optimize: implement efficient approach for PR #8225 - store base64 directly in backend messages

- Remove unnecessary memory caching logic
- Store base64 data URLs directly in ClineMessage.images[] and ApiMessage content when first received
- Eliminate conversion overhead at API call time (base64 already available)
- Keep frontend memory efficient with webview URIs for display
- Much simpler and more efficient than caching approach
- One-time conversion: webview URI → base64 when storing in backend
- API calls use pre-stored base64 directly (no file I/O or conversion needed)

This achieves PR goals with optimal performance: frontend memory efficiency + instant API calls

Author: daniel-lxs

src/core/prompts/responses.ts

@@ -3,7 +3,6 @@ import * as path from "path"
 import * as diff from "diff"
 import { RooIgnoreController, LOCK_TEXT_SYMBOL } from "../ignore/RooIgnoreController"
 import { RooProtectedController } from "../protect/RooProtectedController"
-import { normalizeImageRefsToDataUrls } from "../../integrations/misc/imageDataUrl"
 
 export const formatResponse = {
 	toolDenied: () => `The user denied this operation.`,
@@ -201,23 +200,6 @@ const formatImagesIntoBlocks = (images?: string[]): Anthropic.ImageBlockParam[]
 		: []
 }
 
-/**
- * Async version that converts webview URIs to base64 data URLs before creating image blocks
- * This is the missing piece from PR #8225 - allows frontend to use webview URIs while
- * backend stores base64 for API calls.
- */
-export const formatImagesIntoBlocksAsync = async (images?: string[]): Promise<Anthropic.ImageBlockParam[]> => {
-	if (!images || images.length === 0) {
-		return []
-	}
-
-	// Convert any webview URIs to base64 data URLs
-	const dataUrls = await normalizeImageRefsToDataUrls(images)
-
-	// Now use the regular function to create image blocks
-	return formatImagesIntoBlocks(dataUrls)
-}
-
 const toolUseInstructionsReminder = `# Reminder: Instructions for Tool Use
 
 Tool uses are formatted using XML-style tags. The tool name itself becomes the XML tag name. Each parameter is enclosed within its own set of tags. Here's the structure:

src/core/task/Task.ts

@@ -1212,15 +1212,18 @@ export class Task extends EventEmitter<TaskEvents> implements TaskLike {
 
 		await this.providerRef.deref()?.postStateToWebview()
 
-		await this.say("text", task, images)
+		// Convert webview URIs to base64 data URLs for backend storage (one-time conversion)
+		const { normalizeImageRefsToDataUrls } = await import("../../integrations/misc/imageDataUrl")
+		const base64Images = images ? await normalizeImageRefsToDataUrls(images) : undefined
+
+		await this.say("text", task, base64Images) // Store base64 in backend messages
 		this.isInitialized = true
 
-		// Convert webview URIs to base64 for backend storage
-		const { formatImagesIntoBlocksAsync } = await import("../prompts/responses")
-		let imageBlocks: Anthropic.ImageBlockParam[] = await formatImagesIntoBlocksAsync(images)
+		// Convert base64 to image blocks for API (no conversion needed, already base64)
+		const { formatResponse } = await import("../prompts/responses")
+		let imageBlocks: Anthropic.ImageBlockParam[] = formatResponse.imageBlocks(base64Images)
 
 		// Task starting
-
 		await this.initiateTaskLoop([
 			{
 				type: "text",
@@ -1482,9 +1485,13 @@ export class Task extends EventEmitter<TaskEvents> implements TaskLike {
 		}
 
 		if (responseImages && responseImages.length > 0) {
-			// Convert webview URIs to base64 for backend storage
-			const { formatImagesIntoBlocksAsync } = await import("../prompts/responses")
-			const responseImageBlocks = await formatImagesIntoBlocksAsync(responseImages)
+			// Convert webview URIs to base64 data URLs for backend storage (one-time conversion)
+			const { normalizeImageRefsToDataUrls } = await import("../../integrations/misc/imageDataUrl")
+			const base64ResponseImages = await normalizeImageRefsToDataUrls(responseImages)
+
+			// Convert base64 to image blocks for API (no conversion needed, already base64)
+			const { formatResponse } = await import("../prompts/responses")
+			const responseImageBlocks = formatResponse.imageBlocks(base64ResponseImages)
 			newUserContent.push(...responseImageBlocks)
 		}
 

src/integrations/misc/imageDataUrl.ts

@@ -3,6 +3,7 @@ import * as path from "path"
 
 /**
  * Converts webview URIs to base64 data URLs for API calls.
+ * Simple fallback for cases where base64 isn't already stored in messages.
  * This is the missing piece from PR #8225 that allows webview URIs
  * to be used in frontend while converting to base64 for API calls.
  */