Now supporting Discord & Slack

One API to reach every inbox, phone, and channel.

SendMark is a single messaging API for Email, SMS, Webhooks, Discord, and Slack. Stop wiring up five providers — integrate once and let us handle delivery, retries, and routing.

  • One API for 5 channels
  • Automatic retries & fallback
  • Delivery status webhooks
curl https://api.sendmark.dev/v1/messages \
  -H "Authorization: Bearer $SENDMARK_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "channel": "email",
    "to": "customer@acme.com",
    "from": "billing@yourapp.com",
    "subject": "Your invoice is ready",
    "template": "invoice_ready",
    "data": { "amount": "$42.00" }
  }'

5

Channels, one API

99.99%

Platform uptime

<150ms

Median API response

24/7

Delivery monitoring

Every channel your users are on

Send Email, SMS, Webhooks, Discord, and Slack messages through the same endpoint, the same auth, and the same delivery guarantees.

Email

Transactional and marketing email with high deliverability, templates, and open/click tracking.

SMS

Global SMS delivery with automatic carrier failover, unicode support, and delivery receipts.

Webhook

Signed HTTP callbacks to your own systems with configurable retries and backoff.

Discord

Post rich, formatted alerts to Discord channels through your own server bot.

Slack

Send interactive messages to Slack channels, threads, or direct messages.

And more on the way

WhatsApp, Telegram, and push notifications are on our public roadmap — same API, no extra setup.

Everything you need to notify your users

A single platform to send, track, and retry messages across every channel — without maintaining five separate integrations.

Unified send API

One request shape for Email, SMS, Webhooks, Discord and Slack. Switch channels without rewriting integration code.

Automatic retries

Failed deliveries are retried with exponential backoff, and rerouted to a fallback channel when you configure one.

Delivery events

Get sent, delivered, bounced, and failed events pushed to your own webhook so your app always knows message status.

Built for reliability

Idempotency keys, per-channel rate limiting, and audit logs come standard so you can trust every send.

SDKs & templates

Typed SDKs for Node, Python, and Go, plus reusable message templates with variable interpolation.

Broadcast or 1:1

Send a single transactional message or fan a payload out to every channel a user has connected in one call.

Live in three steps

No per-channel setup. No separate credentials to manage.

01

Create an API key

Sign up and generate a live or test API key from your SendMark dashboard in under a minute.

02

Pick a channel

Call the same /v1/messages endpoint with channel set to email, sms, webhook, discord, or slack.

03

Track delivery

Watch message status update in real time, or subscribe to delivery webhooks from your own backend.

Frequently asked questions

Can't find what you're looking for? Email hello@sendmark.dev.

Simple, usage-based pricing

Pay for what you send. No per-channel add-ons, no surprise fees.

Starter

$0/mo

For side projects and testing your integration.

  • 1,000 messages / month
  • All 5 channels
  • Community support
  • 7-day log retention
Start for free
Most popular

Growth

$49/mo

For production apps sending customer notifications.

  • 50,000 messages / month
  • All 5 channels + fallback routing
  • Delivery webhooks
  • Priority email support
  • 30-day log retention
Get your API key

Scale

Custom

For high-volume senders with custom needs.

  • Unlimited messages
  • Dedicated IPs & SLA
  • Custom retention & audit logs
  • Solutions engineer support
Talk to sales

Ship messaging in an afternoon, not a sprint.

Create a free API key and send your first Email, SMS, Webhook, Discord, or Slack message in minutes.