valvur

io.github.MaverickHQPublished by GitHub account MaverickHQv1.6.1Updated Nov 1, 2026

Offline security scanning for AI-generated code: seven open-source scanners in one MCP server.

Overview

AI-generated overview

Runs offline security scans of a project with seven bundled open-source scanners and returns ranked, exploit-aware findings to an AI assistant.

What you can do
  • Run, monitor and cancel a security scan of the project, with progress and a status of findings, clean or inconclusive
  • Read the last scan's findings, filtered by group, rule, path or status, or one finding in full by fingerprint
  • Check whether a package exists, is a near-miss of a popular name, was published as malicious, or is exposed to dependency confusion
  • Fetch the scanner image, vulnerability database, KEV catalog and package-name index into the local cache
  • Diagnose the machine's readiness to scan, including container runtime, data freshness and MCP client configuration
When to use it
Useful when an assistant writes or reviews code in a repository and you want secrets, vulnerable or hallucinated dependencies, misconfigurations and risky agent configuration checked before committing or adding dependencies. Suited to teams that want scanning results to stay on the local machine.
Requirements
Runs locally over stdio, launched with uvx from the valvur PyPI package. A container runtime (Docker or Podman) is needed for the scanners; Linux, macOS and WSL2 are supported, native Windows is not claimed. No account, API key or environment variable is declared. The first scan fetches public data into a local cache, so network access is needed for that.
Before you install
A scan writes a results folder into the scanned project, including findings and remediation files; the server instructs that it must never be committed. The server asks assistants not to add suppressions or flagged dependencies without asking the human, and notes that a disappearing finding is not proof of a fix. The full profile can send lockfile package names and versions to OSV.dev. Reported precision on maintained code is low, so expect false positives.

Installation

In SourceWeft

  1. Open valvur in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.

Other MCP clients

Follow the launch instructions in the repository.

README

[valvur]

Offline security scanning for AI-generated code.
Seven open-source scanners and AI-specific checks, in one command and one ranked report.

[PyPI] [Python 3.11+] [CI] [OpenSSF Scorecard] [Licence: Apache-2.0]
Scorecard's Code-Review, Branch-Protection and Contributors checks need a second maintainer; valvur has one (MAINTAINERS.md).

Status: 1.6.1, the version this tree declares; the PyPI badge above shows what pip install valvur serves, and the CHANGELOG what each version changed.

In Claude Code: /plugin marketplace add MaverickHQ/valvur, then /plugin install valvur@valvur, and ask it to scan the project.
From a terminal, with Docker or Podman running: uvx valvur scan.

[valvur scans a project whose lockfile pins a package published as malicious, and lists the findings]

Why valvur

  • Seven scanners, one report. Gitleaks, Trivy, OSV-Scanner, Opengrep, Checkov, zizmor and Syft, pinned, installed and run for you in one container, beside valvur's own checks for AI-written code. A vulnerability two of them report is one finding, not two, and everything is ranked together.
  • Nothing leaves your machine, provably. No account, no API key, no telemetry. The Scanners run in one container with no network interface, and your source is copied in, never mounted. Every fetch of public data is recorded in run.json, beside what left the machine: nothing. One command checks it.
  • Built for how AI-generated code breaks. Models invent package names that attackers then register; agent instruction files carry injected directives and hidden Unicode; agent settings leak tokens. valvur checks for each, offline, beside the classic secrets, vulnerable dependencies and misconfigurations.
  • Ten findings that matter, not four hundred. Findings are ranked by whether attackers are exploiting them, from CISA KEV and FIRST EPSS rather than CVSS alone, grouped by rule and directory, with development-only dependencies demoted.
  • You stay in charge. valvur proposes fixes and never applies them. An agent told to reach zero findings can delete code or write suppressions instead, and the finding disappeared is not the vulnerability is fixed.

