twilio-debugging-observability

Overview

Twilio provides several layers of debugging and observability: the Console Debugger for interactive troubleshooting, the Monitor REST API for programmatic alert queries, Event Streams for real-time error streaming, and status callbacks for per-resource delivery tracking. This skill covers the systematic approach to diagnosing issues and setting up production monitoring.

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Prerequisites

• Twilio account with TWILIO_ACCOUNT_SID and TWILIO_AUTH_TOKEN -- see twilio-iam-auth-setup
• SDK: pip install twilio requests / npm install twilio
• For Event Streams: a publicly accessible HTTPS endpoint or AWS Kinesis stream

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Quickstart

Check for recent errors on your account using the Monitor Alerts API.

Python

import os
from twilio.rest import Client

client = Client(os.environ["TWILIO_ACCOUNT_SID"], os.environ["TWILIO_AUTH_TOKEN"])

alerts = client.monitor.alerts.list(log_level="error", limit=10)
for alert in alerts:
    print(f"{alert.date_created}: [{alert.error_code}] {alert.alert_text}")

Node.js

const twilio = require("twilio");
const client = twilio(process.env.TWILIO_ACCOUNT_SID, process.env.TWILIO_AUTH_TOKEN);

const alerts = await client.monitor.alerts.list({ logLevel: "error", limit: 10 });
alerts.forEach(a => {
    console.log(`${a.dateCreated}: [${a.errorCode}] ${a.alertText}`);
});

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Key Patterns

1. Systematic Debugging Workflow

When something fails, work through these layers in order:

1. Check status callbacks FIRST
   (Did your endpoint receive delivery/call status? What error code?)
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2. Check the resource directly via REST API
   (GET /Messages/{sid} or /Calls/{sid} — current state + error_code)
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3. Check number reputation / sender registration
   (Is the number spam-flagged? Is A2P 10DLC registered? Toll-free verified?)
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4. Check the Console Debugger for webhook/TwiML errors
   (Console > Monitor > Errors — shows HTTP request/response details)
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5. Check your webhook endpoint
   (Is it reachable? Responding within 15s? Returning valid TwiML/200?)
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6. Query Monitor Alerts API or Event Streams
   (For patterns across many messages/calls, or historical analysis)