Overview
Global settings are organized into 10 categories:| Category | Purpose | Impact |
|---|---|---|
| System Prompt | Core AI instructions | All conversation nodes |
| Voice Settings | Speech synthesis config | All voice responses |
| LLM Settings | Language model config | All AI-generated responses |
| Noise Cancellation | Audio processing | Call quality |
| Knowledge Base | RAG data sources | Context for responses |
| MCP Tools | Model Context Protocol tools | Available across flow |
| Outcome | Call result tracking | Analytics & reporting |
| Phone Number | Assigned Twilio numbers | Inbound/outbound calls |
| Call Settings | Timeout & behavior | All calls |
| Webhook | External integrations | Event notifications |
System Prompt
The system prompt is the foundational instruction set for your AI agent. It defines the agent’s personality, capabilities, constraints, and overall behavior.Configuration
Best Practices
DO:- Define clear role and purpose
- Specify tone and personality
- List key capabilities
- Include important constraints
- Use variables for dynamic context
- Include node-specific instructions (use node prompts instead)
- Repeat information from knowledge base
- Make it overly prescriptive
- Use extracted variables (only system/custom variables allowed)
Example: Customer Service Agent
Variables in System Prompt
System prompts support system variables and custom variables only:Voice Settings
Control how your agent speaks, including voice selection, speed, pitch, and provider-specific settings.Configuration Schema
Provider Options
Deepgram (Default)
- Voices: aura-asteria-en, aura-athena-en, aura-luna-en, etc.
- Best For: Low latency, cost-effectiveness
- Languages: 30+ languages
- Pricing: ~$0.015/minute
ElevenLabs
- Voices: Custom voice cloning + 100+ premade voices
- Best For: Most natural-sounding speech
- Languages: 29 languages
- Pricing: ~$0.30/minute
PlayHT
- Voices: 900+ ultra-realistic voices
- Best For: Wide language/accent variety
- Languages: 140+ languages
- Pricing: ~$0.24/minute
OpenAI
- Voices: alloy, echo, fable, onyx, nova, shimmer
- Best For: Integration with GPT models
- Languages: 50+ languages
- Pricing: ~$0.015/minute
Voice Parameters Explained
Speed: How fast the agent speaks- 0.5 = Half speed (very slow)
- 1.0 = Normal speed
- 2.0 = Double speed (very fast)
- Recommended: 0.9-1.1 for most use cases
- -20 = Much lower pitch
- 0 = Natural pitch
- +20 = Much higher pitch
- Recommended: -5 to +5 for subtle adjustments
- Low (0-0.3): More expressive, variable
- Medium (0.4-0.6): Balanced
- High (0.7-1.0): Consistent, stable
- Recommended: 0.5 for general use, 0.7+ for formal settings
- Low (0-0.3): More creative interpretation
- Medium (0.4-0.6): Balanced
- High (0.7-1.0): Closer to original voice
- Recommended: 0.75 for cloned voices
Node-Level Overrides
Voice settings can be overridden per node (conversation and start nodes only):Only specified parameters are overridden. Unspecified parameters inherit from global settings.
LLM Settings
Configure the language model that powers your agent’s intelligence.Configuration Schema
Model Options
OpenAI (Default)
- GPT-5: Most capable flagship model
- GPT-5-Mini: Balanced performance and cost
- GPT-5-Nano: Fast and cost-effective
- GPT-4.1: Excellent reasoning capabilities
- GPT-4.1-Mini: Fast, cost-effective
- GPT-4.1-Nano: Ultra-fast, most affordable
- GPT-4o: Capable multimodal model
- GPT-4o-mini: Fast, cost-effective multimodal
- Best For: General use, complex reasoning
Gemini
- Gemini 2.5-Pro: Most capable, excellent reasoning
- Gemini 2.5-Flash: Fast, cost-effective
- Best For: Multimodal tasks, long context
Groq
- GPT-120-OSS: High quality, ultra-fast inference
- GPT-20-OSS: Fast and efficient
- Best For: Real-time responses, cost optimization
DeepMyst
- gpt-4.1-optimize: Optimized GPT-4.1 performance
- gpt-4.1-mini-optimize: Optimized GPT-4.1-mini performance
- Best For: Cost-optimized deployments
Custom (OpenAI Compatible)
- Connect any OpenAI-compatible API endpoint
- Best For: Self-hosted models, custom deployments
Parameter Guide
Temperature (Creativity vs. Consistency)Node-Level Overrides
Like voice settings, LLM settings can be customized per conversation node:Optimization Strategies
For Scripted Responses:- Temperature: 0.1-0.3
- Frequency Penalty: 0.5-1.0
- Model: GPT-4o-mini
- Temperature: 0.8-1.0
- Top P: 0.9
- Model: GPT-4o or Gemini 2.5-Pro
- Temperature: 0.3-0.5
- Max Tokens: 300-500
- Model: GPT-4o (better accuracy)
Noise Cancellation
Advanced audio processing to improve call quality in noisy environments.Configuration
Modes Explained
Disabled (Default)- No audio processing beyond standard telephony
- Lowest latency (~50ms)
- Best for quiet environments
- Most cost-effective
- AI-powered noise suppression
- Filters background sounds (traffic, music, other voices)
- Adds 100-150ms latency
- Additional $0.02/minute cost
Apply Per Setting
Per Conversation (Recommended)- Noise cancellation applied to each utterance
- Better quality for real-time conversation
- More resource-intensive
- Noise cancellation applied once at call start
- Lower resource usage
- Suitable for consistently noisy/quiet environments
When to Enable
✅ Enable When:- Users call from outdoors, vehicles, public spaces
- Background music or TV is common
- Multiple people speaking nearby
- Call center environment with adjacent agents
- Users primarily in quiet offices/homes
- Latency is critical (< 200ms required)
- Cost optimization is priority
- Testing/development environment
Knowledge Base
Attach knowledge sources for Retrieval-Augmented Generation (RAG), allowing your agent to access specific information.What is Knowledge Base?
