Model Context Protocol (MCP) Server: io.github.ahoybuoy/buoy

The MCP server “io.github.ahoybuoy/buoy” provides functionality described as “Design tokens and drift checks for coding agents: use the token, not the hardcoded value.” It focuses on ensuring coding agents rely on design tokens and detect drift against those token values rather than using hardcoded alternatives.

🛠️ Key Features

Design tokens support for coding agents
Drift checks to compare against token-based values
Emphasis on using tokens instead of hardcoded values

🚀 Use Cases

Automated checks for design token drift in agent-driven workflows
Enforcing token usage over hardcoded values in coding agent outputs

⚡ Developer Benefits

Consistent token usage to avoid hardcoded discrepancies
Ability to validate alignment with design tokens via drift checks

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

src/components/Button.tsx:24
  hardcoded-value: #3b82f6 → var(--color-primary) (92% match)

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.

yaml

# .buoy.yaml
project:
  name: acme

system:
  components:
    - packages/ui/src/**
  tokens:
    - packages/tokens/src/**
  owners:
    - name: Checkout
      paths:
        - apps/checkout/**

bash

buoy system map                 # Canonical system vs unmanaged surface area
buoy system impact Button       # Consumers and migration risk for a change
buoy system impact color-primary --kind token

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

bash

# See your design system immediately (zero config)
npx ahoybuoy show all

# Add project configuration and local integrations when ready
npx ahoybuoy dock

No config needed. Buoy auto-detects your framework and starts working immediately.

What It Catches

Issue	Example
Hardcoded colors	`#ff0000` instead of `var(--color-primary)`
Arbitrary spacing	`padding: 17px` instead of design scale
Tailwind escape hatches	`p-[13px]` instead of `p-4`
Naming inconsistencies	`ButtonNew`, `ButtonV2`, `ButtonOld`
Unused components	Defined but never imported or rendered
Semantic mismatches	Same prop typed `string` in one, `number` in another
Repeated patterns	Same Tailwind classes copy-pasted 5+ times
Framework sprawl	React + Vue + jQuery in same codebase
Detached components	Instances without main component

Commands

code

buoy
├── show                    # Read design system info (for AI agents)
│   ├── components          # Components in codebase
│   ├── tokens              # Design tokens found
│   ├── drift               # Design system violations
│   ├── health              # Health score
│   ├── history             # Scan history
│   ├── config              # Current .buoy.yaml configuration
│   ├── skills              # AI agent skill files
│   ├── agents              # Configured AI agents
│   ├── context             # Design system context in CLAUDE.md
│   ├── hooks               # Configured hooks
│   ├── commands            # Installed slash commands
│   ├── graph               # Knowledge graph stats
│   ├── plugins             # Available scanners
│   └── all                 # Everything combined
├── drift                   # Drift detection and fixing
│   ├── scan                # Scan codebase for components/tokens
│   ├── check               # Pre-commit drift check
│   ├── fix                 # Suggest/apply fixes
│   └── ignore              # Ignore existing drift
│       ├── all             # Ignore all current drift (requires --reason)
│       ├── show            # View ignored drift signals
│       ├── add             # Add new drift to ignore list (requires --reason)
│       └── clear           # Remove ignore list
├── rescue                  # Complete measure → repair → guard → prove journey
│   ├── plan                # Build a local baseline and repair plan
│   ├── apply               # Apply reviewed safe fixes on a new branch
│   ├── verify              # Run detected typecheck/test scripts
│   ├── guard               # Record reviewed legacy drift with reasons
│   ├── report              # Generate JSON, Markdown, and HTML evidence
│   └── rollback            # Restore local pre-Rescue backups
├── dock                    # Dock tools into your project
│   ├── config              # Create .buoy.yaml
│   ├── skills              # Create AI agent skills
│   ├── agents              # Set up AI agents
│   ├── context             # Generate CLAUDE.md context
│   ├── hooks               # Set up hooks (--claude for self-validating AI)
│   ├── commands            # Install Claude slash commands
│   ├── plugins             # Show available scanners
│   ├── tokens              # Generate/export design tokens
│   │   ├── compare         # Compare token sources
│   │   └── import          # Import tokens from Figma/CSS
│   └── graph               # Build design system knowledge graph
│       └── learn           # Learn patterns from codebase
└── ahoy                    # Cloud features
    ├── login               # Authenticate
    ├── logout              # Sign out
    ├── status              # Account + bot + sync status
    ├── github              # Set up GitHub PR bot
    ├── gitlab              # Set up GitLab PR bot (soon)
    ├── billing             # Manage subscription
    └── plans               # Compare pricing

For AI Agents

Coding agents hardcode values because they never read your token file. Give them Buoy as an MCP server:

bash

npx @buoy-design/cli mcp install claude   # or cursor, codex, windsurf, all

Claude Code (and any MCP client) gets four tools: list_design_tokens, find_token_for_value (#1a73e8 → --color-primary), check_design_drift (line-level, with the token to use instead) 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:

bash

# Get everything an AI agent needs
buoy show all --json

# Just drift signals
buoy show drift --json

# Components inventory
buoy show components --json

Example output:

json

{
  "components": [...],
  "tokens": [...],
  "drift": {
    "signals": [...],
    "summary": { "total": 12, "critical": 2, "warning": 7, "info": 3 }
  },
  "health": { "score": 78 }
}

Getting Started

Complete a Rescue journey

bash

buoy rescue plan
# Review .buoy/rescue/runs/<run-id>/report.html
buoy rescue apply --run <run-id> --approve
buoy rescue guard --run <run-id> --reason "Reviewed legacy baseline" --actor "Design systems team"
buoy rescue report --run <run-id>

