Tooling API

What is the Tooling API?

• Tooling API exposes metadata information of Org
• We can access Metadata information using REST or SOAP.
• A Simple use case of tooling api is deleting the debug log from the developer console 

What Can be fetch using Tooling API?

• Fetch the metadata about Visualforce Pages, Apex Triggers, Apex classes.
• Get the metadata about an object’s field.
• Get the Code Coverage details of Apex Classes and Triggers.
• Retrieve metadata of custom and standard object properties.
• Retrieve metadata information about Validation Rules and Workflow Rules.
• We can Create, Update Apex Classes and Apex Triggers.
• We can get the RecentItems of our dev-org using Tooling API.

Where can Tooling API be used?

Because Tooling API allows you to change just one element within a complex type, it can be easier to use than Metadata API. Other use cases include:

• Source control integration
•  Continuous integration Ex- Jenkin used tooling api for code coverage validation.
• Apex classes or trigger deployment

How can Tooling API consume?

Using Apex Code

Tooling API can be consumed using HTTP REST API and SOAP method

1. HttpRequest req = new HttpRequest();
   req.setHeader('Authorization', 'Bearer ' + UserInfo.getSessionID()); //Get user Session ID
   req.setHeader('Content-Type', 'application/json');
   String SFdomainUrl=URL.getSalesforceBaseUrl().toExternalForm();
   String query='Select+id,FullName,createdDate,TableEnumOrId,ValidationName,Metadata+from+ValidationRule';
   req.setEndpoint(SFdomainUrl+'/services/data/v33.0/tooling/query/?q='+query);
   req.setMethod('GET');
   Http h = new Http();
   HttpResponse response = h.send(req);

Using Workbench

Using the Developer Console

Check Use tooling API while querying the Apex Test class or Debug log 

To know about other integration API at a glance, pls Click here