diff --git a/packages/api/src/skills/sync/github.spec.ts b/packages/api/src/skills/sync/github.spec.ts
index e0acc27305..ed2f41d342 100644
--- a/packages/api/src/skills/sync/github.spec.ts
+++ b/packages/api/src/skills/sync/github.spec.ts
@@ -308,17 +308,18 @@ describe('createGitHubSkillSyncRunner', () => {
   it('scopes mirror cleanup to the current source and deletes only its absent upstream skills', async () => {
     const keptId = new Types.ObjectId();
     const staleId = new Types.ObjectId();
-    const existingSkill = (upstreamId: string, _id: Types.ObjectId) =>
-      ({
-        ...makeSkill({
-          name: 'research',
-          description: 'Research things',
-          author: new Types.ObjectId(),
-          source: 'github',
-          sourceMetadata: { provider: 'github', sourceId: 'librechat-skills', upstreamId },
-        } as CreateSkillInput),
-        _id,
-      }) as ISkill & { _id: Types.ObjectId };
+    const existingSkill = (upstreamId: string, _id: Types.ObjectId) => {
+      const skill = makeSkill({
+        name: 'research',
+        description: 'Research things',
+        author: new Types.ObjectId(),
+        authorName: 'GitHub Sync',
+        source: 'github',
+        sourceMetadata: { provider: 'github', sourceId: 'librechat-skills', upstreamId },
+      });
+      skill._id = _id;
+      return skill;
+    };
     const listSkillsBySource = jest.fn(async () => [
       existingSkill('librechat-skills:LibreChat/skills:skills/research', keptId),
       existingSkill('librechat-skills:LibreChat/skills:skills/removed', staleId),
diff --git a/packages/api/src/skills/sync/github.ts b/packages/api/src/skills/sync/github.ts
index 8ce41eed2a..af333c6be7 100644
--- a/packages/api/src/skills/sync/github.ts
+++ b/packages/api/src/skills/sync/github.ts
@@ -797,6 +797,22 @@ async function commitRemoteSkill(
   return { skill: created.skill, created: true };
 }
 
+/**
+ * File sync bumps the parent skill's `version` (via file upserts/deletes) but
+ * never changes its authored content, so we must re-read to get past our own
+ * version bumps. A plain re-read would also silently accept and overwrite a
+ * concurrent external edit; compare the refreshed content against the pre-sync
+ * snapshot and treat a changed body/name/description/always-apply as a conflict.
+ */
+function hasExternalSkillEdit(before: ISkill, after: ISkill): boolean {
+  return (
+    before.body !== after.body ||
+    before.name !== after.name ||
+    before.description !== after.description ||
+    (before.alwaysApply ?? false) !== (after.alwaysApply ?? false)
+  );
+}
+
 async function commitExistingRemoteSkillAfterFileSync(
   deps: GitHubSkillSyncDeps,
   prepared: PreparedExistingRemoteSkill,
@@ -808,6 +824,12 @@ async function commitExistingRemoteSkillAfterFileSync(
       `Previously synced skill "${prepared.existing.name}" was removed`,
     );
   }
+  if (hasExternalSkillEdit(prepared.existing, refreshed)) {
+    throw new SkillSyncError(
+      'SKILL_CONFLICT',
+      `Skill "${prepared.existing.name}" was modified during sync`,
+    );
+  }
   return commitRemoteSkill(deps, { ...prepared, existing: refreshed });
 }