Welcome to Zyphr

Zyphr is a developer platform that combines user authentication with multi-channel messaging behind a single, unified API. Authenticate users with passkeys, social sign-in, passwordless, and MFA — then send emails, push notifications, SMS, in-app messages, and chat notifications (Slack, Discord, Microsoft Teams), with webhooks and advanced features like digests, scheduled sending, and audience segmentation.

Why Zyphr?

Building auth and notification infrastructure is complex. You need to:

Stand up secure authentication — passkeys, OAuth, MFA, sessions, password policy
Integrate with multiple providers (SES, FCM, APNs, Twilio)
Handle deliverability, bounces, and complaints
Build dashboards for debugging and analytics
Manage user preferences and unsubscribes
Set up webhooks for delivery events

Zyphr handles all of this for you with:

One API - Authenticate users and send to any channel with a consistent interface
Auth-as-a-Service - Passkeys/WebAuthn, social sign-in, magic links, email & SMS OTP, TOTP MFA, anonymous auth, and organizations
Secure by Default - RS256 tokens with a public JWKS, configurable password policy, breached-password detection, and account lockout
7 Channels - Email, push, SMS, in-app, Slack, Discord, and Microsoft Teams
Notification Workflows - Multi-channel delivery pipelines with branching, delays, and conditions
Notification Digests - Batch notifications into periodic summaries instead of individual messages
Scheduled Sending - Queue messages for future delivery at specific times
Cohorts & Segmentation - Group subscribers for targeted delivery and A/B comparisons
Complete Observability - Track every message's journey from send to delivery
Message Search & Replay - Full-text search across channels and replay failed messages
Smart Fallbacks - Automatically retry failed messages on alternate channels
Subscriber Management - Built-in preference centers and unsubscribe handling
Webhooks - Real-time event notifications with HMAC-SHA256 signatures, retries, and monitoring
Usage Analytics - Real-time usage tracking, usage alerts, and CSV exports
Developer Experience - SDKs, test mode, and detailed documentation

Quick Example

Send an email in seconds:

curl -X POST https://api.zyphr.dev/v1/emails \
  -H "X-API-Key: zy_live_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "user@example.com",
    "subject": "Welcome to Zyphr!",
    "html": "<h1>Hello!</h1><p>Thanks for signing up.</p>"
  }'

Or send a push notification:

curl -X POST https://api.zyphr.dev/v1/push \
  -H "X-API-Key: zy_live_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "user_id": "user_123",
    "title": "New Message",
    "body": "You have a new notification"
  }'

Authentication Methods

Method	Description
Passkeys / WebAuthn	Full FIDO2 — phishing-resistant, passwordless sign-in
Social Sign-In	Google, Apple, Facebook, GitHub, Microsoft — with account linking
Magic Links	One-click sign-in via a secure emailed link
Email OTP	One-time codes by email, for registration and login
Phone / SMS OTP	One-time codes by SMS, for registration and login
Email & Password	Classic credentials with configurable password policy
MFA (TOTP)	Authenticator-app second factor with single-use backup codes
Anonymous	Guest sessions, convertible to full accounts later
Game Center / Play Games	Native mobile-game identity, verified server-side

Supported Channels

Channel	Description	Providers
Email	Transactional and marketing emails	AWS SES
Push	Mobile and web push notifications	FCM, APNs, Web Push
SMS	Text messages	Twilio
In-App	Notification inbox component	Native
Slack	Channel messages and DMs	Slack API (OAuth)
Discord	Server channel messages	Discord Webhooks
Microsoft Teams	Channel messages with Adaptive Cards	Teams Webhooks

Getting Started

Ready to start building? Add authentication with the Auth-as-a-Service guide, or send your first notification in under 5 minutes with the Quickstart Guide.