fix(OpenAI Chat Model Node): Fix loading of custom models when using custom credential URL (#12634)

packages/@n8n/nodes-langchain/nodes/llms/LMChatOpenAi/methods/loadModels.ts

@@ -0,0 +1,37 @@
+import type { ILoadOptionsFunctions, INodeListSearchResult } from 'n8n-workflow';
+import OpenAI from 'openai';
+
+export async function searchModels(
+	this: ILoadOptionsFunctions,
+	filter?: string,
+): Promise<INodeListSearchResult> {
+	const credentials = await this.getCredentials('openAiApi');
+	const baseURL =
+		(this.getNodeParameter('options.baseURL', '') as string) ||
+		(credentials.url as string) ||
+		'https://api.openai.com/v1';
+
+	const openai = new OpenAI({ baseURL, apiKey: credentials.apiKey as string });
+	const { data: models = [] } = await openai.models.list();
+
+	const filteredModels = models.filter((model: { id: string }) => {
+		const isValidModel =
+			(baseURL && !baseURL.includes('api.openai.com')) ||
+			model.id.startsWith('ft:') ||
+			model.id.startsWith('o1') ||
+			(model.id.startsWith('gpt-') && !model.id.includes('instruct'));
+
+		if (!filter) return isValidModel;
+
+		return isValidModel && model.id.toLowerCase().includes(filter.toLowerCase());
+	});
+
+	const results = {
+		results: filteredModels.map((model: { id: string }) => ({
+			name: model.id,
+			value: model.id,
+		})),
+	};
+
+	return results;
+}