glyphs-mini-mcp

A Model Context Protocol (MCP) server that lets an agent build and edit fonts for Glyphs Mini, which has no Python API or plugin system of its own.

Unlike thierryc/Glyphs-mcp — which runs inside full Glyphs 3/4 via from GlyphsApp import … and cannot load into Glyphs Mini — this server runs standalone and edits the .glyphs file on disk with glyphsLib. .glyphs is the exact format Glyphs Mini opens and saves, so the workflow is:

agent → MCP tools edit the .glyphs file → glyphs_open_in_mini → view/edit in Glyphs Mini

It also gives the agent its own rendered-specimen feedback loop (fontmake + Pillow), so it can see the letterforms without needing the app.

Tools (17)

Tool	What it does
glyphs_new_font	Create a single-master .glyphs (with .notdef + space) and set it active
glyphs_open_font	Load an existing .glyphs as the active document
glyphs_save_font	Write the active font back to disk
glyphs_font_summary	Family, UPM, master metrics, glyph names
glyphs_set_metrics	UPM / ascender / descender / x-height / cap-height
glyphs_add_glyph	Add a glyph (Unicode from hex, char, or AGL name) + width
glyphs_set_width	Set advance width (spacing)
glyphs_add_contour	Add a Bézier contour from an explicit node list
glyphs_add_rectangle	Add a rectangle — the right primitive for a stem/bar
glyphs_add_ellipse	Add a real modulated bowl/ring (N/S/E/W extrema, optional counter)
glyphs_add_component	Reference another glyph (reuse: n→m, o→b d p q, accents)
glyphs_get_glyph	Inspect a glyph (unicode, width, contour/component counts)
glyphs_delete_glyph / glyphs_clear_glyph	Remove a glyph / clear its outlines
glyphs_set_kerning	Set a kerning pair
glyphs_render_specimen	Compile to TTF (fontmake) + render text to PNG to inspect shapes
glyphs_open_in_mini	Save and open the .glyphs in Glyphs Mini

Design note: add_rectangle is for stems/bars only; round letters must use add_ellipse (a real Bézier bowl) or add_contour. This mirrors the type-design skill's rule against building letterforms from rectangle primitives.

Requirements

• macOS, Python 3.11–3.14
• Glyphs Mini (to view the result; not required for the server to run)
• Python deps in requirements.txt (mcp, glyphsLib, fonttools, fontmake, skia-pathops, pillow, …)

Install

cd glyphs-mini-mcp
uv venv --python 3.12 .venv
source .venv/bin/activate
uv pip install -r requirements.txt

Register with Claude Code (already done on this machine, user scope):

claude mcp add -s user glyphs-mini -- /ABSOLUTE/PATH/glyphs-mini-mcp/run-mcp.sh

Then restart Claude Code — MCP servers attach at session start, so the mcp__glyphs-mini__* tools only appear in a new session.

Usage sketch

glyphs_new_font(path="~/Test.glyphs", family_name="Test", upm=1000, cap_height=700, x_height=500)
glyphs_add_glyph(name="o", width=560)
glyphs_add_ellipse(name="o", cx=280, cy=250, rx=240, ry=260, counter_rx=148, counter_ry=186)   # a real bowl
glyphs_add_glyph(name="n", width=600)
glyphs_add_rectangle(name="n", x0=0, y0=0, x1=88, y1=500)                                        # a stem
glyphs_add_contour(name="n", nodes=[...])                                                        # the arch
glyphs_render_specimen(text="nono", size=140)     # look at it
glyphs_open_in_mini()                             # view/edit in Glyphs Mini

Caveat: reloading in Glyphs Mini

Glyphs Mini has no scripting, so the server can't force an already-open document to reload. After the agent edits and saves, use File → Revert in Glyphs Mini (or close and let glyphs_open_in_mini reopen it) to see the latest changes.

Files

• server.py — the FastMCP stdio server (glyphs_mini_mcp)
• run-mcp.sh — launcher used by claude mcp add
• requirements.txt, test_smoke.py, test_stdio.py

Trademarks & affiliation

"Glyphs" and "Glyphs Mini" are trademarks of Glyphs GmbH. This project is an independent, unofficial tool and is not affiliated with or endorsed by Glyphs GmbH. The name is used only to describe file-format compatibility (nominative use). It uses no Glyphs proprietary code or SDK — it reads and writes the open .glyphs format via the third-party, Apache-2.0 glyphsLib, and it launches an already-installed Glyphs Mini via macOS open.

Licenses

This project is MIT (see LICENSE). It depends on, but does not vendor, these third-party packages (installed from PyPI):

Package	License
glyphsLib, fontmake	Apache-2.0
fontTools, mcp, pydantic	MIT
skia-pathops	BSD-3-Clause
Pillow	HPND

All permissive and compatible; there is no copyleft dependency.