A comprehensive logo-design skill that turns Claude — or any agent that supports Agent Skills, such as Gemini CLI, Codex CLI, Cursor or GitHub Copilot — into a disciplined identity designer, from the first brief to production-ready SVG files and brand guidelines.

• Principles & process — discovery and briefs, word mapping, choosing the right mark type, concepting, geometric construction, optical corrections (overshoot, bone effect, irradiation…), colour, typography, lockups, testing, presentation, delivery, redesigns and identity systems.
• A reference library of 1,400+ real-world SVG logos, each visually classified by mark type, technique, geometry, subject, typography, mood and industry — searchable from the command line and browsable in a local gallery. Used to study construction, map category conventions and avoid look-alikes (never to copy).
• Dependency-free Python tools — audit an SVG against logo principles, build concept overview sheets and test sheets (16 px pixel test, one-colour, reversed, squint, mirror, contexts, competitor shelf test), create client presentation boards with industry-specific mockups, render PNGs, and export a complete favicon / app-icon / web-manifest set.

Contents: How it works · Install · Examples · Tests · Use · What's inside · Library

flowchart LR
    A[Brief<br/>questions or stated assumptions] --> B[Research<br/>category conventions in the library]
    B --> C[Concepts<br/>8–12 one-liners → build 3 in SVG]
    C --> D[Test & refine<br/>audit · 16 px · one-colour · shelf test]
    D --> E{{Checkpoint<br/>show concepts, recommend, stop}}
    E -- "you pick a direction<br/>and ask for the kit" --> F[Kit<br/>colour · lockups · board · icons · guidelines]
    E -- "you want changes" --> C

The skill always stops at the checkpoint: it shows the concepts as one overview image with a recommendation and offers the full kit. Nothing else is produced until you choose a direction — the kit is most of the work and only makes sense for an approved idea.

/plugin marketplace add kaankiziltug/logo-design-skill
/plugin install logo-design@logo-design-skill

Copy the skill folder into your personal (all projects) or project skills directory:

git clone https://github.com/kaankiziltug/logo-design-skill.git
cp -r logo-design-skill/skills/logo-design ~/.claude/skills/logo-design          # personal
# or: cp -r logo-design-skill/skills/logo-design .claude/skills/logo-design     # per project

Download logo-design.zip from the Releases page (or run python3 tools/package_skill.py) and upload it under Settings → Capabilities → Skills. If your upload has a size limit, use logo-design-lite.zip (everything except the SVG files themselves).

The skill uses the open Agent Skills format (a folder with a SKILL.md), so it works in any agent that supports skills — the instructions are plain Markdown and the tools are plain Python. Clone once, then copy the folder into your agent's skills directory:

git clone https://github.com/kaankiziltug/logo-design-skill.git

cp -r logo-design-skill/skills/logo-design ~/.gemini/skills/logo-design     # Gemini CLI
cp -r logo-design-skill/skills/logo-design ~/.codex/skills/logo-design      # Codex CLI

Start a new session and ask for a logo; the agent picks the skill up from its description. The skill works best with a model that can view images, because it renders its own drafts to PNG and checks them before showing you anything. The .claude-plugin/ folder is only used by Claude Code and is ignored elsewhere.

Twenty-eight fictional briefs, from quiet luxury and neon festivals to B2B SaaS, fintech and health — each run end to end with the skill. For every brand you see exactly what the skill shows at the checkpoint (greyscale concepts with true 64/32/16 px sizes and a recommendation), followed by a colour preview of the chosen direction on mockups picked for that industry. Later batches deliberately push vivid, saturated palettes while still passing the one-colour and 3 : 1 contrast checks. The newest batch takes on three crowded categories: SaaS (no chat bubbles, charts or padlocks), finance (no coins, piggy banks or bank blue) and health (no crosses, pills or heartbeat lines). The latest ten add another ten sectors. In four of them the client picked a different concept at the checkpoint than the one the skill recommended, and the skill refined that choice before colouring it: exactly what the checkpoint is for.

