diff --git a/packages/agent-runtime/src/acp-launch-specs.ts b/packages/agent-runtime/src/acp-launch-specs.ts
index c42000eb8..4096a073a 100644
--- a/packages/agent-runtime/src/acp-launch-specs.ts
+++ b/packages/agent-runtime/src/acp-launch-specs.ts
@@ -29,7 +29,7 @@ export const BUILT_IN_ACP_LAUNCH_SPECS: Readonly<
       // catalog folds effort and the `-fast` tail into one entry per family.
       primaryModels: [
         "auto",
-        "cursor-grok-4.5-medium",
+        "cursor-grok-4.6-medium",
         "gpt-5.6-sol-medium",
         "claude-opus-5-thinking-medium",
         "claude-fable-5-thinking-medium",