Sweep 19 Sep 2026 · 02:36Z Build v2.1.278 500 read Stable v2.1.267 Latest v2.1.278 Next v2.1.278 Feeds RSS JSON llms.txt Unofficial

Claude Code now recognizes a CLAUDE_CODE_HOST_SESSION_ID environment variable

TierUse it nowhow much it should matter to you
Useful3my rating, 1 to 5
Signal2worth watching, 1 to 5
AreaEnvironment Variableswhat it touches
KindNew Featuresin v2.1.274,
Use it now Notable No documentation found

Claude Code now recognizes a CLAUDE_CODE_HOST_SESSION_ID environment variable

What

Claude Code now forwards and recognizes a new environment variable, CLAUDE_CODE_HOST_SESSION_ID, alongside existing ones like CLAUDE_CODE_ENTRYPOINT and CLAUDE_CODE_IS_COWORK.

Why

This lets the host environment that launches Claude Code pass through an identifier for the session it is running inside, which other internal logic (such as entry-point-specific gating) can rely on.

Read from
Names in the bundleCLAUDE_CODE_HOST_SESSION_ID
How sure we are
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubtThe finding does not say what consumes this value or what behavior depends on it.
The name it cites is new in this buildNew in this build: CLAUDE_CODE_HOST_SESSION_ID

See this entry in the whole of v2.1.274 →