Overview

Functions (also called tools) are the core capability system in Sigma Domain. They represent specific actions the platform can perform, from sending emails to querying databases to searching the web.

What is a Function?

A function is a defined action with:

• Name - Identifier like "twilio-createmessage" or "google-search"
• Description - What the function does
• Parameters - Inputs the function needs (some required, some optional)
• Service - The external API or service it connects to
• Output - The result returned after execution

Types of Functions

Built-in Functions

Pre-installed capabilities that come with the platform:

• Web search
• Image search
• Video search
• Place search
• Document editing operations
• Music generation

Imported Functions

Functions you've added by importing external APIs:

• API endpoints converted to callable functions
• Organized into bundles by service (e.g., all Twilio endpoints)
• See Importing Tools for how to import

Proxy Functions (Bundles)

• A single parent function that represents an entire API service
• Contains multiple sub-functions (individual endpoints)
• Example: "twilio" parent with "twilio-createmessage", "twilio-listcalls", etc.
• The AI selects the right sub-function based on your request

How Functions Are Discovered

Automatic Discovery

When you send a message:

1. The Tool Track analyzes your intent
2. It searches the function catalog for relevant functions
3. Matching functions are ranked by relevance
4. Top matches appear as suggestions in the chat

Manual Search

• "Find tools for sending emails"
• "What functions are available for Stripe?"
• "Search for data analysis tools"

Function Suggestions

• Functions appear as clickable cards below the AI response
• Each card shows the function name and description
• Click a function to see details or execute it

Executing a Function

Natural Language Execution

The simplest way - just describe what you want:

• "Send a Twilio SMS to 555-1234 saying 'Meeting at 3pm'"
• The AI identifies the right function and fills in parameters

From Function Suggestions

1. Click on a suggested function card
2. Review the parameters
3. Fill in any missing required parameters
4. Click Execute

Parameter Filling

When a function needs parameters:

• The AI tries to infer parameters from your message
• Missing required parameters are prompted interactively
• Optional parameters use defaults unless you specify them
• Complex parameters (arrays, nested objects) are handled automatically

Understanding Function Results

Success

• The result is displayed in the chat
• Data may be formatted as tables, lists, or JSON
• The AI can explain or summarize the result

Failure

• Error messages explain what went wrong
• Common issues: missing parameters, authentication errors, API limits
• The system may retry automatically (up to 3 attempts)
• See Tool Execution History for debugging

Function Details

Viewing Function Info

• "Tell me about the [function name] tool"
• "What can the Twilio integration do?"
• "What parameters does [function] need?"

Function Metadata

Each function has metadata including:

• Category - Communication, data, search, etc.
• Tags - Keywords for discovery
• Service - Parent API service
• Author - Who created/imported the function
• Proxy type - bundle, workflow, or api

Function Parameters

Required Parameters

• Must be provided for the function to execute
• The AI will ask for them if not provided
• Marked with a required indicator in the UI

Optional Parameters

• Have default values if not specified
• You can override defaults by specifying them
• Not all optional parameters are shown by default

Parameter Types

• String - Text values
• Number - Integer or decimal values
• Boolean - True/false values
• Array - Lists of values
• Object - Complex nested data structures
• Enum - Selection from predefined options

Tips

1. Let the AI choose - Describe your goal and let the AI find the right function
2. Be specific with parameters - "Send SMS to 555-1234" is better than "Send a message"
3. Check suggestions - Review function suggestions before asking the AI to search again
4. Use follow-ups - "Run that function again with a different phone number"
5. Ask for help - "What does this function do?" before executing

Troubleshooting

Function Not Found

• Try different search terms
• Check if the tool has been imported
• The function catalog updates as you import new tools

Parameter Validation Error (422)

• A required parameter is missing or invalid
• Check the function's parameter requirements
• Provide all required parameters in your request

Authentication Required

• The function's API needs credentials
• See Authentication to set up API keys or OAuth