fix: send provider model ids

apps/nextjs/src/app/api/assistant/chat/assistant-stream-error.spec.ts

@@ -0,0 +1,34 @@
+import { describe, expect, test } from "vitest";
+
+import { getAssistantStreamErrorMessage } from "./assistant-stream-error";
+
+describe("assistant stream errors", () => {
+  test("explains invalid provider model identifiers", () => {
+    expect(
+      getAssistantStreamErrorMessage({
+        statusCode: 400,
+        responseBody: JSON.stringify({
+          error: {
+            message: "DeepSeek: DeepSeek V4 Pro (deepseek/deepseek-v4-pro) is not a valid model ID",
+          },
+        }),
+      }),
+    ).toBe("The provider rejected the selected model. Ask an administrator to select a valid model ID.");
+  });
+
+  test.each([
+    [401, "The provider rejected the configured credentials. Ask an administrator to update the API key."],
+    [402, "The provider account has insufficient credits for this request."],
+    [404, "The selected model or chat endpoint was not found. Ask an administrator to verify the model and API URL."],
+    [429, "The model endpoint is rate limited. Wait a moment and try again."],
+    [503, "The model provider is temporarily unavailable. Try again later."],
+  ])("maps provider status %s to an actionable message", (statusCode, expected) => {
+    expect(getAssistantStreamErrorMessage({ statusCode })).toBe(expected);
+  });
+
+  test("recognizes nested timeout errors", () => {
+    expect(getAssistantStreamErrorMessage(new Error("request failed", { cause: new Error("timed out") }))).toBe(
+      "The model endpoint took too long to respond. Try again.",
+    );
+  });
+});

apps/nextjs/src/app/api/assistant/chat/assistant-stream-error.ts

@@ -0,0 +1,61 @@
+const asRecord = (value: unknown): Record<string, unknown> | null =>
+  typeof value === "object" && value !== null && !Array.isArray(value) ? (value as Record<string, unknown>) : null;
+
+const getStatusCode = (error: unknown): number | undefined => {
+  const record = asRecord(error);
+  if (!record) return undefined;
+  const statusCode =
+    typeof record.statusCode === "number"
+      ? record.statusCode
+      : typeof record.status === "number"
+        ? record.status
+        : undefined;
+  if (statusCode !== undefined) return statusCode;
+  return getStatusCode(record.cause) ?? getStatusCode(record.response);
+};
+
+const getErrorMessage = (error: unknown): string => {
+  if (error instanceof Error) {
+    return `${error.message} ${getErrorMessage(error.cause)}`.trim();
+  }
+  const record = asRecord(error);
+  if (!record) return typeof error === "string" ? error : "";
+  const responseBody = typeof record.responseBody === "string" ? record.responseBody : "";
+  const message = typeof record.message === "string" ? record.message : "";
+  return `${message} ${responseBody} ${getErrorMessage(record.cause)}`.trim();
+};
+
+export const getAssistantStreamErrorMessage = (error: unknown) => {
+  const statusCode = getStatusCode(error);
+  const message = getErrorMessage(error);
+
+  if (
+    /\bmodel(?:\s+id)?\b/iu.test(message) &&
+    /\b(invalid|unknown|unavailable|not found|not a valid)\b/iu.test(message)
+  ) {
+    return "The provider rejected the selected model. Ask an administrator to select a valid model ID.";
+  }
+  if (statusCode === 400) {
+    return "The provider rejected the request. The selected model may not support the requested input or tools.";
+  }
+  if (statusCode === 401 || statusCode === 403) {
+    return "The provider rejected the configured credentials. Ask an administrator to update the API key.";
+  }
+  if (statusCode === 402) {
+    return "The provider account has insufficient credits for this request.";
+  }
+  if (statusCode === 404) {
+    return "The selected model or chat endpoint was not found. Ask an administrator to verify the model and API URL.";
+  }
+  if (statusCode === 408 || statusCode === 504 || /\b(timeout|timed out)\b/iu.test(message)) {
+    return "The model endpoint took too long to respond. Try again.";
+  }
+  if (statusCode === 429) {
+    return "The model endpoint is rate limited. Wait a moment and try again.";
+  }
+  if (statusCode !== undefined && statusCode >= 500) {
+    return "The model provider is temporarily unavailable. Try again later.";
+  }
+
+  return "The model endpoint stopped the response. Try again, or ask an administrator to verify its URL, model, and credentials.";
+};

apps/nextjs/src/app/api/assistant/chat/route.ts

@@ -27,6 +27,7 @@ import type {
 
 import { extractMcpTools } from "../../mcp/_extract-tools";
 import { getRequestedMentionIds, sanitizeAttachmentFilename } from "./assistant-chat-input";
+import { getAssistantStreamErrorMessage } from "./assistant-stream-error";
 
 export const maxDuration = 60;
 
@@ -35,8 +36,6 @@ const getToolApprovalSecret = () =>
   Buffer.from(
     hkdfSync("sha256", Buffer.from(env.SECRET_ENCRYPTION_KEY, "hex"), "", "assistant-tool-approval", 32),
   ).toString("base64url");
-const safeStreamError =
-  "The model endpoint stopped the response. Try again, or ask an administrator to verify its URL, model, and credentials.";
 const allowedAttachmentMediaTypes = new Set([
   "image/gif",
   "image/jpeg",
@@ -314,8 +313,6 @@ export async function POST(request: Request) {
   if (!configuration?.enabled || !configuration.modelId || (requiresApiKey && !configuration.encryptedApiKey)) {
     return Response.json({ error: "Homarr Assistant is not configured." }, { status: 503 });
   }
-  const modelId = configuration.modelId;
-
   const thread = await db.query.assistantThreads.findFirst({
     where: and(eq(assistantThreads.id, parsed.data.id), eq(assistantThreads.userId, session.user.id)),
   });
@@ -330,6 +327,7 @@ export async function POST(request: Request) {
     getSelectedModelDetailsAsync(configuration).catch(() => null),
     getMentionContextAsync(context, parsed.data.messages),
   ]);
+  const modelId = selectedModel?.id ?? configuration.modelId;
   if (
     selectedModel &&
     selectedModel.inputModalities.length > 0 &&
@@ -488,6 +486,9 @@ export async function POST(request: Request) {
       },
       onError: ({ error }) => {
         logger.error("Assistant response stream failed", {
+          requestId,
+          provider: configuration.provider,
+          modelId,
           error: error instanceof Error ? error.message : String(error),
         });
       },
@@ -555,7 +556,7 @@ export async function POST(request: Request) {
           },
         };
       },
-      onError: () => safeStreamError,
+      onError: getAssistantStreamErrorMessage,
     });
   } catch (error) {
     logger.error("Assistant response could not start", {