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Paper

Combine the Paper and MailBlastr MCP servers so your agent can turn a Paper design into a MailBlastr template or campaign.

Paper is a design tool built for AI agents. Its MCP server lets an agent read your canvas — layout, styles, copy, and screenshots. Combined with the MailBlastr MCP server, your agent can take a design straight from Paper and turn it into a ready-to-send template or campaign in your MailBlastr account.

The flow:

  1. 1
    Design

    You design an email in Paper.

  2. 2
    Read

    Your agent reads the design through the Paper MCP server.

  3. 3
    Convert

    Your agent converts the design into email-safe HTML using the MailBlastr MCP server and agent skills.

  4. 4
    Create

    Your agent creates a template or campaign in MailBlastr.

Prerequisites

  • The Paper Desktop app installed with a file open (opening a file starts the Paper MCP server automatically).
  • A MailBlastr API key and a verified domain.
  • An MCP client like Claude Code, Cursor, or Claude Desktop.

1. Connect the Paper MCP server

Paper Desktop runs a local MCP server at http://127.0.0.1:29979/mcp whenever a file is open. Connect it in your client:

# Install the official Paper plugin (recommended):
/plugin marketplace add paper-design/agent-plugins
/plugin install paper-desktop@paper

# Or add the MCP server directly:
claude mcp add paper --transport http http://127.0.0.1:29979/mcp --scope user

See the Paper MCP docs for other clients.

2. Connect the MailBlastr MCP server

Add the MailBlastr MCP server with your API key:

claude mcp add mailblastr -e MAILBLASTR_API_KEY=mb_xxxxxxxxx -- npx -y mailblastr-mcp

For more clients and options, see the MCP server overview.

3. Design your email in Paper

Design your email as an artboard. A few tips for designs that translate well to email:

  • Use a single-column layout around 600px wide.
  • Use real copy instead of placeholder text.
  • Use web-safe fonts like System Sans-Serif or System Serif.
  • Use PNG or JPG images instead of SVGs (not supported in email).
For personalization, write the variable directly into the design copy, like Hi {{{NAME|there}}}. Your agent preserves it when creating the template or campaign.

4. Ask your agent to create an email

You can create either a template or a campaign. To create a template, select an artboard in Paper and, with both servers connected, prompt:

Look at the selected artboard in Paper and recreate it as an email template in
MailBlastr. Convert the design to email-safe HTML (inline styles, table-based
layout) using the MailBlastr agent skills. Provide a name, subject, and preview
text that fits the content. Publish the template.

Behind the scenes the agent:

  1. Calls Paper's get_selection and get_screenshot to see the design.
  2. Calls Paper's get_jsx or get_computed_styles to read the exact layout, colors, and copy.
  3. Converts the output into email-safe HTML.
  4. Calls MailBlastr's create-template with the HTML, name, and subject.
  5. Calls MailBlastr's publish-template to make it available for sending.

Templates support variables using triple-brace syntax like {{{USERNAME}}}. Once published, send the template via the Emails API or the dashboard.

To go from design straight to a send, ask for a campaign instead — the agent reads the design the same way, then calls create-campaign with the HTML, sender, subject, and segment. Create it as a draft and review it in the dashboard before sending.

Before sending a campaign you must define which segment should receive it. If you don't have one yet, your agent can create one.

Refine in the visual editor

Templates and campaigns created by your agent are editable in the MailBlastr dashboard. If you want the agent's content to be fully editable in the visual editor, ask it to use compose-template or compose-campaign instead of raw HTML — the agent appears as a named avatar in the editor while it works, and you can hand-tune the result afterwards.

Alternatively, edit the template or campaign directly in the dashboard: select the Editor icon in the top left and Hold to confirm to convert the HTML into a visual template or campaign.

Example: end-to-end prompt

1. Read the "Launch Announcement" artboard from Paper.
2. Convert it to an email-safe HTML email. Preserve the colors, spacing, and
   copy as closely as email clients allow. Use the MailBlastr agent skills.
3. Create it as a campaign in MailBlastr from announcements@yourdomain.com to
   the "Customers" segment, subject "We just launched".
4. Show me a summary and the dashboard link, but do not send it.

Troubleshooting

  • Agent can't reach Paper — make sure Paper Desktop is running with a file open, then restart your agent session.
  • Design looks different in the email — email clients don't support modern CSS. Ensure the MailBlastr agent skills are installed, then ask the agent to use table-based layout and inline styles and to flag anything (custom fonts, complex gradients) that won't survive the conversion.
  • `create-campaign` fails — check that the from address uses a verified domain and that the segment exists.