Found the solution! Here it is, if somebody needs the description. The webview_bind() function in DLL that expects to get a pointer to the function in Pharo can be called like this: ``` WebViewLibrary >> bind: webview name: aString callback: aFFICallback arguments: aByteString ``` ``` ^ self ffiCall: #(void webview_bind(void * webview, const char * aString, FFICallback aFFICallback, void * aByteString)) ``` Before doing the actual call, the callback should be made according to fn signature: ``` doIt := FFICallback ``` ``` signature: #( void (const char *seq, const char *req, void * arg) ) ``` ``` block: [ :seq :req :arg | ``` ``` âdo the stuffâ ``` ``` ]. ``` And the call is then made as: ``` WebViewLibrary new bind: webview name: 'newJsFunctionName' callback: doIt arguments: args. ``` The next challenge is, of course, threading ... Best wishes,\ Tomaz