Docs Getting Started Quickstart

Quickstart

Two paths to your first send. Pick the one that matches what you’re trying to do today.

Pick your path

	Path A — Try in 30s	Path B — Build for real
Best for	Evaluating the API, demos, throwaway scripts	Production transactional email + dashboard for campaigns
Account needed	None — email-only widget	Free signup at app.brixus365.com/signup
Time to first send	30 seconds	~10 minutes (DNS for domain verification)
API key prefix	`bx_preview_…`	`bx_live_…`
Send modes	Starter templates only	Starter templates + raw HTML + your saved templates + batch + SMTP
Sender	Fixed: `noreply@brixus365.dev`	Your verified domain
Send volume (free)	50/day, 1,500/month, 10/min	9,000/month (free plan)
Spark (campaigns)	Not available	Available in dashboard (free)
Inbox & CRM (coming with WhatsApp/SMS)	Not available	Coming with WhatsApp/SMS launch

Most developers start with Path A to verify the API contract works for them, then move to Path B once they’re committing to integration. The two paths share the same endpoints, error envelope, and code samples — your Path A code keeps working after you upgrade, just with a new key value.

Path A — Try in 30 seconds

Get a bx_preview_… key and send a starter template. No signup, no DNS, no waiting.

1. Get your free key

Open the developers page and look for the Get your free API key widget at the top.

Enter your email address
Open the verification email and click the confirm link
Your bx_preview_… key appears on the next screen — copy it now, the full value is shown only once

Save it as an env var so the snippets below just work:

export BRIXUS_API_KEY=bx_preview_your_key_here

2. Send your first email

Bash

1curl -X POST https://app.brixus365.com/api/v1/emails \
2-H "X-API-Key: $BRIXUS_API_KEY" \
3-H "Content-Type: application/json" \
4-d '{
5  "to": "you@example.com",
6  "starterTemplate": "welcome",
7  "variables": { "name": "Friend", "app_name": "My App" }
8}'

You’ll get back a messageId and status: "queued":

{
  "messageId": "fd92bd3f-969a-4ff6-87dc-a8b0a16e0297",
  "status": "queued",
  "from": "noreply@brixus365.dev"
}

Check your inbox. The email arrives within a few seconds.

What you can and can’t do on Path A

Can	Can’t
Send any of the 10 starter templates	Send raw HTML or use your saved templates
Look up message status via `GET /v1/emails/{id}`	Send from your own domain
Test the MCP server with Claude / Cursor	Use the Spark campaigns dashboard
Send up to 50/day, 1,500/month	Inbox & CRM (coming with WhatsApp/SMS)

When you hit any of those limits, sign up free for Path B — same API, more capability.

Path B — Build something real

Free signup gets you the full product: 9,000 sends/month, raw HTML, batch send, SMTP relay, custom domains, Spark campaigns in the dashboard, and everything you’d expect to ship to production. Setup takes ~10 minutes (mostly DNS records for domain verification).

Setup checklist

Path B has a 4-step setup before your first send works. Each step is described in detail in Before you send — here’s the summary:

#	Step	Time
1	Sign up at app.brixus365.com/signup — verify your email with the OTP code	2 min
2	Create an API key in Settings → API Keys → Create. Pick the Send emails (transactional) preset.	1 min
3	Add a sending domain in Settings → Email Setup → Custom Email Domains and add the SPF + DKIM records to your DNS	5–10 min (depends on DNS propagation)
4	Add a verified sender address and click Set as Default	1 min

Don’t skip step 4. The transactional API rejects sends with 403 no_verified_sender until at least one sender address is marked Default, even if your domain is verified.

Send your first production email

Once setup is complete, the same code as Path A works — just with your bx_live_… key. Sender will be your default verified address:

curl -X POST https://app.brixus365.com/api/v1/emails \
  -H "X-API-Key: bx_live_your_key_here" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "customer@example.com",
    "starterTemplate": "welcome",
    "variables": { "name": "Alice", "app_name": "Acme" }
  }'

Response:

{
  "messageId": "dceaaa96-a806-43d2-ac2d-8396bbd3188a",
  "status": "queued",
  "from": "you@your-verified-domain.com"
}

What you can do on Path B

Send via starter templates, your own saved templates, or raw HTML
Send batches of up to 100 messages in one request
Use the SMTP relay with any mail library (Nodemailer, PHPMailer, MailKit, etc.)
Run Spark campaigns in the dashboard — drag-and-drop builder, automations, segments, analytics
9,000 sends/month free, with the option to upgrade for higher volume

Spark (campaigns) is dashboard-only on free. Programmatic campaign sending requires a paid Standard plan. Transactional API + dashboard campaigns is what most teams need to start.

What’s next

You want to…	Go to
See all 10 starter templates and their variables	Starter templates
Use a language we didn’t cover above	Code examples — 11 languages + SMTP
Send via SMTP from an existing mail library	SMTP relay
Wire Claude or another AI agent to send mail	MCP server quickstart
Understand error codes, rate limits, and idempotency	API overview
Walk through the Path B setup in detail	Before you send
Compare free vs paid plans	Pricing

Stuck? Email support@brixus365.com — we read every message.