CLAUDE_CODE_MCP_PREWAIT_SERVERS
A Claude Code environment variable, read out of the shipped bundle. It has been in the build since v2.1.286, including the newest one read.
CLAUDE_CODE_MCP_PREWAIT_SERVERS and CLAUDE_CODE_MCP_PREWAIT_SERVERS_MS name MCP servers for remote worker sessions to wait for before the first turn
Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.286.
In the changelogs
2Releases whose published page names CLAUDE_CODE_MCP_PREWAIT_SERVERS.
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v2.1.286
Remote worker sessions can wait for specific MCP servers before the first turn
CLAUDE_CODE_MCP_PREWAIT_SERVERSandCLAUDE_CODE_MCP_PREWAIT_SERVERS_MSname MCP servers for remote worker sessions to wait for before the first turnfound in this entry's text
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v2.1.286
Two environment variables for waiting on named MCP servers at startup
CLAUDE_CODE_MCP_PREWAIT_SERVERSandCLAUDE_CODE_MCP_PREWAIT_SERVERS_MSappear to let startup wait for particular MCP serversfound in this entry's text
First cited
1The earliest release whose published evidence quoted CLAUDE_CODE_MCP_PREWAIT_SERVERS was v2.1.286, 30 Sep 2026. That is the oldest release this project wrote about it, so it is a floor on the name's age and not the release that introduced it. It is not a presence reading: which builds carried the name is the table below.
Presence across releases
1Build by build
2One row per release since the first build this name was read out of. Absent means the build was read and the name was not in it, never mined means no bundle for that release was ever archived, and a declared type or a default is only ever what that release's own bundle stated.
Read out of the published npm bundle release by release, and out of Anthropic's own documentation as this site captured it. Nothing on this page is a description anybody here wrote about what the environment variable does. All environment variables.