Hogsend

The lifecycle email automation that PostHog teams actually need. Code-first, self-hosted, open source.

PostHog tells you what users do. Resend delivers your emails. Hogsend is the bit in the middle — it listens for events, decides who gets what, waits, checks conditions, and sends. Journeys are TypeScript functions, not YAML configs or drag-and-drop canvases.

Built for small teams (1-10 eng) shipping product-led SaaS who picked PostHog and Resend and now need behavioral sequences without buying a third platform.

Documentation | Getting Started | CLI Reference | Compare

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How It Works

Events flow in from PostHog, journeys react with emails via Resend, engagement data flows back. A closed loop — product analytics and lifecycle email in the same event stream.

Deep dive: How It Works | Why PostHog? | Why Hatchet? | Philosophy

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What You Can Build

• Welcome sequences that branch based on whether the user actually used the product
• Trial-to-paid conversion that watches for usage milestones and sends different emails depending on engagement
• Payment failure recovery — escalating reminders that stop the moment the payment goes through
• Dormancy reactivation — detect inactive users, run a win-back series, track if they come back
• NPS / feedback collection timed after key moments
• Abandoned checkout recovery — start a sequence when checkout begins, exit when it completes
• Cross-journey orchestration — one journey enrolls a user in another, chaining sequences without duplicating logic

Each is a single TypeScript file using defineJourney(). The repo ships with 10 production-ready journeys covering common lifecycle stages.

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Quick Example

A user_signed_up event triggers this journey. It sends a welcome email, waits two days, checks if the user tried the core feature, and nudges them if not:

import { days } from "@hogsend/core";
import { sendEmail } from "../lib/email.js";
import { Events, Templates } from "./constants/index.js";
import { defineJourney } from "./define-journey.js";

export const activationWelcome = defineJourney({
  meta: {
    id: "activation-welcome",
    name: "Activation — Welcome Series",
    enabled: true,
    trigger: { event: Events.USER_CREATED },
    entryLimit: "once",
    exitOn: [{ event: Events.USER_DELETED }],
  },

  run: async (user, ctx) => {
    await sendEmail({
      to: user.email,
      userId: user.id,
      journeyName: user.journeyName,
      template: Templates.ACTIVATION_WELCOME,
      subject: "Welcome — let's get you set up",
    });

    await ctx.sleep({ duration: days(2), label: "post-welcome" });

    const { found } = await ctx.history.hasEvent({
      userId: user.id,
      event: Events.FEATURE_USED,
    });

    if (!found) {
      await sendEmail({
        to: user.email,
        userId: user.id,
        journeyName: user.journeyName,
        template: Templates.ACTIVATION_NUDGE,
        subject: "You haven't tried the key feature yet",
      });
    }
  },
});

That ctx.sleep(days(2)) literally pauses for two days and picks up exactly where it left off — durable execution via Hatchet that survives deploys and restarts.

Full guide: Journeys | Events | Email | Conditions

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Get Started

Deploy to Railway (recommended)

# 1. Click the deploy button above — fills in Resend key + Hatchet token
# 2. Install the CLI and configure everything else
curl -L https://github.com/dougwithseismic/hogsend/releases/latest/download/hogsend_darwin_arm64.tar.gz | tar xz
sudo mv hogsend /usr/local/bin/

# 3. Connect Railway + PostHog + verify the pipeline
hogsend init
hogsend test

The CLI discovers your Railway project, generates secrets, creates a PostHog webhook destination, and fires a test event — zero dashboard visits.

Local Development

git clone https://github.com/dougwithseismic/hogsend.git && cd hogsend
pnpm setup        # Docker, deps, .env
pnpm dev          # API on :3002
# separate terminal:
cd apps/api && hatchet worker dev

Full guide: Installation | Configuration | PostHog Setup

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CLI

hogsend init        # Connect Railway project, configure PostHog webhook, verify pipeline
hogsend setup       # Local dev — Docker, deps, .env
hogsend status      # Health check
hogsend deploy      # Trigger Railway redeploy
hogsend test        # Fire test event, verify it arrives
hogsend journeys    # Enable/disable journeys
hogsend contacts    # Manage contacts (list, create, update, delete, prefs)
hogsend destroy     # Tear down Railway project

Full reference: CLI Reference

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Stack

Concern	Tool
HTTP API	Hono on Node.js
Durable execution	Hatchet (sleeps, retries, event routing)
Database	TimescaleDB (Postgres 18) via Drizzle ORM
Cache	Redis
Email delivery	Resend (@hogsend/plugin-resend)
Product analytics	PostHog (@hogsend/plugin-posthog)
Email templates	React Email
CLI	Go (cobra + charmbracelet)
Deploy	Railway or Docker Compose

Plugins are standalone packages — create your own for Slack, Twilio, or any service. See Creating Plugins.

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Explore the Docs

Section	What's there
Getting Started	Installation, PostHog setup, configuration reference
Concepts	How it works, why PostHog, why Hatchet, philosophy
Compare	Hogsend vs Customer.io, Loops, Brevo, ActiveCampaign — feature matrix and migration
Building	Journeys, events, email, conditions, creating plugins
CLI Reference	Every command documented with examples
Operating	Deployment, auth, monitoring, metrics, bulk ops, troubleshooting
API Reference	Every endpoint with request/response examples

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Contributing

See CONTRIBUTING.md for setup, code style, and how to submit changes.

License

Elastic License 2.0 (ELv2) — use, modify, and self-host freely. You can't offer it as a managed service or remove license key functionality. See LICENSE for full terms.