Merge PR #492: Add blockImages setting

- Setting controls filtering at convertToLlm layer
- Images are always stored in session, filtered dynamically based on current setting
- Toggle mid-session works: LLM sees/doesn't see images already in session
- Fixed SettingsManager.save() to handle inMemory mode for all setters

Closes #492

packages/coding-agent/CHANGELOG.md

@@ -5,6 +5,7 @@
 ### Added
 
 - Session ID is now forwarded to LLM providers for session-based caching (used by OpenAI Codex for prompt caching).
+- Added `blockImages` setting to prevent images from being sent to LLM providers ([#492](https://github.com/badlogic/pi-mono/pull/492) by [@jsinge97](https://github.com/jsinge97))
 
 ### Fixed
 

packages/coding-agent/src/core/sdk.ts

@@ -20,8 +20,8 @@
  * ```
  */
 
-import { Agent, type AgentTool, type ThinkingLevel } from "@mariozechner/pi-agent-core";
-import type { Model } from "@mariozechner/pi-ai";
+import { Agent, type AgentMessage, type AgentTool, type ThinkingLevel } from "@mariozechner/pi-agent-core";
+import type { Message, Model } from "@mariozechner/pi-ai";
 import { join } from "path";
 import { getAgentDir } from "../config.js";
 import { AgentSession } from "./agent-session.js";
@@ -300,6 +300,7 @@ export function loadSettings(cwd?: string, agentDir?: string): Settings {
 		extensions: manager.getExtensionPaths(),
 		skills: manager.getSkillsSettings(),
 		terminal: { showImages: manager.getShowImages() },
+		images: { autoResize: manager.getImageAutoResize(), blockImages: manager.getBlockImages() },
 	};
 }
 
@@ -605,6 +606,43 @@ export async function createAgentSession(options: CreateAgentSessionOptions = {}
 	const promptTemplates = options.promptTemplates ?? discoverPromptTemplates(cwd, agentDir);
 	time("discoverPromptTemplates");
 
+	// Create convertToLlm wrapper that filters images if blockImages is enabled (defense-in-depth)
+	const convertToLlmWithBlockImages = (messages: AgentMessage[]): Message[] => {
+		const converted = convertToLlm(messages);
+		// Check setting dynamically so mid-session changes take effect
+		if (!settingsManager.getBlockImages()) {
+			return converted;
+		}
+		// Filter out ImageContent from all messages, replacing with text placeholder
+		return converted.map((msg) => {
+			if (msg.role === "user" || msg.role === "toolResult") {
+				const content = msg.content;
+				if (Array.isArray(content)) {
+					const hasImages = content.some((c) => c.type === "image");
+					if (hasImages) {
+						const filteredContent = content
+							.map((c) =>
+								c.type === "image" ? { type: "text" as const, text: "Image reading is disabled." } : c,
+							)
+							.filter(
+								(c, i, arr) =>
+									// Dedupe consecutive "Image reading is disabled." texts
+									!(
+										c.type === "text" &&
+										c.text === "Image reading is disabled." &&
+										i > 0 &&
+										arr[i - 1].type === "text" &&
+										(arr[i - 1] as { type: "text"; text: string }).text === "Image reading is disabled."
+									),
+							);
+						return { ...msg, content: filteredContent };
+					}
+				}
+			}
+			return msg;
+		});
+	};
+
 	agent = new Agent({
 		initialState: {
 			systemPrompt,
@@ -612,7 +650,7 @@ export async function createAgentSession(options: CreateAgentSessionOptions = {}
 			thinkingLevel,
 			tools: activeToolsArray,
 		},
-		convertToLlm,
+		convertToLlm: convertToLlmWithBlockImages,
 		sessionId: sessionManager.getSessionId(),
 		transformContext: extensionRunner
 			? async (messages) => {

packages/coding-agent/src/core/settings-manager.ts

@@ -36,6 +36,7 @@ export interface TerminalSettings {
 
 export interface ImageSettings {
 	autoResize?: boolean; // default: true (resize images to 2000x2000 max for better model compatibility)
+	blockImages?: boolean; // default: false - when true, prevents all images from being sent to LLM providers
 }
 
 export interface Settings {
@@ -170,23 +171,23 @@ export class SettingsManager {
 	}
 
 	private save(): void {
-		if (!this.persist || !this.settingsPath) return;
+		if (this.persist && this.settingsPath) {
+			try {
+				const dir = dirname(this.settingsPath);
+				if (!existsSync(dir)) {
+					mkdirSync(dir, { recursive: true });
