Pricing
Your AI does the writing.
Sendinel does the sending.
Starts at $0. Bring your own email provider, SMS carrier, and social channels. Every AI operation leaves a certificate-grade audit trail.
- 50+
- active teams
- 100%
- AI operations auditable
- $0
- SMS markup
Free
$0/mo
No annual commitment required - cancel anytime.
Try the full feature set, zero card required.
Your database · Your email API · Your auth
250 subscribers
500 emails / month
1 sending domain
2 campaigns
5 AI drafts / month
+ 6 more - see full comparison ↓Full MCP - complete AI agent control
Campaign Advisor
Compare all plans below ↓Get started free
You will be inside the dashboard in 2 minutes.
MOST POPULAR
BYOD - Bring Your Own Stack
$19/mo
No annual commitment required - cancel anytime.
Connect your email provider + database. Sendinel adds AI and automation. Flat rate.
Any database · Any email API · Any auth · Stripe
Unlimited* subscribers (bounded by your data layer)
Unlimited* sends (bounded by your email provider)
Full MCP (AI agent control + Synchronex integration)
Campaign Advisor
Multi-channel sequences - Email + SMS in one flow
+ 10 more - see full comparison ↓Activate BYOD - $19/mo
First campaign queued before you finish your coffee.
MOST POPULAR
Managed
$79/mo
No annual commitment required - cancel anytime.
We host everything. You own everything.
Sendinel hosts everything · You bring your Stripe
50,000 emails / month included
50,000 subscribers (100k+ available - see Enterprise below)
Full MCP (AI agent control + Synchronex integration)
Stripe + 8 other payment providers + auth webhook triggers -> automation
2-year log retention
+ 11 more - see full comparison ↓Start Managed - $79/mo
Domain registered and DNS records ready on step 1.
Most teams save 50-70% versus Customer.io or Loops once AI workflow control, audit history, and included managed sends are counted.
Full comparison
| Feature | Free | BYOD - Bring Your Own Stack | Managed |
|---|---|---|---|
| AI Features | |||
| AI email drafts | 5 / month | ||
| MCP (Model Context Protocol) - read tools | |||
| MCP - full AI agent control + Synchronex integration | - | ||
| Campaign Advisor | - | ||
| Certificate audit trail | Limited | ||
| Deliverability | |||
| Monthly sends | 500 | Unlimited* | 50,000 included |
| Subscribers | 250 | Unlimited* | 50,000 |
| Sending domains (sites) | 1 | 10 | 10 |
| Email provider | Bring your own | Bring your own | Sendinel managed |
| DNS auto-configuration | |||
| DMARC monitoring | |||
| Overage sends | - | - | Contact us |
| Channels | |||
| Campaigns | 2 | Unlimited | Unlimited |
| SMS campaigns (BYO carrier - Telnyx / Twilio) | |||
| Multi-channel sequences (Email + SMS) | - | ||
| Inbound SMS + TCPA compliance dashboard | |||
| Social campaigns - 9 platforms, UTM tracking | |||
| Social calendar scheduling | |||
| Integrations | |||
| Infrastructure | Your own | Your own | Sendinel hosted |
| Provider portability | |||
| Billing webhook triggers | - | ||
| Auth / identity triggers | - | ||
| Slack integration | - | ||
| Data & Compliance | |||
| Behavioral segmentation | |||
| One-click unsubscribe | |||
| Data export | Subject requests only | Your DB | Always available |
| Log retention | 30 days | 1 year | 2 years |
* BYOD unlimited subscribers and sends are bounded by your own database and email provider account limits. SMS billed directly by your carrier (Telnyx or Twilio) - Sendinel adds zero markup. MCP (Model Context Protocol) lets AI assistants like Claude and Synchronex control Sendinel directly.
Enterprise
For 250k+ monthly sends, priority support, custom contracts, BAA requirements, or dedicated onboarding.
