Guide

Is texting patients a HIPAA violation?

The short answer: texting patients is fine until an unsecured text carries protected health information. This post draws the line with side-by-side SMS examples, covers the minimum-necessary rule and when a BAA is required, and shows the template pattern that makes it structurally impossible to leak PHI into a text.

watchOS 27 Notifications: What Changed and How to Adapt Your Product Sends

Apple's watchOS 27, announced at WWDC 2026, presents Apple Watch notifications based on relevance instead of arrival time and expands contextual Smart Stack widgets. Because watch notifications mirror iPhone push, your push strategy is your watch strategy. This guide covers what product and B2B notification teams should change: setting APNs interruption levels honestly, writing glanceable payloads, routing by urgency across push, email, SMS, and in-app inbox, using widgets for status content, and handling the split audience after watchOS 27 drops Series 8, Ultra 1, and SE 2.

Your Entire Lifecycle Marketing Department, Run from Claude Fable 5

With the rollout of Claude' Fable model, one thing is becoming increasingly clear. Marketing execution (especially the long-tail work), will be done in an AI editor. In Courier, connect your agent to the MCP server or CLI, install Courier Skills, and keep a small folder of markdown context files. From there, one person with a coding agent covers the work that used to require a lifecycle marketer, an email designer, a marketing ops hire, and an engineer: building journeys, shipping templates, auditing every notification, and debugging delivery without opening a dashboard.

Human-in-the-loop for AI payment agents: building approval notifications that work

AI agents need human approval before taking consequential actions: financial commitments, irreversible changes, decisions that affect other people. This post covers how to design those checkpoints and build the notification infrastructure: multi-channel delivery, live context, escalation, and a back-and-forth question loop between reviewers and the agent.

AI Tools for Product Managers: The Modern PM Stack

The modern PM stack runs on AI at every step: Cursor and Claude Code for build, Pencil and Claude Design for prototyping, Courier for notifications and agent communication, Segment for routing product events and engagement data, PostHog for analytics and LLM evals, and a knowledge system like Notion for shared memory across humans and agents.

Throttling notifications across product, transactional, and marketing streams

A notification throttle that drops every event over a limit works fine for marketing nurtures and fails for product notifications, because product events carry context users actually need. The fix is pairing throttling with auto-batch: overflow events feed a batch node that rolls them up into a single digest, optionally rewritten by an AI node that prioritizes and summarizes the contents. This guide covers per-stream throttle setups for transactional, product, and marketing flows, and how the Courier Journeys AI node and fetch-data node fit into the pattern.

How to Send Notifications from an AI Agent with Courier's MCP Server

AI agents handle support tickets, monitor pipelines, run onboarding flows, and sync CRM data. When they do, someone needs to know what happened. Courier's MCP server gives agents direct access to the full notification API: send across email, push, SMS, Slack, and in-app. Check user preferences before sending. Trigger batch and digest Journeys so high-volume agents don't spam users. This guide covers MCP server setup, CLI tooling, Courier Skills for your IDE, and five real-world patterns with starter prompts.

Build with AI: let your agent handle notifications end to end

Courier's Build with AI toolkit gives coding agents direct access to your notification infrastructure. Four integration points, one goal: let your agent send messages, debug deliveries, manage users, and follow notification best practices without context-switching. Works with Claude Code, Cursor, and any agent that can run shell commands or call MCP tools.

Expo Push Notifications: The Complete Implementation Guide (SDK 52+)

Expo push notifications are alerts sent from a server to a user's phone, even when the app isn't open. To set them up, install the expo-notifications library, ask the user for permission, and get a unique push token for their device. Your server sends a message to Expo's push service with that token, and Expo delivers it through Apple or Google. Push notifications only work on real phones, not simulators. Local notifications are different — they're scheduled by the app itself for things like reminders. You can also route Expo push through services like Courier to add email, SMS, and Slack fallbacks.

Best Email API Providers for Developers in 2026: SendGrid vs Postmark vs Mailgun vs SES vs Resend

Your email provider sticks with you longer than most technical decisions. Courier handles notification infrastructure for thousands of teams, so we went deep on the six email providers that show up most: SendGrid, Postmark, Mailgun, Amazon SES, Resend, and SMTP. This guide covers real API primitives, actual code from each provider's docs, Courier integration examples with provider overrides, and an honest read on where each developer experience holds up and where it breaks down. We also asked Claude to review every API and tell us which one it would wire up first. The answer surprised us.