+				}
 
-		try {
-			const dir = dirname(this.settingsPath);
-			if (!existsSync(dir)) {
-				mkdirSync(dir, { recursive: true });
+				// Save only global settings (project settings are read-only)
+				writeFileSync(this.settingsPath, JSON.stringify(this.globalSettings, null, 2), "utf-8");
+			} catch (error) {
+				console.error(`Warning: Could not save settings file: ${error}`);
 			}
-
-			// Save only global settings (project settings are read-only)
-			writeFileSync(this.settingsPath, JSON.stringify(this.globalSettings, null, 2), "utf-8");
-
-			// Re-merge project settings into active settings
-			const projectSettings = this.loadProjectSettings();
-			this.settings = deepMergeSettings(this.globalSettings, projectSettings);
-		} catch (error) {
-			console.error(`Warning: Could not save settings file: ${error}`);
 		}
+
+		// Always re-merge to update active settings (needed for both file and inMemory modes)
+		const projectSettings = this.loadProjectSettings();
+		this.settings = deepMergeSettings(this.globalSettings, projectSettings);
 	}
 
 	getLastChangelogVersion(): string | undefined {
@@ -398,6 +399,18 @@ export class SettingsManager {
 		this.save();
 	}
 
+	getBlockImages(): boolean {
+		return this.settings.images?.blockImages ?? false;
+	}
+
+	setBlockImages(blocked: boolean): void {
+		if (!this.globalSettings.images) {
+			this.globalSettings.images = {};
+		}
+		this.globalSettings.images.blockImages = blocked;
+		this.save();
+	}
+
 	getEnabledModels(): string[] | undefined {
 		return this.settings.enabledModels;
 	}

packages/coding-agent/src/modes/interactive/components/settings-selector.ts

@@ -25,6 +25,7 @@ export interface SettingsConfig {
 	autoCompact: boolean;
 	showImages: boolean;
 	autoResizeImages: boolean;
+	blockImages: boolean;
 	steeringMode: "all" | "one-at-a-time";
 	followUpMode: "all" | "one-at-a-time";
 	thinkingLevel: ThinkingLevel;
@@ -40,6 +41,7 @@ export interface SettingsCallbacks {
 	onAutoCompactChange: (enabled: boolean) => void;
 	onShowImagesChange: (enabled: boolean) => void;
 	onAutoResizeImagesChange: (enabled: boolean) => void;
+	onBlockImagesChange: (blocked: boolean) => void;
 	onSteeringModeChange: (mode: "all" | "one-at-a-time") => void;
 	onFollowUpModeChange: (mode: "all" | "one-at-a-time") => void;
 	onThinkingLevelChange: (level: ThinkingLevel) => void;
@@ -243,6 +245,16 @@ export class SettingsSelectorComponent extends Container {
 			values: ["true", "false"],
 		});
 
+		// Block images toggle (always available, insert after auto-resize-images)
+		const autoResizeIndex = items.findIndex((item) => item.id === "auto-resize-images");
+		items.splice(autoResizeIndex + 1, 0, {
+			id: "block-images",
+			label: "Block images",
+			description: "Prevent images from being sent to LLM providers",
+			currentValue: config.blockImages ? "true" : "false",
+			values: ["true", "false"],
+		});
+
 		// Add borders
 		this.addChild(new DynamicBorder());
 
@@ -261,6 +273,9 @@ export class SettingsSelectorComponent extends Container {
 					case "auto-resize-images":
 						callbacks.onAutoResizeImagesChange(newValue === "true");
 						break;
+					case "block-images":
+						callbacks.onBlockImagesChange(newValue === "true");
+						break;
 					case "steering-mode":
 						callbacks.onSteeringModeChange(newValue as "all" | "one-at-a-time");
 						break;

packages/coding-agent/src/modes/interactive/interactive-mode.ts

@@ -1936,6 +1936,7 @@ export class InteractiveMode {
 					autoCompact: this.session.autoCompactionEnabled,
 					showImages: this.settingsManager.getShowImages(),
 					autoResizeImages: this.settingsManager.getImageAutoResize(),
+					blockImages: this.settingsManager.getBlockImages(),
 					steeringMode: this.session.steeringMode,
 					followUpMode: this.session.followUpMode,
 					thinkingLevel: this.session.thinkingLevel,
@@ -1962,6 +1963,9 @@ export class InteractiveMode {
 					onAutoResizeImagesChange: (enabled) => {
 						this.settingsManager.setImageAutoResize(enabled);
 					},
+					onBlockImagesChange: (blocked) => {
+						this.settingsManager.setBlockImages(blocked);
+					},
 					onSteeringModeChange: (mode) => {
