01
Onboarding
Get new users to their first "aha".
- Welcome emails for new signups
- Multi-step onboarding sequences
- Feature tutorials triggered by events
- Nudges when users stall mid-setup
- First-week activation drips
- "Aha-moment" reminders
Simple email automation
for B2B SaaS.
Letter sends emails to your SaaS users. Trigger drip campaigns from what they do in your app, or send broadcasts when you have news.
How it works
From your app to their inbox.
From signup to first email in the time it takes to brew a coffee.
Track
Drop the SDK in your backend. Identify your users and track product events with a couple of function calls. We figure out the rest.
Build
Design email flows on a visual canvas. Trigger on events. Branch on properties. Wait, retry, skip. No spreadsheets.
Send
Letter handles SPF, DKIM, throttling, suppression, bounces, opens. Your emails arrive in the inbox. Quietly.
The visual editor
A drag-and-drop visual sequence editor.
Drag and drop triggers, waits, conditions, and emails. Branch on real product events, not vague “user attributes” pulled from a CRM.
- Trigger on any event your product fires
- Branch on event properties or user state
- Wait minutes, hours, days, or until a condition is met
- Per-contact timeline shows exactly what was sent
- Test sends with one click before going live
TRIGGER
Sequence start
Manual / API enrollment
EMAIL
Welcome to Roger!
BRANCH
If user connected GA
EMAIL
Your first insights
EMAIL
Finish your setup
GOAL
User converted
Subscribed to Pro
Use cases
Every email your SaaS needs to send.
Lifecycle drips when your users do something. Broadcasts when you have something to say.
02
Conversion
Turn trials into paid, paid into upgrades.
- Trial-end reminders with usage stats
- Upgrade nudges when users hit plan limits
- Annual-billing offers
- Free-to-paid drip campaigns
- Win-back for expired trials
- Team-expansion prompts
03
Retention
Keep users active. Catch the ones drifting away.
- Wake dormant users back up
- Celebrate milestones and anniversaries
- Announce features to relevant users
- Recover from failed payments
- Early churn-risk signals
- NPS surveys at the right moment
04
Broadcasts
Reach everyone at once, or just the segment that matters.
- Product update announcements
- New feature launches
- Webinar and event invites
- Monthly newsletters to a segment
- Maintenance and incident notices
- Pricing and plan-change updates
Pricing
Pay for what you send.
Free up to 1,000 contacts. Drag the slider to see what scale costs. No hidden seat fees, no event quotas.
1,000 Contacts
$0/mo Free forever · no card required
Free
Everything you need to start. No card required.
Get started, free forever- Up to 5,000 emails sent/month
- All features included
- Unlimited events tracked
- Includes a small "Powered by Letter" badge
Need more than 500k contacts or custom routing? Talk to us →
FAQ
Questions, answered.
Do I need my own email provider?
No. Letter handles delivery end-to-end: SMTP, deliverability, suppression, the lot. Connect a domain, we verify SPF/DKIM, and mail flies. If you'd rather bring your own SES or Postmark, you can.
How does Letter compare to Loops, Customer.io, or Intercom?
Loops and Customer.io are closer cousins, both lifecycle-focused. Letter is more opinionated and smaller in surface area. We don't do support chat (that's Intercom), and we don't sell ourselves as a CDP. We deliver lifecycle email well, and that's the whole job.
What counts as a “contact”?
Any unique person you've identified with Letter: typically a signed-up user, but could be a lead, a waitlist signup, anyone. We don't charge per event, only per contact in your database.
Will Letter feel like a marketing tool?
No. The composer ships MJML, not drag-and-drop blocks. The dashboard shows engineers what shipped to whom, not pretty conversion funnels you'd never look at twice. Letter is built for the people writing the emails, not the people pitching them.
Can I migrate from another tool?
Yes. Import contacts from CSV or directly via API. We can run alongside your existing tool during migration so nothing drops. We've written guides for the common ones.
Install in seconds
Let your agent wire it up.
Let your agent wire it up.
You're sending.
Hand the one-liner to your coding agent, or drop the SDK in yourself. Identify users, track events: sequences fire automatically. No webhooks to configure, no schemas to define.
Set up with AI
npx @letterapp/cli One command wires Letter into your app. It opens your browser to confirm, provisions your key, and installs the SDK. Your key is never pasted into chat.
or wire it up yourself
// npm i @letterapp/node
import { Letter } from "@letterapp/node";
const letter = new Letter({
apiKey: process.env.LETTER_API_KEY!,
});
letter.identify({ userId: user.id, email: user.email });
letter.track({ userId: user.id, event: "signed_up" });
Ready when you are
Send your first email
Send your first email
in ten minutes.
Free up to 1,000 contacts. No credit card. Drop the SDK in, fire your first event, watch it arrive.