CLAUDE_CODE_STREAM_EVENT_MAX_LINE_BYTES
A Claude Code environment variable, read out of the shipped bundle. It has been in the build since v2.1.314, including the newest one read.
CLAUDE_CODE_STREAM_EVENT_HOLD_MS and CLAUDE_CODE_STREAM_EVENT_MAX_LINE_BYTES are new and are passed through to Claude Code when it is run by a host
Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.314.
In the changelogs
2Releases whose published page names CLAUDE_CODE_STREAM_EVENT_MAX_LINE_BYTES.
-
v2.1.314
Two new environment variables for streamed event output
CLAUDE_CODE_STREAM_EVENT_HOLD_MSandCLAUDE_CODE_STREAM_EVENT_MAX_LINE_BYTESare new and are passed through to Claude Code when it is run by a hostfound in this entry's text
-
v2.1.314
Two settings to batch streamed text updates in stream-json output
New CLAUDE_CODE_STREAM_EVENT_HOLD_MS and CLAUDE_CODE_STREAM_EVENT_MAX_LINE_BYTES let stream-json output hold and join small streamed updates
found in this entry's text
First cited
1The earliest release whose published evidence quoted CLAUDE_CODE_STREAM_EVENT_MAX_LINE_BYTES was v2.1.314, 30 Oct 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
1One 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.