Snyk Language Server (Snyk-LS)

Supported features

The language server follows

the Language Server Protocol

and integrates with Snyk Open Source, Snyk Infrastructure as Code, Snyk Code, and Snyk Secrets. For Open Source and IaC it uses the Snyk

CLI as a data provider; Snyk Code uses the Snyk Code API; Secrets scanning uses the CLI where applicable.

Right now the language server supports the following actions:

• Send diagnostics to client on opening a document if it's part of the current set of folders.
• Starting a folder scan on startup and sending diagnostics.
• Starting a workspace scan of all folders on command.
• Cache diagnostics until saving or triggering a new workspace scan.
• Invalidate caches on saving a document and retrieve saved document diagnostics anew.
• Provides range calculation to correctly highlight Snyk Open Source issues in their file.
• Provides formatted hovers with diagnostic details and follow-up links
• Progress reporting to the client for background jobs
• Notifications & Log messages to the client
• Authentication when needed, using OAuth2 or Token authentication and opening a webpage if necessary
• Copying the authentication URL to clipboard if there are problems opening a webpage
• Automatic download of the Snyk CLI if none is found or configured to XDG_DATA_HOME
• Selective activation of products according to settings transmitted
• Scanning errors are reported as diagnostics to the Language Server Client
• Code Lenses to navigate the Snyk Code dataflow from within the editor
• Code Actions for in-editor commands, like opening a browser, doing a quickfix or opening a Snyk Learn lesson

for the found diagnostic

Implemented operations

Language Server Protocol support

Requests

• initialize
• exit
• textDocument/codeAction
• textDocument/codeLens
• textDocument/didClose
• textDocument/didSave
• textDocument/hover
• textDocument/inlineValue
• shutdown
• workspace/didChangeWorkspaceFolders
• workspace/didChangeConfiguration
• workspace/executeCommand
• window/workDoneProgress/create (from server -> client)
• window/showMessageRequest
• window/showDocument

Notifications

• $/progress
• $/cancelRequest
• textDocument/publishDiagnostics
  • params: `types.PublishDiagnosticsParams`
  • example: Snyk Open Source

{
    "uri": "file:///path/to/file",
    "diagnostics": [
      {
        "range": {
          "start": { "line": 1, "character": 0 },
          "end": { "line": 2, "character": 0 },
        },
        "severity": 1,
        "code": "S100",
        "source": "Snyk",
        "message": "Message",
        "tags": ["security"],
        "data": {
          "id": "123",
          "issueType": "vulnerability",
          "packageName": "packageName",
          "packageVersion": "packageVersion",
          "issue": "issue",
          "additionalData": {
            "ruleId": "ruleId",
            "identifiers": {
              "cwe": ["cwe"],
              "cve": ["cve"]
            },
            "description": "description",
            "language": "language",
            "packageManager": "packageManager",
            "packageName": "packageName"
          }
        }
      }
    ]
  }

{
    "uri": "file:///path/to/file",
    "diagnostics": [
      {
        "range": {
          "start": { "line": 1, "character": 0 },
          "end": { "line": 2, "character": 0 },
        },
        "severity": 1,
        "code": "S100",
        "source": "Snyk",
        "message": "Message",
        "tags": ["security"],
        "data": {
          "id": "123",
          "filePath": "filePath",
          "range": {
            "start": { "line": 1, "character": 0 },
            "end": { "line": 2, "character": 0 },
          },
          "additionalData": {
            "message": "message",
            "rule": "rule",
            "ruleId": "ruleId",
            "dataFlow": [
              {
                "filePath": "filePath",
                "range": {
                  "start": { "line": 1, "character": 0 },
                  "end": { "line": 2, "character": 0 },
                },
              }
            ],
            "cwe": "cwe",
            "isSecurityType": true
          }
        }
      }
    ]
  }

• window/logMessage
• window/showMessage

Custom additions to Language Server Protocol (server -> client)

• SDKs callback to retrieve configured SDKs from the client
  • method: `workspace/snyk.sdks`
  • params: `types.WorkspaceFolder`
  • example:

[{
    "type": "java", // or python or go
    "path": "/path/to/sdk" // JAVA_HOME for java, GOROOT for Go, Python executable for Python
  }]

