I have to create/update a jenkins job using its api because all of my jobs are using parameters which are also used by other scripts and I am trying to centralize the script
You can also POST an updated config.xml to the URL which can fetch config.xml, to programmatically update the configuration of a job.
The fetch url pattern: $JENKINS_SERVER/job/$JOB_NAME/config.xml
detailed doc pattern: $JENKINS_SERVER/job/$JOB_NAME/api
example: https://ci.jenkins-ci.org/job/infra_atlassian-base/api/