diff --git a/kitty/fonts/features.py b/kitty/fonts/features.py
new file mode 100644
index 000000000..1b75d202f
--- /dev/null
+++ b/kitty/fonts/features.py
@@ -0,0 +1,149 @@
+#!/usr/bin/env python
+# License: GPLv3 Copyright: 2024, Kovid Goyal <kovid at kovidgoyal.net>
+
+from enum import IntEnum
+from typing import Dict, NamedTuple
+
+
+class Type(IntEnum):
+    boolean: int = 1
+    index: int = 2
+    hidden: int = 3
+
+
+class FeatureDefinition(NamedTuple):
+    name: str
+    type: Type
+
+# From: https://learn.microsoft.com/en-ca/typography/opentype/spec/featurelist
+known_features: Dict[str, FeatureDefinition] = {  # {{{
+    'aalt':	FeatureDefinition('Access All Alternates', Type.index),
+    'abvf':	FeatureDefinition('Above-base Forms', Type.hidden),
+    'abvm':	FeatureDefinition('Above-base Mark Positioning', Type.hidden),
+    'abvs':	FeatureDefinition('Above-base Substitutions', Type.hidden),
+    'afrc':	FeatureDefinition('Alternative Fractions', Type.boolean),
+    'akhn':	FeatureDefinition('Akhand', Type.hidden),
+    'blwf':	FeatureDefinition('Below-base Forms', Type.hidden),
+    'blwm':	FeatureDefinition('Below-base Mark Positioning', Type.hidden),
+    'blws':	FeatureDefinition('Below-base Substitutions', Type.hidden),
+    'calt':	FeatureDefinition('Contextual Alternates', Type.boolean),
+    'case':	FeatureDefinition('Case-Sensitive Forms', Type.hidden),
+    'ccmp':	FeatureDefinition('Glyph Composition / Decomposition', Type.hidden),
+    'cfar':	FeatureDefinition('Conjunct Form After Ro', Type.hidden),
+    'chws':	FeatureDefinition('Contextual Half-width Spacing', Type.boolean),
+    'cjct':	FeatureDefinition('Conjunct Forms', Type.hidden),
+    'clig':	FeatureDefinition('Contextual Ligatures', Type.boolean),
+    'cpct':	FeatureDefinition('Centered CJK Punctuation', Type.boolean),
+    'cpsp':	FeatureDefinition('Capital Spacing', Type.boolean),
+    'cswh':	FeatureDefinition('Contextual Swash', Type.boolean),
+    'curs':	FeatureDefinition('Cursive Positioning', Type.hidden),
+    'c2pc':	FeatureDefinition('Petite Capitals From Capitals', Type.boolean),
+    'c2sc':	FeatureDefinition('Small Capitals From Capitals', Type.boolean),
+    'dist':	FeatureDefinition('Distances', Type.hidden),
+    'dlig':	FeatureDefinition('Discretionary Ligatures', Type.boolean),
+    'dnom':	FeatureDefinition('Denominators', Type.hidden),
+    'dtls':	FeatureDefinition('Dotless Forms', Type.hidden),
+    'expt':	FeatureDefinition('Expert Forms', Type.boolean),
+    'falt':	FeatureDefinition('Final Glyph on Line Alternates', Type.boolean),
+    'fin2':	FeatureDefinition('Terminal Forms #2', Type.hidden),
+    'fin3':	FeatureDefinition('Terminal Forms #3', Type.hidden),
+    'fina':	FeatureDefinition('Terminal Forms', Type.hidden),
+    'flac':	FeatureDefinition('Flattened accent forms', Type.hidden),
+    'frac':	FeatureDefinition('Fractions', Type.boolean),
+    'fwid':	FeatureDefinition('Full Widths', Type.boolean),
+    'half':	FeatureDefinition('Half Forms', Type.hidden),
+    'haln':	FeatureDefinition('Halant Forms', Type.hidden),
+    'halt':	FeatureDefinition('Alternate Half Widths', Type.boolean),
+    'hist':	FeatureDefinition('Historical Forms', Type.boolean),
+    'hkna':	FeatureDefinition('Horizontal Kana Alternates', Type.boolean),
+    'hlig':	FeatureDefinition('Historical Ligatures', Type.boolean),
+    'hngl':	FeatureDefinition('Hangul', Type.boolean),
+    'hojo':	FeatureDefinition('Hojo Kanji Forms (JIS X 0212-1990 Kanji Forms)', Type.boolean),
+    'hwid':	FeatureDefinition('Half Widths', Type.boolean),
+    'init':	FeatureDefinition('Initial Forms', Type.hidden),
+    'isol':	FeatureDefinition('Isolated Forms', Type.hidden),
+    'ital':	FeatureDefinition('Italics', Type.boolean),
+    'jalt':	FeatureDefinition('Justification Alternates', Type.boolean),
+    'jp78':	FeatureDefinition('JIS78 Forms', Type.boolean),
+    'jp83':	FeatureDefinition('JIS83 Forms', Type.boolean),
+    'jp90':	FeatureDefinition('JIS90 Forms', Type.boolean),
+    'jp04':	FeatureDefinition('JIS2004 Forms', Type.boolean),
+    'kern':	FeatureDefinition('Kerning', Type.boolean),
+    'lfbd':	FeatureDefinition('Left Bounds', Type.boolean),
+    'liga':	FeatureDefinition('Standard Ligatures', Type.boolean),
+    'ljmo':	FeatureDefinition('Leading Jamo Forms', Type.hidden),
+    'lnum':	FeatureDefinition('Lining Figures', Type.boolean),
+    'locl':	FeatureDefinition('Localized Forms', Type.hidden),
+    'ltra':	FeatureDefinition('Left-to-right alternates', Type.hidden),
