> ## Documentation Index > Fetch the complete documentation index at: https://giselle.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # Start Node & End Node > Learn how Start and End Nodes in Giselle define the boundaries of your workflow, establishing where user input enters and where the final output is collected. ## Start Node & End Node in Giselle **Start Node** and **End Node** are the essential boundary nodes that define the entry and exit points of any workflow in Giselle. They work as a pair to establish the complete flow of your app, from receiving user input to delivering the final output. ## Start Node The **Start Node** is the entry point of your workflow. It defines the input parameters that users will provide when running your app in the Playground. ### Key Features * **Entry Point**: The Start Node marks where workflow execution begins. All data flows from this node to downstream nodes. * **Parameter Definition**: Define the input parameters that users will fill in when running your app, such as text input fields or file uploads. * **Single Instance**: Each workflow can have only one Start Node. It cannot be duplicated. * **Paired with End Node**: Start and End Nodes are always created together as a pair. ### Default Parameters When you create a new app, the Start Node comes with two default input parameters: 1. **Input(Text)**: A multiline text field for users to enter text content. This is marked as required. 2. **Input(File)**: A file upload field that allows users to attach multiple files. This is optional by default. The Start Node has a single output port that provides the user's input to downstream nodes in your workflow. ### Configuring the Start Node 1. **Select the Node**: Click on the Start Node to open its configuration panel. 2. **Edit App Description**: Customize the app description. ### Output of the Start Node The Start Node has a single **output** that contains the values provided by the user when running the app. This output can be connected to any compatible node's input. ## End Node The **End Node** is the endpoint of your workflow and the place where you define the app's final output. It collects processed data from upstream nodes and presents them as the app's results. ### Key Features * **Workflow Endpoint**: The End Node is where workflow execution completes. Data connected here becomes the app's final result. * **Output Definition**: Specify which node's output to include in the app's final result. You can connect multiple upstream nodes. * **Single Instance**: Each workflow can have only one End Node. It cannot be duplicated. * **Dynamic Input**: The End Node's input is created dynamically when you connect upstream nodes. ### Configuring the End Node 1. **Select the Node**: Click on the End Node to open its configuration panel. 2. **Add Output**: Click the "Add Output" button to select which upstream node's output should be included in the final result. 3. **Manage Connections**: View and disconnect connected nodes as needed. 4. **Enable Structured Output** (optional): Set the Output Format to JSON to assign property names to upstream node outputs, combine outputs from multiple nodes, and define a structured JSON response. ### Output Format The End Node supports two output format options for the final response: * **Raw**: Returns the selected node's output as-is without any processing. * **JSON**: Define a schema to structure the final API response. When you select JSON, the structured output schema definition dialog opens. ![Structured Output (JSON) definition dialog](https://mintcdn.com/giselle/ICu3lP7HlQh5w6qY/en/images/glossary/start-end-nodes/structured-output-json.png?fit=max\&auto=format\&n=ICu3lP7HlQh5w6qY\&q=85\&s=7739fe5011556e460e58c2cc4dbef542) Structured Output (JSON) definition #### Value Selection Each property requires a **Value** (source) to be selected from connected upstream nodes. * Upstream nodes are grouped by type in the list * If a node has structured output defined, you can select the entire object or individual properties ### Connection Rules When connecting nodes to the End Node: * The End Node itself cannot be selected as a source * Nodes already connected cannot be selected again * Nodes without an output cannot be connected ### Input of the End Node The End Node has a single **input** that receives data from connected upstream nodes. The connected data is then presented as the final output of your app. ## Visual Appearance Both Start and End Nodes share a distinctive **capsule-shaped design** that sets them apart from other nodes: * **Start Node**: Has an output handle on the right side for connecting to downstream nodes * **End Node**: Has an input handle on the left side for receiving data from upstream nodes * Both display their respective icons and names ("Start" and "End" by default) ### Connection Status Indicator When the Start Node is properly connected to the End Node through the workflow: * Both nodes display with full opacity * The "Try App in Playground" button becomes enabled When there's no valid path from Start to End: * Both nodes appear slightly faded with dashed borders * The "Try App in Playground" button is disabled ## How They Work Together 1. **User Input**: When someone runs your app, they fill in the parameters defined in the Start Node. 2. **Data Flow**: Input values flow from the Start Node through connected nodes. 3. **Processing**: Data is processed by various nodes (text, file, query, action nodes, etc.). 4. **Collection**: Processed results are collected by the End Node. 5. **Output**: The End Node presents the final output to the user. ### Connection Requirement For your app to be runnable, there must be a valid path from the Start Node to the End Node. The system verifies this connection using a breadth-first search algorithm. Without a valid path, your app cannot be executed in the Playground. ## Start & End Nodes vs. Other Nodes | Feature | Start & End Nodes | Other Nodes | | - | - | - | | Instances per workflow | Exactly one each | Multiple allowed | | Can be duplicated | No | Yes | | Visual style | Capsule-shaped | Card-shaped | | Purpose | Workflow boundaries | Data processing | | Created automatically | Yes, as a pair | No | Start and End Nodes are essential for creating functional apps that accept user input and deliver processed results. This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.