New file-descriptor-based secret passing for subprocesses

Auth tokens can now be handed to subprocesses over file descriptors instead of plaintext environment variables.

Use it now Notable No documentation found New Features

JSON All of v2.1.257

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5Useful: my rating, 1 to 5

4Signal: worth watching, 1 to 5

AuthArea: what it touches

New FeaturesKind: in v2.1.257, 01 Sep 26

What probably matters to youSection of the release

New environment variables — CLAUDE_CODE_OAUTH_TOKEN_FILE_DESCRIPTOR, CLAUDE_CODE_GATEWAY_TOKEN_FILE_DESCRIPTOR, CLAUDE_CODE_API_KEY_FILE_DESCRIPTOR, and CLAUDE_CODE_WEBSOCKET_AUTH_FILE_DESCRIPTOR — let auth tokens be passed to subprocesses via file descriptor instead of plaintext environment variables. The list of secret env vars scrubbed from subprocess environments was also expanded.

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The name it cites is new in this buildNew in this build: CLAUDE_CODE_GATEWAY_TOKEN_FILE_DESCRIPTOR

The build it came inv2.1.257

1 Sep 2026 · 505 entries, this one is #36.

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Names in this entry

envCLAUDE_CODE_OAUTH_TOKEN_FILE_DESCRIPTOR
Login tokens are warmed at startup, and skipped entirely for token-based auth.
envCLAUDE_CODE_GATEWAY_TOKEN_FILE_DESCRIPTOR
Auth tokens can now be handed to subprocesses over file descriptors instead of plaintext environment variables.
envCLAUDE_CODE_API_KEY_FILE_DESCRIPTOR
Auth tokens can now be handed to subprocesses over file descriptors instead of plaintext environment variables.
envCLAUDE_CODE_WEBSOCKET_AUTH_FILE_DESCRIPTOR
Child worker processes no longer inherit your session id, resume prompt or auth handles.

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