
Buoy
io.github.ahoybuoyPublished by GitHub account ahoybuoyv0.8.13Updated Nov 7, 2026
The design system your coding agents check before they ship: tokens plus exact UI fixes.
Overview
Buoy gives coding agents your design system: it lists tokens, maps hardcoded values to tokens, and flags UI drift in code.
- What you can do
- List the design tokens found in a project
- Map a concrete value such as a hex color to the matching token
- Check UI code line by line against the design system and return the token plus an exact line edit
- Return design-system context for the assistant to follow
- Optionally check each style file the assistant edits and hand fixes back before it continues
- When to use it
- Use it when an assistant writes or edits front-end components and you want it to use your tokens and spacing scale instead of hardcoded values. It suits teams with an existing token or component library who want drift caught while code is being written rather than in review.
- Requirements
- Runs as a local stdio process installed from the npm package @buoy-design/cli (Node.js). Installed into a client with the CLI's mcp install command. No configuration is required; it auto-detects the framework, and an optional .buoy.yaml can declare components, tokens and owners.
Installation
In SourceWeft
- Open Buoy in the dashboard and add it to a workspace.
- Enable the server for the chats that should use its tools.
Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.
Other MCP clients
Follow the launch instructions in the repository.
README
Buoy
Catch design drift before it ships.
AI coding tools are fast—but they don't know your design system. They'll write #3b82f6 when you have --color-primary. They'll use padding: 17px when your spacing scale is multiples of 4.
Buoy watches for these issues and helps you fix them.
Code-first System Observability
Your shipped code is the design-system source of truth. Declare the packages you own, then use Buoy to map adoption, unmanaged UI surface area, and the blast radius of a component or token change. Figma and other design tools can remain optional inputs; they are not required for the system map.
This is the foundation for cloud adoption trends, deprecation planning, and AI-assisted iteration reporting: every result is derived from code and can be attributed to a repository path and owner.
Quick Start
No config needed. Buoy auto-detects your framework and starts working immediately.
What It Catches
Commands
For AI Agents
Coding agents hardcode values because they never read your token file. Give them Buoy as an MCP server:
Claude Code (and any MCP client) gets four tools: list_design_tokens, find_token_for_value
(#1a73e8 → --color-primary), check_ui_against_design_system (line-level, with the token and an exact line edit)
and design_system_context. Claude Code also gets a PostToolUse hook that checks every style
file it edits and hands the fixes back before it moves on. See docs/integrations/mcp.
In Claude Code, the plugin bundles all of it: /plugin marketplace add ahoybuoy/buoy, then /plugin install buoy@buoy.
To review every pull request as well, install the free GitHub App; no Buoy account is needed.
The show command outputs JSON for AI agents to consume:
Example output:
Getting Started
Complete a Rescue journey
Rescue keeps ambiguous findings review-only, runs detected project checks after applying high-confidence changes, and retains local backups for rollback. It does not commit, push, open a pull request, or upload source code. See docs/rescue.md for the complete workflow.
Configure Your Project
Smart walkthrough that sets up:
.buoy.yaml— Project configuration- AI agent skills — For Claude Code, Copilot, etc.
- CLAUDE.md context — Design system documentation
- Git hooks — Pre-commit drift checking
Configure severities per drift type
Drift Detection
Quick Check
Fast pre-commit hook friendly. Exits with error code if drift found.
Detailed Analysis
Fix Issues
Ignore Existing Drift
For brownfield projects, ignore existing issues and only flag new ones:
A reason is required when ignoring drift to maintain accountability.
CI Integration
GitHub Actions
Design health badge
Repos scanned by Buoy Cloud get a live score badge for the README:
Green at 80+, yellow at 60+, red below. It updates within five minutes of each scan.
PR Comments with Buoy Cloud
The GitHub bot automatically comments on PRs with drift analysis.
AI Guardrails
Keep AI coding assistants (Copilot, Claude, Cursor) aligned with your design system:
Creates:
- AI Skills — Design system knowledge for Claude Code
- Claude Hooks — Auto-inject context at session start
- CLAUDE.md — Project-specific AI instructions
Self-Validating Agents (Claude Code)
Turn Claude Code into a self-correcting agent. When Claude writes a component, Buoy checks it and feeds corrections back automatically:
This installs a PostToolUse hook that:
- Claude writes/edits a component file
- Hook runs
buoy drift checkon the modified file - If drift detected, feedback returns to Claude
- Claude self-corrects without prompting
Example feedback Claude receives:
Works with React, Vue, Svelte, and Angular components. Skips test files and configs.
Configuration
Works without config, but you can save settings:
Creates .buoy.yaml:
Buoy Cloud
Ship your drift detection to the cloud:
Features:
- PR Bot — Automatic comments on pull requests
- Dashboard — View drift trends over time
- Team sync — Share results across team members
Supported Frameworks
Components: React, Vue, Svelte, Angular, Lit, Stencil, Alpine, HTMX
Templates: Blade, ERB, Twig, Razor, Jinja, Handlebars, EJS, Pug
Tokens: CSS variables, SCSS, Tailwind config, JSON, Style Dictionary
Design Tools: Figma (plugin + API integration)
Philosophy
Inform by default, block by choice.
Buoy shows you what's happening without getting in your way. Teams adopt enforcement when they're ready:
Development
Packages
License
MIT
Source: README.md at commit 6aa1a62
Tools
0Version history
8- v0.8.13LatestNov 7, 2026
- v0.8.12Oct 20, 2026
- v0.8.11Oct 15, 2026
- v0.8.10Oct 14, 2026
- v0.8.9Oct 14, 2026
- v0.8.8Oct 14, 2026
- v0.8.7Sep 24, 2026
- v0.8.1Sep 24, 2026
Score
50% of the applicable checks met
How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.
- Reached in the last 30 days25 pts
Keep the endpoint answering the MCP handshake; SourceWeft probes it every 30 days.
- Auth declared10 pts
Declare the credential headers in the registry entry, or keep the endpoint answering the probe so its auth can be classified.
- Tools listed15 pts
Answer tools/list without a credential, or ship a package that starts in a sandbox without one.
- DescriptionRequired15 pts
- Logo10 pts
- Documentation15 pts
- License10 pts