdLink`, `autocompleteSelected` or `startupIntroAccent`, and `selectionAccent`, respectively.
+`planMode`, `thinkingMax`, `scrollbarThumb`, `startupIntroText`, `startupIntroAccent`, `selectionAccent`, and `autocompleteSelected` are optional for compatibility with existing themes.
+When omitted, `planMode` uses `toolDiffAdded`; the remaining tokens use `thinkingXhigh`, `selectedBg`, `text`, `mdLink`, `autocompleteSelected` or `startupIntroAccent`, and `selectionAccent`, respectively.
 
 ### Core UI (11 colors)
 
@@ -234,9 +236,9 @@ When omitted, they use `thinkingXhigh`, `selectedBg`, `text`, `mdLink`, `autocom
 | `syntaxOperator` | Operators |
 | `syntaxPunctuation` | Punctuation |
 
-### Thinking Level Borders (6 required, 1 optional)
+### Thinking Level Colors (6 required, 1 optional)
 
-Editor border colors indicating thinking level (visual hierarchy from subtle to prominent):
+Legacy thinking-level colors exposed through the theme API for extensions. The built-in editor no longer changes its border by thinking effort:
 
 | Token | Purpose |
 |-------|---------|
@@ -248,11 +250,12 @@ Editor border colors indicating thinking level (visual hierarchy from subtle to
 | `thinkingXhigh` | Extra high thinking |
 | `thinkingMax` | Maximum thinking; optional, falls back to `thinkingXhigh` |
 
-### Bash Mode (1 color)
+### Mode Borders (1 required, 1 optional)
 
 | Token | Purpose |
 |-------|---------|
 | `bashMode` | Editor border in bash mode (`!` prefix) |
+| `planMode` | Editor border and prompt pointer in plan mode; optional, falls back to `toolDiffAdded` |
 
 ### HTML Export (optional)
 

diff --git a/packages/coding-agent/docs/tui.md b/packages/coding-agent/docs/tui.md
@@ -440,7 +440,7 @@ renderResult(result, options, theme, context) {
 | Markdown | `mdHeading`, `mdLink`, `mdLinkUrl`, `mdCode`, `mdCodeBlock`, `mdCodeBlockBorder`, `mdQuote`, `mdQuoteBorder`, `mdHr`, `mdListBullet` |
 | Syntax | `syntaxComment`, `syntaxKeyword`, `syntaxFunction`, `syntaxVariable`, `syntaxString`, `syntaxNumber`, `syntaxType`, `syntaxOperator`, `syntaxPunctuation` |
 | Thinking | `thinkingOff`, `thinkingMinimal`, `thinkingLow`, `thinkingMedium`, `thinkingHigh`, `thinkingXhigh`, `thinkingMax` |
-| Modes | `bashMode` |
+| Modes | `bashMode`, `planMode` |
 
 **Background colors** (`theme.bg(color, text)`):
 

diff --git a/packages/coding-agent/docs/usage.md b/packages/coding-agent/docs/usage.md
@@ -10,7 +10,7 @@ The interface has four main areas:
 
 - **Startup header** - shortcuts, loaded context files, prompt templates, skills, and extensions
 - **Messages** - user messages, assistant responses, tool calls, tool results, notifications, errors, and extension UI
-- **Editor** - where you type; border color indicates the current thinking level
+- **Editor** - where you type; border color indicates plan mode or shell mode
 - **Footer** - the built-in footer keeps the current model, thinking level, and context usage visible.
 
 The editor can be replaced temporarily by built-in UI such as `/settings` or by custom extension UI.
@@ -38,10 +38,10 @@ Type `/` in the editor to open command completion. Extensions can register custo
 |---------|-------------|
 | `/login`, `/logout` | Manage OAuth or API-key credentials |
 | [`/llama`](llama-cpp.md) | Download, load, and unload llama.cpp router models |
-| `/model` | Switch models |
+| `/model` | Switch models, then select thinking effort |
 | `/scoped-models` | Enable/disable models for Ctrl+P cycling |
-| `/plan [on\|off]` | Toggle plan mode, set it explicitly, or reopen a pending plan |
-| `/settings` | Thinking level, theme, message delivery, transport |
+| `/plan [instructions]` | Activate plan mode and optionally submit planning instructions, or reopen/retry a pending plan |
+| `/settings` | Theme, message delivery, transport |
 | `/resume` | Pick from previous sessions |
 | `/new` | Start a new session |
 | `/name <name>` | Set session display name |
@@ -88,8 +88,9 @@ JSON and RPC modes emit the same notices as structured session events.
 
 ## Plan Mode
 
-Start an interactive planning session with `diffex --plan`, toggle it with `/plan`, or set it explicitly with `/plan on` or `/plan off`.
-Plan mode can be changed only while the session is idle.
+Start an interactive planning session with `diffex --plan`, submit `/plan [instructions]`, or press Shift+Tab and type instructions in the editor.
+A bare `/plan` activates planning without submitting a prompt. Shift+Tab toggles plan mode while the session is idle.
+The editor border and prompt pointer change to the theme's plan-mode green while plan mode is active.
 
