diff --git a/functions/_synu_agents/opencode.fish b/functions/_synu_agents/opencode.fish
index 7eed3d89d2705f2fb391899fa9661d748b588dd7..073d623572b92aaffe599133c75d59b061e1809b 100644
--- a/functions/_synu_agents/opencode.fish
+++ b/functions/_synu_agents/opencode.fish
@@ -40,9 +40,9 @@ function _synu_agent_opencode_configure --description "Configure OpenCode model
 end
 
 function _synu_agent_opencode_args --description "Return CLI arguments to pass to opencode"
-    # Return -m flag with selected model
+    # Return -m flag with selected model, prefixed with synthetic/ for provider routing
     echo -m
-    echo $_synu_opencode_selected_model
+    echo "synthetic/$_synu_opencode_selected_model"
 end
 
 function _synu_agent_opencode_interactive --description "Interactive model selection using gum"