Add lita-jira to your Lita instance's Gemfile:
gem "lita-jira"
Add the following variables to your lita config file:
config.handlers.jira.username = 'your_jira_username'
config.handlers.jira.password = 'a_password'
config.handlers.jira.site = 'https://your.jira.instance.example.com/'
config.handlers.jira.context = '' # If your instance is in a /subdirectory, put that here
todo <project> "<subject>" ["<summary>"] - Creates an issue in <project> with <subject> and optionally <summary>
jira <issue> - Shows a short summary <issue>
jira details <issue> - Shows all details about <issue>
jira comment on <issue> <comment text> - Adds <comment text> to <issue>
jira myissues - Displays a list of issues assigned to identified user
jira identify <email address> - Associate your chat user with your email address
jira forget - Remove your chat user / email association
jira whoami - Show your chat user / email association