> For the complete documentation index, see [llms.txt](https://guide.indigo.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://guide.indigo.ai/getting-started/agents-workflows-and-triggers/blocks.md). # Blocks ## Workflow Blocks Our platform offers **4 types of workflow blocks:** 1. [**Message blocks**](/getting-started/agents-workflows-and-triggers/blocks/message-blocks.md) allow you to **deliver static content**, such as **text, images, videos, or cards**, to the user at specific points in the conversation flow, providing engaging, structured content that follows a predefined format. 2. [**Action blocks**](/getting-started/agents-workflows-and-triggers/blocks/action-blocks.md) allow both users and the virtual assistant to **perform specific actions within the conversation flow,** such as sending emails, selecting from multiple predefined options, uploading documents, speaking with a human operator, **ending a voice call**, or **transferring a call** to an external number. 3. [**Logic blocks**](/getting-started/agents-workflows-and-triggers/blocks/logic-blocks.md) allow you to **control and shape the flow of the conversation based on conditions, user inputs, or data from external systems**. They enable your virtual assistant to make decisions, collect and process information, assign values, and connect with APIs—ensuring dynamic, responsive, and intelligent conversational experiences. 4. [**Utility blocks**](/getting-started/agents-workflows-and-triggers/blocks/utility-blocks.md) support behind-the-scenes functionality by enhancing how your assistant processes information and how your team collaborates. They include **tools for generating structured outputs with AI** (like **prompts**) and for **adding internal documentation within workflows** (like notes), helping you build more organized and intelligent assistants. ## Blocks Overview Below is an overview of the available blocks, along with links to dedicated articles that provide detailed descriptions of their functionalities:

Block Type	Block Title	Description
Message	Text	Sending predefined messages
Message	Image	Displaying visual content
Message	Card	Presenting structured, interactive content
Message	Video	Embedding multimedia content
Action	Mail	Sending emails as part of the conversation flow
Action	Quick Reply	Providing predefined options for users to quickly select from
Action	Upload	Allowing users to upload files directly in the conversation
Action	Handover	Seamlessly transferring the conversation to a human operator
Action	API	Sends or receives real-time data from external systems via API
Action	Hang up	Terminates a voice call and optionally triggers a post-call workflow.
Action	Transfer	Transfers a voice call to an external number with waiting and fallback management.
Logic	Reroute	Redirects the conversation to a different agent or workflow
Logic	Condition	Branches the flow based on conditional logic and variable values
Logic	Capture	Collects user input and stores it in a variable
Logic	Set Values	Assigns or resets the value of a variable
Utility	Prompt	Uses AI to generate structured data or intelligent responses from user input
Utility	Notes	Adds internal comments to keep workflows organized

## Variables Variables are the foundation of most workflow blocks. They allow your assistant to **store, recall, and act on data—enabling everything from dynamic conversations to API-based responses**. Whether you're capturing user input, setting conditions, or generating structured outputs, variables power the logic behind your assistant’s behavior. {% hint style="info" %} Learn more about how variables work in the next section: [Variables](/getting-started/workspace/variables.md). {% endhint %}