Brand	Sector	Style	Chosen mark
Kiln	Specialty coffee	Warm, crafted, modern	Letterform + custom wordmark
Zestly	Food delivery	Juicy, cheeky, tomato & lime	Mascot
Maison Orvelle	Luxury fashion	High-contrast Didone	Monogram
Pulsewave	Music festival	Neon on night, kinetic	Abstract letterform
Tinkertrail	Kids' STEM education	Playful, rounded, multi-colour	Letterform
Ralli	Sports app	Dynamic italic, electric coral	Letterform
Alderpeak	Outdoor gear	Rugged, slab, earthy	Pictorial symbol
Driftwell	Hospitality	Azulejo tile, coastal brights	Emblem + symbol
Calmera	Physiotherapy	Soft, organic, calm	Pictorial symbol
Bramble Vet	Veterinary	Friendly character, sunny	Mascot
Voltra	Clean energy	Geometric, volt orange	Abstract symbol
Keyfort	Security SaaS	Strict grid, electric indigo & mint	Abstract symbol
Relaydesk	Support SaaS	Rounded, violet & coral	Abstract symbol
Tracelane	Developer analytics	Technical, acid & pink on carbon	Letterform
Tallybook	Small-business finance	Friendly, tangerine & teal	Letterform
Northvault	Digital banking	Bold tile, hot magenta	Letterform
Mediora	Telehealth	Soft, coral face on teal	Mascot
Brightdose	Online pharmacy	Sunny yellow & cobalt	Letterform
Hearsay	Podcast network	Bold pink, conversational	Letterform (client's pick)
Norrvik	Architecture	Restrained, spruce green	Abstract symbol
Brawnhall	Boxing gym	Heavy, hi-vis orange	Letterform (client's pick)
Solenne	Skincare	Daylight blue & gold	Pictorial (client's pick)
Mothlight	Indie games	Ultraviolet & lamplight	Negative space
Loafwright	Bakery	Warm marigold	Mascot
Stillbrook	Craft brewery	Turquoise & forge orange	Letterform
Marlow & Finch	Real estate	Finch orange & ink	Pictorial ampersand
Kitewire	AI dev tools	Kite red & updraft yellow	Letterform
Roamwheel	Urban mobility	Go lime & ink	Mascot (client's pick)

Small-batch roaster in Istanbul: warm, crafted and modern — not rustic cliché. Must work on bags, cups and an Instagram avatar.

Recommended: Kiln K — a K whose leg is the kiln's arched firing mouth; the arch returns as the n of the wordmark. The audit caught a 60.8° diagonal in an early N and an off-centre symbol before anything was shown.

Independent local kitchens delivered in 25 minutes: fresh, fast, appetising, cheeky — no forks, chef hats, scooters or map pins.

Recommended: Big Grin — a citrus wedge flipped into a cheeky, winking grin: appetite and generosity in one mark. Tomato red with a zest-lime rind and aubergine ink. The skill flags its honest risk too: some people read the wedge as watermelon.

Paris womenswear, made-to-measure and small leather goods: elegant, refined, timeless — no crowns, laurels or gold gradients.

Recommended: Pendant — a Didone M whose vertex holds an O like a pendant at a V-neckline; it still reads at 16 px and is solid enough to emboss on leather. The craft pass dropped a shared-foot "LL" (it read as ORVEILE) and avoided an M-in-a-circle (too close to a famous transit sign).

Three-day electronic music and digital-arts festival by a lake: electric, rhythmic, euphoric — no equaliser bars, headphones or vinyl.

Recommended: Crossing Beams — two stage lights send four tapered beams; where the inner beams cross they draw the W, like raised arms, and they can sweep to the beat. Electric magenta, ultraviolet and cyan on night. Cyan only reaches 1.5 : 1 on white, so the skill keeps it for dark backgrounds.

Hands-on robotics and circuits workshops that tour schools: playful, curious, trustworthy — no lightbulbs, atoms, gears or rockets.

Chosen: Signpost t — the t is a trail signpost pointing kids to the next discovery: a teal stem (the trail) and a coral sign (what's next). The skill had recommended the Workshop Snail; at the checkpoint the client picked the letterform because it stays sturdy for schools and reads at 16 px — exactly what the checkpoint is for.

Book courts, find partners at your level and join leagues: energetic, social, sporty — no tennis balls, crossed rackets, trophies or swooshes.

Recommended: Rally R — one italic stroke goes up, over, back and away, like a rally; the leg was snapped to an exact 60°. Electric coral on night-court ink, with acid lime reserved for dark backgrounds.

Packs, shells and base layers from the Pacific Northwest: rugged, dependable, honest — no generic mountain-and-sun.

Recommended: Cairn — three stacked stones build a summit, a peak and a trail marker in one; the tilted gaps zigzag like a switchback. Rejected along the way: a carabiner a (read as "cl") and tree-ring contours (read as a target).

