How to add an MCP server to Claude Code

TL;DR. Run claude mcp add --transport http {name} {url} --header "Authorization: Bearer {token}" from any terminal. Claude Code registers the MCP server immediately — no restart needed. Verify with claude mcp list.

What is an MCP server?

An MCP server (Model Context Protocol) is an external tool that Claude Code can call — search a database, deploy an app, query an API. MCP is the open protocol Anthropic uses to let Claude Code talk to tools without custom integrations for each one. Any service that speaks MCP is pluggable.

Hatchable's /mcp endpoint exposes tools for creating projects, deploying code, running queries against the project database, and more — all of it available to Claude Code once you register the server.

Before you start

• Claude Code installed. If you don't have it yet: npm install -g @anthropic-ai/claude-code then claude login to connect your Anthropic account.
• A bearer token for the MCP server you're adding. For Hatchable, grab one for free — no signup form — at hatchable.com. Click Copy on any code panel and the command already contains a fresh token.

Add the server

1. Run claude mcp add with the server URL

   Claude Code accepts MCP servers on the HTTP transport with a single command. For Hatchable:

   claude mcp add --transport http hatchable https://hatchable.com/mcp \
     --header "Authorization: Bearer YOUR_TOKEN"

   For a different provider, swap in their URL and token. The format is the same.

2. Verify it registered

   claude mcp list

   You should see hatchable (or whatever name you gave it) in the output, listed as connected. If it's missing, the add step returned an error you'll want to scroll back and read.

3. Try it from inside a Claude Code session

   Open any Claude Code session and ask a question that requires the server. For Hatchable, try:

   claude "Create a new Hatchable project called hello-world and deploy a page that says hi."

   Claude Code will call the MCP server's tools in response. First time through it will ask for permission to invoke each tool — accept or add --allowedTools to your shell alias if you trust the server.

Removing or updating a server

Remove with claude mcp remove {name}. To update (for example, to rotate a token), remove and re-add — claude mcp add will overwrite any existing entry with the same name.

Troubleshooting

Claude Code says "MCP server failed to connect"

Most often this is a transport mismatch. Make sure you passed --transport http for Hatchable — without it, Claude Code tries the default (stdio) and can't find a local binary to launch. Other common causes:

• Token expired. Hatchable auto-signup tokens are good for 30 days of inactivity. Generate a fresh one at hatchable.com.
• Typo in the URL. The endpoint is https://hatchable.com/mcp — not /mcp/ with a trailing slash.
• Behind a corporate proxy. Claude Code honors the standard HTTPS_PROXY env var; if your workplace uses a TLS-inspecting proxy, add it before running claude mcp add.

The server is listed but tools aren't showing up

Run claude mcp list --verbose. If a server is listed but greyed out, Claude Code couldn't fetch its tool manifest — usually a 401 (bad token) or 404 (wrong URL). Re-run the add command with the correct value.

I want Claude Code to auto-approve tools

Pass --allowedTools mcp__hatchable__* to claude when launching, or add it to a .claude/settings.json in the project. Only do this for servers you fully trust — the whole point of the prompt is to give you a chance to refuse.