SuperSend TX + Lovable

Lovable’s install surface is Secrets + a chat prompt: store your stx_ key, paste the prompt, and let Lovable wire server-side sends (often via Supabase Auth).

There is no separate Lovable “connector package.” The agent writes the Edge Function / hook against POST /emails (or SMTP if you prefer Supabase’s custom SMTP UI).

When to use SuperSend TX

Password reset, verification, receipts, and other transactional mail
Branded from on your own domain after DNS verify
Supabase Auth via a Send Email hook / Edge Function, or custom SMTP with a SuperSend TX credential

Lovable projects often use Supabase — see Supabase Auth email for the hook path and the SMTP alternative.

1. Add your API key (Secrets)

Open app.supersendtx.com → API Keys → create a key (stx_…).
In Lovable, open your project Settings → Secrets (or the env/secrets panel Lovable exposes for backend code).
Add:

SUPERSENDTX_API_KEY=stx_your_key_here

Use the secret name exactly — server routes and Edge Functions should read process.env.SUPERSENDTX_API_KEY. Never put the key in client-side React components.

2. Paste this prompt in Lovable chat

Integrate SuperSend TX transactional email into this app.

Docs (read first):
- https://docs.supersendtx.com/guides/supabase
- https://docs.supersendtx.com/ai/agent-skill
- https://docs.supersendtx.com/openapi.yaml
- https://docs.supersendtx.com/builders/lovable
- https://docs.supersendtx.com/smtp

Rules:
1. Store the API key in SUPERSENDTX_API_KEY (already in Lovable Secrets). Never expose stx_ keys in the browser.
2. Prefer POST https://api.supersendtx.com/emails with Authorization: Bearer $SUPERSENDTX_API_KEY (Supabase Edge Function or server route).
3. Alternative: configure Supabase custom SMTP with SuperSend TX (host smtp.supersendtx.com, username supersendtx, password from dashboard SMTP credentials).
4. Until domain verification and Free production unlock (both required: verified domain + payment method on file), sandbox sends must use from "[email protected]" and to only our account email.
5. Add a server-side send path for password-reset / verification email.
6. Use canonical fields: html, text, reply_to. Prefer npm package supersendtx if the backend is Node.

After domain verify + payment method on file (Free production, no charge until upgrade), switch from to [email protected].

Replace “our account email” with the email on your SuperSend TX account if the agent asks.

3. Minimal server send (Node / Edge)

const res = await fetch('https://api.supersendtx.com/emails', {
  method: 'POST',
  headers: {
    Authorization: `Bearer ${process.env.SUPERSENDTX_API_KEY}`,
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    from: '[email protected]',
    to: '[email protected]',
    subject: 'Verify your email',
    html: '<p>Click the link to verify.</p>',
  }),
})

Or install supersendtx and use the SDK — see Next.js.

Sandbox self-test

Send to your SuperSend TX account email only, with from: "[email protected]", until your domain is verified and Free production is unlocked (payment method on file):

{
  "from": "[email protected]",
  "to": "YOUR_ACCOUNT_EMAIL",
  "subject": "SuperSend TX sandbox check",
  "html": "<p>It works.</p>"
}

Production

Add your domain in the SuperSend TX dashboard.
Apply DNS (Cloudflare integration or registrar credentials).
Verify, add a payment method to unlock Free production (no charge until you upgrade), then update from to an address on that domain.

Optional: MCP while you build

If you use Cursor (or another MCP client) alongside Lovable, connect hosted MCP at https://mcp.supersendtx.com/mcp with OAuth — see MCP server. That helps the coding agent; your Lovable app still needs Secrets (or SMTP) for runtime sends.