API Integration Guide

Overview

API integration allows your voice agents to interact with external systems, fetch data, and perform actions beyond conversation. Hamsa’s tool system makes it easy to connect to any HTTP API, enabling powerful workflows like looking up customer data, creating tickets, sending notifications, and more.

What You Can Do with API Integration:

Look up customer information from your CRM
Create and update tickets in your helpdesk
Check inventory and availability
Process orders and payments
Send emails, SMS, and notifications
Update databases and systems
Verify account credentials
Access any HTTP/REST API

Tool System Basics

What Are Tools?

Tools are reusable API configurations that your agents can call during conversations. Think of them as functions your agent can execute. Tool Components:

Name & Description - What the tool does
HTTP Method - GET, POST, PUT, DELETE, PATCH
URL - API endpoint (supports path parameters)
Authentication - API keys, bearer tokens
Headers - Custom HTTP headers
Parameters - JSON schema defining inputs
Messages - What agent says during execution

Creating Your First Tool

Let’s create a tool to look up customer information.

Navigate to Tools

Go to Tools in the sidebar and click Add New Tool

Configure Basic Info

Name: "Lookup Customer by Phone"
Description: "Retrieves customer account information by phone number.
             Returns name, account number, tier, and recent orders.
             Use when caller asks about their account or needs verification."

Configure Tool Settings

Method Type: POST
URL: https://api.yourcrm.com/customers/lookup
Auth Type: JWT Bearer Token
Auth Token: Bearer sk_live_abc123xyz789
Timeout: 10 seconds

Define Parameters

{
  "type": "object",
  "properties": {
    "phone_number": {
      "type": "string",
      "description": "Customer's phone number in E.164 format"
    }
  },
  "required": ["phone_number"]
}

Set Messages (Optional)

Request Start: "Let me look that up for you..."
Request Complete: "I found your account information."

Save Tool

Click Save Tool to create the reusable tool template

Using Tools in Agents

In Flow Agents

Add tools to your conversation flow using Tool Nodes. Example: Customer Lookup Flow

Node 1: Collect_Phone
  Message: "Can I get your phone number to look up your account?"

  Extract Variables:
    - phone_number: "Extract 10-digit phone number"

Node 2: Lookup_Customer (Tool Node)
  Tool: "Lookup Customer by Phone"

  Parameters:
    phone_number: {{phone_number}}

  # Tool executes API call
  # Returns: customer_name, account_number, tier, last_order_date

Node 3: Greet_Customer
  Message: "Welcome back, {{customer_name}}! I see you're a
           {{tier}} member. How can I help you today?"

  Transitions:
    Based on conversation intent

Tool Node Configuration:

Tool Node Settings:
  Tool Template: Select from tool library
  Parameters: Map variables to tool inputs
  Path Parameters: Override URL path variables
  Headers: Override HTTP headers (optional)
  Messages: Custom messages for this use (optional)

In Single Prompt Agents

Add tools to configuration, agent decides when to call them.

Open Agent Configuration

Navigate to your Single Prompt Agent settings

Add Tools

Go to Configuration → Tools → Add Tool

Select Tools

Choose tools from your library

Configure Overrides (Optional)

Override parameters or headers for this specific agent

Update Prompt

Mention tools in your preamble:

## Available Tools

You have access to these tools:
- lookup_customer: Look up customer info by phone number
- create_ticket: Create support tickets
- check_order: Get order status

Use these tools when appropriate to help the caller.

API Patterns

GET Requests - Retrieving Data

Fetch information from your systems. Example: Get Order Status

{
  "name": "Get Order Status",
  "description": "Retrieves order status, tracking info, and estimated delivery.
                 Use when caller asks about their order or delivery.",
  "methodType": "GET",
  "url": "https://api.yourstore.com/orders/:orderId",
  "authType": "jwtAuth",
  "authToken": "Bearer sk_live_123",
  "pathParameters": [
    {
      "name": "orderId",
      "defaultValue": "ORD-12345"
    }
  ],
  "parameters": {
    "type": "object",
    "properties": {
      "orderId": {
        "type": "string",
        "description": "Order ID (format: ORD-XXXXX)"
      }
    },
    "required": ["orderId"]
  }
}

Response Handling:

Tool returns:
  {
    'order_id': 'ORD-12345',
    'status': 'shipped',
    'tracking_number': '1Z999AA10123456784',
    'estimated_delivery': '2024-01-18',
    'items': [...],
  }

Agent can use in response: "Your order {{order_id}} has been {{status}}.
  It's tracking number is {{tracking_number}} and should arrive
  by {{estimated_delivery}}."

