How-To: Enable additional cache-fix settings in VS Code beyond the extension UI

[cnighswonger]

The VS Code extension only exposes 4 settings in the GUI (Debug, Image Keep Last, Output Efficiency Replacement, Strip Git Status), but the interceptor has many more toggles available as environment variables.

Setting env vars in VS Code

Add to your VS Code settings.json:

{
  "terminal.integrated.env.linux": {
    "CACHE_FIX_DEBUG": "1",
    "CACHE_FIX_STRIP_GIT_STATUS": "1",
    "CACHE_FIX_NORMALIZE_IDENTITY": "1",
    "CACHE_FIX_NORMALIZE_CWD": "1",
    "CACHE_FIX_NORMALIZE_SMOOSH": "1",
    "CACHE_FIX_PREFIXDIFF": "1"
  }
}

Use terminal.integrated.env.osx for Mac, terminal.integrated.env.windows for Windows.

Per-extension skip toggles

Disable individual fixes if they cause issues:

CACHE_FIX_SKIP_RELOCATE=1
CACHE_FIX_SKIP_FINGERPRINT=1
CACHE_FIX_SKIP_TOOL_SORT=1
CACHE_FIX_SKIP_TTL=1
CACHE_FIX_SKIP_SMOOSH_SPLIT=1
CACHE_FIX_SKIP_SESSION_START_NORMALIZE=1
CACHE_FIX_SKIP_CONTINUE_TRAILER_STRIP=1
CACHE_FIX_SKIP_DEFERRED_TOOLS_RESTORE=1
CACHE_FIX_SKIP_REMINDER_STRIP=1
CACHE_FIX_SKIP_CACHE_CONTROL_NORMALIZE=1
CACHE_FIX_SKIP_TOOL_USE_INPUT_NORMALIZE=1
CACHE_FIX_SKIP_CACHE_CONTROL_STICKY=1

Opt-in features

These are OFF by default and must be explicitly enabled:

Env Var	What it does
CACHE_FIX_NORMALIZE_IDENTITY=1	Normalize subagent identity string for cache parity
CACHE_FIX_NORMALIZE_CWD=1	Stabilize CWD paths across worktrees
CACHE_FIX_NORMALIZE_SMOOSH=1	Normalize dynamic system-reminder values
CACHE_FIX_STRIP_GIT_STATUS=1	Strip volatile git-status from system prompt
CACHE_FIX_PREFIXDIFF=1	Save prefix snapshots for cross-session diffing
CACHE_FIX_IMAGE_KEEP_LAST=N	Strip base64 images older than N user turns (0 = disabled)

Important: v2.1.113 compatibility

CC v2.1.113 switched from Node.js to a compiled Bun binary. The --import preload mechanism that the interceptor and VS Code extension depend on no longer works on that version.

Workaround: Pin Claude Code to v2.1.112 or earlier:

npm install -g @anthropic-ai/claude-code@2.1.112

We are building a proxy-based replacement that will work with all CC versions including v2.1.113+. See #40 for the design.