OPEN SOURCE / MCP SECURITY
MCP Drift Check is a free, MIT-licensed zero-execution CLI and GitHub Action that finds package references which can resolve to different code later even when the MCP configuration itself has not changed. v0.2.4 covers npx/npm exec, bunx/bun x, pnpm dlx and yarn dlx.
No MCP server execution. No package downloads. No API token. No signup. No telemetry. It emits visible GitHub pull-request annotations, Markdown and SARIF so the same check can run on every pull request.
EXAMPLE REVIEW SIGNALS
RUN IT IN 10 SECONDS
No account, token or agent connection is required. Run it locally, then keep the same check in CI if the signal is useful.
uvx --from git+https://github.com/tomelias10/mcp-drift-check mcp-drift-check scan-workspace- uses: actions/checkout@v4
- uses: tomelias10/mcp-drift-check@v0What it means
The goal is to make dependency mutability visible before a security team decides whether deeper review is warranted.
No. The check identifies a change and review risk, not proof of malicious code or exploitation.
No. It statically parses local configuration files. It does not run configured servers, download packages or contact package registries.
No. The CLI has no telemetry and does not upload scan data. Private triage is a separate, optional step if you want help interpreting a production finding.
Yes. v0.2.4 ships as a GitHub Action, writes a Markdown job summary, emits visible pull-request annotations in GitHub Checks, and can produce SARIF 2.1.0 for GitHub Code Scanning. HIGH mutable references can fail CI.
A configuration can remain unchanged while a mutable package selector resolves to different package code later. That can make a one-time review go stale without a visible config diff.
PRIVATE TRIAGE
Do not put credentials, private configs or customer data into a public GitHub issue. Tell us the problem and deadline privately; we can help determine whether it warrants a scoped review.