• Configuration Notification (protocol v25+)
  • method: `$/snyk.configuration`
  • params: `types.LspConfigurationParam`
  • note: unified map-based protocol — global settings + per-folder settings, each carrying value, source, origin, and lock status
  • example:

{
      "settings": {
          "api_endpoint": { "value": "https://api.snyk.io", "source": "global" },
          "snyk_oss_enabled": { "value": true, "source": "ldx-sync", "originScope": "organization" },
          "proxy_http": { "value": "http://proxy:8080", "source": "ldx-sync-locked", "originScope": "tenant", "isLocked": true }
      },
      "folderConfigs": [
        {
          "folderPath": "/path/to/project",
          "settings": {
              "base_branch": { "value": "main", "source": "folder" },
              "preferred_org": { "value": "org-id", "source": "folder" },
              "snyk_code_enabled": { "value": false, "source": "ldx-sync-locked", "originScope": "group", "isLocked": true },
              "severity_filter_critical": { "value": true, "source": "ldx-sync", "originScope": "organization" },
              "severity_filter_high": { "value": true, "source": "ldx-sync", "originScope": "organization" },
              "severity_filter_medium": { "value": false, "source": "ldx-sync", "originScope": "organization" },
              "severity_filter_low": { "value": false, "source": "ldx-sync", "originScope": "organization" }
          }
        }
      ]
  }

• Custom Publish Diagnostics Notification
  • method: `$/snyk.publishDiagnostics316`
  • params: `types.PublishDiagnosticsParams`
  • note: alias for textDocument/publishDiagnostics

• Authentication Notification
  • method: `$/snyk.hasAuthenticated`
  • params: `types.AuthenticationParams`
  • example:

{
    "token": "the snyk token", // this can be an oauth2.Token string or a legacy token
    "apiUrl": "https://api.snyk.io"
  }

• CLI Path Notification
  • method: `$/snyk.isAvailableCli`
  • params: `types.SnykIsAvailableCli`
  • example:

{
    "cliPath": "/a/path/to/cli-executable"
  }

• Trusted Folder Notification
  • method: `$/snyk.addTrustedFolders`
  • params: `types.SnykTrustedFoldersParams`
  • example:

{
    "trustedFolders": ["/a/path/to/trust"]
  }

• Scan Notification
  • method: `$/snyk.scan`
  • params: `types.ScanParams`
  • example: Successful scan

{
    "status": "success", // possible values: "error", "inProgress", "success"
    "product": "code", // possible values: "code", "oss", "iac", "secrets"
    "folderPath": "/a/path/to/folder",
  }

{
    "status": "error",
    "product": "code",
    "folderPath": "/a/path/to/folder",
    "presentableError": {
      "cliError": {
        "code": "CLI_ERROR_CODE",
        "error": "An error occurred"
      },
      "showNotification": true,
      "treeNodeSuffixError": "(failed)"
    }
  }

• Summary Panel Status Notification
  • method: `$/snyk.scanSummary`
  • params: `types.ScanSummary`
  • example:

{
    "scanSummary": " Summary "
  }

• Register MCP Notification
  • method: `$/snyk.registerMcp`
  • params: `types.SnykRegisterMcpParams`
  • example:

{
      "command": "/path/to/cli",
      "args": [ "mcp", "-t", "stdio" ],
      "env": {
        "ENV1": "value1",
        "ENV2": "value2"
      }
    }

