Claude Discovery

← All discoveries

Close-up of a smartphone wrapped in a chain with a padlock, symbolizing strong security.
Photo by Towfiqu barbhuiya on Pexels
tool

Claude Code 2.1.221 Masks Your Credentials Instead of Just Denying Them

2026-08-05 ยท source:

Claude Code 2.1.221 adds a sandbox credential-masking mode that shows sandboxed commands a sentinel copy of a secrets file while a proxy swaps in the real value on egress, plus a VSCode Focus view that collapses tool activity.

What it is

A Claude Code release that adds a new `mode: "mask"` option for sandboxed credential files on Linux and WSL, alongside a VSCode "Focus view" that hides tool-call noise behind a per-turn summary.

What it does

Instead of just denying access to a credentials file (the old `deny` behavior, which still applies on macOS as a fallback), sandboxed commands can now read a sentinel stand-in for the whole file or specific regex-captured spans, while a proxy substitutes the real secret only on actual network egress. The VSCode Focus view, toggled with `Ctrl+Alt+F`, replaces the running wall of tool calls with an expandable per-turn summary and a live indicator.

Why it matters

This closes a gap between fully denying credential access (which breaks tools that need to read a config file to run) and fully exposing secrets to a sandboxed process, giving commands something that looks like a real credential without letting the value leave the sandbox except through the network proxy that actually needs it. See the full changelog in the v2.1.221 release notes.

How to use it

Update Claude Code, then configure the sandbox credential file setting with `mode: "mask"` and an optional `extract` regex to scope which spans get masked versus passed through as a sentinel; toggle VSCode's Focus view via the command palette or `Ctrl+Alt+F`.

Go to source →
claude-codesandboxsecurityvscode
Related discoveries
Close-up of wooden Scrabble tiles spelling SECURITY, symbolizing cybersecurity and protection.
tool

Was Worktree Isolation Ever Actually Isolated Before 2.1.222?

Claude Code 2.1.222 fixes worktree-isolated sessions and their subagents being able to run destructive git commands against the main checkout, extending isolation to file edits and Bash in every session type.
Retro Apple computers with keyboards displayed in a Tokyo store window, showcasing early tech design.
tool

Claude Code 2.1.219 Makes Claude Opus 5 the Default Opus Model

Claude Code 2.1.219 makes Claude Opus 5 the default Opus model with 1M context and fast mode at $10/$50 per Mtok, and adds a sandbox.network.strictAllowlist setting to silently deny non-allowlisted hosts.
Close-up of a smartphone wrapped in a chain with a padlock, symbolizing strong security.
tool

Claude Code 2.1.214 closes a PowerShell permission bypass

Claude Code 2.1.214 fixes four permission-check bugs, including nested-directory allow rules matching too broadly and a bypass in Windows PowerShell 5.1 sessions.