Knowledge base provides your agent with domain-specific information that’s too large or dynamic for the system prompt. When a user asks a question, relevant knowledge is retrieved and provided to the LLM as context.Supported Sources
Configuration
How It Works
- User asks question
- System searches knowledge base for relevant information
- Top N chunks are retrieved (default: 3-5)
- Chunks are added to LLM context
- LLM generates response using both system prompt and knowledge
- Agent delivers response
Best Practices
Chunking Strategy:- Top K: 3-5 chunks (balance context vs. token usage)
- Similarity Threshold: 0.7+ (avoid irrelevant results)
- Max Context: 2000-4000 tokens total
Testing Knowledge Base
Verify your knowledge base is working:- Ask specific questions from your documents
- Request citations or sources (if configured)
- Ask edge cases not in knowledge base
- Verify agent says “I don’t know” for out-of-scope questions
MCP Tools
Model Context Protocol (MCP) tools are globally available functions that nodes can access.What are MCP Tools?
MCP tools are external capabilities the AI can invoke during conversation:- API integrations
- Database queries
- Custom business logic
- Third-party services
Configuration
Example: CRM Integration
MCP vs. Node Tools
| Feature | MCP Tools | Node Tools |
|---|---|---|
| Availability | All conversation nodes | Single node only |
| Use Case | Frequently needed functions | One-time operations |
| Configuration | Global settings | Per-node settings |
| Overrides | Not available | Per-node parameter overrides |
Best Practices
Good MCP Tools:- Customer lookup by ID/phone
- Business hours check
- Inventory availability
- Account balance query
- Address validation
- Create support ticket (one-time action)
- Send confirmation email (specific workflow step)
- Process payment (security-critical, should be explicit)
Outcome
Define how call results are classified and reported for analytics.Purpose
Outcomes categorize call results for:- Analytics and reporting
- Quality assurance
- Agent performance tracking
- Business intelligence
Configuration
Common Outcome Structures
Simple Categorization:Setting Outcomes in Flow
Outcomes are typically set in End Call nodes:Phone Number
Associate Twilio phone numbers with your flow agent for inbound and outbound calling.Configuration
How It Works
Inbound Calls:- Customer calls assigned Twilio number
- Twilio routes to Hamsa platform
- Flow agent answers and executes
- Agent initiates call via API
- Uses one of assigned numbers as caller ID
- Flow agent executes when customer answers
Multiple Numbers
You can assign multiple phone numbers:All assigned numbers use the same flow configuration. Create separate agents for different flows.
Best Practices
For Local Presence:- Assign area code matching target market
- Use multiple local numbers for different regions
- Different numbers for different marketing campaigns
- Track conversion by incoming number
Call Settings
Configure timeout behaviors and call duration limits.Configuration
Parameters Explained
User Inactivity Timeout:- How long to wait for user input before prompting or ending call
- Too short: Cuts off slow speakers
- Too long: Awkward silences
- Recommended: 15-20 seconds
- Absolute maximum call length
- Prevents runaway costs
- Call ends gracefully when limit reached
- Recommended: 300-600 seconds (5-10 minutes)
- Artificial pause before agent responds
- Makes conversation feel more natural
- Too short: Agent seems rushed
- Too long: Feels unresponsive
- Recommended: 300-500ms
- Allow users to interrupt agent mid-sentence
true: More natural, conversationalfalse: Agent always completes thoughts- Recommended:
truefor customer service,falsefor announcements
- Subtle ambient sound during long pauses
- Prevents “dead air” feeling
- Recommended:
truefor longer calls
- Agent says “Let me check…” or “One moment…” when processing
- Makes delays feel intentional
- Recommended:
truefor complex tool calls
Example Configurations
Quick FAQ Bot:Webhook
Send call events and data to external systems via HTTP webhooks.Configuration
Event Types
Webhooks are triggered for these events:Payload Structure
Authentication Methods
No Auth:Webhook Best Practices
Implementation Tips:- Return 200 OK quickly, process asynchronously
- Implement retry logic on your server
- Log all webhook payloads for debugging
- Validate webhook signatures if possible
- Handle duplicate events gracefully
Global Settings Priority
Understanding how global settings interact with node-level overrides:Override Examples
Voice Settings:Troubleshooting
Common Issues
“System instructions are required” Error- Ensure system prompt field is not empty
- Must be at least 1 character
- Check for whitespace-only content
- Verify voice ID is valid for selected provider
- Check if node override is unintentionally applied
- Ensure provider API key is configured (if custom provider)
- Verify knowledge items are properly indexed
- Check chunk size and overlap settings
- Ensure similarity threshold isn’t too high
- Test with very specific questions from documents
- Verify URL is publicly accessible
- Check authentication credentials
- Ensure endpoint returns 200 OK quickly
- Look for events in webhook logs
- Confirm tools are enabled in global settings
- Verify tool IDs are unique
- Check timeout and retry settings
- Ensure tools are properly registered
Validation
Before saving your flow, ensure:- ✅ System prompt is filled
- ✅ Voice provider and voice ID are valid
- ✅ LLM model is available in your plan
- ✅ Knowledge base items are indexed
- ✅ Webhook URL is valid (if configured)
- ✅ Phone numbers are assigned (if using telephony)