Commands

• `NavigateToRangeCommand` navigates the client to the given range
  • command: `snyk.navigateToRange`
  • args: `path`, `Range`
• `WorkspaceScanCommand` triggers a scan of all workspace folders
  • command: `snyk.workspace.scan`
  • args: empty
• `WorkspaceFolderScanCommand` triggers a scan of the given workspace folder
  • command: `snyk.workspaceFolder.scan`
  • args: `path`
• `OpenBrowserCommand` opens the given URL in the default browser
  • command: `snyk.openBrowser`
  • args: `URL`
• `LoginCommand` triggers the login process
  • command: `snyk.login`
  • args: optional `[authMethod, endpoint, insecure]` — e.g. `["oauth", "https://api.snyk.io", false]` (see configuration HTML bridge); omitted args use current settings
• `CopyAuthLinkCommand` copies the authentication URL to the clipboard
  • command: `snyk.copyAuthLink`
  • args: empty
• `LogoutCommand` triggers the logout process
  • command: `snyk.logout`
  • args: empty
• `TrustWorkspaceFoldersCommand` checks for trusted workspace folders and asks for trust if necessary
  • command: `snyk.trustWorkspaceFolders`
  • args: empty
• `OpenLearnLesson` opens the given lesson on the Snyk Learn website
  • command: `snyk.openLearnLesson`
  • args:
    • `rule string`
    • `ecosystem string`
    • `cwes string` (comma separated), e.g. `CWE-79,CWE-89`
    • `cves string` (comma separated), e.g. `CVE-2018-11776,CVE-2018-11784`
    • `issueType int`

PackageHealth Type = 0
    CodeSecurityVulnerability = 1
    LicenceIssue = 2
    DependencyVulnerability = 3
    InfrastructureIssue = 4

• `GetLearnSession` returns the given lesson on the Snyk Learn website
  • command: `snyk.getLearnLesson`
  • args:
    • `rule string`
    • `ecosystem string`
    • `cwes string` (comma separated), e.g. `CWE-79,CWE-89`
    • `cves string` (comma separated), e.g. `CVE-2018-11776,CVE-2018-11784`
    • `issueType int`

PackageHealth Type = 0
    CodeSecurityVulnerability = 1
    LicenceIssue = 2
    DependencyVulnerability = 3
    InfrastructureIssue = 4

{
  "lessonId": "123",
  "datePublished": "2022-01-01",
  "author": "John Doe",
  "title": "Introduction to Golang",
  "subtitle": "A beginner's guide to Golang",
  "seoKeywords": ["Golang", "Programming", "Beginner"],
  "seoTitle": "Learn Golang",
  "cves": ["CVE-2022-1234", "CVE-2022-5678"],
  "cwes": ["CWE-123", "CWE-456"],
  "description": "This lesson provides an introduction to Golang for beginners",
  "ecosystem": "Programming",
  "rules": ["Rule 1", "Rule 2", "Rule 3"],
  "slug": "golang-intro",
  "published": true,
  "url": "https://example.com/golang-intro",
  "source": "Example.com",
  "img": "https://example.com/images/golang-intro.png"
  }

• `SettingsSastEnabled` triggers the api call to check if Snyk Code is enabled
  • command: `snyk.getSettingsSastEnabled`
  • args: empty
  • returns a `*sast_contract.SastResponse` or, or an error and false if an error occurred
• `GetActiveUser` triggers the api call to get the active logged in user or an error if not logged in
  • command: `snyk.getActiveUser`
  • args: empty
  • returns the active user and its orgs and groups or an error if not logged in.

{
    "id": "123",
    "username": "johndoe",
    "orgs": [
     {
       "name": "org1",
       "id": "org1_id",
       "group": {
          "name": "group1",
          "id": "group1_id"
       }
     }
    ],
  }

• `Code Fix Command` triggers an autofix and applies the changes of the first suggestion
  • command: `snyk.code.fix`
  • args:
    • `codeActionId` string
    • `AffectedFilePath` string
    • `range` Range
  • returns an error if not successful

• `Code Fix Diffs` allows to retrieve the diffs for autofix suggestions
  • command: `snyk.code.fixDiffs`
  • args:
    • issueID string (UUID)
  • returns an array of suggestions:

[{
    "fixId": "123",
    "unifiedDiffsPerFile": {
      "path/to/file": "diff"
    }
  }]

--- /var/folders/vn/77lwfy3974g7vykcm5lr6mkh0000gn/T/Test_SmokeWorkspaceScanOssAndCode952013010/001/1
  +++ /var/folders/vn/77lwfy3974g7vykcm5lr6mkh0000gn/T/Test_SmokeWorkspaceScanOssAndCode952013010/001/1-fixed
  @@ -32,7 +32,8 @@

       test('should set success to OK upon success', function() {
         // GIVEN

  -      comp.password = comp.confirmPassword = 'myPassword';

