Courier Notification Skills

Guidance for building deliverable, compliant, and engaging notifications across all channels.

How to Use This Skill

1. Identify the task — What channel, notification type, or cross-cutting concern is the user working on?
2. Read only what's needed — Use the routing tables below to find the 1-2 files relevant to the task. Do NOT read all files.
3. Check for live docs — For current API signatures and SDK methods, fetch

   https://www.courier.com/docs/llms.txt

4. Synthesize before coding — Plan the complete implementation (channels, routing, compliance, error handling) before writing code.
5. Apply the rules — Each resource file starts with a "Quick Reference" section containing hard rules. Treat these as constraints, not suggestions.
6. Check universal rules — Before generating any notification code, verify it doesn't violate the Universal Rules below.

Universal Rules (Never Violate)

• NEVER send promotional content in transactional notifications (CAN-SPAM violation)
• NEVER batch or delay OTP, password reset, or security alert notifications
• NEVER send SMS without TCPA-compliant consent records
• NEVER skip idempotency keys for transactional sends
• NEVER send during quiet hours (10pm-8am local) unless critical/security
• NEVER expose full email/phone in security change notifications (mask them)
• ALWAYS include "I didn't request this" links in security-related emails
• ALWAYS use E.164 format for phone numbers
• ALWAYS configure SPF + DKIM + DMARC before sending production email
• ALWAYS respect user opt-out preferences immediately
• ALWAYS use

  method: "single"

  unless the notification is critical enough to warrant all channels

Official Courier Documentation

When you need current API signatures, SDK methods, or features not covered in these resources:

1. Fetch

   https://www.courier.com/docs/llms.txt

   — returns a structured index of all Courier documentation
2. Use it to find specific endpoint details, SDK method signatures, and configuration options
3. Prefer the patterns in THIS skill for best practices; use llms.txt for API specifics

Architecture Overview

[User Action / System Event]
            │
            ▼
    ┌───────────────┐
    │ Notification  │
    │   Trigger     │
    └───────┬───────┘
            │
            ▼
    ┌───────────────┐
    │   Routing     │──── User Preferences
    │   Decision    │──── Channel Availability
    └───────┬───────┘──── Urgency Level
            │
            ▼
    ┌───────────────────────────────────────┐
    │           Channel Selection           │
    ├───────┬───────┬───────┬───────┬──────┤
    │ Email │  SMS  │ Push  │ Inbox │ Chat │
    └───┬───┴───┬───┴───┬───┴───┬───┴───┬──┘
        │       │       │       │       │
        ▼       ▼       ▼       ▼       ▼
    [Delivery] [Delivery] [Delivery] [Delivery] [Delivery]
        │       │       │       │       │
        └───────┴───────┴───────┴───────┘
                        │
                        ▼
                ┌───────────────┐
                │   Webhooks    │
                │   & Events    │
                └───────────────┘

Quick Reference

By Channel

Need to...	See
Send emails, fix deliverability, set up SPF/DKIM/DMARC	Email
Send SMS, handle TCPA/10DLC compliance	SMS
Send push notifications, handle iOS/Android differences	Push
Build in-app notification center	Inbox
Send Slack messages with Block Kit	Slack
Send Microsoft Teams messages	MS Teams
Send WhatsApp messages with templates	WhatsApp

By Transactional Type

Need to...	See
Build password reset, OTP, verification, security alerts	Authentication
Build order confirmations, shipping, delivery updates	Orders
Build receipts, invoices, dunning, subscription notices	Billing
Build booking confirmations, reminders, rescheduling	Appointments
Build welcome messages, profile updates, settings changes	Account
Understand transactional notification principles	Transactional Overview

By Growth Type

Need to...	See
Build activation flows, setup guidance, first value	Onboarding
Build feature announcements, discovery, education	Adoption
Build activity notifications, retention, habit loops	Engagement
Build winback, inactivity, cart abandonment	Re-engagement
Build referral invites, rewards, viral loops	Referral
Build promotions, sales, upgrade campaigns	Campaigns
Understand growth notification principles	Growth Overview

Cross-Cutting Guides

Need to...	See
Route across multiple channels, set up fallbacks	Multi-Channel
Manage user notification preferences	Preferences
Ensure GDPR, TCPA, CAN-SPAM compliance	Compliance
Handle retries, idempotency, error recovery	Reliability
Combine notifications, build digests	Batching
Control frequency, prevent fatigue	Throttling
Plan notifications for your app type	Catalog
Reusable code patterns (consent, quiet hours, masking, retry)	Patterns

Minimal File Sets by Task

For common tasks, you only need to read these specific files:

Task	Files to Read
OTP/2FA implementation	authentication.md, sms.md
Password reset	authentication.md, email.md
Order notifications	orders.md, multi-channel.md
Email setup & deliverability	email.md, compliance.md
SMS setup & compliance	sms.md (includes 10DLC, TCPA)
Push notification setup	push.md
In-app inbox setup	inbox.md
Onboarding sequence	onboarding.md, multi-channel.md
Security alerts	authentication.md, multi-channel.md
Digest/batching	batching.md, preferences.md
Payment/billing notifications	billing.md, reliability.md
Appointment reminders	appointments.md, sms.md
WhatsApp templates	whatsapp.md
Slack/Teams integration	slack.md or ms-teams.md

Decision Guide

What are you building?

• A specific notification (OTP, order confirm, password reset, etc.) → Use the Minimal File Sets table above to find exactly which 1-2 files to read.

• A new notification channel (email, SMS, push, Slack, etc.) → See By Channel for the channel-specific guide.

• Notification infrastructure (routing, preferences, reliability, batching) → See Cross-Cutting Guides for the relevant guide.

• Planning which notifications to build for a new app → Start with Catalog, then Email, then Multi-Channel.

• Growth / lifecycle notifications (onboarding, engagement, referral) → Read Growth Overview for consent requirements first, then the specific type.

• Compliance concerns (GDPR, TCPA, CAN-SPAM) → Read Compliance, then channel-specific rules in SMS or Email.

• Debugging delivery issues → Email going to spam? Email. SMS not arriving? SMS. General failures? Reliability.

• Reusable code patterns (consent check, quiet hours, idempotency, fallback) → See Patterns for copy-paste implementations.