POST Requests - Creating Data

Create new records in your systems. Example: Create Support Ticket

{
  "name": "Create Support Ticket",
  "description": "Creates a new support ticket in helpdesk system.
                 Use when caller reports an issue that needs follow-up.",
  "methodType": "POST",
  "url": "https://api.yourdesk.com/v1/tickets",
  "authType": "jwtAuth",
  "authToken": "Bearer sk_live_xyz",
  "headers": [
    {
      "name": "Content-Type",
      "value": "application/json"
    }
  ],
  "parameters": {
    "type": "object",
    "properties": {
      "customer_email": {
        "type": "string",
        "format": "email",
        "description": "Customer's email address"
      },
      "subject": {
        "type": "string",
        "description": "Ticket subject/title"
      },
      "description": {
        "type": "string",
        "description": "Detailed issue description"
      },
      "priority": {
        "type": "string",
        "enum": ["low", "medium", "high", "urgent"],
        "default": "medium",
        "description": "Ticket priority level"
      }
    },
    "required": ["customer_email", "subject", "description"]
  }
}

Usage in Flow:

Node: Create_Ticket (Tool)
  Tool: "Create Support Ticket"

  Parameters:
    customer_email: {{email_address}}
    subject: "Issue reported on phone call"
    description: {{issue_description}}
    priority: {{urgency_level}}

Response Node:
  Message: "I've created ticket {{ticket_id}} for you.
           You'll receive updates at {{customer_email}}."

PUT/PATCH Requests - Updating Data

Modify existing records. Example: Update Customer Preferences

{
  "name": "Update Customer Preferences",
  "description": "Updates customer communication preferences and settings.",
  "methodType": "PATCH",
  "url": "https://api.yourcrm.com/customers/:customerId",
  "authType": "jwtAuth",
  "authToken": "Bearer sk_live_abc",
  "parameters": {
    "type": "object",
    "properties": {
      "customerId": {
        "type": "string",
        "description": "Customer ID"
      },
      "email_notifications": {
        "type": "boolean",
        "description": "Enable email notifications"
      },
      "sms_notifications": {
        "type": "boolean",
        "description": "Enable SMS notifications"
      },
      "preferred_contact_time": {
        "type": "string",
        "enum": ["morning", "afternoon", "evening"],
        "description": "Preferred time to be contacted"
      }
    },
    "required": ["customerId"]
  }
}

DELETE Requests - Removing Data

Delete records (use with caution). Example: Cancel Appointment

{
  "name": "Cancel Appointment",
  "description": "Cancels a scheduled appointment. Use only after confirming
                 the caller wants to cancel.",
  "methodType": "DELETE",
  "url": "https://api.scheduler.com/appointments/:appointmentId",
  "authType": "jwtAuth",
  "authToken": "Bearer sk_live_def",
  "parameters": {
    "type": "object",
    "properties": {
      "appointmentId": {
        "type": "string",
        "description": "Appointment ID to cancel"
      },
      "cancellation_reason": {
        "type": "string",
        "description": "Reason for cancellation"
      }
    },
    "required": ["appointmentId"]
  }
}

Advanced Patterns

Chained API Calls

Call multiple APIs in sequence. Example: Order Fulfillment Chain

Flow: Complete_Order

Step 1: Verify_Inventory (Tool)
  Tool: Check Product Availability
  Parameters:
    product_id: {{product_id}}
    quantity: {{quantity}}

  Returns: in_stock, available_quantity

Step 2: Router - Check Stock
  Conditions:
    - {{in_stock}} == true → Create_Order
    - {{in_stock}} == false → Out_Of_Stock_Message

