Claude Code MCP: Add, Scope and Remove Servers (2026)

What is an MCP server in Claude Code?

MCP (Model Context Protocol) lets Claude Code use outside tools. An MCP server is a small program or remote service that offers tools, such as “search notes” or “save this fact”. Once you add a server, Claude can call its tools in any session that loads it. You set servers up with the claude mcp commands, not by editing settings by hand.

How do you add an MCP server?

There are three common routes. Pick the one that matches your server.

Two details trip people up:

• The -- (double dash) separates Claude’s own options, such as --transport, --env and --scope, from the command that starts the server. Put options before --, and the server’s command after it.
• Use -e KEY=value (or --env) to pass a setting such as an API key to a local server. Use -H "Header: value" (or --header) for a remote server that needs a header, such as a bearer token.

1claude mcp add --transport http notion https://mcp.notion.com/mcp
2
3claude mcp add --env AIRTABLE_API_KEY=YOUR_KEY --transport stdio airtable \
4  -- npx -y airtable-mcp-server

The SSE transport still works, but the docs call it deprecated. Use HTTP where the service offers it.

Which scope should you pick?

The scope decides where a server loads and who else gets it. The default is local.

Use --scope user for a personal memory server you want everywhere. Use --scope project for a server the whole team should share. The team gets a prompt to approve it the first time.

How do you check, change and remove a server?

1claude mcp list              # list all servers and their status
2claude mcp get notion        # show one server's details
3claude mcp remove notion     # remove a server

Inside a session, run /mcp to see status and to log in to servers that need it. A server can show Connected, Needs authentication or Failed to connect. A project server you have not approved shows Pending approval. To reset your approval choices for project servers, run claude mcp reset-project-choices.

Removing a remote server deletes the OAuth tokens that Claude Code stored for it, but it does not revoke them on the provider’s side. To revoke first, run claude mcp logout <name>, then remove it.

How do you write .mcp.json by hand?

Project servers live in .mcp.json. A remote server looks like this:

1{
2  "mcpServers": {
3    "shared-server": {
4      "type": "http",
5      "url": "https://example.com/mcp"
6    }
7  }
8}

A local server uses command, args and env instead of url. Keep secrets out of the file: use ${VAR} to read an environment variable, or ${VAR:-default} to fall back to a default when the variable is not set.

 1{
 2  "mcpServers": {
 3    "api-server": {
 4      "type": "http",
 5      "url": "${API_BASE_URL:-https://api.example.com}/mcp",
 6      "headers": {
 7        "Authorization": "Bearer ${API_KEY}"
 8      }
 9    }
10  }
11}

If a variable is not set and has no default, the config still loads, the text ${VAR} stays as written, and claude mcp list shows a warning. Setting a variable to an empty string counts as set, so the default does not apply. To use the default, unset the variable.

Memory: which MCP servers give Claude Code memory?

An MCP server gives Claude memory only if it saves facts and returns them later. Two options:

• The official Knowledge Graph Memory Server (@modelcontextprotocol/server-memory). It stores entities and relations in a local JSONL file. Set MEMORY_FILE_PATH, because the default file sits in the server’s own install folder:

  1claude mcp add --scope user --env MEMORY_FILE_PATH=$HOME/.claude/memory.jsonl \
  2  memory -- npx -y @modelcontextprotocol/server-memory
  

  The command above is the form from the Claude Code memory guide on this site. Check the server’s README for its current flags before you rely on it.

• Hindsight. Hindsight is an open-source memory server with MIT-licensed self-hosting and the full server in the open-source release. For Claude Code, the supported route is its Coding Agents package, npx @vectorize-io/hindsight-coding-agents install claude-code, which captures memory through hooks. Hindsight Cloud also runs an MCP server at https://api.hindsight.vectorize.io/mcp, which uses OAuth and needs no API key, according to its Grok Bot integration docs (read 2026-10-24). We did not test adding that URL to Claude Code, so check the Hindsight docs for the exact steps.

  On the numbers, Hindsight reports 64.1 on BEAM 10M against Mem0’s 48.6. Mem0’s own comparison page gives both figures, so this is Mem0’s data, not an independent test. Hindsight’s limits matter too: it returns more context per retrieval than Mem0 by default, and each save calls an LLM. Set max_tokens lower if the context is too big.

Claude only calls memory tools when it decides to. Put a line in CLAUDE.md such as “Search memory before you answer questions about past decisions”, or it may never call them. For the full memory picture, see Claude Code memory and AI memory MCP servers. To install Claude Code first, see How to install Claude Code.

Sources

• Claude Code MCP docs, code.claude.com/docs/en/mcp (read 2026-11-12): commands, scopes, .mcp.json, environment variable expansion.
• Claude Code memory guide on this site, for the Knowledge Graph Memory Server command.
• Hindsight facts, coding agents: Hindsight’s coding-agents docs (read 2026-11-12) and the Grok Bot integration README (read 2026-10-24) for the MCP URL.
• Benchmark figures: Mem0’s comparison page, not Hindsight’s own report.