What's the Difference Between Omnichannel & Multichannel

Most teams say "omnichannel" when they mean "multichannel," and in most cases the distinction doesn't matter much. But if you truly want to provide an exceptional customer engagement experience you should know the difference. Both involve sending messages across email, push, SMS, Slack, and in-app. They terms diverge when those channels know about each other. Multichannel means you can reach users on multiple channels. Omnichannel means those channels share state, so a user who reads a push notification won't get the same message via email an hour later. This guide breaks down the real distinctions, when the difference actually matters, and which messaging platforms deliver true omnichannel coordination.

A Resilient Notification Strategy for Regulated Industries

Notification compliance isn't a legal checklist—it's an infrastructure problem. In 2026, Reg E deadlines, HIPAA content rules, and TCPA consent requirements dictate your system architecture. This guide breaks down the engineering constraints of regulated notifications for fintech, healthcare, and insurance. Learn why hard-coded deadlines fail, how "alert without disclosing" works in practice, and why the smart escalation pattern (Push → SMS → Email) is the only way to satisfy both user urgency and regulatory documentation. Build systems that absorb complexity, not application code that breaks every time a state law changes.

The Unsubscribe Paradox: Why Making It Easier to Leave Keeps People Around

Hiding the unsubscribe link doesn't keep people subscribed. It makes them mark you as spam, and spam complaints hurt your sender reputation roughly 1000x more than unsubscribes. The brands with the lowest unsubscribe rates don't achieve it by making the door hard to find. They achieve it by making people not want to leave. This guide covers the math behind why easy unsubscribes protect deliverability, how preference centers reduce list churn, and what your unsubscribe flow should actually look like.

Cross-Channel Notification State: Why Read Receipts Are Harder Than They Look

When a user opens your email, does your app know? For most products, the answer is no. Each channel tracks its own state. Email has read receipts. Push has delivery confirmation. In-app has its own unread count. They don't talk to each other. Users notice. This guide covers the three approaches to notification state management (channel-first, central-first, event-first), when to use each, and how to implement cross-channel sync without overengineering. Includes state diagrams and practical implementation patterns.

The First 48 Hours: Onboarding Notifications That Keep Users Around

The first 48 hours after signup are when users decide if your product is worth their attention. Every notification you send is an audition. Most teams blow it by sending too much too fast: welcome email, feature announcement, tip, CEO note. Day one and you've already trained users to ignore you. This guide breaks down what to send (and what not to send) in the critical first 48 hours, with timing frameworks, example sequences, and the one metric that matters more than open rate. Includes templates for signup confirmation, activation prompts, and day-two follow-ups.

Terminal-First Development vs. IDE: Building Notification Infrastructure with Claude Code and Cursor

AI coding tools split into two camps: terminal agents (Claude Code) and IDE-augmented editors (Cursor). This guide compares both approaches using Courier's CLI and MCP server as the test case. Covers installation, configuration, and practical workflows for building multi-channel notifications. Includes code examples for user management, bulk operations, and automation triggers. Also explores agent-to-agent communication patterns where AI systems need notification infrastructure to coordinate tasks and escalate to humans.

What Is Alert Fatigue?

Alert fatigue occurs when users become desensitized to notifications due to high volume, leading to ignored alerts, missed critical information, and decreased engagement. This problem affects product notifications, DevOps monitoring, healthcare systems, and security operations. This guide covers the psychology behind alert fatigue (habituation and the "cry wolf" effect), how to measure it (open rates, dismiss rates, time-to-action), and five practical strategies to reduce it: batching, prioritization, user preferences, smart channel routing, and timing optimization.

Build Multi-tenant Customer Messaging the Right Way | Branding, User Preferences, Routing

Most teams don’t plan multi-tenant messaging... they back into it when customers want their branding, routing, Slack workspace, and default preferences. This guide shows how to model tenant context so every message uses the right customer defaults without per-customer logic in your codebase.

Notification Observability: How to Monitor Delivery, Engagement, and Provider Health

Notification observability is the practice of monitoring notification delivery, engagement, and provider health using the same tools and discipline you apply to the rest of your application infrastructure. It means tracking whether messages are delivered, opened, and acted on across email, SMS, push, and in-app channels, then surfacing that data in dashboards alongside your other application metrics. Key metrics include delivery rate by channel, bounce and failure rates, provider latency, open rate trends, and click-through rates by template. Teams can build notification observability through DIY webhook handlers that pipe provider events to Datadog or Prometheus, log aggregation from application send logs, or notification platforms with built-in observability integrations. This matters most for multi-channel systems, business-critical notifications like password resets and payment confirmations, and teams using multiple providers with fallback routing.

