@maildun/email Builder

GitHub Actions

Agentic-first email builder: a typed document model, an operations API for LLM agents, a dependency-light HTML renderer, and a modern React editor.

Communication Devops Developer Tools

Add to Cursor Add to VS Code Run on PlugMCP

GitHub npm Website

Add to Cursor Add to VS Code Run on PlugMCP

1{2  "mcpServers": {3    "maildun-email-builder": {4      "command": "npx",5      "args": [6        "-y",7        "@maildun/[email protected]"8      ]9    }10  }11}

.cursor/mcp.jsonMCP server

Transport: stdio
Status: Local

Power your agent

Add this server

The publisher's own command. Not a PlugMCP endpoint.

Add to Cursor Add to VS Code Run on PlugMCP

Host a copy with our keys and logs.

Local command

npx -y @maildun/[email protected]

Claude Code has no install link for a local command. Copy the command below and run it in a terminal.

shClaude Code

1claude mcp add maildun-email-builder -- npx -y @maildun/email-builder@0.5.0

Run in a terminal.

jsonClaude Desktop

1{2  "mcpServers": {3    "maildun-email-builder": {4      "command": "npx",5      "args": [6        "-y",7        "@maildun/[email protected]"8      ]9    }10  }11}

claude_desktop_config.json

Local · npmPublisher installStep-by-step: add this in Claude

Remote URL or a command on your machine? How the two installs differ

Run on PlugMCP

Host a copy with our keys and logs.

A new server you create. It is not this listing's official endpoint. Use the publisher install when you want their URL and their credentials.

Launch

Server facts

Local

Transport: stdio
Version: 0.5.0
Last checked: 2026-10-28

Stars: —
Tools: —
Uptime: —

Tools

No tool list yet. Remote servers get one after the first health check.

FAQ

Questions

How do I install @maildun/email Builder?

Copy the stdio config for Cursor, Claude Desktop, Claude Code, or VS Code on this page. It uses the publisher's install, not a PlugMCP proxy.

Does @maildun/email Builder need an API key?

No required environment variable is listed on this record.

What transport does @maildun/email Builder use?

@maildun/email Builder runs locally over stdio.

When was @maildun/email Builder last checked?

Last checked 2026-10-28. Agentic-first email builder: a typed document model, an operations API for LLM agents, a dependency-light HTML renderer, and a modern React editor.

From the publisher

Documentation

Email Builder

Emails that people and AI can design together.

A typed document model, an operations API for LLM agents, an email-safe HTML renderer and a modern React editor. One package, MIT licensed.

Documentation · Getting started · Agents · MCP

Why

AI is great at writing emails and bad at writing email HTML. Email Builder lets models and people edit the same structured document through the same validated operations, and leaves the HTML to a renderer that knows Outlook.

🧱 A document you can trust. Plain JSON with a Zod schema. Every change is validated, atomic and undoable.
📨 HTML that survives inboxes. Outlook-, Gmail- and mobile-safe HTML plus plain text, from pure TypeScript with no React and no DOM. Runs on servers, edge functions and from a CLI.
🤖 Built for agents. Provider-neutral tools, a system prompt generated from the schemas, and errors written so a model fixes its own mistakes.
✨ An editor people enjoy. Drag and drop, inline rich text, mobile preview, keyboard shortcuts, dark mode, translations, and shadcn/ui styling that matches your app.
👀 Review what the AI changed. AI edits arrive as a proposal the user accepts or rejects in one step.
🔌 MCP server included. Claude, Cursor and other AI clients can design emails in a folder of JSON files.
↪️ Easy to switch. EmailBuilder.js (@usewaypoint/email-builder) designs convert with one call.

