# Adding an operation

An operation names the operation and lists the expected inputs and outputs. The operation element may also contain a fault sub-element that describes any error data the operation may return.

Using these, you can declare four transmission primitives that an endpoint can support:

- One-way: the endpoint receives a message.
- Request-response: the endpoint receives a message, and sends a correlated message.
- Solicit-response: the endpoint sends a message, and receives a correlated message.
- Notification: the endpoint sends a message.

You can add an operation to a port type or a port binding.

To add an operation to a port type, complete the following steps:

1. In the Design view, right-click your port type. Click Add Operation. To select the new operation, click the operation in the port type object.
2. In the Properties view, click the General pane.
3. In the Name field, type the name of the operation.
4. Right click on the operation to add input, output or fault objects. Depending on an operation's inputs and outputs it can be classified as follows:
   - One way operation: input
   - Request response operation: input, output
   - Solicit response operation: output, input
   - Notification operation: output
5. In the Properties view, type any information about the operation you wish the user to read in the Documentation pane.

Tip: You can also create a new operation for your port type using the Outline view. Right click on a port type in the Port Type folder and select Add Operation.

Related concepts
Editing WSDL files with the WSDL Editor
Related tasks
Creating a new WSDL file
Editing WSDL files