feat: add user-configurable search score threshold slider for semantic search (#5027)

- Add optional codebaseIndexSearchMinScore field to codebase index config schema
- Update config manager to prioritize user setting over model-specific thresholds
- Replace text input with intuitive slider interface (0.0-1.0 range, 0.05 steps)
- Add real-time value display and visual progress indication
- Update tests to support new slider component and functionality
- Maintain backward compatibility with existing configurations

This allows users to directly control semantic search sensitivity instead of
relying on hardcoded model-specific thresholds, enabling better nomic-embed-code
support in future PR.

Author: hannesrudolph

packages/types/src/codebase-index.ts

@@ -10,6 +10,7 @@ export const codebaseIndexConfigSchema = z.object({
 	codebaseIndexEmbedderProvider: z.enum(["openai", "ollama", "openai-compatible"]).optional(),
 	codebaseIndexEmbedderBaseUrl: z.string().optional(),
 	codebaseIndexEmbedderModelId: z.string().optional(),
+	codebaseIndexSearchMinScore: z.number().min(0).max(1).optional(),
 })
 
 export type CodebaseIndexConfig = z.infer<typeof codebaseIndexConfigSchema>

src/services/code-index/config-manager.ts

@@ -18,6 +18,7 @@ export class CodeIndexConfigManager {
 	private openAiCompatibleOptions?: { baseUrl: string; apiKey: string; modelDimension?: number }
 	private qdrantUrl?: string = "http://localhost:6333"
 	private qdrantApiKey?: string
+	private searchMinScore?: number
 
 	constructor(private readonly contextProxy: ContextProxy) {
 		// Initialize with current configuration to avoid false restart triggers
@@ -33,7 +34,6 @@ export class CodeIndexConfigManager {
 		const codebaseIndexConfig = this.contextProxy?.getGlobalState("codebaseIndexConfig") ?? {
 			codebaseIndexEnabled: false,
 			codebaseIndexQdrantUrl: "http://localhost:6333",
-			codebaseIndexSearchMinScore: 0.4,
 			codebaseIndexEmbedderProvider: "openai",
 			codebaseIndexEmbedderBaseUrl: "",
 			codebaseIndexEmbedderModelId: "",
@@ -45,6 +45,7 @@ export class CodeIndexConfigManager {
 			codebaseIndexEmbedderProvider,
 			codebaseIndexEmbedderBaseUrl,
 			codebaseIndexEmbedderModelId,
+			codebaseIndexSearchMinScore,
 		} = codebaseIndexConfig
 
 		const openAiKey = this.contextProxy?.getSecret("codeIndexOpenAiKey") ?? ""
@@ -59,6 +60,7 @@ export class CodeIndexConfigManager {
 		this.isEnabled = codebaseIndexEnabled || false
 		this.qdrantUrl = codebaseIndexQdrantUrl
 		this.qdrantApiKey = qdrantApiKey ?? ""
+		this.searchMinScore = codebaseIndexSearchMinScore
 		this.openAiOptions = { openAiNativeApiKey: openAiKey }
 
 		// Set embedder provider with support for openai-compatible
@@ -335,10 +337,16 @@ export class CodeIndexConfigManager {
 	}
 
 	/**
-	 * Gets the configured minimum search score based on the current model.
-	 * Falls back to the constant SEARCH_MIN_SCORE if no model-specific threshold is found.
+	 * Gets the configured minimum search score based on user setting, model-specific threshold, or fallback.
+	 * Priority: 1) User setting, 2) Model-specific threshold, 3) Default SEARCH_MIN_SCORE constant.
 	 */
 	public get currentSearchMinScore(): number {
+		// First check if user has configured a custom score threshold
+		if (this.searchMinScore !== undefined) {
+			return this.searchMinScore
+		}
+
+		// Fall back to model-specific threshold
 		const currentModelId = this.modelId ?? getDefaultModelId(this.embedderProvider)
 		const modelSpecificThreshold = getModelScoreThreshold(this.embedderProvider, currentModelId)
 		return modelSpecificThreshold ?? SEARCH_MIN_SCORE

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

@@ -449,6 +449,45 @@ export const CodeIndexSettings: React.FC<CodeIndexSettingsProps> = ({
 						</div>
 					</div>
 
+					<div className="flex flex-col gap-3">
+						<div className="flex items-center gap-4 font-bold">
+							<div>{t("settings:codeIndex.searchMinScoreLabel")}</div>
+						</div>
+						<div className="flex flex-col gap-3">
+							<div className="flex items-center gap-3">
+								<span className="text-xs text-vscode-descriptionForeground min-w-[30px]">0.0</span>
+								<input
+									type="range"
+									min="0"
+									max="1"
+									step="0.05"
+									value={codebaseIndexConfig.codebaseIndexSearchMinScore || 0.4}
+									onChange={(e) => {
+										const value = parseFloat(e.target.value)
+										setCachedStateField("codebaseIndexConfig", {
+											...codebaseIndexConfig,
+											codebaseIndexSearchMinScore: value,
+										})
+									}}
+									className="flex-1 h-2 bg-vscode-input-background rounded-lg appearance-none cursor-pointer slider"
+									data-testid="search-min-score-slider"
+									style={{
+										background: `linear-gradient(to right, var(--vscode-progressBar-background) 0%, var(--vscode-progressBar-background) ${(codebaseIndexConfig.codebaseIndexSearchMinScore || 0.4) * 100}%, var(--vscode-input-background) ${(codebaseIndexConfig.codebaseIndexSearchMinScore || 0.4) * 100}%, var(--vscode-input-background) 100%)`,
+									}}
+								/>
+								<span className="text-xs text-vscode-descriptionForeground min-w-[30px]">1.0</span>
+							</div>
+							<div className="text-center">
+								<span className="text-sm text-vscode-foreground font-medium">
+									{(codebaseIndexConfig.codebaseIndexSearchMinScore || 0.4).toFixed(2)}
+								</span>
+							</div>
+							<p className="text-vscode-descriptionForeground text-sm mt-1">
+								{t("settings:codeIndex.searchMinScoreDescription")}
+							</p>
+						</div>
+					</div>
+
 					{(!areSettingsCommitted || !validateIndexingConfig(codebaseIndexConfig, apiConfiguration)) && (
 						<p className="text-sm text-vscode-descriptionForeground mb-2">
 							{t("settings:codeIndex.unsavedSettingsMessage")}

