fix, wip

packages/@n8n/nodes-langchain/nodes/vendors/GoogleGemini/actions/text/message.operation.ts

@@ -17,7 +17,7 @@ import type {
 	Tool,
 	GenerateContentGenerationConfig,
 } from '../../helpers/interfaces';
-import { apiRequest } from '../../transport';
+import { streamingRequestWithFallback } from '../../transport';
 import { modelRLC } from '../descriptions';
 
 const properties: INodeProperties[] = [
@@ -319,9 +319,7 @@ export async function execute(this: IExecuteFunctions, i: number): Promise<INode
 			: undefined,
 	};
 
-	let response = (await apiRequest.call(this, 'POST', `/v1beta/${model}:generateContent`, {
-		body,
-	})) as GenerateContentResponse;
+	let response = await streamingRequestWithFallback.call(this, model, body);
 
 	const maxToolsIterations = this.getNodeParameter('options.maxToolsIterations', i, 15) as number;
 	const abortSignal = this.getExecutionCancelSignal();
@@ -361,9 +359,7 @@ export async function execute(this: IExecuteFunctions, i: number): Promise<INode
 			});
 		}
 
-		response = (await apiRequest.call(this, 'POST', `/v1beta/${model}:generateContent`, {
-			body,
-		})) as GenerateContentResponse;
+		response = await streamingRequestWithFallback.call(this, model, body);
 		toolCalls = getToolCalls(response);
 		currentIteration++;
 	}

packages/@n8n/nodes-langchain/nodes/vendors/GoogleGemini/transport/index.ts

@@ -4,6 +4,8 @@ import type {
 	IHttpRequestMethods,
 	ILoadOptionsFunctions,
 } from 'n8n-workflow';
+import { NodeOperationError } from 'n8n-workflow';
+import type { GenerateContentRequest, GenerateContentResponse } from '../helpers/interfaces';
 
 type RequestParameters = {
 	headers?: IDataObject;
@@ -48,3 +50,106 @@ export async function apiRequest(
 
 	return await this.helpers.httpRequestWithAuthentication.call(this, 'googlePalmApi', options);
 }
+async function apiRequestStream(
+	this: IExecuteFunctions | ILoadOptionsFunctions,
+	method: IHttpRequestMethods,
+	endpoint: string,
+	parameters?: RequestParameters,
+): Promise<any> {
+	const { body, qs, option, headers } = parameters ?? {};
+
+	const credentials = await this.getCredentials<GooglePalmApiCredentials>('googlePalmApi');
+
+	let url = `https://generativelanguage.googleapis.com${endpoint}`;
+
+	if (credentials.host) {
+		url = `${credentials.host}${endpoint}`;
+	}
+
+	const streamingQs = { ...qs, alt: 'sse' };
+
+	const options = {
+		headers: {
+			...headers,
+			Accept: 'text/event-stream',
+		},
+		method,
+		body,
+		qs: streamingQs,
+		url,
+		json: false,
+	};
+
+	if (option && Object.keys(option).length !== 0) {
+		Object.assign(options, option);
+	}
+
+	const response = await this.helpers.httpRequestWithAuthentication.call(
+		this,
+		'googlePalmApi',
+		options,
+	);
+
+	return parseStreamingResponse(response);
+}
+
+function parseStreamingResponse(streamData: string): any {
+	const lines = streamData.split('\n');
+	const chunks = [];
+	for (const line of lines) {
+		if (line.startsWith('data: ')) {
+			const data = line.slice(6);
+			if (data === '[DONE]') {
+				break;
+			}
+			try {
+				const parsed = JSON.parse(data);
+				chunks.push(parsed);
+			} catch (e) {
+				continue;
+			}
+		}
+	}
+	if (chunks.length === 0) {
+		throw new NodeOperationError(
+			null as any,
+			'No valid response chunks received from streaming API',
+		);
+	}
+
+	const combinedResponse = {
+		candidates: [
+			{
+				content: {
+					parts: [
+						{
+							//TODO: combine other fields
+							text: chunks
+								.filter((chunk) => chunk.candidates?.[0]?.content?.parts?.[0]?.text)
+								.map((chunk) => chunk.candidates[0].content.parts[0].text)
+								.join(''),
+						},
+					],
+					role: 'model',
+				},
+			},
+		],
+	};
+	return combinedResponse;
+}
+
+export async function streamingRequestWithFallback(
+	this: IExecuteFunctions,
+	model: string,
+	body: GenerateContentRequest,
+) {
+	try {
+		return (await apiRequestStream.call(this, 'POST', `/v1beta/${model}:streamGenerateContent`, {
+			body,
+		})) as GenerateContentResponse;
+	} catch (streamError: any) {
+		return (await apiRequest.call(this, 'POST', `/v1beta/${model}:generateContent`, {
+			body,
+		})) as GenerateContentResponse;
+	}
+}