  +      comp.password = process.env.TEST_PASSWORD;
  +      comp.confirmPassword = process.env.TEST_PASSWORD;

         // WHEN
         comp.changePassword();

• `Code Fix Apply Edit Command` triggers an autofix and applies the changes of the first suggestion
  • command: `snyk.code.fixApplyEdit`
  • args:
    • `fixId` string
  • returns an WorkspaceEdit:

• `Feature Flag Status Command` triggers the api call to check if a feature flag is enabled
  • command: `snyk.getFeatureFlagStatus`
  • args:
    • `featureFlagType` string
  • returns an object with the status of the feature flag and an optional user message

{
      "ok": true, // boolean indicating if the feature is enabled (true or false)
      "userMessage": "Optional message to the user" // present if 'ok' is false
    }

• `Clear Cache` Clears either persisted or inMemory Cache or both.
  • command: `snyk.clearCache`
  • args:
    • `folderUri` string,
    • `cacheType` `persisted` or `inMemory`
• `Generate Issue Description` Generates issue description in HTML.
  • command: `snyk.generateIssueDescription`
  • args:
    • `issueId` string
• `Configuration Dialog` Opens the configuration dialog with all Snyk settings.
  • command: `snyk.workspace.configuration`
  • args: empty
  • returns: HTML string containing the configuration dialog
  • example:

Snyk Configuration
      ...

• `Connectivity Check` Performs comprehensive connectivity diagnostics including network checks, proxy detection, authentication, and organization access.
  • command: `snyk.diagnostics.checkConnectivity`
  • args: empty
  • returns: string (formatted connectivity check results with no ANSI colors)
  • Checks performed:
    • Network connectivity to all Snyk endpoints
    • Proxy configuration detection (including Kerberos env vars)
    • Authentication status
    • Organization access

• `Directory Diagnostics` Performs directory diagnostics for Snyk-used directories, checking existence, writability, and CLI binaries.
  • command: `snyk.diagnostics.checkDirectories`
  • args: optional array of additional directories to check

[
      {
        "pathWanted": "/path/to/check",
        "purpose": "Description of the directory purpose",
        "mayContainCLI": true // whether this directory may contain CLI binaries
      }
    ]

Installation

Download

The release workflow stores the generated executables, so that they can be

downloaded here. Just select the release you want the build

artefacts from and download the zip file attached to it. Currently, executables for Windows, macOS and Linux are

generated.

The currently published binary can be retrieved with this bash script, please keep in mind that

the protocol version is part of the download link and can change to force plugin / language server

synchronization. For further information please see CONTRIBUTING.md.

From Source

• Install the Go version listed in CONTRIBUTING.md (currently Go 1.26.x), set the `GOPATH` and `GOROOT` if needed
• Enter the root directory of this repository
• Execute `go get ./...` to download all dependencies
• Execute `make build && make install` to produce a `snyk-ls` binary

Configuration

Snyk LSP Command Line Flags

`-c ` allows to specify a config file to load before all others

`-f ` allows you to specify a log file instead of logging to the console

`-l ` ` allows to specify the output format (`md` or `html`) for issues

`-v ` prints the version of the Language Server

Configuration

LSP Initialization Options (protocol v25+)

As part of the Initialize message,

`initializationOptions` is unmarshaled into `types.InitializationOptions` (`internal/types/lsp.go`).

Machine settings use pflag canonical names as map keys, each value is a `ConfigSetting` (`value`, optional `changed`, etc.). Only entries with `changed: true` are applied during initialize (IDE defaults must not wipe LDX-sync or GAF defaults).

Init-only metadata (same JSON object, top-level fields): `requiredProtocolVersion`, `deviceId`, `integrationName`, `integrationVersion`, `osPlatform`, `osArch`, `runtimeName`, `runtimeVersion`, `hoverVerbosity`, `outputFormat`, `path`, `trustedFolders`.

