Guide

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.