Design-led surf hostel and café on the Portuguese coast: sunny, laid-back, social — no palm trees, sunsets or surfboard silhouettes.

Recommended: Azulejo Tile — a Portuguese azulejo name tile with a D at its heart; laid edge to edge, the corner quarters join into suns. Atlantic blue, tangerine and sun yellow. The audit snapped the W and R diagonals to exact 75° and 45°.

Rehab, sports physio and pilates: calm, caring, professional — no crosses, heartbeats, spines or hands-with-hearts.

Recommended: Still Heron — a heron balancing on one leg in still water; single-leg balance is a standard rehab and pilates exercise, and nothing else in the category looks like it. An early abstract idea was dropped after the peer test found it too close to an existing mark, and the sage was darkened to reach 3 : 1 contrast.

A family vet for cats and dogs: warm, trustworthy, cheerful — no paws, bones, crosses or stethoscopes.

Recommended: Odd Ears — one smiling face with a pointed cat ear and a floppy dog ear: every cat and dog belongs. Cobalt and berry on sunny yellow. Several ideas were dropped when the reading test turned them into grapes, an anchor or a teapot.

Rooftop solar, home batteries and an energy app: bright, optimistic, dependable — no sun rays, leaves, bolts or plugs.

Recommended: Sun Dock — the sun docks into a battery shaped to hold it, and the gap between them is a crescent moon: sunshine, after dark. Volt orange with night navy. A "charge-level o" was dropped because it read as veltra.

Password manager and team-security SaaS with shared vaults, passkeys and access control: secure, calm, strong — no padlocks, shields, keyholes, fingerprints or chain links.

Recommended: Greek Key — one unbroken wall winds inward: a Greek key that is also a fortress with only one way in. Electric indigo sets it apart from the category's azure blues; the innermost turn glows mint only on indigo and dark surfaces, because mint reaches just 1.4 : 1 on white. A star-fort idea was dropped when it read as a shuriken.

One shared inbox for email, chat and social, with AI that drafts replies and routes tickets: helpful, fast, human — no headsets, robots or speech bubbles.

Recommended: Hand-off — two identical hooks catch each other mid-pass, so no ticket is dropped: one radius and one stroke, repeated with a 180° turn. Coral only reaches 2.1 : 1 on violet, so on violet surfaces the mark turns all white. The craft pass snapped the y to an exact 60° and opened a hook gap that had shrunk to 1.7 units.

Event tracking, funnels and session paths for developers, with an SDK and a CLI: precise, fast, insightful — no bar charts, pie charts, magnifying glasses or up-arrows.

Recommended: Junction T — one lane runs straight on and the other turns off to become the stem: the moment a funnel measures, drawn as the brand initial. Acid green on carbon for the terminal and README, with the turning lane always signal pink. Moving the turning lane inward made the T read at first glance.

Invoicing and bookkeeping for small businesses and sole traders: friendly, tidy, reassuring — no calculators, coins, ledgers or charts.

Recommended: Bookmark T — an open book forms the crossbar and its ribbon bookmark forms the stem: your books, always open at the right page. Tangerine with a lagoon-teal ribbon; on tangerine surfaces the ribbon turns ink, because teal and tangerine are nearly equal in luminance and would vibrate.

A business account with self-saving tax pots and instant invoicing: confident, clear, independent — no bank blue, coins, piggy banks, columns or up-arrows.

Recommended: Seam N — a vault-shaped tile split into two interlocking pots, where the seam between them spells N (and N marks north on every compass). Hot magenta, with electric green kept for dark surfaces only. An electric-green card was tested and dropped because the text on it failed contrast.

Video consultations with a doctor in minutes, e-prescriptions and records in one place: caring, immediate, warm — no crosses, stethoscopes, hearts or pulse lines.

Recommended: Relief — a circle face with closed, smiling eyes and a listening head-tilt: the relief of being looked after, fast. A coral face on a teal stage, with ink eyes and wordmark. An early m concept put its dot top-right, where it read as "mi", so the dot moved down.

Repeat prescriptions delivered to your door, with reminders and pharmacist chat: cheerful, reliable, easy — no green crosses, pills, mortar and pestle or rod of Asclepius.

Recommended: Sunspot b — a lowercase b that holds a small sun in its counter: a bright spot in every day. Sunrise yellow is rare in a green-and-blue category; on yellow bags and app tiles the whole mark turns one-colour cobalt. Rejected along the way: a seven-bar sun that looked like a helmet and a peel that looked like a moon.

