When building applications using the HTTP API, it is important to account for any symbols that might interfere with the API string in some way. As a result, it is best practice to triple encode all API strings before calling the API.
Strings that contain symbols such as plus [+] symbol and ampersands [&], and any Unicode characters, must be triple URL encoded and submitted in their encoded form. This ensures such characters a properly escaped.
Many programming languages have functions available for URL encoding.
URLEncoder.encode(URLEncoder.encode(URLEncoder.encode("string", "UTF-8"), "UTF-8"), "UTF-8");
Running this function three times on any strings you submit will help prevent errors that non-escaped symbols might produce and ensure that Unicode encoded messages are received correctly.