Hi, I have a handler for a post request that uses CouchDB to save a new book: newBookHandler :: ServerPart Response newBookHandler = do methodM POST decodeBody myPolicy title <- look "Title" description <- look "Description" type' <- lookRead "Type" permission <- lookRead "Permission" let author = "Asafe" liftIO $ createBook (Book title type' author description permission) ok $ toResponse ( Template.books "Your new book was just created ! Give it some love now") create is defined like that: createBook book = runCouchDB' $ newDoc db' $ toJSON book However when I perform the post request I get: Server error : Stack overflow. All works fine if I comment the line of createBook. I must be missing something because I was not able to use macid neither...