Maildeno Documentation

Build beautiful, responsive email templates visually — then render them anywhere with a single API call.

Maildeno gives product teams a drag-and-drop email editor and gives developers a clean SDK to inject that output into any application stack.

Where do you want to start?

🚀 Quickstart

New here? Get your first email rendered in under five minutes.

✏️ Email Builder

Learn the editor: templates, merge tags, visibility rules, and exporting.

🔌 SDK Reference

Integrate rendering into your app with the JavaScript, Python, or PHP SDK.

Maildeno is a two-part product:

Email Builder — A visual drag-and-drop editor for designing responsive email templates. Teams can manage layouts, merge tags, visibility rules, and export targets all from the dashboard — no code required.
Render API & SDKs — Fetch a template’s JSON structure via our REST API. Then the SDK’s local render engine — an embedded WebAssembly module for JavaScript/Python, a bundled native binary for PHP — takes that JSON, merges your dynamic data, applies visibility rules, and compiles it locally into HTML, React Email, or MJML — ready to pipe into any email-sending service. Your data stays completely local. Maildeno never sees it.

Capability Description

Capability	Description
Drag-and-drop editor	Build pixel-perfect emails without writing HTML or CSS.
Merge tags	Inject dynamic text, URLs, and HTML attributes at render time.
Visibility rules	Show or hide sections based on context values like `plan` or `country`.
Multi-target export	Render the same template as HTML, React Email, or MJML.
Scoped API keys	Restrict each key to specific render targets for least-privilege access.
Sync + async SDKs	Python SDK ships both `MaildenoClient` (sync) and `AsyncMaildenoClient` (asyncio).
Three official SDKs	JavaScript/TypeScript, Python, and PHP — first-party SDKs with matching feature sets.

Drag-and-drop editor

Build pixel-perfect emails without writing HTML or CSS.

Merge tags

Inject dynamic text, URLs, and HTML attributes at render time.

Visibility rules

Show or hide sections based on context values like plan or country.

Multi-target export

Render the same template as HTML, React Email, or MJML.

Scoped API keys

Restrict each key to specific render targets for least-privilege access.

Sync + async SDKs

Python SDK ships both MaildenoClient (sync) and AsyncMaildenoClient (asyncio).

Three official SDKs

JavaScript/TypeScript, Python, and PHP — first-party SDKs with matching feature sets.

Target SDK value (all SDKs) Use case

Target	SDK value (all SDKs)	Use case
HTML	`"html"`	Any transactional email service (SendGrid, Postmark, SES, etc.)
React Email	`"react-email"`	Next.js / React-based email pipelines
MJML	`"mjml"`	Teams already using MJML for cross-client compatibility

HTML

"html"

Any transactional email service (SendGrid, Postmark, SES, etc.)

React Email

"react-email"

Next.js / React-based email pipelines

MJML

"mjml"

Teams already using MJML for cross-client compatibility