Multichannel Notification Template Management: Version Control, Migration, and Cross-Channel Previews

AI agents are reshaping how products communicate with users. By 2026, 40% of enterprise applications will embed agents that need to send notifications across email, SMS, push, Slack, Teams, and in-app channels autonomously. Managing templates across all these channels with Git-based workflows doesn't scale. This guide covers how teams handle version control and rollback for multichannel templates, which platforms enable designer collaboration without deploys, whether Figma design systems can connect to notification builders, how to migrate templates using APIs and MCP-assisted workflows, how to preview messages across channels side-by-side, open-source options that integrate with SendGrid, Twilio, Firebase, and Slack, and how to localize content from one dashboard. Platforms covered include Courier, Novu, Knock, SuprSend, Dyspatch, Email Love, and React Email, with honest assessments of limitations for each.

Your Notifications Now Have Two Audiences: Humans and AI Agents

AI agents are now filtering, summarizing, and acting on notifications before users ever see them. In late 2024, Anthropic released the Model Context Protocol. By mid-2025, MCP had become the connective tissue for AI agents that take actions on behalf of users. Google followed with A2A. Agentic browsers like Perplexity Comet and Opera Neon started treating the web as something to navigate programmatically. Your notification strategy needs to account for machine interpretation, not just human attention.

Best Notification Infrastructure Software for 2025

Most engineering teams start with SendGrid for email. Then product wants in-app notifications. Marketing needs SMS. Support asks for Slack alerts. Before long, you're maintaining five separate integrations with no unified logic for preferences, routing, or observability. This guide compares the best notification infrastructure platforms for 2025, evaluating cross-channel orchestration, developer experience, drop-in components, and enterprise reliability. Includes head-to-head comparisons (Courier vs Knock, Courier vs Novu), real customer use cases, and guidance on when to build versus buy.

Twilio Integrations with Courier: SMS, SendGrid, Segment

Twilio owns critical notification infrastructure: SMS for billions of messages, SendGrid for email at scale, and Segment for customer data aggregation. Using them together means maintaining three APIs, three credential sets, and zero coordination between channels. Courier solves this by providing a single integration point for all three Twilio products. Connect your accounts, use one API to send across SMS and email, trigger notifications from Segment events, and orchestrate multi-channel delivery with routing rules and failover built in.

Customer Messaging Platforms to Watch in 2026

Customer messaging platforms are shifting from campaign-first tools to real-time, behavior-driven infrastructure. Heading into 2026, the platforms gaining ground prioritize API-first architecture, visual journey orchestration, and intelligent channel routing. Leaders include Courier (developer-first with visual Journeys and embedded components), Knock (workflow-first batching), Customer.io (behavioral automation), and Novu (open-source). Key trends to watch: AI-assisted content, cross-channel preference intelligence, and tighter CDP integration.

How to Use WhatsApp Typing Indicators on Twilio (Public Beta Guide)

Twilio now supports typing indicators for WhatsApp. When your backend takes a few seconds to generate a response, you can show users that something's happening instead of leaving them staring at a silent chat. The indicator appears when you call the new /v2/Indicators/Typing endpoint, automatically marks the message as read, and disappears after your response arrives or 25 seconds pass. This guide covers the API details, implementation patterns for Node.js and Python, when to use typing indicators, and current beta limitations.

Pushbullet Alternative: How to Build Cross-Device Product Messages

Pushbullet proved users demand cross-device notification intelligence. Now product teams need infrastructure to build these capabilities directly into their applications. Courier provides omnichannel messaging infrastructure with cross-channel sync, intelligent routing, multi-provider failover, and consolidated digests. Deliver notifications through 50+ providers across email, SMS, push, Slack, and in-app channels. Meet user expectations with production-ready SDKs, automated workflows, and enterprise-grade reliability.

Transactional, Product, and Marketing Notifications: What Are the Differences?

