From a4fc2b45363ecc3e8ed13069ab84c4dbf41f7abe Mon Sep 17 00:00:00 2001
From: Peter Steinberger <steipete@gmail.com>
Date: Wed, 21 Jan 2026 01:17:35 +0000
Subject: [PATCH] fix: handle fetch streams safely

---
 src/agents/skills-install.ts | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/src/agents/skills-install.ts b/src/agents/skills-install.ts
index 11ad69647..135045936 100644
--- a/src/agents/skills-install.ts
+++ b/src/agents/skills-install.ts
@@ -34,6 +34,10 @@ export type SkillInstallResult = {
   code: number | null;
 };
 
+function isNodeReadableStream(value: unknown): value is NodeJS.ReadableStream {
+  return Boolean(value && typeof (value as NodeJS.ReadableStream).pipe === "function");
+}
+
 function summarizeInstallOutput(text: string): string | undefined {
   const raw = text.trim();
   if (!raw) return undefined;
@@ -154,13 +158,10 @@ async function downloadFile(
     }
     await ensureDir(path.dirname(destPath));
     const file = fs.createWriteStream(destPath);
-    const body = response.body;
-    // Node's Readable.fromWeb expects the node:stream/web type; cast through unknown for DOM streams.
-    const nodeStream = body as unknown as NodeJS.ReadableStream;
-    const readable =
-      typeof nodeStream.pipe === "function"
-        ? nodeStream
-        : Readable.fromWeb(body as unknown as NodeReadableStream);
+    const body = response.body as unknown;
+    const readable = isNodeReadableStream(body)
+      ? body
+      : Readable.fromWeb(body as NodeReadableStream);
     await pipeline(readable, file);
     const stat = await fs.promises.stat(destPath);
     return { bytes: stat.size };