Mantle

Make Claude yours. One theme across Claude Code, your terminal and claude.ai, with real 4K wallpapers, colors that react to what Claude is doing, and a built-in knowledge base of the whole Claude ecosystem.

Mantle is an independent, MIT-licensed project. It is not affiliated with Anthropic.

What you get

Install

In Claude Code

At the Claude Code prompt:

/plugin install mantle --marketplace AkshitTiwarii/mantle

From a shell:

claude plugin install mantle --marketplace AkshitTiwarii/mantle

In the Claude desktop app's Code tab: click + next to the prompt box → Plugins → Add marketplace AkshitTiwarii/mantle → Add plugin.

Then run /mantle to open the studio, or /mantle aurora to apply a theme everywhere.

In any other agent (Atlas only)

npx skills add AkshitTiwarii/mantle --skill mantle-atlas

Target a specific agent with -a cursor, -a codex, -a github-copilot, -a gemini-cli, -a windsurf, -a cline, or -a '*' for all of them.

Let your agent do it

Paste this into Claude Code:

Install Mantle for me: run claude plugin install mantle --marketplace AkshitTiwarii/mantle in the terminal. When it finishes, tell me to run /reload-plugins and then /mantle aurora.

Or into Cursor, Codex, Copilot, Gemini CLI, Windsurf or Cline (swap the -a value):

Install the Mantle Atlas skill: run npx skills add AkshitTiwarii/mantle --skill mantle-atlas -a cursor -y. From now on, whenever I ask which skill, connector, plugin or setting fits a task, use mantle-atlas to answer.

The website's hero has the same prompts, one tab per agent, with a copy button.

Everything Mantle does

1. One theme on every surface

One apply recolors three places at once:

• Claude Code: every interface color — accent, prompt border, diffs, your message background, plan and accept-edits modes, status colors — through a native theme file (~/.claude/themes/mantle.json, selected as Mantle (live) in /theme).
• Your terminal: Claude runs in its own Claude · Mantle tab with the wallpaper and matching colors (all 16 ANSI colors, opacity, blur); your other tabs stay plain.
  • Windows Terminal: run /mantle shortcut on once. After that, typing claude in any PowerShell tab opens Claude in a new Claude · Mantle tab in the same folder (set $env:MANTLE_INLINE = 1 to run it in place; /mantle shortcut off removes the shortcut from your PowerShell profile). Mantle's look is a settings fragment, so your settings.json is never edited, and changes show live. Windows Terminal ties a wallpaper to a profile, not a tab, which is why Claude gets a profile of its own. /mantle terminal everywhere on puts the look on your own profile instead.
  • macOS (iTerm2): written as an iTerm2 Dynamic Profile, Claude · Mantle, which iTerm2 picks up live; /mantle open starts Claude in it. Terminal.app can't load a wallpaper from a file, so it gets Claude Code's colors only.
• claude.ai (Chrome): page colors, a blurred wallpaper behind frosted panels, readable buttons, and a light that sweeps across the top while Claude replies. Done by a bundled Chrome extension that recolors claude.ai's own design tokens.

Each surface can also be customized separately in the studio: its own preset, accent, wallpaper, opacity or blur.

2. Colors that react to Claude

While you work, the Claude Code theme shifts with Claude's state:

On claude.ai a light sweeps across the page and the accent shifts while a reply streams. Turn reactions off with /mantle live off.

3. Wallpapers

• /mantle wallpaper <https URL | image file | off> downloads an image and puts it behind your terminal and claude.ai in one step.
• The website has 48 freely licensed 4K wallpapers (flowers, nature, mountains, NASA/Webb space, ocean, city, minimal, abstract), each credited to its photographer with its license. Every theme preview on the site shows one behind it.
• Your own image works everywhere: attach it on the website (it never leaves your browser tab), point /mantle wallpaper at the file, or pick it in the extension popup.

4. The studio pane

/mantle opens a pane beside the chat with:

• a main preset and a live swatch strip;
• on/off switches for each surface (Claude Code, Windows Terminal, claude.ai) and for live reactions;
• a Claude Code tab: idle accent, thinking color, tool-running color, your message background;
• a Terminal tab: wallpaper path, wallpaper strength, window opacity, acrylic, font, background override;
• a claude.ai tab: wallpaper, blur, dim, panel opacity, accent, the reply glow, and reinstalling the extension files;
• Apply everywhere, with a short log of what changed.

5. Ten presets

Ember, Aurora, Synthwave, Tokyo Night, Catppuccin Mocha, Rosé Pine, Nord Night, Forest, Deep Ocean and Paper (light). They also appear on their own in Claude Code's /theme picker.