Understanding the difference between transactional, product, and marketing notifications is essential for developers building notification infrastructure. Transactional notifications confirm user actions and require no opt-in. Product notifications drive feature adoption through education. Marketing notifications promote sales and require explicit consent. This guide explains the legal requirements, best practices, and when to use each notification type to build compliant systems users trust.Retry

How to Build a Notification Center for Web & Mobile Apps

Building a notification center from scratch takes 3-6 months. This comprehensive guide shows developers how to implement a production-ready notification center with multi-channel support in days using React, React Native, iOS, Android, Flutter, or JavaScript. Learn how to add in-app notifications, toast alerts, push notifications, email, and SMS with automatic cross-channel state synchronization. Compare building custom vs. using platforms like Courier, Novu, and OneSignal. Includes real code examples and best practices.

Toast Messages: When to Use Them vs. Snackbars, Banners, and Push Notifications

Toast messages are fast and lightweight—but when should you use a snackbar, banner, or push notification instead? Learn how to choose the right messaging pattern for a smoother, smarter notification experience.

Top 10 Rules for SMS Messaging

SMS transactional messages have exceptional open rates but just 160 characters to communicate critical information. Whether it's delivery confirmations, security alerts, or payment notifications, these messages must be clear, trustworthy, and actionable. This guide covers 10 essential rules for effective SMS messaging: leading with purpose, ensuring brand clarity, respecting character limits, making actions crystal clear, building trust through proper link hygiene, sharing just enough context, guiding users through security scenarios, mastering timing, providing escape routes, and building unbreakable templates.

How to Embed a Template Designer into Your React Application

Multi-tenant SaaS platforms struggle with giving customers template design control without compromising security. Courier Create solves this with an embeddable React component that provides drag-and-drop editing, variable substitution, and brand customization while maintaining tenant isolation. Learn how companies like Side and Hipages benefit from customer-controlled templates, plus get setup code examples for React 18.2+ integration.

Push Notification Fallbacks: Ensuring Message Delivery with Email, Slack, SMS

Push notifications fail more often than you think - users disable them, uninstall apps, or devices go offline. Smart fallback strategies using email, SMS, and workplace chat (Slack & Microsoft Teams) ensure your critical messages always reach users. Courier's multi-channel routing automatically handles delivery failures, switching between push, email, Slack, Teams, and SMS based on your configuration. Unlike basic notification services, Courier provides intelligent timeout management, provider failover, and robust user preference management.

Top 5 Considerations Before Rolling Out SMS Messages

You've got notifications working. Maybe you're sending emails, or you have push notifications running. Now you're thinking about adding SMS to the mix. SMS can make a real difference when done right, but there are some important things to think through first that'll save you headaches later. This guide covers the 5 most important considerations: smart channel routing, provider flexibility, unified API management, user preference systems, and logging analytics.

Toast Messages and Web Push Notifications: Complete Guide

Complete guide to toast messages and web push notifications for modern user engagement. Learn implementation best practices, platform differences, when to use each notification type, and how Courier's unified notification infrastructure streamlines web push delivery while providing React components for seamless toast integration. Covers timing strategies, visual design standards, and multi-channel routing across email, SMS, and in-app messaging for maximum engagement.

Checklist for Building a Better In-App Notification Center (And How Courier Checks Every Box)

Building a modern notification center requires real-time updates, cross-platform sync, and multi-channel orchestration. Companies like Twilio chose Courier instead of building in-house. This complete checklist covers 7 essential requirements: WebSocket delivery, state sync between web and mobile, email/SMS/push orchestration, audit logging, native SDKs, preference management, and automatic failover. Learn how to implement everything in under an hour vs 6 months of custom development.

Video Tutorial: Getting Started with the New Courier Inbox for React

See how easy it is to add real-time in-app notifications to your React app with the new Courier Inbox for Web. Watch the demo and start building in minutes.

Top 7 Push Notification Providers in 2025

Push notifications drive real-time engagement, but managing multiple providers creates integration complexity. Courier is provider-agnostic orchestration layer for Push, Email, SMS, In-App, and Chat. We evaluated 7 top push services—FCM for universal coverage, APNS for iOS reliability, MagicBell for in-app centers, plus Airship, Pusher Beams, Expo, and AWS SNS. Most apps need multiple providers like FCM + APNS + MagicBell. Instead of custom integrations, use notification orchestration for automatic failover and unified management across email, SMS, and chat channels.