Step 3: Create_Order (Tool)
  Tool: Create Order
  Parameters:
    customer_id: {{customer_id}}
    product_id: {{product_id}}
    quantity: {{quantity}}
    shipping_address: {{shipping_address}}

  Returns: order_id, total_amount, estimated_delivery

Step 4: Process_Payment (Tool)
  Tool: Charge Payment Method
  Parameters:
    customer_id: {{customer_id}}
    amount: {{total_amount}}
    order_id: {{order_id}}

  Returns: payment_status, transaction_id

Step 5: Send_Confirmation (Tool)
  Tool: Send Order Confirmation Email
  Parameters:
    email: {{customer_email}}
    order_id: {{order_id}}
    amount: {{total_amount}}

Step 6: Confirmation_Message
  Message: "Perfect! Your order {{order_id}} is confirmed.
           Total was {{total_amount}} and it should arrive by
           {{estimated_delivery}}. You'll receive a confirmation
           email at {{customer_email}}."

Conditional Tool Execution

Execute tools based on conditions.

Router: Should_Create_Ticket
  Conditions:
    # Issue resolved immediately
    - {{issue_resolved}} == true →
      Thank_And_Close

    # Simple issue, offer self-service
    - {{issue_complexity}} == "low" AND
      {{customer_wants_self_service}} == true →
      Send_Help_Article

    # Complex issue, create ticket
    - {{issue_complexity}} == "high" OR
      {{customer_wants_agent}} == true →
      Create_Ticket_Tool

Create_Ticket_Tool:
  Tool: Create Support Ticket
  Parameters:
    subject: {{issue_summary}}
    description: {{issue_details}}
    priority: {{urgency}}

Error Handling & Retries

Handle API failures gracefully.

Node: Call_API (Tool)
  Tool: Lookup Customer
  Parameters:
    phone: {{phone_number}}

  Transitions:
    # Success path
    - API returns 200 → Success_Node

    # Error paths
    - API returns 404 → Customer_Not_Found
    - API returns 500 → Retry_Or_Fallback
    - Timeout → Retry_Or_Fallback

Customer_Not_Found:
  Message: "I couldn't find an account with that phone number.
           Would you like to create a new account?"

Retry_Or_Fallback:
  Type: Router

  Conditions:
    - {{retry_count}} < 2 →
      Retry_API_Call

    - {{retry_count}} >= 2 →
      "I'm having trouble accessing the system right now.
       Let me transfer you to someone who can help."
      → Transfer_To_Agent

Async Tool Execution

For long-running operations.

{
  "name": "Generate Report",
  "description": "Generates detailed account report (may take 30-60 seconds).",
  "methodType": "POST",
  "url": "https://api.yourservice.com/reports/generate",
  "async": true,
  "timeoutSeconds": 60,
  "parameters": {
    "type": "object",
    "properties": {
      "account_id": {
        "type": "string"
      },
      "report_type": {
        "type": "string",
        "enum": ["summary", "detailed", "transactions"]
      }
    }
  }
}

With async enabled:

Agent behavior:
  "I'm generating your report now. This usually takes about a minute.
   Feel free to ask me anything else while we wait."

  [Agent can continue conversation]
  [Tool completes in background]

  "Your report is ready! I'm sending it to {{email_address}} now."

Authentication Methods

Bearer Token (JWT)

Most common for modern APIs.

{
  "authType": "jwtAuth",
  "authToken": "Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9..."
}

Headers sent:

Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...

API Key in Header

Common for older APIs.

{
  "authType": "none",
  "headers": [
    {
      "name": "X-API-Key",
      "value": "sk_live_abc123xyz789"
    }
  ]
}

No Authentication

For public APIs.

{
  "authType": "none"
}

Custom Authentication

Use headers for custom schemes.

