diff --git a/tools/ui/src/lib/services/backends.service.ts b/tools/ui/src/lib/services/backends.service.ts
index 140839d20b..37420ef79f 100644
--- a/tools/ui/src/lib/services/backends.service.ts
+++ b/tools/ui/src/lib/services/backends.service.ts
@@ -1,15 +1,24 @@
 /**
- * BackendsService - Stateless backend connectivity checks
+ * BackendsService - Stateless backend connectivity checks and model listing
  *
- * Probes a backend's models endpoint to validate its URL and credentials.
- * No reactive state; consumed by the backends settings UI.
+ * Probes a backend's models endpoint to validate its URL and credentials, and
+ * normalizes the response into the UI model shape. No reactive state;
+ * consumed by the backends settings UI and the per-backend model cache.
  */
 
-import type { Backend } from '$lib/types';
+import type { Backend, ModelOption } from '$lib/types';
 import { isAbortError } from '$lib/utils/abort';
 import { getAuthHeadersForBackend } from '$lib/utils/api-headers';
 import { backendModelsUrl } from '$lib/utils/backend';
 
+/** Models returned by a backend, plus the failure detail when the call fails. */
+export interface BackendModelsResult {
+	error?: string;
+	models: ModelOption[];
+	ok: boolean;
+	status: number | null;
+}
+
 /** Outcome of a backend connectivity check. */
 export interface BackendTestResult {
 	error?: string;
@@ -20,14 +29,14 @@ export interface BackendTestResult {
 
 export class BackendsService {
 	/**
-	 * Check that a backend answers on its models endpoint.
+	 * List the models a backend exposes on its models endpoint.
 	 *
-	 * @param backend - Backend to probe. Does not need to be registered yet.
-	 * @param signal - Optional abort signal for a cancelled test.
+	 * @param backend - Backend to query. Does not need to be registered yet.
+	 * @param signal - Optional abort signal for a cancelled request.
 	 */
-	static async test(backend: Backend, signal?: AbortSignal): Promise<BackendTestResult> {
+	static async listModels(backend: Backend, signal?: AbortSignal): Promise<BackendModelsResult> {
 		if (!backend.baseUrl.trim()) {
-			return { error: 'Backend URL is required', ok: false, status: null };
+			return { error: 'Backend URL is required', models: [], ok: false, status: null };
 		}
 
 		try {
@@ -37,25 +46,49 @@ export class BackendsService {
 			});
 
 			if (!response.ok) {
-				return { error: await describeFailure(response), ok: false, status: response.status };
+				return {
+					error: await describeFailure(response),
+					models: [],
+					ok: false,
+					status: response.status
+				};
 			}
 
 			const body = (await response.json()) as { data?: unknown };
-			const modelCount = Array.isArray(body?.data) ? body.data.length : 0;
+			const entries = Array.isArray(body?.data) ? body.data : [];
+			const models = entries.flatMap((entry) => normalizeBackendModel(entry));
 
-			return { modelCount, ok: true, status: response.status };
+			return { models, ok: true, status: response.status };
 		} catch (error) {
 			if (isAbortError(error)) {
-				return { ok: false, status: null };
+				return { models: [], ok: false, status: null };
 			}
 
 			return {
 				error: error instanceof Error ? error.message : String(error),
+				models: [],
 				ok: false,
 				status: null
 			};
 		}
 	}
+
+	/**
+	 * Check that a backend answers on its models endpoint.
+	 *
+	 * @param backend - Backend to probe. Does not need to be registered yet.
+	 * @param signal - Optional abort signal for a cancelled test.
+	 */
+	static async test(backend: Backend, signal?: AbortSignal): Promise<BackendTestResult> {
+		const result = await BackendsService.listModels(backend, signal);
+
+		return {
+			error: result.error,
+			modelCount: result.models.length,
+			ok: result.ok,
+			status: result.status
+		};
+	}
 }
 
 /** Build a human-readable message from a non-OK response. */
@@ -73,3 +106,18 @@ async function describeFailure(response: Response): Promise<string> {
 
 	return status;
 }
+
+/**
+ * Normalize one entry of an OpenAI-compatible `/v1/models` response. External
+ * backends only guarantee an id, so that doubles as the display name.
+ */
+function normalizeBackendModel(entry: unknown): ModelOption[] {
+	if (!entry || typeof entry !== 'object') return [];
+
+	const raw = entry as Record<string, unknown>;
+	const id = typeof raw.id === 'string' ? raw.id.trim() : '';
+
+	if (!id) return [];
+
+	return [{ capabilities: [], id, model: id, name: id }];
+}