 						this.session.setSteeringMode(mode);
 					},

packages/coding-agent/test/block-images.test.ts

@@ -0,0 +1,120 @@
+import { mkdirSync, rmSync, writeFileSync } from "fs";
+import { tmpdir } from "os";
+import { join } from "path";
+import { afterEach, beforeEach, describe, expect, it } from "vitest";
+import { processFileArguments } from "../src/cli/file-processor.js";
+import { SettingsManager } from "../src/core/settings-manager.js";
+import { createReadTool } from "../src/core/tools/read.js";
+
+// 1x1 red PNG image as base64 (smallest valid PNG)
+const TINY_PNG_BASE64 =
+	"iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mP8z8DwHwAFBQIAX8jx0gAAAABJRU5ErkJggg==";
+
+describe("blockImages setting", () => {
+	describe("SettingsManager", () => {
+		it("should default blockImages to false", () => {
+			const manager = SettingsManager.inMemory({});
+			expect(manager.getBlockImages()).toBe(false);
+		});
+
+		it("should return true when blockImages is set to true", () => {
+			const manager = SettingsManager.inMemory({ images: { blockImages: true } });
+			expect(manager.getBlockImages()).toBe(true);
+		});
+
+		it("should persist blockImages setting via setBlockImages", () => {
+			const manager = SettingsManager.inMemory({});
+			expect(manager.getBlockImages()).toBe(false);
+
+			manager.setBlockImages(true);
+			expect(manager.getBlockImages()).toBe(true);
+
+			manager.setBlockImages(false);
+			expect(manager.getBlockImages()).toBe(false);
+		});
+
+		it("should handle blockImages alongside autoResize", () => {
+			const manager = SettingsManager.inMemory({
+				images: { autoResize: true, blockImages: true },
+			});
+			expect(manager.getImageAutoResize()).toBe(true);
+			expect(manager.getBlockImages()).toBe(true);
+		});
+	});
+
+	describe("Read tool", () => {
+		let testDir: string;
+
+		beforeEach(() => {
+			testDir = join(tmpdir(), `block-images-test-${Date.now()}`);
+			mkdirSync(testDir, { recursive: true });
+		});
+
+		afterEach(() => {
+			rmSync(testDir, { recursive: true, force: true });
+		});
+
+		it("should always read images (filtering happens at convertToLlm layer)", async () => {
+			// Create test image
+			const imagePath = join(testDir, "test.png");
+			writeFileSync(imagePath, Buffer.from(TINY_PNG_BASE64, "base64"));
+
+			const tool = createReadTool(testDir);
+			const result = await tool.execute("test-1", { path: imagePath });
+
+			// Should have text note + image content
+			expect(result.content.length).toBeGreaterThanOrEqual(1);
+			const hasImage = result.content.some((c) => c.type === "image");
+			expect(hasImage).toBe(true);
+		});
+
+		it("should read text files normally", async () => {
+			// Create test text file
+			const textPath = join(testDir, "test.txt");
+			writeFileSync(textPath, "Hello, world!");
+
+			const tool = createReadTool(testDir);
+			const result = await tool.execute("test-2", { path: textPath });
+
+			expect(result.content).toHaveLength(1);
+			expect(result.content[0].type).toBe("text");
+			const textContent = result.content[0] as { type: "text"; text: string };
+			expect(textContent.text).toContain("Hello, world!");
+		});
+	});
+
+	describe("processFileArguments", () => {
+		let testDir: string;
+
+		beforeEach(() => {
+			testDir = join(tmpdir(), `block-images-process-test-${Date.now()}`);
+			mkdirSync(testDir, { recursive: true });
+		});
+
+		afterEach(() => {
+			rmSync(testDir, { recursive: true, force: true });
+		});
+
+		it("should always process images (filtering happens at convertToLlm layer)", async () => {
+			// Create test image
+			const imagePath = join(testDir, "test.png");
+			writeFileSync(imagePath, Buffer.from(TINY_PNG_BASE64, "base64"));
+
+			const result = await processFileArguments([imagePath]);
+
+			expect(result.images).toHaveLength(1);
+			expect(result.images[0].type).toBe("image");
+		});
+
+		it("should process text files normally", async () => {
+			// Create test text file
+			const textPath = join(testDir, "test.txt");
+			writeFileSync(textPath, "Hello, world!");
+
+			const result = await processFileArguments([textPath]);
+
+			expect(result.images).toHaveLength(0);
+			expect(result.text).toContain("Hello, world!");
+		});
+	});
+});