fix(OpenAI Node): Filter non-chat models out of the chat model dropdown (#35785)

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
Co-authored-by: Ricardo Espinoza <ricardo@n8n.io>

packages/@n8n/ai-utilities/src/model-discovery/__tests__/model-discovery.test.ts

@@ -73,6 +73,8 @@ describe('model-discovery', () => {
 					{ id: 'gpt-5' },
 					{ id: 'whisper-1' },
 					{ id: 'dall-e-3' },
+					{ id: 'gpt-image-2' },
+					{ id: 'gpt-4o-transcribe' },
 					{ id: 'text-embedding-3-small' },
 					{ id: 'gpt-4o' },
 				],

packages/@n8n/ai-utilities/src/model-discovery/__tests__/openai.test.ts

@@ -1,6 +1,6 @@
-import { shouldIncludeModel } from '../modelFiltering';
+import { shouldIncludeOpenAiModel } from '../providers/openai';
 
-describe('shouldIncludeModel', () => {
+describe('shouldIncludeOpenAiModel', () => {
 	const testCases: Array<{ modelId: string; officialAPI: boolean }> = [
 		// Excluded model types
 		{ modelId: 'babbage-002', officialAPI: false },
@@ -15,9 +15,21 @@ describe('shouldIncludeModel', () => {
 		{ modelId: 'gpt-4o-realtime-preview', officialAPI: false }, // infix check for -realtime
 		{ modelId: 'gpt-3.5-turbo-instruct', officialAPI: false }, // gpt-* with instruct
 
+		// Non-chat families named gpt-*, so caught by infix rather than prefix
+		{ modelId: 'gpt-image-2', officialAPI: false },
+		{ modelId: 'chatgpt-image-latest', officialAPI: false },
+		{ modelId: 'gpt-transcribe', officialAPI: false },
+		{ modelId: 'gpt-4o-transcribe-diarize', officialAPI: false },
+		// Every diarization model OpenAI ships today is also *-transcribe-diarize,
+		// so this pins the -diarize clause on its own
+		{ modelId: 'gpt-4o-diarize', officialAPI: false },
+
 		// Included models (standard chat models)
 		{ modelId: 'gpt-4', officialAPI: true },
 		{ modelId: 'gpt-4o', officialAPI: true },
+		// Unsupported on responses, but supported on chat/completions, which the
+		// OpenAI node's "Message a Model" uses, so it must stay selectable
+		{ modelId: 'gpt-audio', officialAPI: true },
 		{ modelId: 'o1-preview', officialAPI: true },
 		{ modelId: 'ft:gpt-3.5-turbo', officialAPI: true }, // fine-tuned models
 
@@ -28,7 +40,7 @@ describe('shouldIncludeModel', () => {
 
 	describe('Custom API behavior', () => {
 		it.each(testCases)('should include "$modelId"', ({ modelId }) => {
-			expect(shouldIncludeModel(modelId, true)).toBe(true);
+			expect(shouldIncludeOpenAiModel(modelId, true)).toBe(true);
 		});
 	});
 
@@ -39,7 +51,7 @@ describe('shouldIncludeModel', () => {
 		}));
 
 		it.each(testCasesWithAction)('should $action "$modelId"', ({ modelId, officialAPI }) => {
-			expect(shouldIncludeModel(modelId, false)).toBe(officialAPI);
+			expect(shouldIncludeOpenAiModel(modelId, false)).toBe(officialAPI);
 		});
 	});
 });

packages/@n8n/ai-utilities/src/model-discovery/index.ts

@@ -59,9 +59,10 @@ export { listGroqModels } from './providers/groq';
 export { listMistralModels } from './providers/mistral';
 export { listNvidiaModels } from './providers/nvidia';
 export {
-	isOpenAiCustomEndpoint,
 	listOpenAiModels,
 	shouldIncludeOpenAiModel,
+	OFFICIAL_OPENAI_HOSTNAMES,
+	isOpenAiCustomEndpoint,
 } from './providers/openai';
 export { listOpenRouterModels } from './providers/openrouter';
 export { listVercelModels } from './providers/vercel';

packages/@n8n/ai-utilities/src/model-discovery/providers/openai.ts

@@ -1,7 +1,7 @@
 import { baseUrl, bearerHeaders, byName, getJson, idsToModels, type IdItem } from '../request';
 import type { ListModelsFn } from '../types';
 
-const OFFICIAL_OPENAI_HOSTNAMES = ['api.openai.com', 'ai-assistant.n8n.io'];
+export const OFFICIAL_OPENAI_HOSTNAMES = ['api.openai.com', 'ai-assistant.n8n.io'];
 
 export function isOpenAiCustomEndpoint(baseURL?: string): boolean {
 	if (baseURL === undefined) return false;
@@ -14,8 +14,11 @@ export function isOpenAiCustomEndpoint(baseURL?: string): boolean {
 }
 
