Manifest files

Snyk CLI supports a wide range of different programming languages and package managers for open source dependencies. For a complete list of supported manifest files see here.

The CLI defaults to scanning the first supported manifest file it detects. This means you explicitly need to provide the name of the manifest file to scan using the --file flag when a project has multiple manifests.

Note that the Snyk CLI has multiple commands, but for the purpose of scanning you should only use the test command, while making sure to use the --json flag to have the output converted to a machine readable format you are able to parse: snyk test --file=<manifest file> --json

The test command expects the dependencies to already be installed (i.e after mvn install or npm install have been executed) and for package lock files to be present if relevant. If you try to run the scan before the dependencies are installed you can expect to see an error like this:

~/git/goof $ snyk test
Missing node_modules folder: we can't test without dependencies.
Please run 'npm install' first.

For successful runs, you will see a long json file similar to below. To make sense of the data that is returned please see the Data Mapping section of this guide.

"vulnerabilities": [
"CVSSv3": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"alternativeIds": [],
"creationTime": "2019-10-22T12:22:54.665794Z",
"credit": [
"Roman Burunkov"
"cvssScore": 9.8,
"disclosureTime": "2019-10-18T11:17:09Z",
"exploit": "Not Defined",
"fixedIn": [
"functions": [],
"functions_new": [],
"identifiers": {
"CVE": [],
"CWE": [
"NSP": [
"language": "js",
"modificationTime": "2019-11-20T09:48:38.528931Z",
"moduleName": "express-fileupload",
"packageManager": "npm",
"packageName": "express-fileupload",
"patches": [],
"publicationTime": "2019-10-22T15:08:40Z",
"references": [
"title": "GitHub PR",
"url": ""

All paying Snyk customers have license scanning feature included in their plan. The snyk test command will return both vulnerability and license violations in the test results. To distinguish a license violation look for: "type": "license" inside the record fields.

When to rerun scans

To make sure you are presenting to a the user up to date scan results you need to rerun the snyk scan anytime one of the following happens:

  • Any of the manifest files have been edited.

  • A day has passed since the last scan. This is needed as the vulnerability database powering the Snyk CLI constantly collects new vulnerabilities which are relevant for the user to see even if they have not edited the manifest file.

  • Any time the user explicitly reinstalls the dependencies (i.e calls mvn install) as semvers have flexibility in them and a reinstall may fetch different dependency versions than was previously installed even without a manifest file change.