What it finds

areawhat valvur reportsfound by
Hallucinated packagesdependencies that do not exist, or sit one edit from a popular name, checked offline against every name on PyPI, npm, RubyGems, Packagist and crates.iovalvur's dependency-reality Check
Malicious packagesdependencies published as malicious, from OpenSSF's malicious-packagesOSV-Scanner, and the same Check
Agent configurationinjected directives, hidden Unicode, unpinned MCP servers, blanket approval, hooks that run a command, settings that would leakvalvur's ai-artifact Check
Vulnerable dependenciesknown CVEs from lockfiles, ranked by exploitation, with the direct package to bumpTrivy, OSV-Scanner
Secretscredentials in the files and in git historyGitleaks
Codeinjection, path traversal, SSRF, open redirects, XXE and insecure cookies, and model output reaching eval, a shell, a query or the DOMOpengrep, with valvur's rules
InfrastructureTerraform, CloudFormation, Kubernetes and Dockerfile misconfigurationCheckov
CI workflowsunpinned actions, write permissions, template injectionzizmor
Licences and SBOMa missing or contradictory project licence; a CycloneDX SBOM when asked forvalvur's licence-file Check, Syft

What it checks, rule by rule, and what it cannot see: how valvur works.

How it works

  1. A small host shim decides what a scan reads (the files git would publish, plus .env* files and agent configuration), fetches the public data it needs, and records each fetch.
  2. One Scan Container, with no network interface, runs every Scanner over a copy of those files fed on stdin. Nothing in it can change your source.
  3. One findings model normalises and ranks what they report, and the shim writes the Results Folder into your project:
.security-scan/          ← ignores itself in git, so it is never committed├── SUMMARY.md           ← start here: the verdict, anything that failed, the top groups├── REMEDIATION.md       ← a ranked proposal: you choose what to apply├── findings.json        ← every finding, normalised, secrets redacted├── results.sarif        ← SARIF 2.1.0, for code scanning and IDEs└── run.json             ← what ran, what was fetched, and what left the machine: nothing

A scan ends findings, clean or inconclusive. It never says clean when stale data, an uninspected ecosystem or a Scanner that did not finish cannot support it, and it says why.

Measured, not claimed

How much of what valvur claims it finds is measured as the Score: nine tracks scored by the OWASP Benchmark's formula, with a ratchet that no change may fall more than two points under. It is 74.1 out of 100, the same on Linux and on macOS.

trackwhat it holdsscore
sast-pythonthe OWASP Benchmark for Python40.9
sast-jsvalvur's JavaScript twins: ten weaknesses, vulnerable and fixed55.0
secretsten formats, in files and in history100.0
dependencieslockfiles pinned to vulnerable versions; known-malicious packages100.0
package-realitynonexistent, near-miss and malicious names100.0
agent-configurationplanted directives and hidden Unicode, against real files94.3
infrastructureTerraform, Kubernetes, Dockerfile and Actions faults95.0
real-code-precision48 maintained projects, every finding labelled by hand2.3
llm-outputmodel output reaching code, a shell, a query or the DOM: generated twins and five published advisories79.0

Track 8 is precision on maintained code, where almost nothing is a vulnerability: 3 of its 171 findings are real. Track 9 measures the rules for model output reaching a sink: they catch 30 of 34 generated flows with no false alarm, and none of five published advisories in LangChain, LlamaIndex and Vanna, whose flows each cross a function. Each rule's precision is in docs/RULES.md, and the method, the gates and what valvur does not claim are in docs/EVALUATING.md. Read that one sceptically.

Use it

In an AI coding agent

The Claude Code plugin brings the MCP server, a skill that runs the workflow, and a hook that asks you before the agent installs a package valvur flags. Kiro takes it as a power. Any MCP client runs the server with uvx --from valvur valvur-mcp. The agents' guide has the configuration for eleven clients, the seven tools, and the permissions a don't ask mode needs.

