How to get Oracle API information in Oracle Applications

Go to System Administrator -> Assign
Integrated SOA Gateway Responsibility
Then Go to E-Business Suite menu  and select module and see API information with parameters and purpose.

FND API to Delete, Add and Update value set values in Oracle Applications

ALTER SESSION SET CURRENT_SCHEMA = APPS;

DECLARE
   l_err_msg   VARCHAR2 (500) := NULL;

   CURSOR c1
   IS
      SELECT ffv.flex_value_id, ffv.flex_value
        FROM apps.fnd_flex_value_sets ffvs
            ,apps.fnd_flex_values ffv
            ,apps.fnd_flex_values_tl ffvt
       WHERE flex_value_set_name = 'XXXXXXXX'  -- Value Set Name
         AND ffv.flex_value_set_id = ffvs.flex_value_set_id
         AND ffvt.flex_value_id = ffv.flex_value_id
         AND ffvs.flex_value_set_id = ffv.flex_value_set_id
         AND ffvt.LANGUAGE = 'US'
         AND ffv.enabled_flag = 'Y'
         AND ffv.summary_flag = 'N'
         AND ffv.flex_value IN
                ('XXXXX'
                ,'XXXXXXXXXXX'
                ,'XXXXXXXL');
BEGIN
   FOR i IN c1
   LOOP
      apps.fnd_flex_values_pkg.delete_row (i.flex_value_id);
      COMMIT;
      DBMS_OUTPUT.put_line (i.flex_value_id || ' Deleted  Successfully !!!!');
   END LOOP;
EXCEPTION
   WHEN OTHERS
   THEN
      l_err_msg := SQLERRM;
      DBMS_OUTPUT.put_line ('Exception: ' || l_err_msg);
END;