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The Senddio free plan

Free messaging API. All six channels, forever.

The Senddio free plan is a real product, not a demo. You get sampler allowances for every channel, 20 monthly AI credits and agent connectors. Channel setup and plan feature limits apply. 300 emails a day, sampler limits on every other channel, no credit card required.

Start free now See all plans
● Free forever · No card · All 6 channels · AI credits
Email300 / day
9,000 / month
SMS10 / mo
Phone-verified
WhatsApp10 / mo
Connected provider
Push100 / mo
FCM iOS+Android
Slack100 / mo
OAuth install
Telegram100 / mo
Bot API
No tricks

What Free actually means.

No credit card
No trial, no expiry, no auto-upgrade
Real production
Same /v1/send and uptime as Pro
AI credits included
20 / month — agent & template features
MCP + OpenAI ready
Drop into Claude Desktop in 30 seconds
Five minutes flat

From sign-up to first send.

  1. 01Sign upEmail + password. No card.
  2. 02Verify a domainPublish SPF/DKIM/DMARC — we generate them.
  3. 03Create an API keysdo_live_… returned exactly once.
  4. 04POST /v1/sendPick channel: email · sms · whatsapp · push · slack · telegram.
  5. 05Watch it landLogs tick queued → sent → delivered, live.
POST /v1/send · your first message
202 Accepted
curl https://api.senddio.com/v1/send \
  -H "Authorization: Bearer sdo_live_…" \
  -H "Content-Type: application/json" \
  -d '{
    "channel": "email",
    "from":    "hello@yourdomain.com",
    "to":      "you@example.com",
    "subject": "First send",
    "html":    "<p>It works.</p>"
  }'

# → { "id": "sdo_msg_…", "status": "queued" }
No tricks

Why the Senddio free plan is a real product.

Most free plans for developer tools are demos — artificially restricted to push you towards a paid tier within the first week. Features get locked behind upgrade prompts, email verification gets throttled to ten sends a day, and AI features appear in the navigation but do nothing until you add a card.

The Senddio free plan runs on the same production platform as Pro. Your domain verification checks your published DNS. Your email uses the same isolated transactional and broadcast delivery pools. Your API key format is identical — sdo_live_ — because it is a live key, not a sandboxed one. The sampler limits on SMS and WhatsApp exist to prevent abuse, not to preview the feature.

The 300 emails per day limit is a real ceiling for a real reason — it costs us real money to warm IP ranges, maintain email infrastructure, and keep your sender reputation clean. Within published Free limits, you can use: SPF, DKIM and DMARC verification in the dashboard, bounce classification and suppression list, open and click tracking that you control per request, inbound reply threading.

The AI credits (20 per month on Free) unlock spam scoring, the template generator and the anomaly detection feed. The Claude MCP server and OpenAI tool schemas are fully functional — your agent can send its first production message on the free tier with an agent-scoped key and every send labelled correctly in the dashboard. There is no paid AI tier unlocking you have to do first.

The shift

Most free plans are demos. This one ships your product.

  • No more 100-emails-a-day limits that run out by Tuesday.
  • No more credit-card field on the signup form.
  • No more “upgrade to access this channel” prompts.
  • No more locking AI and agent features behind Enterprise.

A free plan that genuinely runs your product.

Suggested integration milestones

Your first 30 days, for $0.

01
Day 1
Sender setup completed and first test send queued
02
Day 3
Domain verified, second channel wired
03
Week 1
First on-demand spam score reviewed
04
Day 30
9,000 emails sent. Still no invoice.
●Every milestone above ships on the Free plan. No card, no upgrade gate.
FAQ

Free plan — FAQ

There isn't one. Free is a real product tier we run forever. The sampler quotas on SMS, WhatsApp, push, Slack and Telegram exist to prevent abuse, not to push you to upgrade — they're generous enough for a side project. When you want production volume, paid plans start at $9.

Yes for low-volume transactional email (300/day) and notification channels. For real SMS / WhatsApp volume, move to Pro. Free has published volume and feature limits; webhooks and audit logs require an eligible paid plan.

Yes. Free uses the same infrastructure as paid plans — encrypted credentials, suppression lists, audit-able key creation. Free includes seven days of history; webhooks, audit logs and longer retention are plan-gated.

Yes. Install @senddio/mcp-server in Claude Desktop or import our OpenAI tool schemas. Free gives the agent its own scoped key and labels every send with agent name in the dashboard.

Upgrade in-app to Starter ($9), Pro ($79), or contact us for Enterprise. Your domains, keys, members, webhooks and message history all carry over.

Sign up. Send. Done.

All six channels, AI credits and agent tools — included, free, forever.

Start free Read the docs
● 300 emails/day · All 6 channels · AI credits · No card