Github Commit Status API with Bamboo from Atlassian. Add those to your plan as Script.

complete.sh

# specs and cukes results are stored in JUnit format under test-reports
if (grep 'failures="[^0]"' test-reports/* || grep 'errors="[^0]"' test-reports/*); then
  curl -H "Authorization: token MY_TOKEN" --request POST --data '{"state": "failure", "description": "Failed!", "target_url": "${bamboo.buildResultsUrl}"}' https://api.github.com/repos/USER/REPO/statuses/${bamboo.repository.revision.number} > /dev/null
else
  curl -H "Authorization: token MY_TOKEN" --request POST --data '{"state": "success", "description": "Success!", "target_url": "${bamboo.buildResultsUrl}"}' https://api.github.com/repos/USER/REPO/statuses/${bamboo.repository.revision.number} > /dev/null
fi

pending.sh

curl -H "Authorization: token MY_TOKEN" --request POST --data '{"state": "pending", "description": "Build is running", "target_url": "${bamboo.buildResultsUrl}"}' https://api.github.com/repos/USER/REPO/statuses/${bamboo.repository.revision.number} > /dev/null

thanks!

For windows builds use Script without powershell option and

curl --data "{\"state\": \"pending\", \"description\": \"Build is running\", \"target_url\": \"${bamboo.buildResultsUrl}\"}" https://api.github.com/repos/OWNER/REPO/statuses/${bamboo.planRepository.revision} -H "Authorization: token TOKEN"```