feat(Chat Trigger Node): Add support for file uploads & harmonize public and development chat (#9802)

Signed-off-by: Oleg Ivaniv <me@olegivaniv.com>

packages/@n8n/chat/src/api/generic.ts

@@ -5,15 +5,23 @@ async function getAccessToken() {
 export async function authenticatedFetch<T>(...args: Parameters<typeof fetch>): Promise<T> {
 	const accessToken = await getAccessToken();
 
+	const body = args[1]?.body;
+	const headers: RequestInit['headers'] & { 'Content-Type'?: string } = {
+		...(accessToken ? { authorization: `Bearer ${accessToken}` } : {}),
+		...args[1]?.headers,
+	};
+
+	// Automatically set content type to application/json if body is FormData
+	if (body instanceof FormData) {
+		delete headers['Content-Type'];
+	} else {
+		headers['Content-Type'] = 'application/json';
+	}
 	const response = await fetch(args[0], {
 		...args[1],
 		mode: 'cors',
 		cache: 'no-cache',
-		headers: {
-			'Content-Type': 'application/json',
-			...(accessToken ? { authorization: `Bearer ${accessToken}` } : {}),
-			...args[1]?.headers,
-		},
+		headers,
 	});
 
 	return (await response.json()) as T;
@@ -37,6 +45,28 @@ export async function post<T>(url: string, body: object = {}, options: RequestIn
 		body: JSON.stringify(body),
 	});
 }
+export async function postWithFiles<T>(
+	url: string,
+	body: Record<string, unknown> = {},
+	files: File[] = [],
+	options: RequestInit = {},
+) {
+	const formData = new FormData();
+
+	for (const key in body) {
+		formData.append(key, body[key] as string);
+	}
+
+	for (const file of files) {
+		formData.append('files', file);
+	}
+
+	return await authenticatedFetch<T>(url, {
+		...options,
+		method: 'POST',
+		body: formData,
+	});
+}
 
 export async function put<T>(url: string, body: object = {}, options: RequestInit = {}) {
 	return await authenticatedFetch<T>(url, {

packages/@n8n/chat/src/api/message.ts

@@ -1,4 +1,4 @@
-import { get, post } from '@n8n/chat/api/generic';
+import { get, post, postWithFiles } from '@n8n/chat/api/generic';
 import type {
 	ChatOptions,
 	LoadPreviousSessionResponse,
@@ -20,7 +20,27 @@ export async function loadPreviousSession(sessionId: string, options: ChatOption
 	);
 }
 
-export async function sendMessage(message: string, sessionId: string, options: ChatOptions) {
+export async function sendMessage(
+	message: string,
+	files: File[],
+	sessionId: string,
+	options: ChatOptions,
+) {
+	if (files.length > 0) {
+		return await postWithFiles<SendMessageResponse>(
+			`${options.webhookUrl}`,
+			{
+				action: 'sendMessage',
+				[options.chatSessionKey as string]: sessionId,
+				[options.chatInputKey as string]: message,
+				...(options.metadata ? { metadata: options.metadata } : {}),
+			},
+			files,
+			{
+				headers: options.webhookConfig?.headers,
+			},
+		);
+	}
 	const method = options.webhookConfig?.method === 'POST' ? post : get;
 	return await method<SendMessageResponse>(
 		`${options.webhookUrl}`,