{
  "authType": "none",
  "headers": [
    {
      "name": "X-Custom-Auth",
      "value": "custom_token_here"
    },
    {
      "name": "X-Client-ID",
      "value": "client_123"
    }
  ]
}

Parameter Schemas

Basic Types

String Parameter:

{
  "email": {
    "type": "string",
    "format": "email",
    "description": "Customer email address"
  }
}

Number Parameter:

{
  "quantity": {
    "type": "number",
    "minimum": 1,
    "maximum": 100,
    "description": "Number of items to order"
  }
}

Boolean Parameter:

{
  "send_confirmation": {
    "type": "boolean",
    "default": true,
    "description": "Send confirmation email"
  }
}

Enum Parameter:

{
  "priority": {
    "type": "string",
    "enum": ["low", "medium", "high", "urgent"],
    "default": "medium",
    "description": "Ticket priority level"
  }
}

Complex Types

Object Parameter:

{
  "shipping_address": {
    "type": "object",
    "properties": {
      "street": { "type": "string" },
      "city": { "type": "string" },
      "state": { "type": "string" },
      "zip": { "type": "string" }
    },
    "required": ["street", "city", "state", "zip"]
  }
}

Array Parameter:

{
  "product_ids": {
    "type": "array",
    "items": {
      "type": "string"
    },
    "description": "List of product IDs to order"
  }
}

Using Variables in Parameters

Map conversation variables to API parameters.

Tool Configuration:
  Parameters:
    customer_id: { { account_number } } # From DTMF input
    customer_name: { { customer_name } } # From extraction
    call_timestamp: { { current_datetime } } # System variable
    caller_phone: { { user_number } } # System variable
    issue_description: { { issue_details } } # From extraction

Path Parameters

Use dynamic URL segments. URL Template:

https://api.yourservice.com/customers/:customerId/orders/:orderId

Configuration:

{
  "url": "https://api.yourservice.com/customers/:customerId/orders/:orderId",
  "pathParameters": [
    {
      "name": "customerId",
      "defaultValue": "CUST-12345"
    },
    {
      "name": "orderId",
      "defaultValue": "ORD-67890"
    }
  ]
}

Usage in Flow:

Tool Node:
  Tool: Get Order Details

  Path Parameters:
    customerId: { { customer_id } }
    orderId: { { order_number } }

Actual URL called: https://api.yourservice.com/customers/CUST-98765/orders/ORD-11111

Response Handling

Using API Responses

Tool responses become available as variables. API Response:

{
  "customer": {
    "id": "CUST-12345",
    "name": "John Smith",
    "email": "[email protected]",
    "tier": "gold",
    "balance": 1250.5
  },
  "orders": [
    {
      "id": "ORD-11111",
      "status": "shipped",
      "total": 99.99
    }
  ]
}

Available Variables:

Variables auto-created:
  {{customer.id}}
  {{customer.name}}
  {{customer.email}}
  {{customer.tier}}
  {{customer.balance}}
  {{orders[0].id}}
  {{orders[0].status}}
  {{orders[0].total}}

Using in Conversation:

Node: Greet_Customer
  Message: "Welcome back, {{customer.name}}! I see you're a
           {{customer.tier}} member with an account balance of
           ${{customer.balance}}."

Node: Order_Status
  Message: "Your most recent order {{orders[0].id}} is
           {{orders[0].status}}."

Response Validation

Check API responses before using.

Tool Node: Lookup_Customer
  Tool: Get Customer Info

  # Returns customer data or error

Validation Router:
  Conditions:
    # Success case
    - {{api_response_status}} == 200 →
      Use_Customer_Data

    # Customer not found
    - {{api_response_status}} == 404 →
      "I couldn't find an account with that information.
       Would you like to create a new account?"

    # Server error
    - {{api_response_status}} >= 500 →
      "I'm having trouble accessing the system right now.
       Let me try again."
      → Retry_Or_Transfer

    # Any other error
    - Always →
      "Something went wrong. Let me connect you with someone
       who can help."
      → Transfer_To_Agent

Complete Integration Examples

Example 1: CRM Customer Lookup & Update

Flow: Customer_Service_Call

Node 1: Collect_Phone
  Message: "Can I get your phone number?"

