Tooling API Objects and Namespaces

Tooling API objects provide programmatic access to data and metadata. The Tooling API WSDL includes four namespaces.

Namespace	Used for	Prefix
`sobject.tooling.soap.sforce.com`	Tooling API sObjects. Some sObjects have a Metadata field defined in the `mns` namespace. This namespace is available in API version 37.0 and later.	`ens`
`fault.tooling.soap.sforce.com`	Tooling API error codes. This namespace is available in API version 37.0 and later.	`fns`
`tooling.soap.sforce.com`	General complex types, describe results, and all enum types in the Tooling API.	`tns`
`metadata.tooling.soap.sforce.com`	Objects and types that occur in both the Metadata API WSDL and the Tooling API WSDL. Elements in the two WSDLs might be defined differently.	`mns`

Objects and types that are identical in the Tooling API and Metadata API WSDLs are documented in the Metadata API Developer Guide.

Objects and types that are different in the Tooling API WSDL or occur only in the Tooling API WSDL are documented in this guide.

Frequently occurring system fields are described in System Fields. You can verify the complete list of fields for an object by generating and reviewing the Tooling API WSDL.

Object Quick-Reference Tables, System Fields, and SOQL Limitations

Learn about objects, system fields that occur on most objects, and SOQL limitations that apply to some objects in Tooling API. An alphabetical list of objects is also available.