MCP Server Reference

Paper MCP Server Tools

Paper's MCP server runs locally when Paper Desktop is open. It listens on http://127.0.0.1:29979/mcp and exposes 22 tools split into read, write, and export categories. This is the most polished MCP server in the design tool ecosystem as of May 2026.

Read Tools

Tool	Parameters	Returns	Notes
get_basic_info	---	File name, page name, node count, artboard list	Overview of open file
get_selection	---	Selected node IDs, names, types, size	Current selection context
get_node_info	nodeId	Size, visibility, lock, parent, children, text	Detailed node data
get_children	nodeId	Direct children: IDs, names, types	One level deep
get_tree_summary	nodeId, depth?	Compact text summary of subtree	Optional depth limit
get_screenshot	nodeId, scale?	Base64 image (1x or 2x)	Visual capture
get_jsx	nodeId, format	JSX string (tailwind or inline-styles)	Key tool for design-to-code
get_computed_styles	nodeIds[]	Computed CSS styles (batch)	Production-ready values
get_fill_image	nodeId	Base64 JPEG of image fill	Extract embedded images
get_font_family_info	fontFamily	Availability, weights, styles	Check font access
get_guide	topic	Guided workflow steps	e.g., "figma-import"

Write Tools

Tool	Parameters	Returns	Notes
create_artboard	name?, styles?	New artboard ID	Create new canvas area
write_html	html, mode, parentId?	Updated node IDs	Parse HTML, add or replace nodes
set_text_content	nodeIds[], content	Updated count	Batch text update
rename_nodes	nodeIds[], names	Updated count	Batch rename
duplicate_nodes	nodeIds[]	New IDs, descendant ID map	Deep clone
move_nodes	nodeIds[], parentId?, index?	Updated positions	Reparent and reorder
update_styles	nodeIds[], styles	Updated count	Batch CSS updates
delete_nodes	nodeIds[]	Deleted count	Cascade delete descendants
finish_working_on_nodes	artboardIds[]	---	Clear working indicator

Export Tool

Tool	Parameters	Returns	Notes
export	nodes[], format?, scale?	Exported files	PNG, JPG, SVG, MP4; overrides like 2x, 512w, 1080p

Pencil MCP Server Tools

Pencil exposes design tools through its IDE extension and CLI. The MCP server provides access to .pen files, design variables, component definitions, and code generation.

Capability	Details
File operations	Read and write .pen files
Design variables	Access variables and convert to CSS custom properties
Components	Read component definitions with slots and overrides
Code export	Generate React + Tailwind from .pen designs
Node manipulation	Insert, copy, update, replace, move, delete nodes
Visual capture	Screenshots and export to PNG, JPEG, WEBP, PDF
Search	Search nodes by pattern or ID
Variables and themes	Get and set design variables and themes

Configure Pencil's MCP server in OpenCode:

// opencode.json
{
  "mcp": {
    "pencil": {
      "type": "remote",
      "url": "http://127.0.0.1:/mcp",
      "enabled": true
    }
  }
}

OpenPencil MCP Server Tools

OpenPencil's built-in MCP server ships as the pen-mcp package. It provides a layered design workflow and code generation pipeline.

Document and Design Tools

Tool Category	Capabilities
Document operations	Read, create, modify .op files; multi-page support
Node manipulation	Insert, update, move, delete nodes
Style guides	get_style_guide_tags, get_style_guide for visual styles
Design workflow	design_skeleton, design_content, design_refine
Prompt retrieval	Segmented: load schema, layout, roles, icons, planning as needed

Codegen Tools

// Codegen pipeline
codegen_plan        → plan the code generation
codegen_submit_chunk → submit code chunks incrementally
codegen_assemble    → assemble final output
codegen_clean       → clean temporary files

Install OpenPencil's MCP server from the OpenPencil UI: Settings > MCP > Install for [Agent]. One-click setup.

Figma MCP Server Tools

Figma's official MCP server provides read-only access to design files. As of May 2026, write access is not available --- agents can read but cannot modify Figma files.

Capability	Details
Read design files	Node tree, component definitions, styles
Selection context	Get current selection
Variables	Read variables (must have element selected that uses the variable)
Styles	Text styles, color variables, effect styles

Known limitations: SVG fills returned as images, component instance color overrides not reliably returned, spacer elements ignored, and code-connected components not reliably converted.

Configure Figma's MCP server in Claude Desktop:

// Claude Desktop config
{
  "mcpServers": {
    "figma": {
      "command": "npx",
      "args": [
        "-y",
        "figma-developer-mcp",
        "--figma-api-key=$FIGMA_API_KEY",
        "--stdio"
      ]
    }
  }
}

Miro MCP Server Tools

Miro's MCP server enables AI-powered whiteboarding. It provides read and limited write access to Miro boards.

Capability	Details
Read board content	Sticky notes, shapes, text, connectors
Write board elements	Create and modify board elements (limited)
Board metadata	Access board structure and metadata

Miro uses OAuth-based authentication. Available through Miro's developer platform. Compatible with Claude Code and Cursor.

MagicPattern MCP Tools

MagicPattern generates design patterns --- dots, gradients, waves, blobs --- via MCP. Agents can create and customize patterns, then export them as SVG, PNG, or CSS backgrounds.

Capability	Details
Pattern generation	Dots, gradients, waves, blobs, and more
Customization	Colors, spacing, density parameters
Export formats	SVG, PNG, CSS backgrounds

API key-based authentication. Compatible with Claude Code. Free and paid tiers available.

Configuration Reference by Agent Platform

The same MCP server needs different configuration in each agent. Here are the snippets for Paper's MCP server --- the pattern is the same for other servers, just change the URL.

Claude Code (plugin, recommended):

# Add marketplace
/plugin marketplace add paper-design/agent-plugins
# Install plugin
/plugin install paper-desktop@paper

Claude Code (manual):

claude mcp add paper --transport http http://127.0.0.1:29979/mcp --scope user

Codex CLI:

Settings > MCP Servers > Streamable HTTP
Name: paper
URL: http://127.0.0.1:29979/mcp

OpenCode:

// opencode.json
{
  "mcp": {
    "paper": {
      "type": "remote",
      "url": "http://127.0.0.1:29979/mcp",
      "enabled": true
    }
  }
}

GitHub Copilot:

// .vscode/mcp.json
{
  "servers": {
    "paper": {
      "type": "http",
      "url": "http://127.0.0.1:29979/mcp"
    }
  }
}

Cursor:

/add-plugin paper-desktop
# Or search "paper-desktop" in Cursor Marketplace

Antigravity:

// mcp_config.json
{
  "mcpServers": {
    "paper": {
      "serverUrl": "http://127.0.0.1:29979/mcp"
    }
  }
}

Claude Desktop (manual):

// Settings > Developer > Edit Config
{
  "mcpServers": {
    "paper": {
      "command": "npx",
      "args": ["mcp-remote", "http://127.0.0.1:29979/mcp"]
    }
  }
}

Troubleshooting MCP Connections

MCP connections break. It is the most common source of friction in agent-driven design workflows. Here are the issues I see most often.

Symptom	Cause	Fix
Agent cannot find MCP tools	Host tool not running or MCP not connected	Restart the agent session
MCP shows connected but tools fail	Stale connection after long session	Restart both the agent and the host tool
Agent hallucinates tool parameters	LLM context drift over long sessions	Restart the agent session
Rate limit errors after upgrade	Limits not reset after plan change	Update Paper Desktop (About > Check for updates) then restart
Cannot reach 127.0.0.1 on Windows WSL	WSL networking isolation	Enable mirrored mode networking in WSL config