Credentials handled differently for child processes when…

Credentials handled differently for child processes when ANTHROPIC_UNIX_SOCKET is set

With ANTHROPIC_UNIX_SOCKET set, placeholder credentials are recognized and auth tokens are no longer passed to child processes

Group of 3 You'll notice Internal Changes

JSON All of v2.1.309

You'll noticeTier: how much it should matter to you

3Useful: my rating, 1 to 5

3Signal: worth watching, 1 to 5

AuthArea: what it touches

Internal ChangesKind: in v2.1.309, 22 Oct 26

What probably matters to youSection of the release

Unclear It is not clear whether more or fewer secrets are now passed to programs Claude Code starts.

What

ANTHROPIC_UNIX_SOCKET is an environment variable (a named value set before starting a program) that sends Claude Code's API traffic through a local socket, for example in a sandboxed or proxied setup. When it is set, Claude Code changes how it handles credentials for the programs it starts (child processes):

A new check treats CLAUDE_CODE_OAUTH_TOKEN or ANTHROPIC_API_KEY as a placeholder value, not a real secret.
The code that gives ANTHROPIC_AUTH_TOKEN or ANTHROPIC_API_KEY to a child process now gives it nothing in this case.
The list of values removed from a child process's environment now uses this new check instead of the old inline comparison against a placeholder, and draws on one more source list (including CLAUDE_CODE_SUBSCRIPTION_TYPE).

Why

If you run Claude Code behind a socket that substitutes credentials, programs it starts no longer receive those auth tokens from it. Anything that depended on finding ANTHROPIC_AUTH_TOKEN or ANTHROPIC_API_KEY there may need another way to get them.

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 doubtIt is not clear whether more or fewer secrets are now passed to programs Claude Code starts.

See this entry in the whole of v2.1.309 →

The build it came inv2.1.309

22 Oct 2026 · 281 entries, this one is #12.

Use it now14
You'll notice167
Nothing to try yet16
Under the hood84

Either side of it

v2.1.308Older

Open the release →

Names in this entry

envANTHROPIC_UNIX_SOCKET
Environment variables your org policy blocks can no longer sneak through by changing their capitalization.
envCLAUDE_CODE_OAUTH_TOKEN
Three artifact environment variables are now recognised, with the API token stripped from spawned processes as a secret.
envANTHROPIC_API_KEY
API key sent as X-Api-Key header. When set, this key is used instead of your Claude Pro, Max, Team, or Enterprise subscription even if you are logged in. In non-interactive mode (-p), the key is always used when present. In interactive mode, you are prompted to approve the key once before it overrides your subscription. To use your subscription instead, run unset ANTHROPIC_API_KEY
envANTHROPIC_AUTH_TOKEN
Custom value for the Authorization header (the value you set here will be prefixed with Bearer )
envCLAUDE_CODE_SUBSCRIPTION_TYPE
Subscription type attached to OAuth credentials supplied from outside: when the token comes from CLAUDE_CODE_OAUTH_TOKEN, CLAUDE_CODE_OAUTH_TOKEN_FILE_DESCRIPTOR or another externally supplied token, the credentials carry this value as subscriptionType, or null when it is unset or empty. Claude Code sets it itself when a background session consumes an auth snapshot and when it hands a token to a child process it launches, and removes it from the environment it passes to subprocesses.

Is this right?