 Plan mode exposes `submit_plan` and canonical `read`, `grep`, `find`, and `ls` repository inspection tools when caller restrictions permit them.
 Extension tools, SDK custom tools, shell execution, and file mutation tools are unavailable until the plan is accepted or discarded.

diff --git a/packages/coding-agent/src/core/extensions/runner.ts b/packages/coding-agent/src/core/extensions/runner.ts
@@ -73,7 +73,7 @@ const RESERVED_KEYBINDINGS_FOR_EXTENSION_CONFLICTS = [
 	"app.clear",
 	"app.exit",
 	"app.suspend",
-	"app.thinking.cycle",
+	"app.plan.toggle",
 	"app.model.cycleForward",
 	"app.model.cycleBackward",
 	"app.model.select",

diff --git a/packages/coding-agent/src/core/keybindings.ts b/packages/coding-agent/src/core/keybindings.ts
@@ -15,7 +15,7 @@ export interface AppKeybindings {
 	"app.clear": true;
 	"app.exit": true;
 	"app.suspend": true;
-	"app.thinking.cycle": true;
+	"app.plan.toggle": true;
 	"app.model.cycleForward": true;
 	"app.model.cycleBackward": true;
 	"app.model.select": true;
@@ -70,9 +70,9 @@ export const KEYBINDINGS = {
 		defaultKeys: process.platform === "win32" ? [] : "ctrl+z",
 		description: "Suspend to background",
 	},
-	"app.thinking.cycle": {
+	"app.plan.toggle": {
 		defaultKeys: "shift+tab",
-		description: "Cycle thinking level",
+		description: "Toggle plan mode",
 	},
 	"app.model.cycleForward": {
 		defaultKeys: "ctrl+p",
@@ -242,7 +242,6 @@ const KEYBINDING_NAME_MIGRATIONS = {
 	clear: "app.clear",
 	exit: "app.exit",
 	suspend: "app.suspend",
-	cycleThinkingLevel: "app.thinking.cycle",
 	cycleModelForward: "app.model.cycleForward",
 	cycleModelBackward: "app.model.cycleBackward",
 	selectModel: "app.model.select",

diff --git a/packages/coding-agent/src/core/slash-commands.ts b/packages/coding-agent/src/core/slash-commands.ts
@@ -19,7 +19,7 @@ export interface BuiltinSlashCommand {
 export const BUILTIN_SLASH_COMMANDS: ReadonlyArray<BuiltinSlashCommand> = [
 	{ name: "settings", description: "Open settings menu" },
 	{ name: "model", description: "Select model (opens selector UI)", argumentHint: "<provider/model>" },
-	{ name: "plan", description: "Toggle plan mode", argumentHint: "[on|off]" },
+	{ name: "plan", description: "Start a planning prompt", argumentHint: "[instructions]" },
 	{ name: "scoped-models", description: "Enable/disable models for Ctrl+P cycling" },
 	{ name: "export", description: "Export session (HTML default, or specify path: .html/.jsonl)" },
 	{ name: "import", description: "Import and resume a session from a JSONL file" },

diff --git a/packages/coding-agent/src/modes/interactive/components/settings-selector.ts b/packages/coding-agent/src/modes/interactive/components/settings-selector.ts
@@ -1,4 +1,3 @@
-import type { ThinkingLevel } from "@earendil-works/diffex-agent-core";
 import type { Transport } from "@earendil-works/diffex-ai";
 import {
 	type Component,
@@ -35,16 +34,6 @@ const SETTINGS_SUBMENU_SELECT_LIST_LAYOUT: SelectListLayoutOptions = {
 	maxPrimaryColumnWidth: 32,
 };
 
-const THINKING_DESCRIPTIONS: Record<ThinkingLevel, string> = {
-	off: "No reasoning",
-	minimal: "Very brief reasoning (~1k tokens)",
-	low: "Light reasoning (~2k tokens)",
-	medium: "Moderate reasoning (~8k tokens)",
-	high: "Deep reasoning (~16k tokens)",
-	xhigh: "Extra-high reasoning (~32k tokens)",
-	max: "Maximum reasoning",
-};
-
 const DEFAULT_PROJECT_TRUST_LABELS: Record<DefaultProjectTrust, string> = {
 	ask: "Ask",
 	always: "Always trust",
@@ -66,8 +55,6 @@ export interface SettingsConfig {
 	followUpMode: "all" | "one-at-a-time";
 	transport: Transport;
 	httpIdleTimeoutMs: number;
-	thinkingLevel: ThinkingLevel;
-	availableThinkingLevels: ThinkingLevel[];
 	currentTheme: string;
 	terminalTheme: TerminalTheme;
 	availableThemes: string[];
@@ -102,7 +89,6 @@ export interface SettingsCallbacks {
 	onFollowUpModeChange: (mode: "all" | "one-at-a-time") => void;
 	onTransportChange: (transport: Transport) => void;
 	onHttpIdleTimeoutMsChange: (timeoutMs: number) => void;
-	onThinkingLevelChange: (level: ThinkingLevel) => void;
 	onThemeChange: (theme: string) => void;
 	onThemePreview?: (theme: string) => void;
 	onHideThinkingBlockChange: (hidden: boolean) => void;
@@ -607,28 +593,6 @@ export class SettingsSelectorComponent extends Container {
 						() => done(),
 					),
 			},
-			{
-				id: "thinking",
-				label: "Thinking level",
-				description: "Reasoning depth for thinking-capable models",
-				currentValue: config.thinkingLevel,
-				submenu: (currentValue, done) =>
-					new SelectSubmenu(
-						"Thinking Level",
-						"Select reasoning depth for thinking-capable models",
-						config.availableThinkingLevels.map((level) => ({
-							value: level,
-							label: level,
-							description: THINKING_DESCRIPTIONS[level],
-						})),
-						currentValue,
-						(value) => {
-							callbacks.onThinkingLevelChange(value as ThinkingLevel);
-							done(value);
-						},
-						() => done(),
-					),
-			},
 			{
 				id: "tui-mode",
 				label: "TUI mode",