Developer Guide: Supercharge Twilio Workflows with Courier, Segment, and SendGrid

Supercharge Twilio Workflows with Courier, Segment, SendGrid, Twilio SMS

If you're using Twilio products—Segment, SendGrid, and SMS—you've already invested in a world-class messaging infrastructure. But while each tool excels at what it does, connecting them into a seamless, responsive notification system often requires a custom-built backend, fragmented logic, and manual error handling.

Courier makes that unnecessary. Acting as the orchestration layer between these tools, Courier turns real-time user behavior into smart, multi-channel messaging workflows—without requiring you to wire everything together yourself.

Twilio is both a customer and investor in Courier. Their own teams use Courier to orchestrate notifications internally. Here’s how you can do the same.

SendGrid + Courier → Smarter, Personalized Email at Scale

SendGrid is built for high-volume, reliable email delivery—perfect for transactional messages, onboarding flows, and product updates. But when it comes to triggering those emails based on user behavior, managing templates across use cases, or reacting to real-time events, most teams end up building and maintaining custom backend logic.

That’s where Courier comes in.

Courier connects to your existing SendGrid account and acts as the orchestration layer that adds logic, personalization, and cross-channel control—all without adding more code or dashboards to your workflow.

With Courier, you can:

• Design and manage branded email templates using a visual editor or JSON
• Personalize content using real-time user traits from Segment
• Trigger email sends from live product events like trial_started or checkout_completed
• Build logic to wait, branch, retry, or fall back to other channels automatically

Here’s a simple example of how that works in practice:

• A welcome email is sent via SendGrid
• If the user opens it, a follow-up email is triggered with next steps
• If they don’t open within 2 hours, a reminder is sent via Twilio SMS
• If the user is currently active in your app, an in-app message replaces the SMS

You don’t have to write a single line of branching logic or spin up a queue to make this happen. It all lives in Courier’s visual workflow builder—fully integrated with SendGrid.

And when it comes to visibility, Courier provides a single dashboard to track:

• Message status (sent, delivered, failed, skipped)
• Engagement (opens, clicks)
• Provider-level logs (including SendGrid delivery responses)
• Cross-channel outcomes, so you can see email, SMS, and push in one place

By combining Courier’s orchestration with SendGrid’s delivery infrastructure, you get a flexible, personalized email system that adapts to user behavior and scales as your messaging needs grow.

Twilio SMS + Courier → Conditional, Time-Aware Messaging

Twilio SMS is a top-tier solution for sending fast, reliable text messages—ideal for time-sensitive alerts, security codes, and transactional updates. But on its own, it’s a delivery engine, not a decision-making system.

When you need to coordinate SMS with other channels, enforce timing rules, or respond to user behavior in real time, you're often left building custom logic: backend queues, engagement polling, retries, and channel fallbacks.

Courier simplifies all of that by turning Twilio SMS into a behavior-aware, fully orchestrated part of your notification stack.

With Courier, you can build workflows that:

• Delay messages until a specific condition is met (e.g. wait 2 hours after an email is sent)
• Trigger SMS only if the user hasn’t opened or engaged with a previous message
• Replace SMS with an in-app or push notification if the user is currently active
• Respect channel preferences, so SMS is skipped entirely if a user has opted out

Here’s a practical example:

• A user is sent an onboarding email via SendGrid
• If unopened after two hours, Courier automatically sends an SMS reminder via Twilio
• If the app detects the user is currently active, Courier cancels the SMS and delivers the message via in-app instead

Courier handles retries, time-based rules, and conditional delivery—all configured in one place. You don’t need to maintain separate delivery queues or build fallback logic for edge cases.

And like with email, Courier gives you full visibility into every SMS event:

• Delivery and error logs from Twilio
• Engagement metadata if available
• Cross-channel message history for each user

Instead of treating SMS as a standalone channel, Courier makes it a coordinated part of a larger, intelligent system—where timing, preferences, and user context drive what gets sent, when, and how.

