Vibe code your own
Substack in an afternoon.
nusletter.dev is the email API made for people who build with AI. Copy one of our prompts into Lovable, Bolt, Cursor or Claude, and your app can send newsletters straight away. We look after delivery, bounces and unsubscribes so you can focus on your readers.
await fetch("https://api.nusletter.dev/v1/send", { method: "POST", headers: { Authorization: `Bearer ${NUSLETTER_KEY}` }, body: JSON.stringify({ from: "Sam <sam@mynewsletter.com>", to: subscriber.email, subject: "Issue #12: What I learned this week", html: issueHtml, // unsubscribe link + headers added for you }), });
Own your newsletter. Skip the platform fees.
Platforms like Substack and beehiiv take a cut of your revenue and own the relationship with your readers. With AI builders you can now make your own platform. The hard part is sending email properly. That is the bit we do.
Prompt first, not docs first
Every feature comes with a ready made prompt. Paste it into your AI tool and it writes the integration for you, correctly, the first time.
Compliance built in
Unsubscribe links, one click unsubscribe headers, bounce handling and complaint suppression happen automatically on every send.
Simple, honest pricing
Pay for the emails you send. No percentage of your subscription revenue, no lock in. Your list is yours to export any time.
From idea to first issue in four steps.
No SMTP settings, no DNS rabbit holes, no reading pages of API reference.
Create an account and verify your domain
Add your sending domain and we give you the exact DNS records to paste in. We check SPF, DKIM and DMARC for you before you send anything.
Copy a prompt
Choose what you want to build: a signup form with double opt in, a welcome email, a weekly issue sender. Each one is a single prompt.
Paste it into your AI builder
Lovable, Bolt, v0, Cursor, Replit or Claude Code. The prompt tells it exactly how to talk to our API, store subscribers and respect unsubscribes.
Hit send
Your app sends through our infrastructure. You get delivery, open and bounce data back through webhooks and a clean dashboard.
The prompt is the integration.
Here is the kind of prompt you get in your dashboard. Your key and domain are filled in for you.
Paste this into your AI builder:
Add a newsletter signup form to my app using the nusletter.dev API.
1. Store subscribers in my database with fields: email, status
(pending, active, unsubscribed), created_at, confirmed_at.
2. When someone signs up, save them as "pending" and send a
confirmation email via POST https://api.nusletter.dev/v1/send
with a unique confirm link. Use my key from NUSLETTER_KEY.
3. Only mark them "active" after they click the confirm link.
4. Never send newsletters to anyone who is not "active".
5. Add a /webhooks/nusletter route that marks a subscriber as
"unsubscribed" when we receive an unsubscribe, bounce or
complaint event.
Welcome sequence
Send a friendly hello the moment someone confirms, then a short series over their first week.
Weekly issue sender
Write in a simple editor, preview, then send to every active subscriber in safe batches.
Paid tiers
Connect Stripe and send members only issues to paying subscribers. Keep 100% of what you earn.
Built to land in the inbox, and to stay there.
Good delivery comes from good sending habits. We bake them into the platform so every customer protects the reputation everyone shares. Spam is not welcome here, and we enforce that.
- Permission only. Our prompts set up double opt in by default. Bought, rented or scraped lists are banned under our Acceptable Use Policy.
- Unsubscribe on every email. We add a visible unsubscribe link and RFC 8058 one click List Unsubscribe headers to every newsletter send.
- Automatic suppression. Hard bounces, complaints and unsubscribes are added to a suppression list instantly, and we never send to those addresses again.
- Authenticated domains. Every sender must verify their domain with SPF, DKIM and DMARC before sending.
- Live monitoring. We watch bounce and complaint rates per account and pause sending automatically if they rise above safe limits.
- Gradual warm up. New accounts start with modest daily limits that grow as they show healthy engagement.
- Human review. New accounts are reviewed before their limits are raised, and abuse reports are investigated within one business day.
Start free. Pay as you grow.
Final pricing will be confirmed at launch. Early access members lock in these rates.
Creator
- 25,000 emails a month
- 3 verified domains
- Open and click tracking
- Priority support
Publisher
- 150,000 emails a month
- Unlimited domains
- Dedicated sending setup
- Help migrating your list
Questions, answered.
Do I need to know how to code?
Not really. If you can use an AI app builder, you can use nusletter.dev. Our prompts do the technical work and explain each step as they go.
How is this different from Resend or Mailgun?
They are great for developers who read docs. We are built for people who build with AI. Everything is shaped around prompts, sensible defaults and newsletter use cases, with compliance switched on from day one.
What can I send?
Newsletters and transactional email (confirmations, receipts, password resets) to people who have asked to hear from you. Cold outreach, purchased lists and anything misleading are not allowed. See our Acceptable Use Policy.
How do you handle bounces and complaints?
Automatically. Hard bounces and spam complaints are suppressed instantly so you never email that address again, and you get a webhook so your own database stays in sync. Accounts with high bounce or complaint rates are paused and reviewed.
Can I bring my existing list?
Yes, as long as everyone on it opted in to hear from you. We may ask how the list was collected, and we run an import check that removes invalid and risky addresses before your first send.
Who owns my subscribers?
You do. Subscribers live in your own app and database. We only process addresses to deliver the emails you send, and you can export or delete your data at any time.
Your newsletter. Your platform. Your rules.
We are letting builders in a few at a time. Say hello and we will get you set up.
Get early access