diff --git a/src/channels/line/adapter.test.ts b/src/channels/line/adapter.test.ts
index db649cc..6dd908d 100644
--- a/src/channels/line/adapter.test.ts
+++ b/src/channels/line/adapter.test.ts
@@ -74,6 +74,56 @@ describe('LineAdapter', () => {
     expect(mockFetch.mock.calls[0]?.[0]).toBe('https://api.line.me/v2/bot/message/push');
   });
 
+  it('send emits URL attachments and warns for binary attachments', async () => {
+    const warnSpy = vi.spyOn(console, 'warn').mockImplementation(() => {});
+    const adapter = new LineAdapter({
+      channelAccessToken: 'token',
+      channelSecret: 'secret',
+    });
+    await adapter.connect();
+    mockFetch.mockResolvedValue({
+      ok: true,
+      status: 200,
+      text: async () => '',
+    } as Response);
+
+    await adapter.send('U123', {
+      text: 'hello line',
+      attachments: [
+        { mimeType: 'text/plain', url: 'https://example.com/file.txt', filename: 'file.txt' },
+        { mimeType: 'image/png', data: 'aGVsbG8=' },
+      ],
+    });
+
+    expect(mockFetch).toHaveBeenCalledTimes(2);
+    const secondBody = JSON.parse(String(mockFetch.mock.calls[1]?.[1]?.body ?? '{}'));
+    expect(secondBody.messages?.[0]?.text).toBe('file.txt: https://example.com/file.txt');
+    expect(warnSpy).toHaveBeenCalledWith('LINE: skipping attachment data (image/png) — upload not implemented');
+    warnSpy.mockRestore();
+  });
+
+  it('send delivers URL attachment even when text is empty', async () => {
+    const adapter = new LineAdapter({
+      channelAccessToken: 'token',
+      channelSecret: 'secret',
+    });
+    await adapter.connect();
+    mockFetch.mockResolvedValue({
+      ok: true,
+      status: 200,
+      text: async () => '',
+    } as Response);
+
+    await adapter.send('U123', {
+      text: '   ',
+      attachments: [{ mimeType: 'text/plain', url: 'https://example.com/file.txt', filename: 'file.txt' }],
+    });
+
+    expect(mockFetch).toHaveBeenCalledTimes(1);
+    const body = JSON.parse(String(mockFetch.mock.calls[0]?.[1]?.body ?? '{}'));
+    expect(body.messages?.[0]?.text).toBe('file.txt: https://example.com/file.txt');
+  });
+
   it('handleRequest validates signature and dispatches text event', async () => {
     const adapter = new LineAdapter({
       channelAccessToken: 'token',
diff --git a/src/channels/line/adapter.ts b/src/channels/line/adapter.ts
index b3ae055..844e8ac 100644
--- a/src/channels/line/adapter.ts
+++ b/src/channels/line/adapter.ts
@@ -70,13 +70,27 @@ export class LineAdapter implements ChannelAdapter {
     }
 
     const text = message.text.trim();
-    if (!text) {
+    const attachments = message.attachments ?? [];
+    if (!text && attachments.length === 0) {
       return;
     }
 
-    const chunks = text.length > MAX_MESSAGE_LENGTH ? splitMessage(text, MAX_MESSAGE_LENGTH) : [text];
-    for (const chunk of chunks) {
-      await this.sendPush(peerId, chunk);
+    if (text) {
+      const chunks = text.length > MAX_MESSAGE_LENGTH ? splitMessage(text, MAX_MESSAGE_LENGTH) : [text];
+      for (const chunk of chunks) {
+        await this.sendPush(peerId, chunk);
+      }
+    }
+
+    for (const attachment of attachments) {
+      if (attachment.url) {
+        const line = attachment.filename ? `${attachment.filename}: ${attachment.url}` : attachment.url;
+        await this.sendPush(peerId, line);
+        continue;
+      }
+      if (attachment.data) {
+        console.warn(`LINE: skipping attachment data (${attachment.mimeType}) — upload not implemented`);
+      }
     }
   }
 
diff --git a/src/channels/zalo/adapter.test.ts b/src/channels/zalo/adapter.test.ts
index 201b1b3..af62bec 100644
--- a/src/channels/zalo/adapter.test.ts
+++ b/src/channels/zalo/adapter.test.ts
@@ -63,6 +63,50 @@ describe('ZaloAdapter', () => {
     expect(String(mockFetch.mock.calls[0]?.[0])).toContain('/v3.0/oa/message/cs');
   });
 
