fix: prevent browser tool image accumulation to avoid AWS Bedrock 20-image limit

- Add addBrowserActionToApiHistory method to Task class that removes previous browser screenshots before adding new ones
- Modify browserActionTool to use new method instead of direct addToApiConversationHistory
- Add resetBrowserScreenshotTracking method to clear tracking when browser is closed
- Fixes issue #6348 where continuous browser tool usage would accumulate screenshots and hit AWS Bedrock's 20-image limit

This implements @daniel-lxs's recommendation to only send the most recent screenshot instead of accumulating all screenshots in conversation history.

Author: roomote

src/core/task/Task.ts

@@ -214,6 +214,7 @@ export class Task extends EventEmitter<ClineEvents> {
 
 	// Computer User
 	browserSession: BrowserSession
+	private lastBrowserScreenshotMessageId?: string // Track the last message with browser screenshot
 
 	// Editing
 	diffViewProvider: DiffViewProvider
@@ -508,6 +509,57 @@ export class Task extends EventEmitter<ClineEvents> {
 		await this.saveApiConversationHistory()
 	}
 
+	/**
+	 * Add a browser action result to conversation history, removing previous browser screenshots
+	 * to prevent hitting provider image limits (e.g., AWS Bedrock's 20-image limit).
+	 */
+	async addBrowserActionToApiHistory(
+		toolResult: string | Array<Anthropic.TextBlockParam | Anthropic.ImageBlockParam>,
+	) {
+		// Remove previous browser screenshot from conversation history
+		if (this.lastBrowserScreenshotMessageId) {
+			// Find and remove images from the last browser action message
+			for (let i = this.apiConversationHistory.length - 1; i >= 0; i--) {
+				const message = this.apiConversationHistory[i]
+				if (message.role === "user" && Array.isArray(message.content)) {
+					// Check if this message contains the last browser screenshot
+					const hasToolResult = message.content.some(
+						(block) => block.type === "text" && block.text.includes("[browser_action Result]"),
+					)
+					if (hasToolResult) {
+						// Remove image blocks from this message, keep only text blocks
+						message.content = message.content.filter((block) => block.type === "text")
+						break
+					}
+				}
+			}
+		}
+
+		// Add the new browser action result
+		const content = Array.isArray(toolResult) ? toolResult : [{ type: "text" as const, text: toolResult }]
+		const messageWithTs = {
+			role: "user" as const,
+			content,
+			ts: Date.now(),
+		}
+
+		// Track this message if it contains images
+		const hasImages = Array.isArray(toolResult) && toolResult.some((block) => block.type === "image")
+		if (hasImages) {
+			this.lastBrowserScreenshotMessageId = messageWithTs.ts.toString()
+		}
+
+		this.apiConversationHistory.push(messageWithTs)
+		await this.saveApiConversationHistory()
+	}
+
+	/**
+	 * Reset browser screenshot tracking when browser is closed
+	 */
+	resetBrowserScreenshotTracking() {
+		this.lastBrowserScreenshotMessageId = undefined
+	}
+
 	async overwriteApiConversationHistory(newHistory: ApiMessage[]) {
 		this.apiConversationHistory = newHistory
 		await this.saveApiConversationHistory()

src/core/tools/browserActionTool.ts

@@ -158,17 +158,25 @@ export async function browserActionTool(
 				case "resize":
 					await cline.say("browser_action_result", JSON.stringify(browserActionResult))
 
-					pushToolResult(
-						formatResponse.toolResult(
+					{
+						const toolResult = formatResponse.toolResult(
 							`The browser action has been executed. The console logs and screenshot have been captured for your analysis.\n\nConsole logs:\n${
 								browserActionResult?.logs || "(No new logs)"
 							}\n\n(REMEMBER: if you need to proceed to using non-\`browser_action\` tools or launch a new browser, you MUST first close cline browser. For example, if after analyzing the logs and screenshot you need to edit a file, you must first close the browser before you can use the write_to_file tool.)`,
 							browserActionResult?.screenshot ? [browserActionResult.screenshot] : [],
-						),
-					)
+						)
+
+						// Use the new method to manage browser screenshot history
+						await cline.addBrowserActionToApiHistory(toolResult)
+
+						pushToolResult(toolResult)
+					}
 
 					break
 				case "close":
+					// Reset browser screenshot tracking when browser is closed
+					cline.resetBrowserScreenshotTracking()
+
 					pushToolResult(
 						formatResponse.toolResult(
 							`The browser has been closed. You may now proceed to using other tools.`,