Install

npm install @maildun/email-builder

Quick start

Edit with the React editor:

import { EmailEditor } from '@maildun/email-builder/editor';
import '@maildun/email-builder/styles.css';

export function Compose() {
  return (
    <div style={{ height: '100vh' }}>
      <EmailEditor defaultValue={design} onChange={save} />
    </div>
  );
}

Render the stored JSON anywhere:

import { renderEmail } from '@maildun/email-builder';

const { html, text, warnings } = renderEmail(design);

Generate with any LLM:

import { buildSystemPrompt, createAgentSession, runTool, toAnthropicTools } from '@maildun/email-builder/agent';

const session = createAgentSession(design);
// system: buildSystemPrompt(), tools: toAnthropicTools(session.tools)
// for each tool call: runTool(session.tools, call.name, call.input)
session.getDocument(); // the new design

Connect an AI client over MCP:

claude mcp add email-builder -- npx -y @maildun/email-builder mcp --dir ./emails

Documentation


What is Email Builder?	How the pieces fit together
Getting started	Install, edit, save, render and send
The document · Blocks	The JSON model, theme tokens and every block
Operations · Validation	Changing and checking documents
Rendering and sending · CLI	HTML, plain text, providers, other languages
Using the editor · Styling	Props, images, merge tags, theming, dark mode
Agent tools · AI in the editor · MCP	Let models design emails
Custom blocks	Your own block types
Migrating from EmailBuilder.js	Convert existing designs
API reference	Everything exported

The docs are also readable on GitHub in docs/.

Entry points

Import	Contents	Needs React
`@maildun/email-builder`	Schema, operations, validation, lint, sections, templates, renderer	No
`@maildun/email-builder/editor`	`<EmailEditor>`, `EditorStore`, hooks	Yes (19)
`@maildun/email-builder/styles.css`	Precompiled editor styles, for any React app	–
`@maildun/email-builder/core.css`	Editor styles for Tailwind CSS 4 + shadcn/ui apps	–
`@maildun/email-builder/agent`	Agent tools, system prompt, provider adapters	No
`@maildun/email-builder/compat`	`fromEmailBuilderJs`	No
`@maildun/email-builder/mcp`	`EmailMcpServer`, `serveStdio` (Node)	No

Contributing

bun install
bun run dev         # playground at http://localhost:5173
bun run test
bun run docs:dev    # this documentation at http://localhost:5174

See the contributing guide.

License

MIT. Parts of the UI and stylesheet come from shadcn/ui, Tailwind CSS and tw-animate-css (all MIT); see THIRD_PARTY_NOTICES.md. The EmailBuilder.js importer and font presets follow EmailBuilder.js (MIT) for compatibility.

@maildun/email Builder

GitHub Actions

Agentic-first email builder: a typed document model, an operations API for LLM agents, a dependency-light HTML renderer, and a modern React editor.

Communication Devops Developer Tools

Add to Cursor Add to VS Code Run on PlugMCP

GitHub npm Website

Add to Cursor Add to VS Code Run on PlugMCP

1{2  "mcpServers": {3    "maildun-email-builder": {4      "command": "npx",5      "args": [6        "-y",7        "@maildun/[email protected]"8      ]9    }10  }11}

.cursor/mcp.jsonMCP server

Transport: stdio
Status: Local

Power your agent

Add this server

The publisher's own command. Not a PlugMCP endpoint.

Add to Cursor Add to VS Code Run on PlugMCP

Host a copy with our keys and logs.

Local command

npx -y @maildun/[email protected]

Claude Code has no install link for a local command. Copy the command below and run it in a terminal.

shClaude Code

1claude mcp add maildun-email-builder -- npx -y @maildun/email-builder@0.5.0

Run in a terminal.

jsonClaude Desktop

1{2  "mcpServers": {3    "maildun-email-builder": {4      "command": "npx",5      "args": [6        "-y",7        "@maildun/[email protected]"8      ]9    }10  }11}

claude_desktop_config.json

Local · npmPublisher installStep-by-step: add this in Claude

Remote URL or a command on your machine? How the two installs differ

Run on PlugMCP

Host a copy with our keys and logs.

A new server you create. It is not this listing's official endpoint. Use the publisher install when you want their URL and their credentials.

Launch

Server facts

Local

Transport: stdio
Version: 0.5.0
Last checked: 2026-10-28

Stars: —
Tools: —
Uptime: —

Tools

No tool list yet. Remote servers get one after the first health check.

FAQ

Questions

How do I install @maildun/email Builder?