webview-ui/src/components/settings/__tests__/CodeIndexSettings.spec.tsx

@@ -43,6 +43,9 @@ vi.mock("@src/i18n/TranslationContext", () => ({
 				"settings:codeIndex.clearDataDialog.description": "This will remove all indexed data",
 				"settings:codeIndex.clearDataDialog.cancelButton": "Cancel",
 				"settings:codeIndex.clearDataDialog.confirmButton": "Confirm",
+				"settings:codeIndex.searchMinScoreLabel": "Search Score Threshold",
+				"settings:codeIndex.searchMinScoreDescription":
+					"Minimum similarity score (0.0-1.0) required for search results. Lower values return more results but may be less relevant. Higher values return fewer but more relevant results.",
 			}
 			return translations[key] || key
 		},
@@ -158,6 +161,7 @@ describe("CodeIndexSettings", () => {
 			codebaseIndexEmbedderProvider: "openai" as const,
 			codebaseIndexEmbedderModelId: "text-embedding-3-small",
 			codebaseIndexQdrantUrl: "http://localhost:6333",
+			codebaseIndexSearchMinScore: 0.4,
 		},
 		apiConfiguration: {
 			codeIndexOpenAiKey: "",
@@ -204,7 +208,7 @@ describe("CodeIndexSettings", () => {
 
 			expect(screen.getByText("Base URL")).toBeInTheDocument()
 			expect(screen.getByText("API Key")).toBeInTheDocument()
-			expect(screen.getAllByTestId("vscode-textfield")).toHaveLength(6) // Base URL, API Key, Embedding Dimension, Model ID, Qdrant URL, Qdrant Key
+			expect(screen.getAllByTestId("vscode-textfield")).toHaveLength(6) // Base URL, API Key, Embedding Dimension, Model ID, Qdrant URL, Qdrant Key (Search Min Score is now a slider)
 		})
 
 		it("should hide OpenAI Compatible fields when different provider is selected", () => {
@@ -817,6 +821,59 @@ describe("CodeIndexSettings", () => {
 		})
 	})
 
+	describe("Search Minimum Score Slider", () => {
+		it("should render search minimum score slider", () => {
+			render(<CodeIndexSettings {...defaultProps} />)
+
+			expect(screen.getByTestId("search-min-score-slider")).toBeInTheDocument()
+			expect(screen.getByText("Search Score Threshold")).toBeInTheDocument()
+		})
+
+		it("should display current search minimum score value", () => {
+			const propsWithScore = {
+				...defaultProps,
+				codebaseIndexConfig: {
+					...defaultProps.codebaseIndexConfig,
+					codebaseIndexSearchMinScore: 0.65,
+				},
+			}
+
+			render(<CodeIndexSettings {...propsWithScore} />)
+
+			const slider = screen.getByTestId("search-min-score-slider")
+			expect(slider).toHaveValue("0.65")
+			expect(screen.getByText("0.65")).toBeInTheDocument()
+		})
+
+		it("should call setCachedStateField when slider value changes", () => {
+			render(<CodeIndexSettings {...defaultProps} />)
+
+			const slider = screen.getByTestId("search-min-score-slider")
+			fireEvent.change(slider, { target: { value: "0.8" } })
+
+			expect(mockSetCachedStateField).toHaveBeenCalledWith("codebaseIndexConfig", {
+				...defaultProps.codebaseIndexConfig,
+				codebaseIndexSearchMinScore: 0.8,
+			})
+		})
+
+		it("should use default value when no score is set", () => {
+			const propsWithoutScore = {
+				...defaultProps,
+				codebaseIndexConfig: {
+					...defaultProps.codebaseIndexConfig,
+					codebaseIndexSearchMinScore: undefined,
+				},
+			}
+
+			render(<CodeIndexSettings {...propsWithoutScore} />)
+
+			const slider = screen.getByTestId("search-min-score-slider")
+			expect(slider).toHaveValue("0.4")
+			expect(screen.getByText("0.40")).toBeInTheDocument()
+		})
+	})
+
 	describe("Error Handling", () => {
 		it("should handle invalid provider gracefully", () => {
 			const propsWithInvalidProvider = {

webview-ui/src/i18n/locales/en/settings.json

@@ -56,6 +56,8 @@
 		"ollamaUrlLabel": "Ollama URL:",
 		"qdrantUrlLabel": "Qdrant URL",
 		"qdrantKeyLabel": "Qdrant Key:",
+		"searchMinScoreLabel": "Search Score Threshold",
+		"searchMinScoreDescription": "Minimum similarity score (0.0-1.0) required for search results. Lower values return more results but may be less relevant. Higher values return fewer but more relevant results.",
 		"startIndexingButton": "Start Indexing",
 		"clearIndexDataButton": "Clear Index Data",
 		"unsavedSettingsMessage": "Please save your settings before starting the indexing process.",