Courier

Sending product notifications sounds simple until you're maintaining separate integrations for email, SMS, push, Slack and in-app messages — each with its own quirks, templates and failure modes. Courier untangles that mess: it's a multichannel messaging platform that orchestrates all your customer notifications and lifecycle journeys from one place.

One API for every channel

Courier lets you send across email, SMS, push notifications, Slack, MS Teams and in-app channels through a single set of APIs and SDKs, plus a visual designer for building and automating engagement workflows. Instead of wiring up and babysitting a different provider for each channel, you integrate once and route messages wherever they need to go. For developers, that consolidation removes a genuinely tedious chunk of work and a lot of ongoing maintenance.

Journeys, preferences and analytics

Courier goes beyond one-off sends to orchestrate whole lifecycle journeys, with built-in user preference management so recipients control what they get and how — increasingly a compliance necessity, not just a nicety. Omnichannel analytics show how messages perform across channels, and template editing keeps your content consistent. Multi-tenant support with isolated data configurations makes it viable for platforms serving many customers. It pairs naturally with transactional email tools like MailerSend in a modern messaging stack.

Built for the AI-agent era

Courier has leaned into the moment with AI agent integration, letting you run Claude and other frontier models within messaging journeys. As products increasingly involve AI agents that need to communicate, having messaging infrastructure that treats agents as first-class participants is a forward-looking advantage.

Reliable at scale

Because notifications are often mission-critical (a password reset that never arrives is a real problem), Courier is built to deliver reliably across channels at the scale enterprises require, with the observability to know what's happening.

Who it's for

Courier suits developers, product teams, growth teams and enterprises from startups to Fortune 500 — particularly SaaS platforms, healthcare, fintech and developer platforms that send lots of customer notifications across channels.

Pricing

Courier is freemium with a 'start sending for free' option and paid tiers as your volume grows. The free entry point lets you integrate and test multichannel notifications before committing to a plan.

The hidden cost Courier eliminates is maintenance: every messaging channel you add by hand becomes something to monitor, update and debug forever, and those integrations quietly rot as providers change their APIs. By centralizing all of it behind one platform with shared analytics and preferences, Courier turns an ever-growing pile of brittle integrations into a single, observable system — which is exactly the kind of leverage a small engineering team needs.

Bottom line: Courier is the notification infrastructure layer for modern products — one API and a visual designer to orchestrate email, SMS, push, Slack and in-app messages (and even AI agents), replacing a tangle of per-channel integrations.