NotifKit vs Courier

Courier is a hosted, multi-tenant notification platform built around visual designers and SaaS tiers. NotifKit is a self-hosted, code-first engine in your own infrastructure (PostgreSQL + Redis), with zero per-message markup, complete data privacy and native AI integration.

The short version

If non-technical marketing staff must design transactional email templates in a hosted web app, and you're comfortable routing customer PII through a third-party cloud, Courier is built for that.

If your engineering team treats notifications as critical infrastructure, wants workflows in Git, won't pay a SaaS tax per message, and must keep user data in your private VPC, NotifKit is a battle-tested engine you own completely.

Feature comparison

Pricing & total cost of ownership (TCO)

Past the free tier, Courier charges per message. Standard self-serve pricing is $0.005 per notification after the first 10,000 free sends, or a negotiated enterprise contract. Provider fees (Twilio, Resend, AWS SES, APNs/FCM) come on top of Courier's platform fee.

Monthly TCO by notification volume

Total cost of ownership by volume, with a standard delivery mix (10% Twilio SMS @ $0.0079, 70% Resend/SES Email @ $0.0001–$0.0008, 20% FCM Push @ $0):

Key architectural differences

1. Data privacy and compliance

Courier is a multi-tenant cloud service. Every send transmits the recipient's email address, phone number, push tokens and the rendered message (often billing amounts, reset tokens, or personal health and financial data) to Courier's servers.

NotifKit runs in your private network. Customer profiles, contacts and logs stay in your PostgreSQL database, and NotifKit talks directly to the upstream gateway (e.g. Resend, Twilio, FCM) over TLS. No third-party data processor agreement (DPA) or external retention audit needed.

2. Code-defined workflows vs cloud automation graphs

Courier coordinates multi-channel sequences with Courier Automations (a node-based DAG builder and JSON schema API). Visual builders appeal to non-technical stakeholders but let notification logic drift out of sync with application state.

In NotifKit, workflows are TypeScript, run by durable Redis Stream state machines. They can sleep for days, wait for domain events (like setup.completed), and resume cleanly across worker restarts:

import { workflow } from "notifkit";

workflow("user-onboarding", async ({ step, event }) => {
  // Step 1: Send welcome email immediately
  await step.notify({
    template: "welcome-email",
    channels: ["email"],
    data: { name: event.name },
  });

  // Step 2: Wait for 3 days (survives restarts and deploys)
  await step.wait("3d");

  // Step 3: Check if user completed setup; if not, send reminder
  const completed = await step.waitForEvent("setup.completed", {
    timeout: "2d",
    match: { userId: event.user.id },
  });

  if (!completed) {
    await step.notify({
      template: "setup-reminder",
      channels: ["push", "sms"],
      fallback: true,
    });
  }
});

3. Local-first AI agent integration via Model Context Protocol (MCP)

Both support the Model Context Protocol (MCP) for assistants like Claude Code and Cursor. Courier's MCP server talks to its remote multi-tenant cloud; NotifKit's runs inside your private network, so assistants can inspect PostgreSQL recipient records, preview Handlebars rendering and query Redis Stream queues without sending operational data to a third party.

When to choose what