Open Pencil

OpenPencil

OpenPencil provides a CLI and MCP server for .fig design files and the running OpenPencil editor.

Use two modes:

• App mode — connect to the running OpenPencil editor by omitting the file argument.
• Headless mode — work with .fig files directly by passing a file path.

# App mode — operates on the document open in the editor
openpencil tree

# Headless mode — operates on a .fig file
openpencil tree design.fig

Current reference version: OpenPencil 0.12.x. The MCP server exposes 106 tools in 0.12.0.

Requirements

# CLI
bun add -g @open-pencil/cli

# MCP server used by the desktop app and external MCP clients
bun add -g @open-pencil/mcp

The desktop app starts openpencil-mcp-http automatically in production Tauri builds when @open-pencil/mcp is installed globally and exposes automation on:

• HTTP/RPC: http://127.0.0.1:7600
• WebSocket bridge: ws://127.0.0.1:7601
• MCP Streamable HTTP: http://127.0.0.1:7600/mcp

CLI Commands

openpencil --help

Commands in 0.12.x:

• info — document overview: pages, node counts, fonts
• tree — print hierarchy with types and sizes
• pages — list pages
• node — detailed node properties by ID
• selection — current selection from the running app
• find — find nodes by name/type
• query — XPath selectors for node search
• variables — list variables and collections
• export — export PNG/JPG/WEBP/SVG/PDF/JSX/.fig
• convert — convert between supported document formats
• analyze — colors, typography, spacing, repeated clusters
• lint — consistency, structure, and accessibility checks
• formats — supported document/export formats
• eval — execute JavaScript with the Figma Plugin API

Inspect

openpencil info design.fig
openpencil tree design.fig
openpencil tree --page "Components" --depth 3  # app mode
openpencil pages design.fig
openpencil node design.fig --id 1:23
openpencil node --id 1:23  # app mode
openpencil selection --json
openpencil variables design.fig
openpencil variables --collection "Colors" --type COLOR

Search and XPath query

openpencil find design.fig --name "Button"
openpencil find --type FRAME                          # app mode
openpencil find design.fig --type TEXT --page "Home"
openpencil find design.fig --name "Card" --type COMPONENT --limit 50

openpencil query design.fig "//FRAME"
openpencil query design.fig "//FRAME[@width  1000]"             # app mode

Common node types: FRAME, TEXT, RECTANGLE, ELLIPSE, VECTOR, GROUP, COMPONENT, COMPONENT_SET, INSTANCE, SECTION, LINE, STAR, POLYGON, SLICE, BOOLEAN_OPERATION.

Export and convert

openpencil export design.fig -o hero.png
openpencil export -o hero.png                         # app mode
openpencil export design.fig --node 1:23 -s 2 -o button@2x.png
openpencil export design.fig -f jpg -q 85 -o preview.jpg
openpencil export design.fig -f svg --node 1:23 -o icon.svg
openpencil export design.fig -f pdf -o page.pdf
openpencil export design.fig -f fig -o roundtrip.fig
openpencil export design.fig -f jsx -o component.jsx
openpencil export design.fig -f jsx --style tailwind -o component.tsx
openpencil export design.fig --thumbnail --width 1920 --height 1080
openpencil export --page "Components" -o components.png

openpencil convert design.fig -o design.pen
openpencil formats

Analyze and lint

openpencil analyze colors design.fig
openpencil analyze colors --similar --threshold 10     # app mode
openpencil analyze typography design.fig --group-by size
openpencil analyze spacing design.fig --grid 8
openpencil analyze clusters design.fig --min-count 3
openpencil lint design.fig
openpencil lint design.fig --json

Eval (Figma Plugin API)

Execute JavaScript against the document using a Figma Plugin API-compatible runtime:

openpencil eval design.fig -c 'figma.currentPage.findAll(n => n.type === "TEXT").length'

# App mode — modifies the live document in the editor
openpencil eval -c '
  const buttons = figma.currentPage.findAll(n => n.name === "Button");
  buttons.forEach(b => { b.cornerRadius = 8 });
  buttons.length + " buttons updated"
'

# Modify and save to the same file
openpencil eval design.fig -w -c '
  const texts = figma.currentPage.findAll(n => n.type === "TEXT");
  texts.forEach(t => { t.fontSize = 16 });
'

# Save to a different file
openpencil eval design.fig -o modified.fig -c '...'

# Read code from stdin
echo 'figma.currentPage.children.map(n => n.name)' | openpencil eval design.fig --stdin

Every command that reports structured data supports --json when appropriate.

MCP Server

Stdio MCP clients

Use Bun by default:

{
  "mcpServers": {
    "open-pencil": {
      "command": "bunx",
      "args": ["openpencil-mcp"]
    }
  }
}

If @open-pencil/mcp is installed globally, direct binaries also work:

{
  "mcpServers": {
    "open-pencil": {
      "command": "openpencil-mcp"
    }
  }
}

HTTP / Streamable HTTP

export PORT=7600
export OPENPENCIL_MCP_AUTH_TOKEN=secret       # optional auth for /mcp
export OPENPENCIL_MCP_CORS_ORIGIN="*"         # optional CORS
export OPENPENCIL_MCP_ROOT=/path/to/files     # enables/scopes open_file/save_file paths

openpencil-mcp-http
# or: bunx openpencil-mcp-http

MCP workflow

1. Open/create a document — open_file { path } when OPENPENCIL_MCP_ROOT is configured, or new_document {}.
2. Query — get_page_tree, find_nodes, query_nodes, get_node, list_pages, get_current_page.
3. Inspect — get_jsx, diff_jsx, describe, export_image, export_svg, export_pdf.
4. Modify — render, batch_update, update_node, set_fill, set_layout, create_shape, import_svg, etc.
5. Navigate — after creating or editing visible canvas content, call select_nodes and viewport_zoom_to_fit { id } (or node_bounds + viewport_set) so the user can see the result in the running editor.
6. Save/export — save_file, export_image, export_svg, export_pdf, or CLI export.