Twelve narrative and interview shows about culture, science and true stories: curious, expressive, warm — no microphones, headphones, sound waves or speech bubbles.

Chosen: Pull-up Chair — a lowercase h whose ascender is a backrest tilted back 15°: pull up a chair, stay for the story. The skill had recommended Curious Ear (a question mark whose hook is an ear); the client picked the chair at the checkpoint, and the skill thinned its seat to match the legs before colouring it in Hearsay Pink.

Scandinavian studio for timber housing, libraries and schools, known for daylight: precise, calm, enduring — no houses, roofs, blueprints or compasses.

Recommended: Knot — timber grain bending around one offset knot, where a branch once reached for the light. A first favourite (an N cut through a timber block) was dropped in review because it looked too much like Northvault in this series; the accent moved from orange to spruce green to keep the set varied.

A boxing and conditioning gym in an old warehouse, with classes for complete beginners: tough, disciplined, welcoming — no gloves, lightning, skulls or fists.

Chosen: Hall B — a heavy B whose counters are the old hall's fanlight and arched door, the doorway lit in hi-vis orange: the door's open, the work's inside. The skill had recommended Open Ropes; after the client's pick, the craft pass enlarged the window and deepened the waist so the B no longer read as a D at 16 px.

Sunlight-smart skincare (serums, daily SPF, barrier creams): luminous, fresh, gentle — no leaves, drops, faces or sun rays.

Chosen: Persienne — the sun seen through louvred shutters: let the light in, keep the glare out. The skill had recommended Day of Sun (an S of 13 suns); for the chosen shutters it reworked the proportions and the slat rhythm so the mark stays clear of striped marks such as IBM's.

An eight-person studio making cozy adventure games about exploring at night: curious, warm, mysterious — no controllers, pixel hearts or big-eyed mascots.

Recommended: Half-light Moth — a moth on the edge of the lamplight: one half is a shadow, the other half is light cut out of the night. Ultraviolet with lamplight yellow.

A neighbourhood sourdough bakery where the bakers start at 3 am: warm, generous, cheerful — no wheat, rolling pins or chef hats.

Recommended: Early Lark — a round loaf that is also a lark: the ear of its score lifts into the crest. Crust marigold with a jam-pink beak, and one solid silhouette that stamps in a single ink on kraft bags.

Craft brewery and taproom in a converted riverside mill: characterful, bold, local — no hops, barrels, mugs or anchors.

Recommended: Wall-tie S — the forged iron S-anchor that holds the old mill's walls together, bolted through its middle. A heron idea was dropped in review because Calmera in this series already stands on one leg.

A boutique estate agency known for honest valuations and great photography: trustworthy, warm, premium — no roofs, houses, keys or map pins.

Recommended: Finch Ampersand — the & in the name is a perched finch: the partnership and the name in one sign. After the checkpoint the client asked for a bigger beak; it grew 1.5× with one clean join to the throat, and the & still reads first at 16 px.

A developer platform for building, testing and deploying AI agents: reliable, fast, controllable — no sparkles, brains, circuits or robot heads.

Recommended: Kite-cut K — three straight cuts divide a solid kite into panels, and the seams spell K: autonomy, always on a line. Kite red with an updraft-yellow panel, away from the category's blues and violets.

A monthly e-bike subscription for city commuters: light, fast, optimistic — no bike silhouettes, lightning or eco leaves.

Chosen: Roamie — a tyre on two legs with a half-lidded smirk: a wheel with somewhere to be. The skill's first pick read as a play button in review, and its second (an m/w ambigram) lost to the mascot at the checkpoint; the craft pass then split tyre and rim so it reads as a wheel, not a donut.

Every concept goes through svg_audit.py and preview_sheet.py before the checkpoint. The test sheet puts the options side by side at 96 and 32 px, in one colour and reversed, then walks each one down a size ladder to 16 px — here it shows why Maison Orvelle's wordmark (B) needs a companion mark while the monogram (A) holds up:

The audit turns craft rules into checks. The same run, two files — the recommended lockup and the emblem that was not recommended:

$ python3 scripts/svg_audit.py a-lockup.svg b-emblem.svg

=== a-lockup.svg
viewBox 0 0 905 256 · aspect 3.535 (horizontal) · colours 1 · anchors 205
· INFO [complexity] 205 anchor points (library median 75, p75 155). Check every point earns its place.
production-readiness score: 99/100