+    'ltrm':	FeatureDefinition('Left-to-right mirrored forms', Type.hidden),
+    'mark':	FeatureDefinition('Mark Positioning', Type.hidden),
+    'med2':	FeatureDefinition('Medial Forms #2', Type.hidden),
+    'medi':	FeatureDefinition('Medial Forms', Type.hidden),
+    'mgrk':	FeatureDefinition('Mathematical Greek', Type.boolean),
+    'mkmk':	FeatureDefinition('Mark to Mark Positioning', Type.hidden),
+    'mset':	FeatureDefinition('Mark Positioning via Substitution', Type.hidden),
+    'nalt':	FeatureDefinition('Alternate Annotation Forms', Type.index),
+    'nlck':	FeatureDefinition('NLC Kanji Forms', Type.boolean),
+    'nukt':	FeatureDefinition('Nukta Forms', Type.hidden),
+    'numr':	FeatureDefinition('Numerators', Type.hidden),
+    'onum':	FeatureDefinition('Oldstyle Figures', Type.boolean),
+    'opbd':	FeatureDefinition('Optical Bounds', Type.boolean),
+    'ordn':	FeatureDefinition('Ordinals', Type.boolean),
+    'ornm':	FeatureDefinition('Ornaments', Type.index),
+    'palt':	FeatureDefinition('Proportional Alternate Widths', Type.boolean),
+    'pcap':	FeatureDefinition('Petite Capitals', Type.boolean),
+    'pkna':	FeatureDefinition('Proportional Kana', Type.boolean),
+    'pnum':	FeatureDefinition('Proportional Figures', Type.boolean),
+    'pref':	FeatureDefinition('Pre-Base Forms', Type.hidden),
+    'pres':	FeatureDefinition('Pre-base Substitutions', Type.hidden),
+    'pstf':	FeatureDefinition('Post-base Forms', Type.hidden),
+    'psts':	FeatureDefinition('Post-base Substitutions', Type.hidden),
+    'pwid':	FeatureDefinition('Proportional Widths', Type.boolean),
+    'qwid':	FeatureDefinition('Quarter Widths', Type.boolean),
+    'rand':	FeatureDefinition('Randomize', Type.boolean),
+    'rclt':	FeatureDefinition('Required Contextual Alternates', Type.hidden),
+    'rkrf':	FeatureDefinition('Rakar Forms', Type.hidden),
+    'rlig':	FeatureDefinition('Required Ligatures', Type.hidden),
+    'rphf':	FeatureDefinition('Reph Forms', Type.hidden),
+    'rtbd':	FeatureDefinition('Right Bounds', Type.boolean),
+    'rtla':	FeatureDefinition('Right-to-left alternates', Type.hidden),
+    'rtlm':	FeatureDefinition('Right-to-left mirrored forms', Type.hidden),
+    'ruby':	FeatureDefinition('Ruby Notation Forms', Type.boolean),
+    'rvrn':	FeatureDefinition('Required Variation Alternates', Type.hidden),
+    'salt':	FeatureDefinition('Stylistic Alternates', Type.index),
+    'sinf':	FeatureDefinition('Scientific Inferiors', Type.boolean),
+    'size':	FeatureDefinition('Optical size', Type.hidden),
+    'smcp':	FeatureDefinition('Small Capitals', Type.boolean),
+    'smpl':	FeatureDefinition('Simplified Forms', Type.boolean),
+    'ssty':	FeatureDefinition('Math script style alternates', Type.hidden),
+    'stch':	FeatureDefinition('Stretching Glyph Decomposition', Type.hidden),
+    'subs':	FeatureDefinition('Subscript', Type.boolean),
+    'sups':	FeatureDefinition('Superscript', Type.boolean),
+    'swsh':	FeatureDefinition('Swash', Type.index),
+    'titl':	FeatureDefinition('Titling', Type.boolean),
+    'tjmo':	FeatureDefinition('Trailing Jamo Forms', Type.hidden),
+    'tnam':	FeatureDefinition('Traditional Name Forms', Type.boolean),
+    'tnum':	FeatureDefinition('Tabular Figures', Type.boolean),
+    'trad':	FeatureDefinition('Traditional Forms', Type.index),
+    'twid':	FeatureDefinition('Third Widths', Type.boolean),
+    'unic':	FeatureDefinition('Unicase', Type.boolean),
+    'valt':	FeatureDefinition('Alternate Vertical Metrics', Type.boolean),
+    'vatu':	FeatureDefinition('Vattu Variants', Type.hidden),
+    'vchw':	FeatureDefinition('Vertical Contextual Half-width Spacing', Type.hidden),
+    'vert':	FeatureDefinition('Vertical Writing', Type.boolean),
+    'vhal':	FeatureDefinition('Alternate Vertical Half Metrics', Type.boolean),
+    'vjmo':	FeatureDefinition('Vowel Jamo Forms', Type.hidden),
+    'vkna':	FeatureDefinition('Vertical Kana Alternates', Type.boolean),
+    'vkrn':	FeatureDefinition('Vertical Kerning', Type.boolean),
+    'vpal':	FeatureDefinition('Proportional Alternate Vertical Metrics', Type.boolean),
+    'vrt2':	FeatureDefinition('Vertical Alternates and Rotation', Type.boolean),
+    'vrtr':	FeatureDefinition('Vertical Alternates for Rotation', Type.boolean),
+    'zero':	FeatureDefinition('Slashed Zero', Type.boolean),
+}
+for i in range(1, 100):
+    known_features[f'cv{i:2d}'] = FeatureDefinition(f'Character Variant {i}', Type.index)
+for i in range(1, 20):
+    known_features[f'ss{i:2d}'] = FeatureDefinition(f'Stylistic Set {i}', Type.boolean)
+# }}}
+
+