  DTMF Input Capture:
    Variable: phone_number
    Digit Limit: 10
    Termination Key: #

Node 2: Lookup_Customer (Tool)
  Tool: CRM Customer Lookup

  Tool Config:
    Method: POST
    URL: https://api.crm.com/v1/customers/search
    Auth: Bearer {{CRM_API_KEY}}

  Parameters:
    phone: {{phone_number}}

  Returns:
    - customer_id
    - customer_name
    - email
    - tier
    - last_contact_date

Node 3: Greet_Customer
  Message: "Hi {{customer_name}}! How can I help you today?"

  Extract: request_type

Node 4: Handle_Request
  [Process customer request]

Node 5: Update_Contact_Log (Tool)
  Tool: Update Customer Record

  Tool Config:
    Method: PATCH
    URL: https://api.crm.com/v1/customers/{{customer_id}}
    Auth: Bearer {{CRM_API_KEY}}

  Parameters:
    customer_id: {{customer_id}}
    last_contact_date: {{current_datetime}}
    last_contact_reason: {{request_type}}
    contact_notes: {{conversation_summary}}

Node 6: Thank_You
  Message: "Thanks for calling, {{customer_name}}!"

Example 2: E-commerce Order Management

Flow: Order_Inquiry

Node 1: Get_Order_Number
  Message: "What's your order number?"

  Extract: order_number
    Instructions: "Extract order number (format ORD-XXXXX)"

Node 2: Fetch_Order (Tool)
  Tool: Get Order Details

  Tool Config:
    Method: GET
    URL: https://api.shop.com/orders/:orderId
    Auth: Bearer {{SHOP_API_KEY}}

  Path Parameters:
    orderId: {{order_number}}

  Returns:
    - status
    - tracking_number
    - items
    - total
    - estimated_delivery

Node 3: Order_Status_Router
  Conditions:
    - {{status}} == "delivered" → Already_Delivered
    - {{status}} == "shipped" → In_Transit
    - {{status}} == "processing" → Being_Processed
    - {{status}} == "cancelled" → Cancelled_Info

In_Transit:
  Message: "Your order is on the way! Tracking number is
           {{tracking_number}} and it should arrive by
           {{estimated_delivery}}."

  Extract: needs_help
    "Does the caller need anything else?"

  Conditions:
    - {{needs_help}} contains "change address" → Cannot_Change_Shipped
    - {{needs_help}} contains "cancel" → Cannot_Cancel_Shipped
    - {{needs_help}} == "no" → Thank_You

Already_Delivered:
  Message: "Our records show this order was delivered on
           {{delivery_date}}."

  Extract: issue_type

  Router:
    - {{issue_type}} contains "didn't receive" → File_Missing_Claim
    - {{issue_type}} contains "damaged" → File_Damage_Claim
    - {{issue_type}} contains "return" → Start_Return_Process

File_Damage_Claim (Tool):
  Tool: Create Claim

  Tool Config:
    Method: POST
    URL: https://api.shop.com/claims
    Auth: Bearer {{SHOP_API_KEY}}

  Parameters:
    order_id: {{order_number}}
    claim_type: "damaged"
    description: {{damage_description}}

  Returns: claim_id

Node: Claim_Confirmation
  Message: "I've created claim {{claim_id}} for you. Our team will
           review it and contact you within 24 hours at {{customer_email}}."

Example 3: Appointment Scheduling System

Flow: Schedule_Appointment

Node 1: Identify_Customer
  Message: "What's your phone number?"

  Extract: phone_number

Node 2: Get_Available_Slots (Tool)
  Tool: Check Availability

  Tool Config:
    Method: GET
    URL: https://api.scheduler.com/slots/available
    Auth: Bearer {{SCHEDULER_API_KEY}}

  Parameters:
    service_type: {{service_type}}
    start_date: {{current_date}}
    days_ahead: 14

  Returns: available_slots (array)

Node 3: Present_Options
  Message: "I have availability on:
           - {{available_slots[0].date}} at {{available_slots[0].time}}
           - {{available_slots[1].date}} at {{available_slots[1].time}}
           - {{available_slots[2].date}} at {{available_slots[2].time}}

           Which works best for you?"