Common questions
Is there a per-subscriber fee?
No. Never. Flat rate. Add 100 subscribers or 100,000 - same price. BYOD volume is bounded by your own provider limits, and Managed higher-volume tiers are available through Enterprise.
What does BYOD vs Managed mean?
BYOD means you own and operate your own infrastructure - Sendinel is the brain. Managed means Sendinel hosts the whole stack for you. Either way, you bring your own Stripe account since we're never in the middle of your billing.
What does bring your own stack mean?
On Free and BYOD, you connect your own data layer, email provider, and auth system - whatever you're already running. Supabase, Airtable, Auth0, your own Postgres - if it can store records, Sendinel can work with it. Same for your email API: Resend, SendGrid, SES, Postmark. Sendinel sits on top and runs the AI, automation, and campaign logic. Your data stays in your infrastructure. We just make it intelligent.
Why do I bring my own Stripe?
Your Stripe account is between you and your customers. Sendinel is never a payment processor. On BYOD and Managed, you connect your Stripe webhook to Sendinel so we can react to billing events - upgrades, churn, payment failures - and fire the right email sequences automatically.
What are MCP tools?
Sendinel ships an MCP (Model Context Protocol) server. Connect Claude, Cursor, or any MCP-compatible AI agent and run your entire email operation by talking to it - create campaigns, enroll subscribers, approve drafts, pull analytics. Every operation in the dashboard is also available to AI agents. BYOD and Managed only.
How does SMS work?
Bring your own Telnyx or Twilio account. Sendinel connects to it and handles campaign creation, delivery, inbound replies (STOP/START/HELP), suppression, and a full TCPA compliance dashboard - opt-out records retained for 10 years per carrier requirements. You pay the carrier directly. Sendinel adds zero SMS markup. You can mix email and SMS in the same sequence.
What can I do with social campaigns?
Sendinel tracks cross-platform social performance using UTM-tagged links - every signup that comes from a post is attributed to the right platform, campaign, and date. The scheduling calendar lets you plan posts across Instagram, LinkedIn, Twitter/X, Facebook, TikTok, YouTube, and Pinterest from one place.
How are you different from Customer.io's AI Agent?
Customer.io is an AI-native engagement platform tied to its sending pipe. Sendinel is a multi-provider control plane: Resend, SendGrid, Postmark, SES, Mailgun, and your own data layer - plus SMS and social. The other difference is auditability. Sendinel records certificate-style reasoning and tool traces so teams can review why an AI action happened, not just that it happened.
What is Synchronex and how does it connect to Sendinel?
Synchronex is a separate AI marketing platform that generates campaign content, selects audiences, and decides send timing based on your brand brain. Sendinel is the execution layer it talks to. Connect them via MCP and the full loop runs autonomously - Synchronex writes, Sendinel publishes to email, SMS, or social, and analytics flow back so Synchronex can improve the next campaign.
Can I export my data on Managed?
Yes, always. Full CSV export for subscribers, email log, campaigns, suppressions - any time, no questions asked. You're never locked in.
The autonomous stack
Pair Sendinel with Synchronex
Sendinel is the execution layer - it sends email, fires SMS, publishes to social, and tracks everything. Synchronex is the intelligence layer - it decides what to say, when, and to whom. Connect them via MCP and your campaigns run end-to-end.
Step 1
Synchronex thinks
Brand Brain generates campaign copy, selects the right segment, and queues the send based on your goals and audience signals.
Step 2
Sendinel executes
Sendinel's MCP tools receive the instruction and publish to email, SMS, or social across any provider.
Step 3
Analytics loop back
Open rates, clicks, SMS replies, and social signups flow back through MCP read tools so Synchronex can optimize the next send.
Requires Sendinel BYOD or Managed + Synchronex ProLearn about Synchronex →
Start free. Upgrade when you're ready.
No card required on the free plan. Takes about 5 minutes to send your first email.