Twilio Segment + Courier → Real-Time, Triggered Messaging

Twilio Segment is one of the best tools for collecting real-time customer data. It tracks user behavior across your product and syncs traits like account type, location, and usage patterns—giving you a unified view of who your users are and what they’re doing.

But Segment’s job is to capture data, not act on it. Out of the box, it doesn’t send messages or manage workflows. Turning that data into actionable communication usually means setting up webhook listeners, writing glue code, and wiring up separate notification services.

Courier removes that complexity by integrating directly with Segment as a destination. When Segment sends an event, Courier can immediately trigger a workflow—sending a message, branching logic based on traits, or escalating across channels.

With Courier, you can:

• Trigger notifications from real-time Segment events like user_signed_up, trial_started, or cart_abandoned
• Use user traits (e.g. plan_type, company_size, locale) to personalize content or route by channel
• Build workflows that react to user behavior without backend orchestration

Here’s how it works in practice:

• A user starts a free trial → Segment sends the trial_started event
• Courier checks the user’s preferences and sends a welcome email via SendGrid
• If the email isn’t opened in two hours, Courier sends a follow-up SMS via Twilio
• If the user is actively using your app, Courier skips the SMS and delivers an in-app message instead

There’s no polling, no custom middleware, and no brittle workflows to maintain. You define the logic once—Courier executes it every time an event fires, exactly as you’ve configured.

This turns Segment from a passive data pipeline into an active messaging trigger—connected to a system that knows how to personalize, time, and deliver each message based on real user behavior.

How Courier Orchestrates the Twilio Stack: Segment, SendGrid, and SMS

Each tool in the Twilio stack plays a specialized role: Segment captures real-time user behavior and traits, SendGrid delivers email at scale, and Twilio SMS handles urgent, transactional text messaging. They’re powerful on their own—but without orchestration, you’re left stitching together logic, managing delivery manually, and handling edge cases in your backend.

Courier is the missing piece that brings them all together.

It acts as the orchestration layer across the Twilio stack—connecting data from Segment, triggering messages via SendGrid and Twilio SMS, managing user preferences, and ensuring messages are delivered through the right channel at the right time.

Here’s how that unified system works in practice:

1. Segment tracks a trial_started event from your app
2. Courier evaluates logic and sends a welcome email via SendGrid
3. If the email goes unopened after two hours, Courier triggers a reminder via Twilio SMS
4. If the user is active in your app during that time, Courier skips the SMS and shows an in-app message instead
5. Every message, event, and outcome is tracked in Courier’s centralized log

All of this happens inside one visual workflow—or via Courier’s API—without spinning up message queues, writing retry logic, or syncing dashboards across services.

By orchestrating the Twilio stack, Courier transforms a set of best-in-class tools into a unified, intelligent messaging system. You stop managing infrastructure and start building smarter, more responsive user experiences.

Why Twilio Uses Courier to Power Its Own Messaging Workflows

Courier isn’t just compatible with the Twilio stack—it’s trusted by Twilio itself.

Twilio is both a customer and an investor in Courier. Internally, their teams use Courier to simplify how messages are orchestrated across channels, streamline notification logic, and give product and growth teams the ability to iterate on workflows without writing code.

For a company that builds the infrastructure behind email, SMS, and customer data, choosing Courier to coordinate those tools is a strong endorsement. It shows that even at Twilio’s scale, the problem isn’t just sending messages—it’s managing logic, personalization, preferences, and delivery across multiple channels and products.

Courier makes that orchestration easier—so much so that Twilio uses it for their own internal systems.

If Twilio trusts Courier to power its own stack, you can too.

Frequently Asked Questions

Can I use Courier with both Twilio SMS and SendGrid at the same time?

Yes. Courier is built to orchestrate messages across multiple providers. You can send an email through SendGrid and a follow-up SMS via Twilio within the same workflow.

