fix(editor): Show correct error messages on Ask AI (#16913)

packages/cli/src/controllers/ai.controller.ts

@@ -8,7 +8,7 @@ import {
 } from '@n8n/api-types';
 import { AuthenticatedRequest } from '@n8n/db';
 import { Body, Post, RestController } from '@n8n/decorators';
-import type { AiAssistantSDK } from '@n8n_io/ai-assistant-sdk';
+import { type AiAssistantSDK, APIResponseError } from '@n8n_io/ai-assistant-sdk';
 import { Response } from 'express';
 import { OPEN_AI_API_CREDENTIAL_TYPE } from 'n8n-workflow';
 import { strict as assert } from 'node:assert';
@@ -16,7 +16,10 @@ import { WritableStream } from 'node:stream/web';
 
 import { FREE_AI_CREDITS_CREDENTIAL_NAME } from '@/constants';
 import { CredentialsService } from '@/credentials/credentials.service';
+import { BadRequestError } from '@/errors/response-errors/bad-request.error';
+import { ContentTooLargeError } from '@/errors/response-errors/content-too-large.error';
 import { InternalServerError } from '@/errors/response-errors/internal-server.error';
+import { TooManyRequestsError } from '@/errors/response-errors/too-many-requests.error';
 import { WorkflowBuilderService } from '@/services/ai-workflow-builder.service';
 import { AiService } from '@/services/ai.service';
 import { UserService } from '@/services/user.service';
@@ -106,6 +109,19 @@ export class AiController {
 		try {
 			return await this.aiService.askAi(payload, req.user);
 		} catch (e) {
+			if (e instanceof APIResponseError) {
+				switch (e.statusCode) {
+					case 413:
+						throw new ContentTooLargeError(e.message);
+					case 429:
+						throw new TooManyRequestsError(e.message);
+					case 400:
+						throw new BadRequestError(e.message);
+					default:
+						throw new InternalServerError(e.message, e);
+				}
+			}
+
 			assert(e instanceof Error);
 			throw new InternalServerError(e.message, e);
 		}

packages/cli/src/errors/response-errors/content-too-large.error.ts

@@ -0,0 +1,7 @@
+import { ResponseError } from './abstract/response.error';
+
+export class ContentTooLargeError extends ResponseError {
+	constructor(message: string, hint: string | undefined = undefined) {
+		super(message, 413, 413, hint);
+	}
+}

packages/cli/src/errors/response-errors/too-many-requests.error.ts

@@ -0,0 +1,7 @@
+import { ResponseError } from './abstract/response.error';
+
+export class TooManyRequestsError extends ResponseError {
+	constructor(message: string, hint: string | undefined = undefined) {
+		super(message, 429, 429, hint);
+	}
+}