The Rumicat API lets you create and send newsletters from your own tools. One key, a few endpoints, done in under two minutes.

Get Your API Key

Go to rumicat.com/settings/api and click "Generate new key." Give it a name (like the tool you're connecting), copy the key, and store it somewhere safe. You won't see it again.

Your key looks like this: rumi_a1b2c3d4...

Include it in every request as a header:

Authorization: Bearer rumi_your_key_here

Create a Newsletter

Send your content as HTML. We convert it to our editor format automatically. Images from external URLs are downloaded and hosted on our CDN.

POST https://app.rumicat.com/api/v1/newsletters

Body:

{"title": "Your Newsletter Title", "content": "<h3>Hello</h3><p>Your content here.</p>"}

The response includes a dashboard_url that links directly to the editor where you can review the draft. It also includes a web_url the public archive link, which shows up after sending if your publication has the archive enabled.

Send It

Once your draft is ready, send it to all subscribers:

POST https://app.rumicat.com/api/v1/newsletters/{id}/send

Or schedule it for later by including a body:

{"scheduled_at": "2026-04-15T09:00:00Z"}

Sending runs the same checks as the dashboard: content moderation, email verification, spam check. If something's flagged, you'll get a clear error telling you what to fix.

Preview First

Want to see what it looks like before sending? Send a test email to your own inbox:

POST https://app.rumicat.com/api/v1/newsletters/{id}/preview

No body needed. The preview goes to the email address of the publication owner.

Other Endpoints

GET /api/v1/newsletters List your newsletters. Filter by status: draft, sent, scheduled.

GET /api/v1/newsletters/{id} Check the status and details of a specific newsletter.

DELETE /api/v1/newsletters/{id} Delete a draft you no longer need. Only works on drafts.

Supported HTML

Keep it simple. These tags work:

Everything else gets stripped. The result looks identical to creating content in the editor.

Errors

All errors return a JSON object with a code and a message. Common ones:

That's It

Create a key, push content, preview if you want, send. If you run into anything, reach out at rumicat@nternet.company.