FontFYI — Font Tools for AI Agents

Pure Python Google Fonts toolkit. Access 50 popular fonts metadata, generate CSS import URLs, browse 10 web-safe font stacks, and get 15 curated heading + body pairings — all with zero dependencies.

Install: pip install fontfyi · Web: fontfyi.com · API: REST API · npm: npm install fontfyi

When to Use

• User asks to look up a Google Font's metadata (category, variants, subsets, designer)
• User needs a CSS font-family declaration or Google Fonts import URL
• User wants font pairing suggestions for heading + body combinations
• User asks about web-safe font stacks for system fonts, monospace, serif, etc.
• User needs to generate <link> tags or Homebrew install commands for fonts

Tools

get_font(slug) -> dict | None

Look up font metadata by slug.

from fontfyi import get_font

font = get_font("inter")
font["family"]           # 'Inter'
font["category"]         # 'sans-serif'
font["variants"]         # ['100', '200', '300', 'regular', '500', '600', '700', '800', '900']
font["subsets"]          # ['cyrillic', 'greek', 'latin', 'latin-ext', 'vietnamese']
font["designer"]         # 'Rasmus Andersson'
font["popularity_rank"]  # 6

search(query, limit=20) -> list[dict]

Search fonts by family name (case-insensitive).

from fontfyi import search

results = search("rob")
for font in results:
    print(f"{font['family']} ({font['category']})")
# Roboto (sans-serif)
# Roboto Condensed (sans-serif)
# Roboto Mono (monospace)
# Roboto Slab (serif)

css_family(family, category) -> str

Generate a CSS font-family declaration with proper fallback.

from fontfyi import css_family

css_family("Inter", "sans-serif")       # "'Inter', sans-serif"
css_family("Roboto Mono", "monospace")  # "'Roboto Mono', monospace"
css_family("Playfair Display", "serif") # "'Playfair Display', serif"

google_fonts_url(family, weights=None) -> str

Generate a Google Fonts CSS2 import URL.

from fontfyi import google_fonts_url

google_fonts_url("Inter", [400, 700])
# 'https://fonts.googleapis.com/css2?family=Inter:wght@400;700&display=swap'

google_fonts_url("Roboto")
# 'https://fonts.googleapis.com/css2?family=Roboto&display=swap'

google_fonts_link(family, weights=None) -> str

Generate a complete HTML <link> tag for Google Fonts.

from fontfyi import google_fonts_link

google_fonts_link("Inter", [400, 700])
# '<link rel="stylesheet" href="https://fonts.googleapis.com/css2?family=Inter:wght@400;700&display=swap">'

get_pairings_for(font_slug) -> list[FontPairing]

Get all curated pairings that include a given font.

from fontfyi import get_pairings_for

for p in get_pairings_for("inter"):
    print(f"{p.heading} + {p.body} ({p.mood}, score: {p.score})")
# inter + merriweather (professional-modern, score: 9)
# poppins + inter (modern-friendly, score: 9)
# space-grotesk + inter (tech-modern, score: 8)
# plus-jakarta-sans + inter (modern-clean, score: 8)
# inter + source-serif-4 (modern-readable, score: 8)

get_stack(slug) -> FontStack | None

Get a web-safe CSS font stack preset.

from fontfyi import get_stack

stack = get_stack("system-ui")
stack.name   # 'System UI'
stack.stack  # "system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif"

stack = get_stack("monospace-code")
stack.stack  # "ui-monospace, 'Cascadia Code', 'Source Code Pro', Menlo, Consolas, 'DejaVu Sans Mono', monospace"

parse_variants(variants) -> tuple[list[int], bool]

Parse Google Fonts variant strings into numeric weights and italic flag.

from fontfyi import parse_variants

weights, has_italic = parse_variants(["100", "regular", "700", "italic", "700italic"])
weights      # [100, 400, 700]
has_italic   # True

weight_name(weight) -> str

Get the CSS weight name for a numeric weight value.

from fontfyi import weight_name

weight_name(400)  # 'Regular'
weight_name(700)  # 'Bold'
weight_name(300)  # 'Light'

homebrew_install_cmd(family) -> str

Generate a Homebrew cask install command for a font.

from fontfyi import homebrew_install_cmd

homebrew_install_cmd("JetBrains Mono")  # 'brew install --cask font-jetbrains-mono'
homebrew_install_cmd("Inter")           # 'brew install --cask font-inter'

REST API (No Auth Required)

curl https://fontfyi.com/api/font/inter/
curl https://fontfyi.com/api/search/?q=roboto
curl https://fontfyi.com/api/pairings/inter/
curl https://fontfyi.com/api/stack/system-ui/
curl https://fontfyi.com/api/random/

Full spec: OpenAPI 3.1.0

Font Stacks Reference

Stack	CSS Value
System UI	system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, ...
Neo-grotesque	Inter, Roboto, 'Helvetica Neue', 'Arial Nova', ...
Transitional	Charter, 'Bitstream Charter', 'Sitka Text', Cambria, serif
Old Style	'Iowan Old Style', 'Palatino Linotype', ...
Humanist Sans	Seravek, 'Gill Sans Nova', Ubuntu, Calibri, ...
Geometric Humanist	Avenir, Montserrat, Corbel, ...
Monospace Code	ui-monospace, 'Cascadia Code', 'Source Code Pro', Menlo, ...
Monospace Slab	'Nimbus Mono PS', 'Courier New', monospace
Industrial	Bahnschrift, 'DIN Alternate', 'Franklin Gothic Medium', ...
Rounded Sans	ui-rounded, 'Hiragino Maru Gothic ProN', Quicksand, ...

CSS Weight Names

Weight	Name
100	Thin
200	Extra Light
300	Light
400	Regular
500	Medium
600	Semi Bold
700	Bold
800	Extra Bold
900	Black

Demo

Creative FYI Family

Part of the FYIPedia ecosystem: ColorFYI, EmojiFYI, SymbolFYI, UnicodeFYI.