=== b-emblem.svg
viewBox 0 0 256 256 · aspect 1.0 (square) · colours 1 · anchors 374
▲ WARN [complex] 374 anchor points — more than 95% of comparable reference logos (median 53).
▲ WARN [near-miss-angle] 8 straight edge(s) are 0.3–3° off a clean angle … (expected for type set on a curve)
▲ WARN [tiny-detail] 6 sub-shape(s) smaller than 1/48 of the canvas: 4.3×3.1 at (40,77) …
production-readiness score: 76/100

Just ask — the skill triggers on logo, wordmark, monogram, brand mark, app icon, favicon, rebrand and critique requests:

"Design a logo for Harbor, a savings app for first-time savers. It should feel calm and safe." "Here's our current logo (logo.svg) — critique it and suggest a refresh." "Give me three wordmark directions for a specialty coffee roaster called Kiln." "Turn this symbol into favicon, app icon and one-colour versions, plus a one-page usage guide."

Tools can also be run directly:

cd skills/logo-design
python3 scripts/search_library.py --technique negative-space --exemplary
python3 scripts/search_library.py --industry payments-fintech --summary
python3 scripts/svg_audit.py my-logo.svg
python3 scripts/concept_sheet.py a.svg b.svg c.svg --names "A" "B" "C" --recommend 1 -o concepts.png
python3 scripts/preview_sheet.py my-logo.svg --refs-industry developer-tools -o preview.html
python3 scripts/render_png.py my-logo.svg --size 512 -o my-logo.png
python3 scripts/export_variants.py my-logo.svg --mono "#0F7C80" --icon-bg "#0F7C80" --web-icons
open assets/library/gallery.html      # browse the library visually

Requires Python 3.8+ (standard library only). PNG/ICO export uses whatever renderer is available: cairosvg, rsvg-convert, Inkscape, a Chromium-based browser (Chrome, Edge, Brave) or macOS Quick Look.

skills/logo-design/
├── SKILL.md                     # workflow, checkpoint, principles, red flags, tool guide
├── references/                  # loaded on demand
│   ├── principles.md            # the twelve principles, mnemonic model, simplicity, relevance, longevity
│   ├── discovery-brief.md       # question bank, brief template, word mapping
│   ├── mark-types.md            # wordmark → combination: pros, cons, decision guide
│   ├── visual-techniques.md     # geometry, grids, balance, optical corrections, negative space, gradients…
│   ├── color.md · typography.md · process.md · svg-construction.md
│   ├── testing-checklist.md · presentation-delivery.md · identity-system.md
│   ├── redesign.md · critique.md
│   └── library-guide.md         # library contents, data insights, curated examples by technique
├── scripts/
│   ├── concept_sheet.py         # one-image concept overview shown at the checkpoint
│   ├── search_library.py        # query the 1,400+ logo library (filters, --summary, --format paths)
│   ├── svg_audit.py             # structure, colours, complexity, near-miss angles, tiny details, centring
│   ├── preview_sheet.py         # HTML test sheet (sizes, backgrounds, treatments, contexts, shelf test)
│   ├── presentation_board.py    # client presentation with six industry-specific mockups per concept
│   ├── render_png.py            # SVG → transparent PNG at exact sizes, favicon.ico
│   ├── export_variants.py       # black / white / mono / square / favicon / app-icon, PNGs, full web-icon set
│   └── build_catalog.py         # maintainers: rebuild catalog, stats and gallery
├── templates/                   # brand-guidelines template, presentation spec example
└── assets/library/              # svg/ (1,400+ files), catalog.json, classifications.json, stats.json, gallery.html

1,400+ files · ≈1,200 brands · 233 brands with both a lockup and a standalone icon · mark types: abstract 24 %, combination 21 %, pictorial 20 %, letterform 15 %, wordmark 10 %, emblem 4 %, mascot 4 %, lettermark 3 % · median 2 colours, 75 % use ≤ 3 · gradients in 19 % · 141 flagged as exemplary teaching examples. More in references/library-guide.md.

Skill text, scripts, templates and catalog data: MIT. The logo files in assets/library/svg/ are trademarks of their respective owners, included for reference and education only and not covered by the MIT license — see TRADEMARKS.md. The brands in the examples are fictional briefs created to demonstrate the skill.

Contributions welcome: new classified logos (with redistribution rights), better scripts, translations, evals.