 /**
- * Source: LMChatOpenAi `methods/loadModels.ts` — on the official API, exclude
- * non-chat model families; on custom (proxy/self-hosted) hosts include all.
+ * On the official API, exclude non-chat model families; on custom
+ * (proxy/self-hosted) hosts include all, since their naming is not OpenAI's.
+ *
+ * Single source of truth for every OpenAI model dropdown: the LMChatOpenAi
+ * sub-node, the OpenAI node's `modelSearch`, and the agents model catalog.
  */
 export function shouldIncludeOpenAiModel(modelId: string, isCustomApi: boolean): boolean {
 	if (isCustomApi) return true;
@@ -24,6 +27,13 @@ export function shouldIncludeOpenAiModel(modelId: string, isCustomApi: boolean):
 		modelId.startsWith('davinci') ||
 		modelId.startsWith('computer-use') ||
 		modelId.startsWith('dall-e') ||
+		// Newer non-chat families are named gpt-*, so they clear the gpt- prefix and
+		// have to be matched by infix. Only list families unsupported on *both*
+		// chat/completions and responses: gpt-audio-* is absent on purpose, it works
+		// on chat/completions.
+		modelId.includes('-image') ||
+		modelId.includes('-transcribe') ||
+		modelId.includes('-diarize') ||
 		modelId.startsWith('text-embedding') ||
 		modelId.startsWith('tts') ||
 		modelId.includes('-tts') ||

packages/@n8n/nodes-langchain/nodes/vendors/OpenAi/helpers/modelFiltering.ts

@@ -1,30 +0,0 @@
-/**
- * Determines whether a model should be included in the model list based on
- * whether it's a custom API and the model's ID.
- *
- * @param modelId - The ID of the model to check
- * @param isCustomAPI - Whether this is a custom API (not official OpenAI)
- * @returns true if the model should be included, false otherwise
- */
-export function shouldIncludeModel(modelId: string, isCustomAPI: boolean): boolean {
-	// For custom APIs, include all models
-	if (isCustomAPI) {
-		return true;
-	}
-
-	// For official OpenAI API, exclude certain model types
-	return !(
-		modelId.startsWith('babbage') ||
-		modelId.startsWith('davinci') ||
-		modelId.startsWith('computer-use') ||
-		modelId.startsWith('dall-e') ||
-		modelId.startsWith('text-embedding') ||
-		modelId.startsWith('tts') ||
-		modelId.includes('-tts') ||
-		modelId.startsWith('whisper') ||
-		modelId.startsWith('omni-moderation') ||
-		modelId.startsWith('sora') ||
-		modelId.includes('-realtime') ||
-		(modelId.startsWith('gpt-') && modelId.includes('instruct'))
-	);
-}

packages/@n8n/nodes-langchain/nodes/vendors/OpenAi/methods/__tests__/listSearch.test.ts

@@ -30,6 +30,8 @@ describe('modelSearch', () => {
 					{ id: 'babbage-002' },
 					{ id: 'whisper-1' },
 					{ id: 'dall-e-3' },
+					{ id: 'gpt-image-2' },
+					{ id: 'gpt-4o-transcribe' },
 					{ id: 'gpt-4o-realtime-preview' },
 				],
 			});

packages/@n8n/nodes-langchain/nodes/vendors/OpenAi/methods/listSearch.ts

@@ -1,3 +1,7 @@
+import {
+	OFFICIAL_OPENAI_HOSTNAMES,
+	shouldIncludeOpenAiModel,
+} from '@n8n/ai-utilities/model-discovery';
 import type {
 	IDataObject,
 	ILoadOptionsFunctions,
@@ -7,7 +11,6 @@ import type {
 import type { Assistant } from 'openai/resources/beta/assistants';
 import type { Model } from 'openai/resources/models';
 
-import { shouldIncludeModel } from '../helpers/modelFiltering';
 import { apiRequest } from '../transport';
 
 export async function fileSearch(
@@ -78,8 +81,11 @@ export async function modelSearch(
 ): Promise<INodeListSearchResult> {
 	const credentials = await this.getCredentials<{ url: string }>('openAiApi');
 	const url = credentials.url && new URL(credentials.url);
-	const isCustomAPI = !!(url && !['api.openai.com', 'ai-assistant.n8n.io'].includes(url.hostname));
-	return await getModelSearch((model) => shouldIncludeModel(model.id, isCustomAPI))(this, filter);
+	const isCustomAPI = !!(url && !OFFICIAL_OPENAI_HOSTNAMES.includes(url.hostname));
+	return await getModelSearch((model) => shouldIncludeOpenAiModel(model.id, isCustomAPI))(
+		this,
+		filter,
+	);
 }
 
 export async function videoModelSearch(