Yocoolab

@yocoolab/mcp-server

MCP (Model Context Protocol) server that exposes Yocoolab feedback threads and design selections as tools for Claude Code and other MCP-compatible clients.

With this installed, your AI coding assistant can:

• List and triage open design feedback threads on your repo
• Pull rich context for a thread (selection, screenshot, conversation, files touched)
• Reply to designers and mark threads as addressed
• Open PRs that close out feedback threads
• Inspect element context and selection history from the Yocoolab Chrome extension
• Read companion chat messages, AI conversations, and Pendo product analytics

Recommended: the hosted Yocoolab MCP (nothing to install)

Most people no longer need this package. Yocoolab hosts the MCP server at https://app.yocoolab.com/mcp. Your agent signs in to Yocoolab in the browser the first time, so there is no token to paste:

claude mcp add --transport http --scope user yocoolab https://app.yocoolab.com/mcp

Then type /mcp in Claude Code, choose yocoolab, and Authenticate. Setup for Cursor, VS Code, the Claude app, and headless agents (agent token in a header) is at app.yocoolab.com/connect.

Always-on agent: to have one computer pick up every Send to Agent in your workspace by itself (it runs Claude Code), run this on that computer:

curl -fsSL https://app.yocoolab.com/agent/install.sh | sh

Switching from this package to the hosted server? Remove the old entry first (claude mcp remove yocoolab, repeat until none is found). Otherwise Claude may keep using the old one.

Use this package only if you need what runs on your own machine: the local bridge on :9800 for live selections from the Chrome extension.

Install (local package)

One command:

npx -y @yocoolab/mcp-server@3 setup

The setup wizard auto-detects your installed AI agents (Claude Code, Cursor, Cline, Roo Code, Windsurf) and writes the correct MCP config for each. Restart your agent and the yocoolab server appears with all tools available.

init is kept as an alias for setup for backwards compatibility with v1.0.x install instructions.

If you'd rather configure manually, the equivalent ~/.mcp.json looks like:

{
  "mcpServers": {
    "yocoolab": {
      "command": "npx",
      "args": ["-y", "@yocoolab/mcp-server@3"],
      "env": {
        "YOCOOLAB_API_URL": "https://app.yocoolab.com",
        "YOCOOLAB_TOKEN": "<your-yocoolab-jwt>",
        "GITHUB_TOKEN": "<your-github-pat>",
        "YOCOOLAB_BRIDGE_PORT": "9800",
        "YOCOOLAB_BRIDGE_WORKSPACE": "/absolute/path/to/your/workspace"
      }
    }
  }
}

The @3 version pin keeps you on the v3 major line — you'll receive bug fixes and new features automatically, but a future v4 with breaking changes won't break your setup. v3.0.0 removed the activity monitor and no longer writes Claude Code hooks into ~/.claude/settings.json; see CHANGELOG.md if you are upgrading from v2.

Requirements

• Node.js 20 or newer. We test on Node 20 and 22 in CI. We support whichever Node.js versions are currently in Active LTS or Maintenance LTS status, and drop versions within 30 days of their EOL. Node 18 was dropped in v2.0.0 (EOL April 2025).
• A Yocoolab account and JWT token — get yours from the Yocoolab Chrome extension settings, or via your account at app.yocoolab.com.
• A GitHub personal access token with repo scope, if you want to use the PR-creation tools (create_pr_for_thread). The token is auto-detected if you have the GitHub CLI installed and authenticated (gh auth login). No GITHUB_TOKEN env var needed in that case. Otherwise, create one at github.com/settings/tokens/new?scopes=repo.

