diff --git a/clients/macos/vellum-assistant/Features/MainWindow/Panels/IdentityPanel.swift b/clients/macos/vellum-assistant/Features/MainWindow/Panels/IdentityPanel.swift
index 80c05b0c091..3f0e1fa4d64 100644
--- a/clients/macos/vellum-assistant/Features/MainWindow/Panels/IdentityPanel.swift
+++ b/clients/macos/vellum-assistant/Features/MainWindow/Panels/IdentityPanel.swift
@@ -301,12 +301,15 @@ struct IdentityPanel: View {
             let response = await SkillsClient().fetchSkillsList(includeCatalog: false)
             if let response {
                 let enabled = response.skills.filter { $0.status == "enabled" }
+                let map = await Task.detached {
+                    var m: [String: SkillCategory] = [:]
+                    m.reserveCapacity(enabled.count)
+                    for skill in enabled {
+                        m[skill.id] = inferCategory(skill)
+                    }
+                    return m
+                }.value
                 skills = enabled
-                var map: [String: SkillCategory] = [:]
-                map.reserveCapacity(enabled.count)
-                for skill in enabled {
-                    map[skill.id] = inferCategory(skill)
-                }
                 skillCategoryLookup = map
             }
         }
diff --git a/clients/macos/vellum-assistant/Features/MainWindow/Panels/SkillsManager.swift b/clients/macos/vellum-assistant/Features/MainWindow/Panels/SkillsManager.swift
index 96be2872b4f..bea40aefbb6 100644
--- a/clients/macos/vellum-assistant/Features/MainWindow/Panels/SkillsManager.swift
+++ b/clients/macos/vellum-assistant/Features/MainWindow/Panels/SkillsManager.swift
@@ -37,6 +37,7 @@ final class SkillsManager {
     /// Cached skill-id -> category map, rebuilt whenever `skills` changes.
     /// Use `category(for:)` for O(1) lookups instead of calling `inferCategory` in view bodies.
     private(set) var categoryMap: [String: SkillCategory] = [:]
+    @ObservationIgnored private var categoryFingerprints: [String: String] = [:]
     var loadedBodies: [String: String] = [:]
     var isLoading = false
     var uninstallResult: SkillsStore.UninstallResult?
@@ -122,11 +123,20 @@ final class SkillsManager {
 
     private func rebuildCategoryMap(from skills: [SkillInfo]) {
         var map: [String: SkillCategory] = [:]
+        var fingerprints: [String: String] = [:]
         map.reserveCapacity(skills.count)
+        fingerprints.reserveCapacity(skills.count)
         for skill in skills {
-            map[skill.id] = inferCategory(skill)
+            let fp = skill.name + "\0" + skill.description
+            if let cached = categoryMap[skill.id], categoryFingerprints[skill.id] == fp {
+                map[skill.id] = cached
+            } else {
+                map[skill.id] = inferCategory(skill)
+            }
+            fingerprints[skill.id] = fp
         }
         categoryMap = map
+        categoryFingerprints = fingerprints
     }
 
     // MARK: - Recomputation