fix: mediaUrl fallback to directPath for newsletter uploads

Newsletter endpoints return only direct_path (no url field).
Use direct_path as fallback so mediaUrl is never silently undefined.
Also update WAMediaUploadFunction return type to reflect that
mediaUrl may be undefined when only direct_path is present.

Resolves Copilot review comments on PR #311.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/Defaults/index.ts

@@ -157,6 +157,15 @@ export const MEDIA_PATH_MAP: { [T in MediaType]?: string } = {
 	'thumbnail-sticker-pack': '/mms/thumbnail-sticker-pack'
 }
 
+export const NEWSLETTER_MEDIA_PATH_MAP: { [T in MediaType]?: string } = {
+	image: '/newsletter/newsletter-image',
+	video: '/newsletter/newsletter-video',
+	document: '/newsletter/newsletter-document',
+	audio: '/newsletter/newsletter-audio',
+	sticker: '/newsletter/newsletter-image',
+	'thumbnail-link': '/newsletter/newsletter-image'
+}
+
 export const MEDIA_HKDF_KEY_MAPPING = {
 	audio: 'Audio',
 	document: 'Document',

src/Socket/messages-send.ts

@@ -1051,7 +1051,7 @@ export const makeMessagesSocket = (config: SocketConfig) => {
 				const bytes = encodeNewsletterMessage(patched as proto.IMessage)
 				binaryNodeContent.push({
 					tag: 'plaintext',
-					attrs: {},
+					attrs: mediaType ? { mediatype: mediaType } : {},
 					content: bytes
 				})
 				const stanza: BinaryNode = {

src/Types/Message.ts

@@ -990,8 +990,16 @@ export type MessageGenerationOptionsFromContent = MiscMessageGenerationOptions &
 
 export type WAMediaUploadFunction = (
 	encFilePath: string,
-	opts: { fileEncSha256B64: string; mediaType: MediaType; timeoutMs?: number }
-) => Promise<{ mediaUrl: string; directPath: string; meta_hmac?: string; ts?: number; fbid?: number }>
+	opts: { fileEncSha256B64: string; mediaType: MediaType; timeoutMs?: number; newsletter?: boolean }
+) => Promise<{
+	mediaUrl: string | undefined
+	directPath: string
+	meta_hmac?: string
+	ts?: number
+	fbid?: number
+	thumbnailDirectPath?: string
+	thumbnailSha256?: string
+}>
 
 export type MediaGenerationOptions = {
 	logger?: ILogger

src/Utils/messages-media.ts

@@ -10,7 +10,13 @@ import { join } from 'path'
 import { Readable, Transform } from 'stream'
 import { URL } from 'url'
 import { proto } from '../../WAProto/index.js'
-import { DEFAULT_ORIGIN, MEDIA_HKDF_KEY_MAPPING, MEDIA_PATH_MAP, type MediaType } from '../Defaults'
+import {
+	DEFAULT_ORIGIN,
+	MEDIA_HKDF_KEY_MAPPING,
+	MEDIA_PATH_MAP,
+	type MediaType,
+	NEWSLETTER_MEDIA_PATH_MAP
+} from '../Defaults'
 import type {
 	BaileysEventMap,
 	DownloadableMessage,
@@ -681,6 +687,10 @@ type MediaUploadResult = {
 	meta_hmac?: string
 	ts?: number
 	fbid?: number
+	thumbnail_info?: {
+		thumbnail_sha256?: string
+		thumbnail_direct_path?: string
+	}
 }
 
 export type UploadParams = {
@@ -825,11 +835,21 @@ export const getWAUploadToServer = (
 	{ customUploadHosts, fetchAgent, logger, options }: SocketConfig,
 	refreshMediaConn: (force: boolean) => Promise<MediaConnInfo>
 ): WAMediaUploadFunction => {
-	return async (filePath, { mediaType, fileEncSha256B64, timeoutMs }) => {
+	return async (filePath, { mediaType, fileEncSha256B64, timeoutMs, newsletter }) => {
 		// send a query JSON to obtain the url & auth token to upload our media
 		let uploadInfo = await refreshMediaConn(false)
 
-		let urls: { mediaUrl: string; directPath: string; meta_hmac?: string; ts?: number; fbid?: number } | undefined
+		let urls:
+			| {
+					mediaUrl: string
+					directPath: string
+					meta_hmac?: string
+					ts?: number
+					fbid?: number
+					thumbnailDirectPath?: string
+					thumbnailSha256?: string
+			  }
+			| undefined
 		const hosts = [...customUploadHosts, ...uploadInfo.hosts]
 
 		fileEncSha256B64 = encodeBase64EncodedStringForUpload(fileEncSha256B64)
@@ -851,7 +871,11 @@ export const getWAUploadToServer = (
 			logger.debug(`uploading to "${hostname}"`)
 
 			const auth = encodeURIComponent(uploadInfo.auth)
-			const url = `https://${hostname}${MEDIA_PATH_MAP[mediaType]}/${fileEncSha256B64}?auth=${auth}&token=${fileEncSha256B64}`
+			const mediaPath = (newsletter ? NEWSLETTER_MEDIA_PATH_MAP[mediaType] : undefined) || MEDIA_PATH_MAP[mediaType]
+			let url = `https://${hostname}${mediaPath}/${fileEncSha256B64}?auth=${auth}&token=${fileEncSha256B64}`
+			if (newsletter) {
+				url += '&server_thumb_gen=1'
+			}
 
 			let result: MediaUploadResult | undefined
 			try {
@@ -868,11 +892,13 @@ export const getWAUploadToServer = (
 
 				if (result?.url || result?.direct_path) {
 					urls = {
-						mediaUrl: result.url!,
+						mediaUrl: result.url || result.direct_path!,
 						directPath: result.direct_path!,
 						meta_hmac: result.meta_hmac,
 						fbid: result.fbid,
-						ts: result.ts
+						ts: result.ts,
+						thumbnailDirectPath: result.thumbnail_info?.thumbnail_direct_path,
+						thumbnailSha256: result.thumbnail_info?.thumbnail_sha256
 					}
 					break
 				} else {

src/Utils/messages.ts

@@ -196,10 +196,11 @@ export const prepareWAMessageMedia = async (
 		)
 
 		const fileSha256B64 = fileSha256.toString('base64')
-		const { mediaUrl, directPath } = await options.upload(filePath, {
+		const { directPath, thumbnailDirectPath, thumbnailSha256 } = await options.upload(filePath, {
 			fileEncSha256B64: fileSha256B64,
 			mediaType: mediaType,
-			timeoutMs: options.mediaUploadTimeoutMs
+			timeoutMs: options.mediaUploadTimeoutMs,
+			newsletter: true
 		})
 
 		await fs.unlink(filePath)
@@ -207,10 +208,12 @@ export const prepareWAMessageMedia = async (
 		const obj = WAProto.Message.fromObject({
 			// todo: add more support here
 			[`${mediaType}Message`]: (MessageTypeProto as any)[mediaType].fromObject({
-				url: mediaUrl,
+				// url intentionally omitted — newsletters use directPath only
 				directPath,
 				fileSha256,
 				fileLength,
+				thumbnailDirectPath,
+				thumbnailSha256: thumbnailSha256 ? Buffer.from(thumbnailSha256, 'base64') : undefined,
 				...uploadData,
 				media: undefined
 			})