---
type: Knowledge Bundle
title: Euromailing developer knowledge
description: Machine-readable documentation bundle (OKF v0.1) for the Euromailing email platform — transactional API, contact/list sync, Rails integration, inbound routing.
resource: https://euromailing.com
tags: [email, transactional, api, rails]
timestamp: 2026-07-06T00:00:00Z
---

# Euromailing knowledge bundle

Euromailing is a European (EU-hosted, GDPR-native) email platform. This
bundle is a directory of markdown documents with YAML frontmatter,
following the Open Knowledge Format v0.1 conventions. Discovery entry
point for agents: `https://euromailing.com/llms.txt`.

## Contents

- [API overview & authentication](api/index.md) — base URL, keys, scopes, rate limits, error envelope
- [Transactional email API](api/transactional-emails.md) — the most-used surface: one-off mail (password resets, receipts) via HTTP
- [Contacts API](api/contacts.md) — CRUD + idempotent upsert keyed on email
- [Lists API](api/lists.md) — CRUD + subscribe/unsubscribe by email
- [Rails gem guide](guides/rails-gem.md) — euromailing-rails: ActionMailer delivery, user sync, lists
- [Inbound to ActionMailbox](guides/inbound-actionmailbox.md) — receive mail in a Rails app

## Facts an agent should not guess

- Base URL: `https://euromailing.com` (no separate api. host)
- Auth: `Authorization: Bearer eml_live_…` — keys are created in the
  Euromailing dashboard under Account → API keys
- Transactional sending requires the key to be **bound to a verified
  sending domain**; the From address must be on that domain
- Transactional mail carries **no unsubscribe headers** by design
- Sending requires an active subscription; accounts without one receive
  HTTP 402 with code `payment_required`