Use GitHub's private reporting form:

Security → Report a vulnerability https://github.com/isnow890/usage-check/security/advisories/new

Do not open a public issue for anything that could expose credentials or network access. If the form is unavailable, open a regular issue that says only that you have a report and would like a private channel.

This is a personal project maintained on a best-effort basis. There is no response SLA. Expect an acknowledgement when the report is read, and then either a fix or an explanation of why the report is out of scope.

Stated plainly, because it decides which reports matter:

• It reads OAuth tokens and billing credentials that already exist on the machine: ~/.codex, ~/.claude.json, the Claude Code login keychain entry, ~/.gemini, the codex-router store, and the OpenCode database.
• It sends derived access tokens to the provider quota APIs they belong to. Nothing is sent to a third party.
• It writes only under ~/.usage-check/ and the launchd log files.

• Any path that reads a credential and sends it somewhere other than the provider it belongs to.
• Any path that writes outside ~/.usage-check/ and the launchd logs, or that modifies a credential store instead of reading it.
• Unauthenticated network exposure beyond what is documented below.
• A dependency doing something the source code does not.

• The default install listens on every interface. next start without -H listens on *:4317, so any device that can route to the machine — including anything else on the same Wi-Fi — opens the dashboard without authenticating. That is the documented default because it is what makes phone access work with no extra setup, and it is a deliberate trade rather than an oversight. Install with --tailscale to bind 127.0.0.1 and publish the dashboard to your tailnet only. The footer reports which of the two is live.
• The OAuth client id and secret in lib/collectors/antigravity.mjs. Those are Antigravity's own public client credentials, shipped inside the desktop app and reproduced by every third-party client that reads its quota. They are not user secrets. See the README.
• The Gemini/Antigravity quota endpoint is undocumented, so it can change or disappear without notice. That is a reliability problem, not a security one.