Can I call the API from a Node / Python / Bun app, or only Workers?

Any runtime that can speak HTTPS can call `POST /api/email/send`. The official `@flowmails/flowmails-sdk` wraps the REST call for Node, Bun, and Deno; Workers calls go through the same SDK or the raw REST endpoint.

How does the SDK compare to Resend / SendGrid SDKs?

Same shape: `client.messages.send({ from, to, subject, html, text, attachments })` returns a `{ id, status }` object. The difference is that Flowmails' send call hits a Worker in your Cloudflare account — not a shared multi-tenant ESP — so the data path stays under your control.

What happens to email if Cloudflare Email Services is in maintenance?

Email Services status is published at cloudflarestatus.com. Flowmails surfaces accepted / rejected / failed events to your dashboard and (optionally) via webhook so your application can react. There is no automatic retry layer in the base product — pair Flowmails with a small in-app retry queue if your SLA requires it.

Self-hosted · CFFlowmails

Runtime v0.1Login

For Transactional email API

Self-hosted on Cloudflare

Flowmails as a transactional email API: POST /api/email/send from your Worker

Cloudflare Workers can't talk to a traditional SMTP relay without a third-party bridge. Most teams bolt on SendGrid or Resend to fill that gap, which means a separate billing relationship, a separate dashboard, and a per-email fee. Flowmails removes the bolt-on: you POST to `https://<your-zone>.workers.dev/api/email/send` (or use the Flowmails SDK from any runtime), and the Worker in your Cloudflare account sends through Cloudflare Email Services directly. There is no SMTP relay, no per-email markup from Flowmails, and no shared sending IP from a SaaS — your domain sends from your Cloudflare zone. Transactional senders typically ship the first email in under an hour: connect the Cloudflare account, verify the zone, mint an API key, hit the SDK.

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What hurts today

The transactional email api pain points

Cloudflare Workers can't natively SMTP — most teams bolt on SendGrid / Resend

Per-email pricing compounds fast at scale (10K+ transactional emails / month)

Hosted ESPs add a separate dashboard, separate billing, and a shared sending IP

How Flowmails answers

What you get instead

Single `POST /api/email/send` from any Workers-compatible runtime

Outbound sends go through Cloudflare Email Services — no SMTP relay, no per-email markup

Domain sends from your Cloudflare zone (DKIM / SPF / DMARC align automatically)

FAQ

Common questions from transactional email api

Other personas

All Flowmails for pages

For Indie developers For SaaS support teams For Agencies and studios For Privacy-sensitive products