feat(morph): add Morph Fast Apply settings and strategy selection

packages/types/src/global-settings.ts

@@ -205,6 +205,7 @@ export const SECRET_STATE_KEYS = [
 	"fireworksApiKey",
 	"featherlessApiKey",
 	"ioIntelligenceApiKey",
+	"morphApiKey",
 	"vercelAiGatewayApiKey",
 ] as const
 

packages/types/src/provider-settings.ts

@@ -101,6 +101,10 @@ const baseProviderSettingsSchema = z.object({
 	diffEnabled: z.boolean().optional(),
 	todoListEnabled: z.boolean().optional(),
 	fuzzyMatchThreshold: z.number().optional(),
+	// Morph Fast Apply - optional provider-scoped controls
+	morphFastApplyEnabled: z.boolean().optional(),
+	morphApiKey: z.string().optional(),
+
 	modelTemperature: z.number().nullish(),
 	rateLimitSeconds: z.number().optional(),
 	consecutiveMistakeLimit: z.number().min(0).optional(),

src/core/task/Task.ts

@@ -394,17 +394,18 @@ export class Task extends EventEmitter<TaskEvents> implements TaskLike {
 
 		// Only set up diff strategy if diff is enabled.
 		if (this.diffEnabled) {
-			// Default to old strategy, will be updated if experiment is enabled.
+			// Default to legacy single-file strategy
 			this.diffStrategy = new MultiSearchReplaceDiffStrategy(this.fuzzyMatchThreshold)
 
-			// Check experiment asynchronously and update strategy if needed.
+			// Prefer MultiFile when Morph Fast Apply is enabled, otherwise respect experiment flag.
 			provider.getState().then((state) => {
 				const isMultiFileApplyDiffEnabled = experiments.isEnabled(
 					state.experiments ?? {},
 					EXPERIMENT_IDS.MULTI_FILE_APPLY_DIFF,
 				)
+				const isMorphFastApplyEnabled = state.apiConfiguration?.morphFastApplyEnabled === true
 
-				if (isMultiFileApplyDiffEnabled) {
+				if (isMorphFastApplyEnabled || isMultiFileApplyDiffEnabled) {
 					this.diffStrategy = new MultiFileSearchReplaceDiffStrategy(this.fuzzyMatchThreshold)
 				}
 			})

src/core/webview/generateSystemPrompt.ts

@@ -27,15 +27,20 @@ export const generateSystemPrompt = async (provider: ClineProvider, message: Web
 		maxConcurrentFileReads,
 	} = await provider.getState()
 
-	// Check experiment to determine which diff strategy to use
+	// Determine which diff strategy to use:
+	// - If Morph Fast Apply is enabled, force MultiFile strategy for best tolerance and batching
+	// - Otherwise, fall back to experiment flag to choose between MultiFile and single-file strategies
 	const isMultiFileApplyDiffEnabled = experimentsModule.isEnabled(
 		experiments ?? {},
 		EXPERIMENT_IDS.MULTI_FILE_APPLY_DIFF,
 	)
+	const isMorphFastApplyEnabled = apiConfiguration?.morphFastApplyEnabled === true
 
-	const diffStrategy = isMultiFileApplyDiffEnabled
+	const diffStrategy = isMorphFastApplyEnabled
 		? new MultiFileSearchReplaceDiffStrategy(fuzzyMatchThreshold)
-		: new MultiSearchReplaceDiffStrategy(fuzzyMatchThreshold)
+		: isMultiFileApplyDiffEnabled
+			? new MultiFileSearchReplaceDiffStrategy(fuzzyMatchThreshold)
+			: new MultiSearchReplaceDiffStrategy(fuzzyMatchThreshold)
 
 	const cwd = provider.cwd
 

webview-ui/src/components/settings/ApiOptions.tsx

@@ -1,7 +1,7 @@
 import React, { memo, useCallback, useEffect, useMemo, useState } from "react"
 import { convertHeadersToObject } from "./utils/headers"
 import { useDebounce } from "react-use"
-import { VSCodeLink, VSCodeButton } from "@vscode/webview-ui-toolkit/react"
+import { VSCodeLink, VSCodeButton, VSCodeCheckbox, VSCodeTextField } from "@vscode/webview-ui-toolkit/react"
 import { ExternalLinkIcon } from "@radix-ui/react-icons"
 
 import {
@@ -765,6 +765,32 @@ const ApiOptions = ({
 							fuzzyMatchThreshold={apiConfiguration.fuzzyMatchThreshold}
 							onChange={(field, value) => setApiConfigurationField(field, value)}
 						/>
+
+						{/* Morph Fast Apply - provider-scoped controls */}
+						<div className="pl-3 border-l-2 border-vscode-button-background space-y-2">
+							<label className="block font-medium">Morph Fast Apply</label>
+							<div className="flex flex-col gap-1">
+								<VSCodeCheckbox
+									checked={Boolean(apiConfiguration.morphFastApplyEnabled)}
+									onChange={(e: any) =>
+										setApiConfigurationField("morphFastApplyEnabled", e.target.checked)
+									}>
+									Enable Morph Fast Apply (fuzzy multi-file)
+								</VSCodeCheckbox>
+
+								<VSCodeTextField
+									value={apiConfiguration?.morphApiKey || ""}
+									type="password"
+									onInput={(e: any) => setApiConfigurationField("morphApiKey", e.target.value)}
+									placeholder="Optional API key">
+									Morph API key (optional)
+								</VSCodeTextField>
+								<div className="text-sm text-vscode-descriptionForeground">
+									When enabled, apply_diff uses faster tolerant matching across multiple files. An API
+									key is only required if using a hosted Morph service.
+								</div>
+							</div>
+						</div>
 						{selectedModelInfo?.supportsTemperature !== false && (
 							<TemperatureControl
 								value={apiConfiguration.modelTemperature}