CLAUDE_CODE_MCP_PREWAIT_SERVERS_MS

Updated October 14, 2026 by Alex Sorokoletov

CLAUDE_CODE_MCP_PREWAIT_SERVERS_MS is a Claude Code environment variable. Added in v2.1.286 and still present in v2.1.295. It is not in the official reference.

Status	Present in v2.1.295
Added	Added in v2.1.286
Category	MCP
Official docs	Not listed

How to set it

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

export CLAUDE_CODE_MCP_PREWAIT_SERVERS_MS=<value>
claude

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

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

Related variables

CLAUDE_CODE_MCP_PREWAIT_SERVERS
ENABLE_CLAUDEAI_MCP_SERVERS: Enable Claude.ai-hosted MCP servers.
CLAUDE_CODE_SKIP_PLUGIN_MCP_SERVERS
CLAUDE_CODE_SKIP_PLUGIN_MCP_SERVERS_EXCEPT
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.
CLAUDE_CODE_MAX_MCP_DESCRIPTION_LENGTH
CLAUDE_CODE_MCP_ALLOWLIST_ENV: Specifies an allowlist of environment variables that MCP servers can access.
CLAUDE_CODE_MCP_AUTO_BACKGROUND_MS

Frequently asked questions

Which Claude Code version has CLAUDE_CODE_MCP_PREWAIT_SERVERS_MS?

Added in v2.1.286 and still present in v2.1.295.

How do I set CLAUDE_CODE_MCP_PREWAIT_SERVERS_MS?

Export it before starting Claude Code (export CLAUDE_CODE_MCP_PREWAIT_SERVERS_MS=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.