Configuration

Env var	Required	Default	Description
YOCOOLAB_TOKEN	no	—	Your Yocoolab JWT (from the Chrome extension). When unset, thread feedback tools are disabled but bridge / companion / selection tools still work.
YOCOOLAB_API_URL	no	https://app.yocoolab.com	Yocoolab API base URL
GITHUB_TOKEN	only for PR tools	—	GitHub PAT with repo scope. Auto-detected — if gh CLI is installed and authenticated (gh auth token), no env var is needed. Placeholder values like <your GitHub PAT> are detected and safely ignored.
YOCOOLAB_BRIDGE_PORT	no	9800	Local port for the HTTP bridge to the Chrome extension
YOCOOLAB_BRIDGE_WORKSPACE	no	process.cwd()	Absolute path to your project workspace, used to resolve file references in selections
YOCOOLAB_AGENT_NAME	no	Claude Code	Display name shown in the Chrome extension's agent picker
YOCOOLAB_PROJECT_PR_LINKS	no	1	Set to 0 to restore the pre-2.5 behaviour: mark_thread_addressed without PR/preview link fields, GitHub-only PR guidance in the prompt
YOCOOLAB_AGENT_TYPE	no	claude-code	Agent type identifier (claude-code, roo, cline, cursor, windsurf, or custom)

CLI

yocoolab-mcp           Run the MCP server (used by your agent via .mcp.json)
yocoolab-mcp setup     Interactive setup — auto-detects agents and writes their configs
yocoolab-mcp init      Alias for `setup` (backwards compatible with v1.0.x)
yocoolab-mcp --help    Show this help

The mcp-server command is a synonym for yocoolab-mcp. Either works.

Tools

The server exposes tools across several categories:

• Threads — list_open_threads, get_thread_context, add_thread_message, mark_thread_addressed, create_pr_for_thread
  • On a link-only project (no GitHub App connection) open the PR with your own git/gh, then call mark_thread_addressed with pr_url (and pr_branch, preview_url when you have them). The PR fields land on the thread and the preview link goes into the review message; get_thread_context prints the project's repo links so you know which repository it points at. create_pr_for_thread remains for GitHub-connected owner/name workspaces.
• Selection / Bridge — get_latest_selection, get_selection_history, get_element_context, find_source_for_selection, ai_analyze_page
• Companion — get_companion_messages, reply_to_companion
• AI — get_ai_conversations
• Deployment — get_deployment_preview
• Pendo (optional) — pendo_list_guides, pendo_page_analytics, pendo_feature_usage, pendo_track_event

For full tool descriptions and parameters, your MCP client will list them after the server starts.

Troubleshooting

yocoolab-mcp: command not found — make sure you're on v1.0.1 or newer. Run npx -y @yocoolab/mcp-server@latest setup to get the current release.

[yocoolab] Warning: YOCOOLAB_TOKEN not set — thread feedback tools are disabled without a token, but bridge / companion / selection tools still work. To enable everything, run yocoolab-mcp setup to (re)generate the config with your JWT.

Tools don't appear in your agent after install — restart your agent completely (quit & reopen). MCP servers load at startup.

Port 9800 is already in use — another instance of the MCP server is running, or another app has the port. Set YOCOOLAB_BRIDGE_PORT to a different value (e.g. 9801) in your .mcp.json.

Verbose diagnostic logs — set DEBUG=yocoolab:* in your env block. All diagnostic output goes to stderr (so it doesn't interfere with the MCP stdio protocol on stdout).

PR creation says "GitHub token not configured" — the create_pr_for_thread tool needs a GitHub token. Two ways to fix:

1. Auto-detect (easiest): install the GitHub CLI and run gh auth login. The server picks up the token automatically.
2. Manual: create a personal access token with repo scope and add GITHUB_TOKEN: "ghp_..." to your MCP config's env block. If your config has a placeholder value like <your GitHub PAT>, the server detects it and shows a helpful message instead of crashing with a 401.

Support

• Documentation: this README, plus inline tool descriptions visible in your MCP client
• Bug reports: github.com/Yocoolab/mcp-server/issues (use the bug template)
• Security issues: see SECURITY.md — do not open a public issue
• Other questions: [email protected]

Development

git clone https://github.com/Yocoolab/mcp-server.git
cd mcp-server
npm install
npm run build       # compile TypeScript to dist/
npm test            # run the vitest suite
npm run dev         # tsc --watch

See CONTRIBUTING.md for the full contributor workflow.

Security & supply chain

• Released with npm provenance — every published version is cryptographically signed by GitHub Actions OIDC, traceable back to the exact commit and workflow run.
• Each release ships with a CycloneDX SBOM attached to the GitHub Release.
• We run npm audit signatures and CodeQL static analysis in CI on every PR.
• See SECURITY.md for vulnerability reporting.

License

Apache 2.0 — © 2026 Yocoolab