From the command line

The Scanners run in a container, so the machine needs Docker or Podman; valvur doctor says what is missing.

bash
pip install valvur          # or: uv tool install valvurvalvur scan                 # offline by default; --profile full adds the registries' answersvalvur check npm left-pad   # before an install: real, a near-miss, or malicious?valvur gate . --fail-on high --no-inconclusive

The command-line guide has every command, what a first scan fetches, the Results Folder, and the settings files.

In CI

yaml
- uses: MaverickHQ/valvur-action@16b19e275f843419887873ed536a71f872607e24 # v0.2  with: { fail-on: high, no-inconclusive: "true" }

The action scans, uploads results.sarif to code scanning and gates the job. The CI guide covers the gate, the image as a step of its own, and GitLab.

Built on open-source scanners

valvur builds no detection engine. Seven open-source Scanners do that and deserve the credit; valvur adds one File Set, one findings model, exploit-aware ranking, and three Checks of its own. All of them run in one container, fed a copy of the files. run.json records the version of each that ran, and raw/ keeps what each said.

ScannerLicenceReadsRuns
GitleaksMITSecrets in the files scanned and in git history, the newest 5,000 commits or 200 MBalways
TrivyApache-2.0Known vulnerabilities in dependencies, from lockfiles, against its database in the host cachealways
OSV-ScannerApache-2.0Lockfiles against OSV's data, which carries the known-malicious MAL- packages nothing else here reports. On offline, OSV's offline database for each ecosystem present, fetched into the host cache; on full, OSV.dev's API, which receives lockfile names and versionsalways
OpengrepLGPL-2.1Static analysis: pinning rules, a sink inventory at INFO, taint rules from a model call to a sink, and taint rules from request dataalways
CheckovApache-2.0Infrastructure misconfiguration: Terraform, CloudFormation, Kubernetes, Dockerfiles, other CI systemswhere there is infrastructure other than GitHub workflows
zizmorMITGitHub Actions workflows: unpinned actions, write permissions, template injectionwhere there are workflows
SyftApache-2.0The SBOM, and the dependency licences read from itwhen asked for: scan --sbom, or sbom = true under [scan]
CheckReads
ai-artifactAgent configuration: injected directives, hidden Unicode, unpinned MCP servers, blanket approval, hooks that run a command, and local settings that would leak
dependency-realityEvery declared dependency against the Name Index: does it exist, and on full, how old and how adopted is it. Every declared or locked one against the known-malicious list, built daily from OpenSSF's malicious-packages
licence-fileThe project's own licence: missing, or contradicting what the manifest declares

Exploit intelligence comes from CISA KEV and FIRST EPSS: public primary sources, auditable and mirrorable. No proprietary database, and nothing to lock you in.

What it does not do

  • No reachability analysis. We do not prove a vulnerable function is called.
  • No autonomous fixing. You choose the fixes.
  • No penetration testing. No DAST, no exploitation, no scanning of deployed systems.
  • No code-quality analysis. Security only.
  • We will not out-detect commercial SAST. We win on trust, breadth in one artifact, and prioritisation, not on engine depth.

Platforms

platformsupport
Linux, Docker and PodmanSupported. Every commit runs the e2e suite against Docker and Podman on amd64, and against Docker on arm64, and a scan with the published image on both; the acceptance set runs nightly on GitHub's Linux runner
macOS, Docker Desktop or PodmanSupported, and tested by hand on an Apple-silicon Mac through Docker Desktop at every phase's exit: the acceptance set and the e2e suite against the image built from that commit (docs/acceptance/). Not on every commit: a container runtime needs nested virtualisation, which GitHub's macOS runners do not offer
linux/amd64 and linux/arm64Both: one image index, signed, with an SBOM for each
Windows via WSL2Supported: inside WSL valvur is running on Linux
Native WindowsNot claimed. Untested, and valvur says so at startup
SELinux-enforcing hosts (RHEL, Fedora)Supported. Your source is copied into the scan and never mounted, so its SELinux label does not matter; valvur labels its own cache mounts

Air-gapped? The database, the Name Index and its malicious list, KEV, EPSS and OSV's databases all live outside the image, and each has a mirror setting. See docs/AIR-GAPPED.md.

