From 186fdf6b0616a3080232cc5bbc213944924f3a2c Mon Sep 17 00:00:00 2001
From: Peter Steinberger <steipete@gmail.com>
Date: Thu, 22 Jan 2026 23:16:03 +0000
Subject: [PATCH] fix: refine slack uploadV2 payload (#1447) (thanks @jdrhyne)

---
 CHANGELOG.md                                  |  2 +-
 src/slack/send.ts                             |  3 +-
 .../send.uploadV2-omits-filetype.test.ts      | 52 +++++++++++++++++++
 3 files changed, 54 insertions(+), 3 deletions(-)
 create mode 100644 src/slack/send.uploadV2-omits-filetype.test.ts

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 305150cea4..41f098cdd8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@ Docs: https://docs.clawd.bot
 - BlueBubbles: stop typing indicator on idle/no-reply. (#1439) Thanks @Nicell.
 - Auto-reply: only report a model switch when session state is available. (#1465) Thanks @robbyczgw-cla.
 - Control UI: resolve local avatar URLs with basePath across injection + identity RPC. (#1457) Thanks @dlauer.
+- Slack: remove deprecated `filetype` field from `files.uploadV2` to eliminate API warnings. (#1447) Thanks @jdrhyne.
 - Agents: surface concrete API error details instead of generic AI service errors.
 - Docs: fix gog auth services example to include docs scope. (#1454) Thanks @zerone0x.
 
@@ -15,7 +16,6 @@ Docs: https://docs.clawd.bot
 
 ### Fixes
 - Control UI: ignore bootstrap identity placeholder text for avatar values and fall back to the default avatar. https://docs.clawd.bot/cli/agents https://docs.clawd.bot/web/control-ui
-- Slack: remove deprecated `filetype` field from `files.uploadV2` to eliminate API warnings. (#1447)
 
 ## 2026.1.21
 
diff --git a/src/slack/send.ts b/src/slack/send.ts
index cfc6c47072..1dba06c24a 100644
--- a/src/slack/send.ts
+++ b/src/slack/send.ts
@@ -88,13 +88,12 @@ async function uploadSlackFile(params: {
   threadTs?: string;
   maxBytes?: number;
 }): Promise<string> {
-  const { buffer, contentType, fileName } = await loadWebMedia(params.mediaUrl, params.maxBytes);
+  const { buffer, fileName } = await loadWebMedia(params.mediaUrl, params.maxBytes);
   const basePayload = {
     channel_id: params.channelId,
     file: buffer,
     filename: fileName,
     ...(params.caption ? { initial_comment: params.caption } : {}),
-    // Note: filetype is deprecated in files.uploadV2, Slack auto-detects from file content
   };
   const payload: FilesUploadV2Arguments = params.threadTs
     ? { ...basePayload, thread_ts: params.threadTs }
diff --git a/src/slack/send.uploadV2-omits-filetype.test.ts b/src/slack/send.uploadV2-omits-filetype.test.ts
new file mode 100644
index 0000000000..620889791b
--- /dev/null
+++ b/src/slack/send.uploadV2-omits-filetype.test.ts
@@ -0,0 +1,52 @@
+import type { WebClient } from "@slack/web-api";
+import { describe, expect, it, vi } from "vitest";
+
+import { loadConfig } from "../config/config.js";
+import { loadWebMedia } from "../web/media.js";
+import { sendMessageSlack } from "./send.js";
+
+vi.mock("../config/config.js", () => ({
+  loadConfig: vi.fn(),
+}));
+
+vi.mock("../web/media.js", () => ({
+  loadWebMedia: vi.fn(),
+}));
+
+const loadConfigMock = vi.mocked(loadConfig);
+const loadWebMediaMock = vi.mocked(loadWebMedia);
+
+describe("slack send", () => {
+  it("omits filetype in files.uploadV2 payload", async () => {
+    loadConfigMock.mockReturnValue({ channels: { slack: {} } } as never);
+    loadWebMediaMock.mockResolvedValue({
+      buffer: Buffer.from("data"),
+      contentType: "image/png",
+      fileName: "test.png",
+      kind: "image",
+    });
+
+    const uploadV2 = vi.fn().mockResolvedValue({ files: [{ id: "F123" }] });
+    const postMessage = vi.fn().mockResolvedValue({ ts: "123.456" });
+    const client = {
+      files: { uploadV2 },
+      chat: { postMessage },
+    } as unknown as WebClient;
+
+    const result = await sendMessageSlack("channel:C123", "hello", {
+      mediaUrl: "https://example.com/test.png",
+      token: "xoxb-test",
+      client,
+    });
+
+    expect(uploadV2).toHaveBeenCalledTimes(1);
+    const payload = uploadV2.mock.calls[0]?.[0] as Record<string, unknown>;
+    expect(payload).toMatchObject({
+      channel_id: "C123",
+      filename: "test.png",
+      initial_comment: "hello",
+    });
+    expect("filetype" in payload).toBe(false);
+    expect(result).toEqual({ messageId: "F123", channelId: "C123" });
+  });
+});