6. Mantle Atlas, the knowledge base

Ask Claude things like:

• "Is there a skill for filling PDF forms?"
• "Connect Claude to Jira."
• "How do I make Claude run my tests after every edit?"
• "What's the best way to share our team's prompts?"
• "How can I change how Claude Code looks?"

Atlas answers with 1–3 options, best first: what each does, when to use it, when to skip it, the exact install command, and how to use it afterwards. It also flags anything that needs API keys or broad access.

What it knows:

Tools that ship with it:

node mantle/skills/mantle-atlas/scripts/search.mjs "jira" --type connectors
node mantle/skills/mantle-atlas/scripts/search.mjs "pdf forms" --live   # also asks skills.sh and the MCP Registry now
node mantle/skills/mantle-atlas/scripts/refresh.mjs                     # rebuild the index from live sources (~10 min)

Claude always knows Atlas exists; the guides and index load only when a question needs them, so your context isn't flooded. Atlas never edits your memory on its own. If you ask it to "always remember," it shows you a three-line note for ~/.claude/CLAUDE.md and adds it only on your yes.

Sources: skills.sh, each skill's SKILL.md on GitHub, the official MCP Registry, Anthropic's plugin marketplaces and the Claude Code docs.

7. The website

cd web
npm install
npm run dev

Open http://127.0.0.1:5173.

• Gallery: themes, wallpapers, skills, connectors and plugins in one place, each with its maker's logo. Theme cards preview live on hover, cycling through Claude's states over their wallpaper. Every listing links to its source and copies its install command in one click.
• Set up with your agent: prompts for Claude Code, Cursor, Codex, GitHub Copilot, Gemini CLI, Windsurf, Cline or any agent.
• Make a theme: start from a preset, or build a theme straight from a wallpaper or your own photo (the colors are read in your browser; nothing is uploaded). Lock the colors you like and shuffle the rest with Space, undo with Ctrl+Z, check contrast on every color, and share the result as a link. Claude Code, claude.ai and the terminal update live over the wallpaper; export a Claude Code theme, a Windows Terminal scheme and a claude.ai payload.
• My Claude: a local companion (127.0.0.1 only) lists the skills, plugins, connectors, themes and marketplaces you already have, with secrets masked. Its only write is applying a Mantle theme after you confirm.

Commands

Where it works

The Claude desktop app's interface can't be themed: its bundle is integrity-checked. Mantle's plugin and Atlas still run in its Code tab.

Load the claude.ai extension

1. Run /mantle apply once; it writes the extension to ~/.claude/mantle/chrome-extension.
2. In Chrome open chrome://extensions, turn on Developer mode, click Load unpacked, and pick that folder.

After that every apply reaches open claude.ai tabs within seconds. The popup works on its own too: presets, accent, wallpaper upload or URL, blur, dim, panel opacity, the reply glow.

Privacy and safety

• Everything runs on your machine. The plugin makes no network calls except downloading a wallpaper you asked for.
• The website's local companion binds to 127.0.0.1, reads ~/.claude read-only, masks secrets, and writes only themes/mantle.json after you confirm.
• Atlas recommends; it never installs or configures anything unless you ask.
• Third-party skills and MCP servers run with your permissions. Atlas tells you which ones need keys or broad access; review their source before installing.

Repository layout

mantle/                    Claude Code plugin
  hooks/register.tsx       the mod: /mantle, studio pane, live reactions, wallpaper
  chrome-extension/        claude.ai extension (content script, popup, palettes)
  themes/                  10 presets as standalone Claude Code themes
  skills/mantle-atlas/     the knowledge-base skill
    SKILL.md
    references/            curated guides
    data/                  full index (skills, connectors, plugins)
    scripts/               search.mjs, refresh.mjs
  tests/                   plugin tests
web/                       the website (Vite, React, Tailwind, motion)
  server/                  local companion for My Claude
PRODUCT.md, DESIGN.md      product and design records

Develop

claude --plugin-dir ./mantle      # run the plugin from this folder
claude plugin validate ./mantle   # check the manifest and hooks
claude plugin test ./mantle       # run the plugin tests
cd web && npm run build           # type-check and build the site

Credits

• Presets Tokyo Night, Catppuccin Mocha, Rosé Pine and Nord Night adapt the colors of Tokyo Night, Catppuccin, Rosé Pine and Nord.
• Wallpapers come from Wikimedia Commons and NASA, each credited on its card with its license (public domain, CC0, CC BY, CC BY-SA).
• Agent logos from Simple Icons (CC0); trademarks belong to their owners.
• UI components from Aceternity UI; design process with Impeccable.
• Skill and connector data from skills.sh and the official MCP Registry.

License

MIT, see LICENSE.