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

# Step 2: Add Nodes

> Nodes are the fundamental building blocks of your conversation flow.

## What are Nodes?

Nodes are the fundamental building blocks of your conversation flow. Each node represents a specific step or action in your agent's conversation, with its own logic, behavior, and purpose.

## Key Concepts

* **Node Type**: Determines the node's functionality (conversation, subagent, function call, logic, etc.)
* **Edges**: Connections between nodes that define the conversation flow
* **Transition Conditions**: Rules that determine when and where to move next
* **Fine-tuning**: Each node can be optimized independently for better performance

## Why Use Nodes?

By breaking complex workflows into individual nodes:

* **Precise Control**: Define exact behavior for each conversation scenario
* **Better Performance**: Fine-tune specific parts without affecting others
* **Easier Debugging**: Isolate and fix issues in specific conversation paths
* **Reusability**: Connect nodes in different ways for various flows

## Node Types Available

### Conversation Nodes

* **Conversation Node**: Handle dialogue and user interactions without tool calling
* **Subagent Node**: Handle dialogue and user interactions with tool calling
* **Extract DV Node**: Extract and store dynamic variables from conversations

### Action Nodes

* **Function Node**: Execute custom functions and API calls
* **Code Node**: Execute JavaScript code directly without an external server
* **SMS Node**: Send SMS messages during the call
* **MCP Node**: Integrate with Model Context Protocol tools

### Call Control Nodes

* **Call Transfer Node**: Transfer calls to other phone numbers
* **Transfer Agent Node**: Transfer to another agent
* **Press Digit Node**: Send DTMF tones (press digits)
* **End Node**: Terminate the call gracefully

### Logic Nodes

* **Logic Split Node**: Create conditional branches based on variables

## Add a Node

<Steps>
  <Step title="Select node type">
    Click from the left sidebar to select the node type you want to add. Click on it and it will be added to the canvas.
  </Step>

  <Step title="Configure the node">
    Click on the node, check the settings on the right, and fill in node instructions inside the node. Check out the respective node guide for more details.
  </Step>

  <Step title="Add transition conditions as needed">
    Add edges by clicking on the bottom part of the node and add your transition conditions. Check out the next step for more details.
  </Step>

  <Step title="Connect node">
    Click and hold the circle to start a line that connects this node to other nodes, and other nodes to this node.
  </Step>
</Steps>

## Organize Nodes

After adding many nodes, the canvas can get cluttered. Use the **Organize** button to automatically arrange the nodes.