Here’s an example using Courier’s JSON payload format:

{
  "message": {
    "to": {
      "email": "jane@example.com",
      "phone_number": "+14155550123"
    },
    "template": "onboarding-welcome",
    "routing": {
      "method": "all",
      "channels": ["email", "sms"]
    },
    "providers": {
      "email": "sendgrid",
      "sms": "twilio"
    }
  }
}

How do I trigger a Courier message from a Segment event?

Courier integrates directly with Segment as a Destination. You can use Segment’s client-side SDK to send an event that Courier will receive and use to trigger a notification workflow.

analytics.track("user_signed_up", {
  userId: "1234",
  plan_type: "pro",
  email: "jane@example.com"
});

Courier receives that event and triggers a workflow based on user_signed_up.

Can I set up fallback logic like “email first, then SMS if not opened”?

Yes. Courier supports time-based and engagement-based conditions in its workflows. For example:

• Send a welcome email via SendGrid
• Wait 2 hours
• If the email isn’t opened → send an SMS via Twilio
• If the user is online → skip SMS and show in-app notification instead

All of this can be configured without writing custom backend logic.

What does a basic Twilio SMS send look like without Courier?

Here’s a plain example using the Twilio Node.js SDK:

const accountSid = "ACXXXXXXXXXXXXXXXXXXXXXXXXXXXX";
const authToken = "your_auth_token";
const client = require("twilio")(accountSid, authToken);

client.messages.create({
  body: "Hello from Twilio",
  from: "+12345678901",
  to: "+14155550123"
});

With Courier, you define SMS behavior within a broader workflow, including personalization, fallback, and logging—no direct provider code required.

How does Courier handle user preferences?

Courier has a built-in Preferences Center that allows users to control how they receive messages. Preferences can be used to route or suppress messages dynamically.

Example of preference-aware routing configuration:

{
  "routing": {
    "method": "single",
    "channels": ["email", "sms"],
    "strategy": "user-preference"
  }
}

Courier automatically respects user opt-ins and opt-outs across channels.

Can I personalize messages using Segment traits?

Yes. Courier allows you to insert dynamic data from Segment into your templates. For example:

Hi {{first_name}}, welcome to the {{plan_type}} plan!

These values are passed as data in the Courier message payload and populated in the template at send time.

What happens if Twilio or SendGrid has an outage?

Courier supports provider failover logic. If a message fails via your primary provider, you can configure an automatic fallback to a secondary provider or channel.

Courier also includes provider health metrics and delivery logs so you can monitor failure rates.

Can I build these workflows without code?

Yes. Courier offers a drag-and-drop visual builder where you can:

• Add delays
• Branch based on engagement
• Insert fallback logic
• Respect user preferences
• Trigger messages from Segment events

You can also export and manage workflows as code (JSON) if preferred.

How does Courier track delivery and engagement?

Courier provides a single dashboard where you can view:

• Delivery status (sent, delivered, failed, skipped)
• Engagement (opens, clicks, bounces)
• Provider-level logs from Twilio, SendGrid, and others
• Full user message history across all channels

How secure is Courier?

Courier is SOC 2 compliant and supports GDPR, CCPA, and HIPAA. You can control data retention, redact PII, and manage encrypted credentials across environments.

Can I use Courier for push or in-app messaging?

Yes. Courier supports multiple channels beyond email and SMS:

• Push notifications via Firebase (FCM), Airship, Expo
• In-app notifications via Courier Inbox SDK
• Chat via Slack, Microsoft Teams, WhatsApp

Example Firebase web push setup:

importScripts('https://www.gstatic.com/firebasejs/8.2.7/firebase-app.js');
importScripts('https://www.gstatic.com/firebasejs/8.2.7/firebase-messaging.js');

const firebaseConfig = {
  apiKey: "<API_KEY>",
  authDomain: "vue-push-notifications.firebaseapp.com",
  projectId: "vue-push-notifications",
  storageBucket: "vue-push-notifications.appspot.com",
  messagingSenderId: "365691417480",
  appId: "<APP_ID>"
};

const app = firebase.initializeApp(firebaseConfig);

Courier allows you to include push and in-app messaging in the same workflow alongside email and SMS.