MCP_CONNECT_TIMEOUT_MS
A Claude Code environment variable, read out of the shipped bundle. It has been in the build since v2.1.138, including the newest one read.
What it is
Very large MCP_TIMEOUT values are capped instead of overflowing and timing out instantly.
Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.227.
Presence across releases
| Releases | Reading | Declared type | Default |
|---|---|---|---|
| 2.1.245 – 2.1.250 5 releases | never mined | — | — |
| 2.1.160 – 2.1.243 75 releases | in the build | int | — |
| 2.1.138 – 2.1.159 20 releases | in the build | — | — |
A row reading never mined is a release with no archived bundle behind it. Nothing was read out of it, so nothing here says whether the name was in it. A declared type or a default is only ever what that release's own bundle stated.
Changelog entries naming it
-
v2.1.227Huge MCP timeout values no longer fire instantly
Very large MCP_TIMEOUT values are capped instead of overflowing and timing out instantly.
named in this entry
Documentation pages
- Connect to external tools with MCP mentions it Claude Code CLI
A reference table page is one whose own table defines this name, and it is where the description above came from. A page that mentions it carries the name somewhere in its text and may say nothing about it at all. Every page carrying it.
Names beside it
Every environment variable in the inventory starting mcp_connect, up to twelve of them.
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.