Copy the stdio config for Cursor, Claude Desktop, Claude Code, or VS Code on this page. It uses the publisher's install, not a PlugMCP proxy.

Does @maildun/email Builder need an API key?

No required environment variable is listed on this record.

What transport does @maildun/email Builder use?

@maildun/email Builder runs locally over stdio.

When was @maildun/email Builder last checked?

Last checked 2026-10-28. Agentic-first email builder: a typed document model, an operations API for LLM agents, a dependency-light HTML renderer, and a modern React editor.

From the publisher

Documentation

Email Builder

Emails that people and AI can design together.

A typed document model, an operations API for LLM agents, an email-safe HTML renderer and a modern React editor. One package, MIT licensed.

Documentation · Getting started · Agents · MCP

Why

🧱 A document you can trust. Plain JSON with a Zod schema. Every change is validated, atomic and undoable.
📨 HTML that survives inboxes. Outlook-, Gmail- and mobile-safe HTML plus plain text, from pure TypeScript with no React and no DOM. Runs on servers, edge functions and from a CLI.
🤖 Built for agents. Provider-neutral tools, a system prompt generated from the schemas, and errors written so a model fixes its own mistakes.
✨ An editor people enjoy. Drag and drop, inline rich text, mobile preview, keyboard shortcuts, dark mode, translations, and shadcn/ui styling that matches your app.
👀 Review what the AI changed. AI edits arrive as a proposal the user accepts or rejects in one step.
🔌 MCP server included. Claude, Cursor and other AI clients can design emails in a folder of JSON files.
↪️ Easy to switch. EmailBuilder.js (@usewaypoint/email-builder) designs convert with one call.

Install

npm install @maildun/email-builder

Quick start

Edit with the React editor:

import { EmailEditor } from '@maildun/email-builder/editor';
import '@maildun/email-builder/styles.css';

export function Compose() {
  return (
    <div style={{ height: '100vh' }}>
      <EmailEditor defaultValue={design} onChange={save} />
    </div>
  );
}

Render the stored JSON anywhere:

import { renderEmail } from '@maildun/email-builder';

const { html, text, warnings } = renderEmail(design);

Generate with any LLM:

import { buildSystemPrompt, createAgentSession, runTool, toAnthropicTools } from '@maildun/email-builder/agent';

const session = createAgentSession(design);
// system: buildSystemPrompt(), tools: toAnthropicTools(session.tools)
// for each tool call: runTool(session.tools, call.name, call.input)
session.getDocument(); // the new design

Connect an AI client over MCP:

claude mcp add email-builder -- npx -y @maildun/email-builder mcp --dir ./emails

Documentation


What is Email Builder?	How the pieces fit together
Getting started	Install, edit, save, render and send
The document · Blocks	The JSON model, theme tokens and every block
Operations · Validation	Changing and checking documents
Rendering and sending · CLI	HTML, plain text, providers, other languages
Using the editor · Styling	Props, images, merge tags, theming, dark mode
Agent tools · AI in the editor · MCP	Let models design emails
Custom blocks	Your own block types
Migrating from EmailBuilder.js	Convert existing designs
API reference	Everything exported

The docs are also readable on GitHub in docs/.

Entry points

Import	Contents	Needs React
`@maildun/email-builder`	Schema, operations, validation, lint, sections, templates, renderer	No
`@maildun/email-builder/editor`	`<EmailEditor>`, `EditorStore`, hooks	Yes (19)
`@maildun/email-builder/styles.css`	Precompiled editor styles, for any React app	–
`@maildun/email-builder/core.css`	Editor styles for Tailwind CSS 4 + shadcn/ui apps	–
`@maildun/email-builder/agent`	Agent tools, system prompt, provider adapters	No
`@maildun/email-builder/compat`	`fromEmailBuilderJs`	No
`@maildun/email-builder/mcp`	`EmailMcpServer`, `serveStdio` (Node)	No

Contributing

bun install
bun run dev         # playground at http://localhost:5173
bun run test
bun run docs:dev    # this documentation at http://localhost:5174

See the contributing guide.