Courier

Integrate Courier, add notification features, and debug delivery problems across email, SMS, push, in-app inbox, Slack, Teams, and WhatsApp.

The Model

One send call does the whole job. You address a user (or list, audience, or tenant), content comes from a template or inline, routing picks the channels, and preferences gate delivery. Courier renders, routes, and delivers; your app supplies the trigger and the data.

Multi-step flows (anything with a delay, a branch, or aggregation) are journeys, defined as JSON and invoked by API.

How to Use This Skill

1. Route first. Where to Look picks the 1–2 files for the task. Don't read the tree.
2. Ask when the request is ambiguous. Channel? Transactional or lifecycle? New code or existing? Which language? Skip the questions when the request is already specific.
3. Verify shapes against a live source rather than memory. The installed SDK's own types are ground truth.
4. Apply the rules. Universal Rules and each file's Quick Reference are constraints, not suggestions. (sdk-reference.md is a lookup table and has none.)

If the project already has @trycourier/courier or trycourier installed, skip quickstart's install steps and assume client exists.