Privacy

valvur collects nothing: no account, no API key, no telemetry, and no part of it reports on you or your code. The results stay in .security-scan/, which ignores itself in git. What the host fetches is public data, each fetch recorded in run.json. python3 scripts/verify-offline.py checks it, and on Linux unshare -rn valvur scan proves it (how).

Documentation

guidefor
How it worksthe offline proof, every check, and the ranking
AI coding agentsthe plugin, the power, eleven MCP clients and the seven tools
Command linethe commands, the Results Folder and the settings
CIthe gate, the GitHub Action and the image in a pipeline
Evaluating valvurthe audit: the Score, the gates and the limits
Ruleseach static-analysis rule's measured precision
Air-gapped usemirrors for every data source
Every documentthe protocol, the decisions, releasing and the records

Community and support

  • Questions and ideas: Discussions.
  • Bugs, and findings valvur missed: https://github.com/MaverickHQ/valvur/issues, with the tarball valvur doctor --bundle writes: versions and the last run.json, never your source, raw output or findings.
  • Security: a suspected vulnerability in valvur, a false clean included, goes privately by SECURITY.md.
  • Contributing: CONTRIBUTING.md has the setup and the short list of what is refused on principle. MAINTAINERS.md says who maintains valvur, one person today, and what you can rely on. There is no paid tier and no support contract.

Licence

Apache-2.0, see LICENSE; chosen over MIT for the explicit patent grant. Bundled Scanners keep their own licences, listed above and in NOTICE. valvur adds no GPL or AGPL component; the Alpine base carries GPL userland as every Linux container does, and the published SBOM discloses all of it (ADR-0005).

Source: README.md at commit 0213001

Tools

7

scan

Run a security scan of a project and return the result, with progress on the way; calling it while a scan runs here attaches to that scan. Writes results into .security-scan/ and never modifies your source.

Parametersfreshprofilebudget_sworkspace

findings

The last scan's findings, worst first and bounded: filter by `group`, `rule`, `path` or `status`, or give a `fingerprint` for that finding in full, with its evidence, exploitation, dependency path and the Scanners that reported it.

Parameterspathrulegrouplimitstatusinventoryworkspacefingerprintinclude_suppressed

scan_status

What the last scan actually did: which scanners ran, which failed, and whether the result is complete.

Parametersworkspace

scan_cancel

Stop a running scan: its containers are killed, nothing is written, and the previous results (if any) stand. What Ctrl-C does on the command line.

Parametersworkspace

update

Fetch what a scan reads, now: the image if absent, the vulnerability database, the CISA KEV catalog and the package-name index, into this machine's cache; progress on the way, and the answer is what was fetched. Public data comes in; nothing of any workspace leaves.

Parametersif_stale

doctor

Check that this machine can scan, before scanning: the container runtime, the image, the vulnerability database, the package-name index, SELinux, TLS trust, and which MCP client configuration names valvur. One line per check with the fix on any that would fail a scan. Changes nothing but the containers of scans whose process ended, which it removes.

Parametersnetworkworkspace

check_package

Before adding a dependency: whether each package exists on its registry, is one edit from a far more popular one, was published as malicious, or is exposed to dependency confusion by this project's registry configuration. Answered from this machine's cache; no registry is asked, because asking about a hallucinated name tells whoever watches what to register. Never add a flagged package, or a replacement for it, without asking the human.

Parameterspackagesrequiredworkspace

Version history

2
  1. v1.6.1LatestNov 1, 2026
  2. v1.6.0Oct 29, 2026

Score

90% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 days25 pts
  • Auth declared10 pts

    Declare the credential headers in the registry entry, or keep the endpoint answering the probe so its auth can be classified.

  • Tools listedRequired15 pts
  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts
  • License10 pts