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Getting Connected

A comprehensive guide on connecting MCP clients to the Hyphen AI platform, covering authentication options (OAuth and API keys) and setup for various clients like Claude Code, Claude Desktop, claude.ai, Cursor, and VS Code.

Connect your MCP client to https://mcp.hyphen.ai/ and authenticate with your Hyphen account. This guide covers both authentication options and setup for the most common clients.

Table of Contents

Authentication

Every MCP request needs a Hyphen credential. There are two options, and both resolve to the same identity and permissions:

  1. OAuth (recommended) — clients that support the MCP OAuth discovery flow (Claude Code, Claude Desktop, claude.ai, Cursor) authenticate automatically: the server answers the first unauthenticated request with a challenge, and the client opens a browser window to sign you in through auth.hyphen.ai.
  2. API key — create an API key in the Hyphen App under Settings → API Keys and send it as the x-api-key header. Use this for CI, headless agents, or clients without OAuth support.

📘 API keys carry the access they were granted at creation time. Scope them to the projects your agent actually needs.

Claude Code

# OAuth
claude mcp add --transport http hyphen https://mcp.hyphen.ai/

# or with an API key
claude mcp add --transport http hyphen https://mcp.hyphen.ai/ --header "x-api-key: "

With OAuth, adding the server doesn't sign you in yet — inside Claude Code, run /mcp, select hyphen, and authenticate; a browser window opens the first time.

Claude Desktop and claude.ai

Go to Settings → Connectors → Add custom connector, paste https://mcp.hyphen.ai/, and sign in when prompted.

Cursor

Use the one-click install, or add the server to ~/.cursor/mcp.json:

{
  "mcpServers": {
    "hyphen": {
      "url": "https://mcp.hyphen.ai/"
    }
  }
}

VS Code

Use the one-click install, or add the server to your mcp.json with an API key:

{
  "servers": {
    "hyphen": {
      "type": "http",
      "url": "https://mcp.hyphen.ai/",
      "headers": { "x-api-key": "" }
    }
  }
}

📘 VS Code's OAuth sign-in depends on dynamic client registration, which Hyphen's authorization server doesn't offer yet (see troubleshooting) — the API key header is the reliable path in VS Code today.

Other Clients

Any client that speaks streamable HTTP works. The generic mcpServers shape, with an API key for clients that don't handle the OAuth flow:

{
  "mcpServers": {
    "hyphen": {
      "type": "streamable-http",
      "url": "https://mcp.hyphen.ai/",
      "headers": { "x-api-key": "" }
    }
  }
}

Picking an Organization

Your organization is resolved automatically from your credential. If you belong to more than one organization, pin the one a client should use by putting its ID in the URL:

https://mcp.hyphen.ai//

Verify the Connection

Ask your assistant something like "Who am I in Hyphen?" — it should call the whoami tool and answer with your user, member, and organization. From there, try "List my projects" or "What feature flags haven't been evaluated lately?"

Troubleshooting

  • The OAuth sign-in fails in your client. Some clients require OAuth dynamic client registration, which Hyphen's authorization server does not offer yet. Fall back to an API key in any client that lets you set request headers — Claude Code, Cursor, VS Code, and generic mcpServers configs. (Claude Desktop and claude.ai don't accept custom headers, but their connector flow signs in with OAuth and doesn't need one.)
  • You see a 401 before signing in. That is the OAuth flow working as designed: the first unauthenticated request is challenged, and the challenge tells the client where to sign in. If your client never opens a browser after the 401, configure an API key instead.
  • Tools fail with permission errors. Tool calls run with your Hyphen permissions (or the API key's). If you can't do something in the Hyphen App, the MCP server can't do it either — ask an organization admin to adjust your role or the key's access.