MCP Servers

Extend Claude Code with Model Context Protocol servers that add new tools, resources, and capabilities.

Model Context Protocol (MCP) is an open standard that lets Claude Code connect to external servers that expose additional tools and data sources. An MCP server might give Claude access to a database, a SaaS API, a code execution environment, or any other capability you want to add to your workflow.

Adding MCP servers

Use the claude mcp add CLI subcommand to register a server. The server name, command (or URL), and scope are required.

Stdio servers (local process)

Stdio servers run as a local subprocess. Claude Code spawns the process and communicates over stdin/stdout.

# Basic stdio server
claude mcp add my-server -- npx my-mcp-server

# With environment variables
claude mcp add -e API_KEY=xxx my-server -- npx my-mcp-server

# With explicit subprocess flags
claude mcp add my-server -- my-command --some-flag arg1

HTTP servers (remote)

HTTP servers are reachable over the network. Pass --transport http and a URL.

# Add an HTTP server
claude mcp add --transport http sentry https://mcp.sentry.dev/mcp

# With custom headers (e.g. bearer token)
claude mcp add --transport http corridor https://app.corridor.dev/api/mcp \
  --header "Authorization: Bearer YOUR_TOKEN"

SSE servers

Server-Sent Events (SSE) transport is also supported for streaming servers:

claude mcp add --transport sse my-sse-server https://example.com/sse

If the command argument looks like a URL but --transport is not specified, Claude Code defaults to stdio and warns you. Always pass --transport http or --transport sse when adding a remote server.

Server scope

Every server is registered at a specific scope that determines which settings file stores it and who can use it.

--scope local · default

Stored in .claude/settings.local.json in the current project directory. Applies only to this machine and this project. Gitignored. This is the default.

--scope user

Stored in ~/.claude/settings.json. Available in all projects on this machine.

--scope project

Stored in .claude/settings.json in the current project directory. Committed to version control — all teammates who check out the project get this server.

# Add to user scope (available everywhere on this machine)
claude mcp add --scope user my-server -- npx my-mcp-server

# Add to project scope (committed to version control)
claude mcp add --scope project my-server -- npx my-mcp-server

Managing servers

/mcp command

Inside a Claude Code session, run /mcp to open the interactive MCP server manager. From there you can view connection status, enable/disable servers, and reconnect.

/mcp

CLI subcommands

# List all configured servers
claude mcp list

# Remove a server
claude mcp remove my-server

# Enable/disable a server (session-level toggle)
/mcp enable my-server
/mcp disable my-server
/mcp disable all

Reconnect

If a server loses its connection, reconnect it without restarting the session:

/mcp reconnect my-server

OAuth authentication

HTTP and SSE servers that require OAuth can be configured with a client ID and secret:

claude mcp add --transport http \
  --client-id YOUR_CLIENT_ID \
  --client-secret \
  my-oauth-server https://api.example.com/mcp

The --client-secret flag prompts for the secret interactively (or reads from the MCP_CLIENT_SECRET environment variable). Secrets are stored in the system keychain, not in settings files.

Use --callback-port if the authorization server requires a pre-registered redirect URI:

claude mcp add --transport http \
  --client-id YOUR_CLIENT_ID \
  --client-secret \
  --callback-port 8085 \
  my-server https://api.example.com/mcp

Using MCP tools in conversations

Once connected, MCP tools appear automatically alongside built-in tools. Reference them naturally in your conversation:

“Use the database tool to look up orders placed in the last 7 days.”

Claude selects the appropriate MCP tool and asks for permission (subject to your permissions configuration) before calling it.

Enterprise MCP controls

Organizations can restrict which MCP servers users may configure:

allowedMcpServers · object[]

Allowlist of servers that may be used. Each entry matches by serverName, serverCommand, or serverUrl. If undefined, all servers are allowed. An empty array blocks all servers.

{
  "allowedMcpServers": [
    { "serverName": "sentry" },
    { "serverUrl": "https://*.internal.example.com/*" }
  ]
}

deniedMcpServers · object[]

Denylist of servers that are explicitly blocked. Takes precedence over allowedMcpServers.

{
  "deniedMcpServers": [
    { "serverCommand": ["npx", "untrusted-server"] }
  ]
}

allowManagedMcpServersOnly · boolean

When true (set in managed settings), the allowedMcpServers allowlist is only read from managed settings. Users can still add their own servers, but only the admin-defined allowlist governs which are permitted.

Example MCP servers

Sentry

Connect to Sentry to query issues, releases, and performance data directly from your workflow.

claude mcp add --transport http sentry \
  https://mcp.sentry.dev/mcp

GitHub

Interact with GitHub repositories, pull requests, and issues using the official MCP server.

claude mcp add --scope user github \
  -- npx @modelcontextprotocol/server-github

PostgreSQL

Give Claude read access to a PostgreSQL database for querying and schema inspection.

claude mcp add -e DB_URL=postgres://... pg-server \
  -- npx @modelcontextprotocol/server-postgres

Filesystem

Extend the directories Claude can read beyond the project root.

claude mcp add --scope user filesystem \
  -- npx @modelcontextprotocol/server-filesystem /data

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