feat(Azure OpenAI Chat Model Node): Implement Azure Entra ID OAuth2 Authentication (#15003)

packages/@n8n/nodes-langchain/nodes/llms/LmChatAzureOpenAi/credentials/api-key.ts

@@ -0,0 +1,45 @@
+import { NodeOperationError, OperationalError, type ISupplyDataFunctions } from 'n8n-workflow';
+
+import type { AzureOpenAIApiKeyModelConfig } from '../types';
+
+/**
+ * Handles API Key authentication setup for Azure OpenAI
+ */
+export async function setupApiKeyAuthentication(
+	this: ISupplyDataFunctions,
+	credentialName: string,
+): Promise<AzureOpenAIApiKeyModelConfig> {
+	try {
+		// Get Azure OpenAI Config (Endpoint, Version, etc.)
+		const configCredentials = await this.getCredentials<{
+			apiKey?: string;
+			resourceName: string;
+			apiVersion: string;
+			endpoint?: string;
+		}>(credentialName);
+
+		if (!configCredentials.apiKey) {
+			throw new NodeOperationError(
+				this.getNode(),
+				'API Key is missing in the selected Azure OpenAI API credential. Please configure the API Key or choose Entra ID authentication.',
+			);
+		}
+
+		this.logger.info('Using API Key authentication for Azure OpenAI.');
+
+		return {
+			azureOpenAIApiKey: configCredentials.apiKey,
+			azureOpenAIApiInstanceName: configCredentials.resourceName,
+			azureOpenAIApiVersion: configCredentials.apiVersion,
+			azureOpenAIEndpoint: configCredentials.endpoint,
+		};
+	} catch (error) {
+		if (error instanceof OperationalError) {
+			throw error;
+		}
+
+		this.logger.error(`Error setting up API Key authentication: ${error.message}`, error);
+
+		throw new NodeOperationError(this.getNode(), 'Failed to retrieve API Key', error);
+	}
+}