+  it('send emits URL attachments and warns for binary attachments', async () => {
+    const warnSpy = vi.spyOn(console, 'warn').mockImplementation(() => {});
+    const adapter = new ZaloAdapter({ oaAccessToken: 'token' });
+    await adapter.connect();
+    mockFetch.mockResolvedValue({
+      ok: true,
+      status: 200,
+      text: async () => '',
+    } as Response);
+
+    await adapter.send('uid-1', {
+      text: 'hello zalo',
+      attachments: [
+        { mimeType: 'text/plain', url: 'https://example.com/file.txt', filename: 'file.txt' },
+        { mimeType: 'application/pdf', data: 'aGVsbG8=' },
+      ],
+    });
+
+    expect(mockFetch).toHaveBeenCalledTimes(2);
+    const secondBody = JSON.parse(String(mockFetch.mock.calls[1]?.[1]?.body ?? '{}'));
+    expect(secondBody.message?.text).toBe('file.txt: https://example.com/file.txt');
+    expect(warnSpy).toHaveBeenCalledWith('Zalo: skipping attachment data (application/pdf) — upload not implemented');
+    warnSpy.mockRestore();
+  });
+
+  it('send delivers URL attachment even when text is empty', async () => {
+    const adapter = new ZaloAdapter({ oaAccessToken: 'token' });
+    await adapter.connect();
+    mockFetch.mockResolvedValue({
+      ok: true,
+      status: 200,
+      text: async () => '',
+    } as Response);
+
+    await adapter.send('uid-1', {
+      text: ' ',
+      attachments: [{ mimeType: 'text/plain', url: 'https://example.com/file.txt', filename: 'file.txt' }],
+    });
+
+    expect(mockFetch).toHaveBeenCalledTimes(1);
+    const body = JSON.parse(String(mockFetch.mock.calls[0]?.[1]?.body ?? '{}'));
+    expect(body.message?.text).toBe('file.txt: https://example.com/file.txt');
+  });
+
   it('handleEvent emits inbound message', async () => {
     const adapter = new ZaloAdapter({ oaAccessToken: 'token', requireMention: false });
     const inbound: Array<{ channel: string; senderId: string; text: string }> = [];
diff --git a/src/channels/zalo/adapter.ts b/src/channels/zalo/adapter.ts
index 01bc693..bceb384 100644
--- a/src/channels/zalo/adapter.ts
+++ b/src/channels/zalo/adapter.ts
@@ -60,13 +60,27 @@ export class ZaloAdapter implements ChannelAdapter {
     }
 
     const text = message.text.trim();
-    if (!text) {
+    const attachments = message.attachments ?? [];
+    if (!text && attachments.length === 0) {
       return;
     }
 
-    const chunks = text.length > MAX_MESSAGE_LENGTH ? splitMessage(text, MAX_MESSAGE_LENGTH) : [text];
-    for (const chunk of chunks) {
-      await this.sendText(peerId, chunk);
+    if (text) {
+      const chunks = text.length > MAX_MESSAGE_LENGTH ? splitMessage(text, MAX_MESSAGE_LENGTH) : [text];
+      for (const chunk of chunks) {
+        await this.sendText(peerId, chunk);
+      }
+    }
+
+    for (const attachment of attachments) {
+      if (attachment.url) {
+        const line = attachment.filename ? `${attachment.filename}: ${attachment.url}` : attachment.url;
+        await this.sendText(peerId, line);
+        continue;
+      }
+      if (attachment.data) {
+        console.warn(`Zalo: skipping attachment data (${attachment.mimeType}) — upload not implemented`);
+      }
     }
   }