Integration Platform
Courier integrates with 50+ notification providers across email, in-app, SMS, push, and chat channels. You can connect the providers your system already uses—like SendGrid, Twilio, Firebase, Slack, and others—and send notifications through them with a single API call. Using Courier allows you to:- Route messages through preferred or region-specific providers
- Automatically fail over to backups when a provider is unavailable
- Track delivery performance and error rates in real time
- Enable full message log observability for engineering and support teams
Setting Up Your First Provider
Provider Configuration
To connect a provider:- Get API credentials — Obtain your API key or authentication token from the provider.
- Add the provider in Courier — In your Courier workspace, open the Integrations Catalog and add a new provider from the available list.
- Test the connection — Verify your credentials and confirm that Courier can successfully send through the provider.
- Configure routing — Decide how Courier uses this provider for message delivery and define channel priorities or fallbacks.
Provider Categories
Courier supports providers across five main channel types:- Email — SendGrid, Mailgun, AWS SES, and more
- In-App — Courier’s built-in Inbox for web and mobile applications
- SMS — Twilio, MessageBird, Plivo, and more
- Push — Firebase FCM, Airship, OneSignal, and more
- Chat — Slack, Microsoft Teams, WhatsApp, and more
Courier Inbox provides a ready-to-use, in-app notification center that syncs with other channels automatically. You can customize its appearance, handle read states, and track engagement—all without building a notification UI from scratch.
Monitoring Provider Performance
Provider Metrics
Track provider health and performance directly in Courier’s Analytics Dashboard.Monitor delivery rates, latency, and error rates to quickly detect issues and optimize routing. For details on monitoring and analytics, see Analytics Overview.
Integration Features
Fallback and Routing
Courier automatically retries or switches to backup providers when a primary provider fails. You can define custom routing logic to control which providers are used and in what order. Learn more in Channel Priority.Rate Limit Management
When a provider returns a rate limit error (HTTP 429), Courier automatically queues the message and retries using exponential backoff:| Attempt | Delay |
|---|---|
| 1 | 5 seconds |
| 2 | 10 seconds |
| 3 | 20 seconds |
| 4 | 40 seconds |
| 5 | 60 seconds |
| 6 | 2 minutes |
| 7 | 4 minutes |
| 8 | 8 minutes |
| 9 | 12 minutes |
| 10+ | 15 minutes |
Retry-After header, Courier respects that timing instead of the default backoff schedule.
After exhausting retries, Courier attempts failover to an alternative provider or channel if one is configured. If no alternatives exist, the message is marked as UNDELIVERABLE.
For a full overview of retry strategies across message delivery, status tracking, and webhooks, see Delivery Reliability & Retries.