ENABLE_CLAUDEAI_MCP_SERVERS

Updated October 13, 2026 by Alex Sorokoletov

ENABLE_CLAUDEAI_MCP_SERVERS is a Claude Code environment variable: Enable Claude.ai-hosted MCP servers. Its release history is not tracked here. It is listed in the official reference.

Status	Present in v2.1.294
Category	MCP
Official docs	Listed

How to set it

For one session, export it in the shell that starts Claude Code:

export ENABLE_CLAUDEAI_MCP_SERVERS=<value>
claude

To apply it to every session, add it to the env object of a settings file:

// ~/.claude/settings.json
{
  "env": {
    "ENABLE_CLAUDEAI_MCP_SERVERS": "<value>"
  }
}

Related variables

CLAUDE_CODE_ENABLE_REFRESH_MCP_TOOLS: Enables an on-demand MCP-tool refresh capability, grouped with CLAUDE_CODE_ENABLE_TASKS and CLAUDE_CODE_ENABLE_REMOTE_RECAP.
ENABLE_MCP_LARGE_OUTPUT_FILES: Enable large output files for MCP.
CLAUDE_CODE_MCP_PREWAIT_SERVERS
CLAUDE_CODE_MCP_PREWAIT_SERVERS_MS
CLAUDE_CODE_SKIP_PLUGIN_MCP_SERVERS
CLAUDE_CODE_SKIP_PLUGIN_MCP_SERVERS_EXCEPT
CLAUDE_CODE_MAX_MCP_DESCRIPTION_LENGTH
CLAUDE_CODE_MCP_ALLOWLIST_ENV: Specifies an allowlist of environment variables that MCP servers can access.

Frequently asked questions

What does ENABLE_CLAUDEAI_MCP_SERVERS do?

Enable Claude.ai-hosted MCP servers

Which Claude Code version has ENABLE_CLAUDEAI_MCP_SERVERS?

Its release history is not tracked here.

How do I set ENABLE_CLAUDEAI_MCP_SERVERS?

Export it before starting Claude Code (export ENABLE_CLAUDEAI_MCP_SERVERS=value), or add it to the "env" object in ~/.claude/settings.json to apply it to every session.

All variables, searchable: Claude Code environment variables.