diff --git a/crates/buzz-agent/src/config.rs b/crates/buzz-agent/src/config.rs
index f06849c7d1..9ed697ca4e 100644
--- a/crates/buzz-agent/src/config.rs
+++ b/crates/buzz-agent/src/config.rs
@@ -184,6 +184,7 @@ pub fn anthropic_thinking_config(
 fn anthropic_model_supports_xhigh(model: &str) -> bool {
     model.starts_with("claude-opus-4-7")
         || model.starts_with("claude-opus-4-8")
+        || model.starts_with("claude-opus-5")
         || model.starts_with("claude-sonnet-5")
         || model.starts_with("claude-fable-5")
         || model.starts_with("claude-mythos-5")
@@ -606,6 +607,7 @@ fn is_adaptive_thinking_model(model: &str) -> bool {
     model.starts_with("claude-opus-4-6")
         || model.starts_with("claude-opus-4-7")
         || model.starts_with("claude-opus-4-8")
+        || model.starts_with("claude-opus-5")
         // Sonnet 5.x (any patch/date suffix after "claude-sonnet-5").
         || model.starts_with("claude-sonnet-5")
         // Sonnet 4.6 exactly (not Sonnet 4.5 or earlier — not in the adaptive table).
diff --git a/desktop/src/features/agents/ui/effortTable.fixture.json b/desktop/src/features/agents/ui/effortTable.fixture.json
index ed44c7581b..defb1f86de 100644
--- a/desktop/src/features/agents/ui/effortTable.fixture.json
+++ b/desktop/src/features/agents/ui/effortTable.fixture.json
@@ -41,6 +41,13 @@
     "validValues": ["low", "medium", "high", "xhigh", "max"],
     "defaultValue": "high"
   },
+  {
+    "note": "Anthropic adaptive xhigh-capable: claude-opus-5",
+    "provider": "anthropic",
+    "model": "claude-opus-5",
+    "validValues": ["low", "medium", "high", "xhigh", "max"],
+    "defaultValue": "high"
+  },
   {
     "note": "Anthropic adaptive xhigh-capable: claude-mythos-5",
     "provider": "anthropic",