MCP Tools in 0.12.0 (106 total)

Read and selection (17): get_selection, get_node, find_nodes, get_page_tree, get_current_page, list_pages, select_nodes, query_nodes, get_components, switch_page, page_bounds, list_fonts, list_available_fonts, get_jsx, diff_jsx, describe, node_tree

Create and import (12): render, create_shape, create_component, create_instance, create_page, create_vector, create_slice, import_svg, search_icons, insert_icon, fetch_icons, stock_photo

Modify (24): update_node, batch_update, set_layout, set_layout_child, set_radius, set_fill, set_stroke, set_text, set_text_properties, set_effects, set_opacity, set_font, set_visible, set_constraints, set_rotation, set_minmax, set_font_range, set_text_resize, set_blend, set_locked, set_stroke_align, set_image_fill, set_variable, bind_variable

Structure (16): delete_node, reparent_node, node_resize, clone_node, node_move, rename_node, group_nodes, ungroup_node, flatten_nodes, node_to_component, node_bounds, node_ancestors, node_children, node_bindings, node_replace_with, arrange

Variables (9): list_variables, list_collections, get_variable, find_variables, create_variable, delete_variable, get_collection, create_collection, delete_collection

Vector and viewport (15): boolean_union, boolean_subtract, boolean_intersect, boolean_exclude, path_get, path_set, path_scale, path_flip, path_move, viewport_get, viewport_set, viewport_zoom_to_fit, export_svg, export_pdf, export_image

Analyze and generation (9): analyze_colors, analyze_typography, analyze_spacing, analyze_clusters, diff_create, diff_show, design_to_tokens, design_to_component_map, calc

File and prompts (4): save_file, open_file, new_document, get_codegen_prompt

> Tool availability can depend on server mode. open_file, save_file, and disk-writing export paths require OPENPENCIL_MCP_ROOT for path scoping.

Key tools for agents

• query_nodes — XPath selectors to find specific nodes without fetching the full tree.
• get_jsx — inspect any node as JSX in the same format accepted by render.
• diff_jsx — compare two nodes structurally before editing.
• describe — semantic analysis of role, visual style, layout, and design issues.
• batch_update — apply multiple node updates efficiently.
• export_image / export_svg / export_pdf — visual verification and deliverables.
• viewport_zoom_to_fit / viewport_set / viewport_get — keep the live editor focused on the created or edited design.
• get_codegen_prompt — retrieve OpenPencil's current JSX/codegen guidance.

JSX Rendering

Use the render tool or eval to create component trees. If unsure about JSX syntax, call get_codegen_prompt first.

  Title
  Description text
  
    
      Action
    
  

Elements: Frame, Text, Rectangle, Ellipse, Line, Star, Polygon, Group, Section, Component, Instance.

Text content is the child content of ``. Use design-JSX props, not Figma API field names:

Design faster with AI

Common props:

| Prop | Meaning | |------|---------| | w, h | Width, height (number or "hug" / "fill") | | flex | "row" or "col" | | grid, columns, rows | CSS Grid, e.g. columns="1fr 200px 1fr" | | gap, rowGap, columnGap | Item spacing | | p, px, py, pt, pr, pb, pl | Padding | | justify | "start", "center", "end", "between" | | items | "start", "center", "end", "stretch" | | grow | Flex grow factor | | bg | Fill color (hex) | | rounded, roundedTL/TR/BL/BR | Corner radius | | stroke, strokeWidth | Stroke color and weight | | opacity | 0–1 | | rotate | Degrees | | overflow | "hidden" to clip children | | shadow | "offsetX offsetY blur #color" | | blur | Layer blur | | size, weight, font, color, textAlign | Text properties | | colStart, rowStart, colSpan, rowSpan | Grid child positioning |

Tips

• Omit the file path to work with the document open in the running OpenPencil editor.
• Start with info or get_page_tree to understand the document.
• Use tree --depth 2 or query_nodes to avoid overwhelming output on large files.
• Export specific nodes with --node for faster visual checks.
• Use export_image after changes to verify visual quality.
• After creating a visible design, select it and zoom the editor to it: select_nodes { ids: [id] } then viewport_zoom_to_fit { id }.
• If zoom-to-fit is unavailable in a client, use node_bounds to calculate the center and call viewport_set { x, y, zoom }.
• Use analyze colors --similar to find near-duplicate colors.
• Use eval for Figma Plugin API operations not covered by a dedicated CLI/MCP tool.
• Use --json when piping CLI output to scripts.
• In app mode, eval and MCP modifications are reflected live in the editor.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: open-pencil
• Source: open-pencil/skills
• License: MIT

Install and usage instructions live in the source repository linked above.