  Extract: preferred_slot

Node 4: Book_Appointment (Tool)
  Tool: Create Appointment

  Tool Config:
    Method: POST
    URL: https://api.scheduler.com/appointments
    Auth: Bearer {{SCHEDULER_API_KEY}}

  Parameters:
    customer_phone: {{phone_number}}
    slot_id: {{selected_slot_id}}
    service_type: {{service_type}}
    notes: {{appointment_notes}}

  Returns:
    - appointment_id
    - confirmation_code

Node 5: Send_Confirmation (Tool)
  Tool: Send SMS Confirmation

  Tool Config:
    Method: POST
    URL: https://api.sms.com/send
    Auth: Bearer {{SMS_API_KEY}}

  Parameters:
    to: {{phone_number}}
    message: "Your appointment is confirmed for {{appointment_date}}
              at {{appointment_time}}. Confirmation code: {{confirmation_code}}"

Node 6: Verbal_Confirmation
  Message: "Perfect! You're all set for {{appointment_date}} at
           {{appointment_time}}. I've sent a confirmation to your phone.
           Is there anything else I can help with?"

Troubleshooting

Tool Not Being Called

Check:

Tool description is clear about when to use it
Tool is added to agent configuration
Agent prompt mentions the tool
Conversation provides context for tool use

Solutions:

Improve tool description
Add explicit examples to prompt
Mention tool capabilities in greeting

API Call Failing

Check:

URL is correct and accessible
Authentication credentials are valid
Required parameters are provided
Headers are correctly formatted
Firewall/network allows requests

Debug:

Test API with curl or Postman
Check API response in call logs
Verify parameter values in logs
Check for CORS issues

Wrong Parameters Passed

Check:

Variable names match exactly
Variables are populated before tool call
Parameter schema is correct
Data types match expectations

Solutions:

Verify variable extraction works
Check variable values in call logs
Add validation before tool call
Use correct variable syntax: {{variable_name}}

Timeout Issues

Check:

API response time
Timeout setting in tool config
Network latency

Solutions:

Increase timeout value
Optimize API performance
Use async mode for slow operations
Add retry logic

Next Steps

Tools Documentation

Complete guide to the tool system

Data Collection

Collect data to pass to APIs

Webhooks

Receive events from Hamsa

Variables

Use variables in tool parameters

Getting Started

Capabilities

Projects

Administration

Documentation Index

​Overview

​Tool System Basics

​What Are Tools?

​Creating Your First Tool

​Using Tools in Agents

​In Flow Agents

​In Single Prompt Agents

​API Patterns

​GET Requests - Retrieving Data

​POST Requests - Creating Data

​PUT/PATCH Requests - Updating Data

​DELETE Requests - Removing Data

​Advanced Patterns

​Chained API Calls

​Conditional Tool Execution

​Error Handling & Retries

​Async Tool Execution

​Authentication Methods

​Bearer Token (JWT)

​API Key in Header

​No Authentication

​Custom Authentication

​Parameter Schemas

​Basic Types

​Complex Types

​Using Variables in Parameters

​Path Parameters

​Response Handling

​Using API Responses

​Response Validation

​Complete Integration Examples

​Example 1: CRM Customer Lookup & Update

​Example 2: E-commerce Order Management

​Example 3: Appointment Scheduling System

​Troubleshooting

​Next Steps

Tools Documentation

Data Collection

Webhooks

Variables

Overview

Tool System Basics

What Are Tools?

Creating Your First Tool

Using Tools in Agents

In Flow Agents

In Single Prompt Agents

API Patterns

GET Requests - Retrieving Data

POST Requests - Creating Data

PUT/PATCH Requests - Updating Data

DELETE Requests - Removing Data

Advanced Patterns

Chained API Calls

Conditional Tool Execution

Error Handling & Retries

Async Tool Execution

Authentication Methods

Bearer Token (JWT)

API Key in Header

No Authentication

Custom Authentication

Parameter Schemas

Basic Types

Complex Types

Using Variables in Parameters

Path Parameters

Response Handling

Using API Responses

Response Validation

Complete Integration Examples

Example 1: CRM Customer Lookup & Update

Example 2: E-commerce Order Management

Example 3: Appointment Scheduling System

Troubleshooting

Next Steps