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

bash

buoy dock

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

yaml

# .buoy.yaml
project:
  name: my-app

drift:
  severity:
    hardcoded-value: critical
    naming-inconsistency: warning

  # Ignore specific drift (filter by type, file, component, token, value, severity)
  ignore:
    - type: hardcoded-value
      file: "src/legacy/**"
    - severity: info

  # Promote matching drift to a higher severity
  promote:
    - type: hardcoded-value
      file: "src/components/**"
      to: critical
      reason: "Design system components must use tokens"

  # Enforce — always treat matching drift as critical
  enforce:
    - type: naming-inconsistency
      component: "^Button"
      reason: "Button naming is standardized"

health:
  # CI gate — exit code 1 if health score falls below threshold
  failBelow: 70

Drift Detection

Quick Check

bash

buoy drift check

Fast pre-commit hook friendly. Exits with error code if drift found.

Detailed Analysis

bash

buoy show drift

json

{
  "drifts": [
    {
      "type": "hardcoded-value",
      "severity": "warning",
      "file": "src/components/Button.tsx",
      "line": 24,
      "message": "#3b82f6 should use var(--color-primary)",
      "suggestion": "var(--color-primary)"
    }
  ]
}

Fix Issues

bash

buoy drift fix                    # Interactive fix suggestions
buoy drift fix --dry-run          # Preview changes
buoy drift fix --apply            # Apply reviewed high-confidence fixes

Ignore Existing Drift

For brownfield projects, ignore existing issues and only flag new ones:

bash

buoy drift ignore all -r "Legacy code before design system"     # Ignore all current drift with reason
buoy drift ignore add -r "Third-party components"               # Add new drift to ignore list
buoy drift ignore show                                          # View ignored drift with reasons
buoy drift check                                                # Only fails on new drift

A reason is required when ignoring drift to maintain accountability.

CI Integration

GitHub Actions

yaml

name: Design System Check
on: [pull_request]

jobs:
  buoy:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: "20"
      - run: npx ahoybuoy drift check

Design health badge

Repos scanned by Buoy Cloud get a live score badge for the README:

markdown

[![design health](https://api.buoy.design/badges/OWNER/REPO.svg)](https://buoy.design)

Green at 80+, yellow at 60+, red below. It updates within five minutes of each scan.

PR Comments with Buoy Cloud

bash

# Set up GitHub PR bot
buoy ahoy login
buoy ahoy github

The GitHub bot automatically comments on PRs with drift analysis.

AI Guardrails

Keep AI coding assistants (Copilot, Claude, Cursor) aligned with your design system:

bash

# Set up AI agents with design system context
buoy dock agents

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:

bash

buoy mcp install claude     # MCP server + line-level hook (recommended)
buoy dock hooks --claude    # hook only, component-level

This installs a PostToolUse hook that:

Claude writes/edits a component file
Hook runs buoy drift check on the modified file
If drift detected, feedback returns to Claude
Claude self-corrects without prompting

Example feedback Claude receives:

code

⚠️ Design drift detected in Button.tsx:

• hardcoded-value: Component "Button" has 3 hardcoded colors: #3b82f6, #ffffff, #1e40af

Run `buoy show drift` for full details.

Works with React, Vue, Svelte, and Angular components. Skips test files and configs.

Configuration

Works without config, but you can save settings:

bash

buoy dock config

Creates .buoy.yaml:

yaml

project:
  name: my-app

sources:
  react:
    enabled: true
    include:
      - src/**/*.tsx
    exclude:
      - "**/*.test.*"
  tokens:
    enabled: true
    files:
      - design-tokens.css

Buoy Cloud

Ship your drift detection to the cloud:

bash

buoy ahoy login             # Authenticate
buoy ahoy status            # View account, bot, sync status
buoy ahoy github            # Set up GitHub PR bot
buoy ahoy billing           # Manage subscription

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:

bash

buoy show drift             # Just show me
buoy drift check            # Pre-commit check (fails on critical)
buoy drift check --fail-on warning    # Fail on warning or above
buoy drift check --fail-on none       # Never fail (report only)
buoy drift check --staged             # Only check staged files

Development

bash

# Install dependencies
pnpm install

# Build all packages
pnpm build

# Run tests
pnpm test

# Run CLI locally
node apps/cli/dist/bin.js show all

Packages

Package	Description
`@buoy-design/cli`	Command-line interface
`@buoy-design/core`	Domain models and drift detection engine
`@buoy-design/scanners`	Framework-specific code scanners
`ahoybuoy`	CLI wrapper (`npx ahoybuoy`)
`buoy-design`	CLI wrapper (`npx buoy-design`)

License

MIT

io.github.ahoybuoy/buoy

Model Context Protocol (MCP) Server: io.github.ahoybuoy/buoy

🛠️ Key Features

🚀 Use Cases

⚡ Developer Benefits

Topics

Buoy

Code-first System Observability

Quick Start

What It Catches

Commands

For AI Agents

Getting Started

Complete a Rescue journey

Configure Your Project

Configure severities per drift type

Drift Detection

Quick Check

Detailed Analysis

Fix Issues

Ignore Existing Drift

CI Integration

GitHub Actions

Design health badge

PR Comments with Buoy Cloud

AI Guardrails

Self-Validating Agents (Claude Code)

Configuration

Buoy Cloud

Supported Frameworks

Philosophy

Development

Packages

License

Install

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