Top 6 Email Service Providers for Transactional Notifications in 2025

Comprehensive guide to the 6 best email service providers for transactional notifications in 2025. Compare SendGrid for high-volume enterprise delivery, Mailgun for developer APIs and routing control, Resend for React-based templates, AWS SES at $0.10/1000 emails for cost efficiency, Postmark with <2 second delivery for critical notifications, and SMTP for universal compatibility. Learn why most teams need multiple ESPs, how to meet new SPF/DKIM/DMARC requirements for Gmail, Yahoo, and Outlook.

Courier + Segment: A Guide to Event-Driven Messaging

Courier's native, bidirectional Twilio Segment connection enables real-time event-driven messaging with engagement feedback loops. Trigger multi-channel notifications (email, SMS, push, in-app) from Segment track events like "Trial Started" or "Feature Used." Courier sends engagement data back to Segment for behavioral analytics. Build automated workflows with drag-and-drop editor, conditional logic, and channel fallbacks. Supports SendGrid, Twilio, and native Inbox components for comprehensive notification orchestration.

Best Practices for SMS Tools and Text Message API Implementation

Courier delivers easy access to the messaging providers you use, all in a familiar language and with documentation that’s comprehensive and easy to follow. This page will give you an overview of the SMS providers supported by Courier’s text messaging API, so that you can assess if moving towards a messaging management tool is right for you.

How to Use a Push API to Send Notifications from your Mobile App

This article dives into the topic of push notifications and explains how to use Courier’s push API to deliver simple, one-time push notifications to Android or iOS systems.

How to Choose the Right SMS API for Your Project

In this article, we explain how to choose the right SMS API provider for your needs. We also cover how using Courier can help save a lot of the headache of deciding on a provider, as well as how it offers extra functionality to enhance your SMS sending strategy.

Top 7 Push Notification APIs

Push notifications are a great way to keep users engaged with a product. Used properly, they can significantly increase your click-through rate compared to an email blast. Read our comparison which considers 7 of the top providers against the following set of factors: API documentation/SDK: how easily the service integrates with your code, how accurate the documentation is, and whether the service supports all mobile languages Features: what the main service features are and whether it has common features for notification APIs Price: what the cheapest plan is, what exactly it covers, and how the pricing scales

How to Send Android Push Notifications with Firebase Cloud Messaging and Courier

Learn how to send Android push notifications using Firebase Cloud Messaging (FCM) and the Courier SDK to simplify setup, manage tokens, and deliver messages reliably.

Push Notifications vs In-App Messages: Key Differences, Use Cases, and Implementation Guide

Learn the key differences between push notifications and in-app messages, with real-world use cases and implementation guides for Android, iOS, React, and JavaScript apps. Discover how to engage users across platforms using Courier’s multichannel notification API — including support for toast messages, push alerts, and in-app inboxes.

A Developer’s Guide to Notification APIs

A notification API is a combination of backend infrastructure and both server- and client-side SDKs that enable developers to build notifications in web and mobile apps. In this guide, we delve deeper into notification APIs, their role in transactional and marketing notifications, practical use cases, and the indirect benefits they offer.

Transactional Emails Demystified: From Selecting Providers to Delivery Best Practices

This article explains transactional email, compares email service providers, and presents best practices for implementing and managing transactional email.

The Product Manager's Guide To Building Notification Systems: Optimized Automation Logic

Tailored notifications are essential for a positive user experience. Learn how automation tools make it easy to customize user notifications.

The Product Manager's Guide To Building Notification Systems: Omni-channel Analytics

This is part 4 of a 5 part series. In this article, we talk about omni-channel analytics, why analytics are hard for notifications, and what we believe is needed to empower PMs. We’ll also share some specific tips on making the best of analytics data to design a more informed notification experience for your users.

The Product Manager's Guide To Building Notification Systems: Preferences Management

This is part 3 in a 5 part series. In this article, we’ll cover notification preferences — what they are and which preference options you should consider including in your app — and share some tips on which more advanced options you could build to delight your customers.

The Product Manager's Guide To Building Notification Systems: Decoupling Templates From Code

This is part 2 of a 5 part series. In this article, we explain how decoupling notifications from your application’s codebase can help make notification projects less complex and less risky for product teams.

The Product Manager’s Guide to Designing a Great Notification Experience

Notifications aren’t just messages—they’re a core part of your product experience. Learn how to design smarter, better-timed notifications that build trust, drive engagement, and keep users connected across every channel.