Claude Code Billing Guard 0.1
Watches whether Claude Code is billing your Pro/Max subscription or your
pay-per-token API key, and warns you the instant it switches. Free, local,
no telemetry, no network calls.
Install
In VS Code: Extensions view → search "Claude Code Billing Guard" → Install.
Or from the Marketplace directly: https://marketplace.visualstudio.com/items?itemName=ayauho.claude-code-billing-guard
Why this exists
Claude Code can silently and sometimes irreversibly switch from subscription
billing to API billing — documented across multiple long-open GitHub issues
on anthropics/claude-code (#62770, #44669, #34486, #40660, #2944, #27990,
#43260). The existing usage-tracker extensions answer "how much have I
spent" — none of them answer "am I even in the billing mode I think I'm in."
This does.
Honest limitations — read before relying on this
- The credential-file detection is a best guess. It was built from a
research document's reference to a
credentials/default.json file, not
from confirmed access to every Claude Code version's actual on-disk
schema. If status shows "Unknown" instead of a clear verdict, that's the
tool correctly refusing to guess rather than a bug. Open the file at the
path in claudeCodeBillingGuard.credentialPath (VS Code settings) yourself, check its
real field names, and set the override if needed.
- The environment-variable signal is the reliable one. If
ANTHROPIC_API_KEY or ANTHROPIC_AUTH_TOKEN is set anywhere in the
environment your terminal/VS Code session inherits, this tool will catch
it. That's the documented trigger behind every issue cited above.
- "Restore subscription mode" does not auto-run anything. It opens a
plain read-only document with suggested next steps, for you to review and
copy into a terminal yourself if you want to. It deliberately doesn't type
anything into a live shell — even harmless comment lines get recorded in
shell history, which isn't a footprint this tool should leave. Exact CLI
syntax can change between versions; this tool isn't going to guess and
execute on your behalf.
Building from source (for development)
Most people don't need this — use Install above instead. This is only for
modifying the code yourself.
cd claude-code-billing-guard
npm install -g @vscode/vsce # one-time, if you don't have it
Then either:
- Quick test: open this folder in VS Code, press
F5 to launch an
Extension Development Host window. It will activate there.
- Install as a real extension:
vsce package to produce
claude-code-billing-guard-0.1.0.vsix, then in VS Code: Extensions view →
... menu → "Install from VSIX...".
Settings
| Setting |
Default |
What it does |
claudeCodeBillingGuard.credentialPath |
"" (auto-detect) |
Override the path to Claude Code's local credential file if auto-detection doesn't find it on your machine. |
claudeCodeBillingGuard.pollIntervalMs |
15000 |
How often to re-check, in milliseconds. |
What this is not
Not a usage or cost dashboard — that space already has solid free tools.
Not a replacement for Anthropic's own auth system. Not connected to any
server. If you want team-wide alerts when a teammate's seat drifts onto
metered billing, that's a 1.0 idea, gated on whether 0.1 actually gets used
by the people who already filed these bugs.
