Testing | SignalWire

Testing Stages

1. Local Testing

Run agent locally
Test with swaig-test CLI
Verify SWML output

2. Tunnel Testing

Expose via ngrok
Make real calls
Test end-to-end

3. Production Testing

Deploy to production server
Test with real phone
Monitor call logs

swaig-test CLI

Test agents without making calls:

# List available functions
swaig-test my_agent.py --list-tools
# View SWML output
swaig-test my_agent.py --dump-swml
# Execute a function
swaig-test my_agent.py --exec get_weather --city Seattle
# Raw JSON output
swaig-test my_agent.py --dump-swml --raw

Local Server Testing

Run your agent locally using the appropriate command for your language:

Language	Start Command
Python	`python my_agent.py`
TypeScript	`npx tsx my_agent.ts`

Then test the endpoint (the HTTP interface is identical regardless of language):

# In another terminal, test the endpoint (use credentials from agent output or env vars)
curl -X POST -u "$SWML_BASIC_AUTH_USER:$SWML_BASIC_AUTH_PASSWORD" http://localhost:3000/ \
  -H "Content-Type: application/json" \
  -d '{"call_id": "test-123"}'

Using ngrok

Expose local server for real calls:

# Terminal 1: Run agent
python my_agent.py
# Terminal 2: Start ngrok
ngrok http 3000

Copy the ngrok HTTPS URL and configure in SignalWire.

Test Call Checklist

Basic Functionality

Call connects successfully
Agent greeting plays
Speech recognition works
Agent responds appropriately

Function Calls

Functions execute correctly
Results returned to AI
AI summarizes results properly

Edge Cases

Silence handling
Interruption handling
Long responses
Multiple function calls

Error Handling

Invalid input handled
Function errors handled gracefully
Timeout behavior correct

Viewing Logs

In SignalWire dashboard:

Go to Logs
Find your test call
View details:
- Call duration
- SWML executed
- Function calls
- Errors

Debugging with Logs

Add logging to your agent:

import logging
logging.basicConfig(level=logging.DEBUG)
class MyAgent(AgentBase):
    def __init__(self):
        super().__init__(name="my-agent")
        self.log.info("Agent initialized")
    def my_handler(self, args, raw_data):
        self.log.debug(f"Function called with args: {args}")
        self.log.debug(f"Raw data: {raw_data}")
        result = "Some result"
        self.log.info(f"Returning: {result}")
        return FunctionResult(result)

Testing Transfers

Test call transfers carefully. The transfer API is the same across languages via FunctionResult:

Language	Transfer Call
Python	`FunctionResult("Transferring").connect(number, final=True)`
TypeScript	`new FunctionResult("Transferring").connect(number, true)`

def test_transfer(self, args, raw_data):
    # Use a test number you control
    test_number = "+15551234567"
    return (
        FunctionResult("Transferring now")
        .connect(test_number, final=True)
    )

Testing SMS

Test SMS sending. The SMS API follows the same pattern across languages:

Language	Send SMS
Python	`FunctionResult("Sent").send_sms(to_number=to, from_number=from_, body=msg)`
TypeScript	`new FunctionResult("Sent").sendSms({ toNumber: to, fromNumber: from, body: msg })`

def test_sms(self, args, raw_data):
    # Send to your own phone for testing
    return (
        FunctionResult("Sent test SMS")
        .send_sms(
            to_number="+15551234567",  # Your test phone
            from_number="+15559876543", # Your SignalWire number
            body="Test message from agent"
        )
    )

Load Testing

For production readiness:

Test concurrent call handling
Monitor server resources
Check response times under load
Verify function execution at scale
Test database/API connection pooling

Common Test Scenarios

Scenario	What to Test
Happy path	Normal conversation flow
No speech	Silence and timeout handling
Background noise	Speech recognition accuracy
Rapid speech	Interruption handling
Invalid requests	Error handling
Function errors	Graceful degradation
Long calls	Memory and stability

Automated Testing

Create test scripts:

import requests
def test_swml_endpoint():
    """Test that SWML endpoint returns valid response"""
    response = requests.post(
        "http://localhost:3000/",
        json={"call_id": "test-123"},
        headers={"Content-Type": "application/json"}
    )
    assert response.status_code == 200
    data = response.json()
    assert "version" in data
    assert data["version"] == "1.0.0"
def test_function_execution():
    """Test that functions execute correctly"""
    response = requests.post(
        "http://localhost:3000/swaig",
        json={
            "function": "get_weather",
            "argument": {"parsed": [{"city": "Seattle"}]},
            "call_id": "test-123"
        }
    )
    assert response.status_code == 200