Demo Jenkins REST API install a plugin

Leverage the Jenkins REST API to automate common CI/CD tasks—listing jobs, inspecting job details, triggering parameterized builds, and installing plugins programmatically. This tutorial demonstrates each step using curl commands, JSON/XML endpoints, and Jenkins API tokens.

Key Jenkins REST API Endpoints

Endpoint	Action	HTTP Method
`/api/json?tree=jobs[name]`	List all jobs	GET
`/job/{JOB_NAME}/api/json`	Retrieve detailed job metadata	GET
`/job/{JOB_NAME}/buildWithParameters`	Trigger a parameterized build	POST
`/crumbIssuer/api/json`	Obtain CSRF crumb	GET
`/pluginManager/installNecessaryPlugins`	Install one or more plugins	POST

1. Retrieving the List of Jobs

Fetch all jobs in JSON and limit the fields with the tree parameter to minimize payload:

curl http://JENKINS_URL/api/json?tree=jobs[name]

Sample response:

{
  "_class": "hudson.model.Hudson",
  "jobs": [
    {"_class":"hudson.model.FreeStyleProject","name":"ascii-build-job"},
    {"_class":"hudson.model.FreeStyleProject","name":"ascii-deploy-job"},
    {"_class":"hudson.model.FreeStyleProject","name":"ascii-test-job"},
    {"_class":"hudson.model.FreeStyleProject","name":"Generate ASCII Artwork"},
    {"_class":"org.jenkinsci.plugins.workflow.job.WorkflowJob","name":"hello-world-pipeline"},
    {"_class":"org.jenkinsci.plugins.workflow.multibranch.WorkflowMultiBranchProject","name":"jenkins-hello-world"},
    {"_class":"org.jenkinsci.plugins.workflow.job.WorkflowJob","name":"parameterized-pipeline-job"}
  ]
}

The tree=jobs[name] query reduces the JSON to just the name field of each job.

2. Retrieving Job Details

Query a specific job’s API endpoint with authentication. Using jq formats the JSON:

curl -u admin:API_TOKEN \
  http://JENKINS_URL/job/parameterized-pipeline-job/api/json | jq

Abbreviated example output:

{
  "name": "parameterized-pipeline-job",
  "url": "http://JENKINS_URL/job/parameterized-pipeline-job/",
  "buildable": true,
  "builds": [
    {"number":5,"url":".../job/parameterized-pipeline-job/5/"},
    {"number":4,"url":".../job/parameterized-pipeline-job/4/"}
  ],
  "nextBuildNumber": 6,
  "property": [
    {
      "_class": "hudson.model.ParametersDefinitionProperty",
      "parameterDefinitions": [
        {
          "name": "BRANCH_NAME",
          "defaultParameterValue": {"value": "main"},
          "description": "The Git branch to build"
        },
        {
          "name": "APP_PORT",
          "defaultParameterValue": {"value": "6767"},
          "description": "Application port for tests"
        }
      ]
    }
  ]
}

3. Triggering a Build with Parameters

Use the buildWithParameters endpoint to start a parameterized job. Always use the POST method:

curl -u admin:API_TOKEN \
  -X POST \
  http://JENKINS_URL/job/parameterized-pipeline-job/buildWithParameters \
  -d BRANCH_NAME=test \
  -d APP_PORT=6767

If Jenkins enforces CSRF protection, you will receive a 403 No valid crumb error unless you include a valid crumb header.

3.1 Obtaining and Using a Crumb

Fetch the crumb from Jenkins:

CRUMB=$(curl -u admin:API_TOKEN \
  http://JENKINS_URL/crumbIssuer/api/json | jq -r .crumb)

Include the crumb in your build request:

curl -u admin:API_TOKEN \
  -H "Jenkins-Crumb:$CRUMB" \
  -X POST \
  http://JENKINS_URL/job/parameterized-pipeline-job/buildWithParameters \
  -d BRANCH_NAME=test \
  -d APP_PORT=6767

After triggering, verify in the Jenkins UI that build #6 is “in progress”:

The image shows a Jenkins dashboard for a parameterized pipeline job, displaying a successful build history and a test result trend graph with all tests passed.

4. Installing a Plugin via REST API

You can install plugins by posting an XML payload to the installNecessaryPlugins endpoint.

curl -u admin:API_TOKEN \
  -X POST http://JENKINS_URL/pluginManager/installNecessaryPlugins \
  -H 'Content-Type: text/xml' \
  -d '<jenkins>
        <install plugin="emotional-jenkins-plugin@1.2" />
        <!-- Add more <install plugin="groupId/artifactId@version" /> entries as needed -->
      </jenkins>'

Always authenticate using an API token and set Content-Type: text/xml when sending XML payloads.

Once the request completes, navigate to Manage Jenkins → Manage Plugins → Advanced to monitor download progress:

The image shows a Jenkins interface displaying the download progress of various plugins, all marked as successful. The left sidebar includes options like Updates, Available plugins, Installed plugins, and Advanced settings.

Conclusion

In this article, you have learned how to:

List and filter jobs using the Jenkins REST API
Retrieve detailed metadata for a given job
Trigger parameterized builds, handling CSRF crumbs
Install and manage Jenkins plugins programmatically

Use these API techniques to integrate Jenkins into your automation workflows and scale your CI/CD pipelines.

Introduction and Basics

Jenkins Setup and Interface

Extending Jenkins and Administration

Jenkins Pipelines

Automation and Security

Setting up CI Pipeline

Code Quality and Testing

Containerization and Deployment

Kubernetes and GitOps

AWS Lambda and Advanced Deployment Techniques

Jenkins Administration and Monitoring - Part 1

Shared Libraries in Jenkins

Agents and Nodes in Jenkins

Pipeline Enhancement and Caching

Pipeline Structure and Scripted vs Declarative

Jenkins Administration and Monitoring - Part 2

Backup and Configuration Management

Demo Jenkins REST API install a plugin

Key Jenkins REST API Endpoints

1. Retrieving the List of Jobs

2. Retrieving Job Details

3. Triggering a Build with Parameters

3.1 Obtaining and Using a Crumb

4. Installing a Plugin via REST API

Conclusion

Links and References

Watch Video

​Key Jenkins REST API Endpoints

​1. Retrieving the List of Jobs

​2. Retrieving Job Details

​3. Triggering a Build with Parameters

​3.1 Obtaining and Using a Crumb

​4. Installing a Plugin via REST API

​Conclusion

​Links and References

Watch Video

Key Jenkins REST API Endpoints

1. Retrieving the List of Jobs

2. Retrieving Job Details

3. Triggering a Build with Parameters

3.1 Obtaining and Using a Crumb

4. Installing a Plugin via REST API

Conclusion

Links and References