I found an undocumented isConnectedTo method, which might be useful chuck_lang.h: // ugen API //----------------------------------------------------------------------------- CK_DLL_CTOR( ugen_ctor ); CK_DLL_DTOR( ugen_dtor ); CK_DLL_MFUN( ugen_op ); CK_DLL_MFUN( ugen_cget_op ); CK_DLL_MFUN( ugen_last ); CK_DLL_MFUN( ugen_cget_last ); CK_DLL_MFUN( ugen_next ); CK_DLL_MFUN( ugen_cget_next ); CK_DLL_MFUN( ugen_gain ); CK_DLL_MFUN( ugen_cget_gain ); CK_DLL_MFUN( ugen_numChannels ); CK_DLL_MFUN( ugen_cget_numChannels ); CK_DLL_MFUN( ugen_chan ); CK_DLL_MFUN( ugen_connected ); chuck_lang.cpp: // add isConnectedTo func = make_new_mfun( "int", "isConnectedTo", ugen_connected ); func->add_arg( "UGen", "right" ); func->doc = "Return true if this ugen's output is connected to the input of the argument. Return false otherwise. "; if( !type_engine_import_mfun( env, func ) ) goto error; and a get_num_src() method which appears not to be exposed via the ChucK API chuck_ugen.h: public: // src t_CKBOOL add( Chuck_UGen * src, t_CKBOOL isUpChuck ); t_CKBOOL remove( Chuck_UGen * src ); t_CKVOID remove_all( ); t_CKBOOL set_max_src( t_CKUINT num ); t_CKUINT get_num_src( ); t_CKBOOL is_connected_from( Chuck_UGen * src ); t_CKUINT disconnect( t_CKBOOL recursive ); t_CKUINT system_tick( t_CKTIME now ); t_CKUINT system_tick_v( t_CKTIME now, t_CKUINT numFrames ); t_CKBOOL alloc_v( t_CKUINT size ); Is that what I would need? michael On Mon, Dec 7, 2015 at 11:55 AM, Michael Heuer wrote:

Is it possible to query whether a UGen has an input or not? If anything has been chucked to it, in other words.

Thanks,

michael