> ## Documentation Index
> Fetch the complete documentation index at: https://developer.watson-orchestrate.ibm.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Mapping inputs and outputs

You can manually map the inputs and outputs of your nodes using the `map_input()` and `map_output()` methods. To do this, call `map_input()` or `map_output()` in your node and provide the following values:

* `map_input()` Parameters

  | Parameter       | Type   | Required | Description                             |
  | --------------- | ------ | -------- | --------------------------------------- |
  | input\_variable | string | Yes      | The variable you want to map.           |
  | expression      | string | Yes      | The expression used to map the input.   |
  | default\_value  | string | No       | The default value for the mapped input. |

* `map_output()` Parameters

  | Parameter        | Type   | Required | Description                              |
  | ---------------- | ------ | -------- | ---------------------------------------- |
  | output\_variable | string | Yes      | The variable you want to map.            |
  | expression       | string | Yes      | The expression used to map the output.   |
  | default\_value   | string | No       | The default value for the mapped output. |

The following example shows how to use `map_input()` and `map_output()` to map values for a node:

```py Python [expandable] theme={null}
'''
Build a simple hello world agentic workflow that will combine the result of two tools.
'''

from pydantic import BaseModel
from ibm_watsonx_orchestrate.flow_builder.flows import END, Flow, flow, START

from .get_hello_message import get_hello_message
from .combine_names import combine_names

class Name(BaseModel):
    """
    This class represents a person's name.

    Attributes:
        first_name (str): The person's first name.
        last_name (str): The person's last name.
    """
    first_name: str
    last_name: str

class Message(BaseModel):
    msg: str

@flow(
        name = "hello_message_flow",
        input_schema=Name,
        output_schema=Message
    )
def build_hello_message_flow_datamap(aflow: Flow = None) -> Flow:
    """
    Creates a agentic workflow with two tools: get_hello_message and combine_names.
    Args:
        flow (Flow, optional): The agentic workflow to be built. Defaults to None.
    Returns:
        Flow: The created agentic workflow.
    """
    combine_names_node = aflow.tool(combine_names)
    combine_names_node.map_input(input_variable="first_name", expression="flow.input.first_name")
    combine_names_node.map_input(input_variable="last_name", expression="flow.input.last_name", default_value="default_last_name")

    get_hello_message_node = aflow.tool(get_hello_message, output_schema=Message)

    aflow.edge(START, combine_names_node).edge(combine_names_node, get_hello_message_node).edge(get_hello_message_node, END)

    aflow.map_output(output_variable="msg", expression="flow.get_hello_message_node.msg")

    return aflow
```