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What is SendyKit?

SendyKit is agent-first, human-friendly email ops — a Go-powered layer that wraps around your existing Sendy installation without touching core and gives humans and agents a modern API, CLI, analytics, AI, health diagnostics, and managed email operations. Think Iron Man’s suit: Sendy is the person inside. SendyKit is the armor, the HUD, the weapons systems, the AI assistant, and the flight capability.

Quick Install

Get SendyKit running in under 5 minutes with one command.

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Why SendyKit?

125 REST Endpoints

Modern JSON API with proper HTTP methods, pagination, filtering, and structured errors. Sendy’s 7 legacy POST endpoints → 125 RESTful endpoints.

240+ CLI Commands

Full CLI with shell completion. Agent-friendly, composable with pipes. No other email platform has this.

AI Authoring

Generate subject lines, full emails, A/B variants, campaign insights. Bring your own AI provider key.

Analytics Intelligence

Engagement scoring, geographic breakdown, send-time optimization, bot detection, Apple MPP filtering.

Health Doctor

68 automated diagnostic checks across 9 categories. Auto-fix safe issues. Scheduled monitoring with alerts.

Multi-Provider SMTP

Use SendGrid, Brevo, Postmark, or any SMTP — not just SES. Encrypted credentials. Automatic failover.

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How It Works

┌──────────────────────────────────────────────────────────┐
│                  SENDYKIT EXOSKELETON                    │
│                                                          │
│   REST API  ·  CLI  ·  Admin UI  ·  Visual Editor       │
│   Analytics · AI · SMTP · Doctor · Audit · Billing       │
│                         │                                │
│              reads (never writes core tables)             │
│                         ▼                                │
│              ┌───────────────────┐                       │
│              │  SENDY PHP CORE   │                       │
│              │  Unchanged · $69  │                       │
│              └───────────────────┘                       │
└──────────────────────────────────────────────────────────┘
SendyKit reads Sendy’s MySQL database and adds its own tables (prefixed sendykit_) via versioned migrations. Sendy keeps working exactly as before.

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Choose Your Path

Self-Hosted

One-time purchase. Install on your server alongside Sendy. Full feature access. Optional managed SMTP pool and AI credits.

SaaS

Managed hosting at sendykit.dev. No Sendy license needed. Subscription pricing with included sending.

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For AI Agents

SendyKit is the first email marketing platform built for agents as first-class citizens. Not a dashboard with an API bolted on — an API with optional dashboards. 
# Agent manages email with CLI — no dashboard needed
sendykit subscribers add --email lead@example.com --list onboarding --brand 2
sendykit campaigns list --brand 2 --sort open_rate --limit 5 --json | jq '.[0]'
sendykit campaigns create --brand 2 --subject "Re-engagement" --template re-engage.html
Agents can also handle premium actions with Stripe-native machine-payment proofs. Use the API and CLI as the primary surfaces, with Stripe machine payments as the live premium-action path.

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By the Numbers

MetricCount
REST API endpoints125
CLI commands240+
Admin pages7
Health checks68
Automated tests351
Spec documents30
Background workers6
DB migrations7
Binary size~10MB