Example shape:

{
  "requiredProtocolVersion": "25",
  "integrationName": "VISUAL_STUDIO_CODE",
  "integrationVersion": "1.0.0",
  "deviceId": "00000000-0000-0000-0000-000000000000",
  "path": "/usr/local/bin",
  "trustedFolders": ["/safe/project"],
  "settings": {
    "snyk_oss_enabled": { "value": true, "changed": true },
    "snyk_code_enabled": { "value": true, "changed": true },
    "snyk_iac_enabled": { "value": true, "changed": true },
    "api_endpoint": { "value": "https://api.snyk.io", "changed": true },
    "organization": { "value": "org-slug-or-uuid", "changed": true },
    "token": { "value": "secret-token", "changed": true },
    "proxy_insecure": { "value": false, "changed": true },
    "authentication_method": { "value": "oauth", "changed": true },
    "scan_automatic": { "value": true, "changed": true },
    "severity_filter_critical": { "value": true, "changed": true },
    "severity_filter_high": { "value": true, "changed": true },
    "severity_filter_medium": { "value": true, "changed": true },
    "severity_filter_low": { "value": true, "changed": true },
    "issue_view_open_issues": { "value": true, "changed": true },
    "issue_view_ignored_issues": { "value": false, "changed": true },
    "scan_net_new": { "value": false, "changed": true },
    "risk_score_threshold": { "value": 400, "changed": true },
    "cli_path": { "value": "/path/to/snyk", "changed": true },
    "automatic_download": { "value": true, "changed": true },
    "binary_base_url": { "value": "https://downloads.snyk.io", "changed": true },
    "cli_release_channel": { "value": "stable", "changed": true }
  },
  "folderConfigs": [
    {
      "folderPath": "/path/to/workspace",
      "settings": {
        "base_branch": { "value": "main", "changed": true },
        "preferred_org": { "value": "org-id", "changed": true },
        "org_set_by_user": { "value": true, "changed": true }
      }
    }
  ]
}

Registered flag names and precedence rules are documented in docs/configuration.md.

Runtime updates use `workspace/didChangeConfiguration` with the same payload envelope: LSP `settings` is an `LspConfigurationParam` whose fields are `settings` (map), `folderConfigs`, and optional `trustedFolders` — see `types.DidChangeConfigurationParams` in `internal/types/lsp.go`.

Workspace Trust

As part of examining the codebase for vulnerabilities, Snyk may automatically execute code on your computer to obtain

additional data for analysis. For example, this includes invoking the package manager (e.g., pip, gradle, maven, yarn,

npm, etc.)

to get dependency information for Snyk Open Source. Invoking these programs on untrusted code that has malicious

configurations may expose your system to malicious code execution and exploits.

To safeguard from using the language server on untrusted folders, our language server will ask for folder trust

before running scans against these folders. When in doubt, do not grant trust.

The trust feature is enabled by default. When a folder is trusted, all sub-folders are also trusted. After a folder

is trusted, Snyk Language Server notifies the Language Server Client with the custom `$/snyk.addTrustedFolders`

notification,

which contains a list of currently trusted folder paths. Based on this, a client can then implement logic to intercept

this notification and persist the decision and trust in the IDE or Editor storage mechanism.

Trust dialogs can be disabled by setting `enableTrustedFoldersFeature` to `false` in the initialization options. This

will disable all trust prompts and checks.

An initial set of trusted folders can be provided by setting `trustedFolders` to an array of paths in the

`initializationOptions`. These folders will be trusted on startup and will not prompt the user to trust them.

Environment variables

Snyk LS and Snyk CLI support and need certain environment variables to function:

1. `HTTP_PROXY`, `HTTPS_PROXY` and `NO_PROXY` to define the http proxy to be used

1. `JAVA_HOME` to analyse Java JVM-based projects via Snyk CLI

1. `PATH` to find maven when analysing Maven projects, to find python, etc

Auto-Configuration

To automatically add these variables to the environment, Snyk LS searches for the following files, with the order

determining precedence. If the executable is not called from an already configured environment (e.g. via

`zsh -i -c 'snyk-ls'`), you can also specify config file with the `-c` command line flag for setting the above mentioned

variables. Snyk LS reads the following files in the given precedence and order, not overwriting the already loaded

variables.

given config file via -c flag
/.snyk.env
$HOME/.snyk.env

Any lines that contain an environment variable in the format

`VARIABLENAME=VARIABLEVALUE` are added automatically to the environment if not already existent. This adheres to the

`dotenv` format. In case of `.profile`, `.zshrc`, etc., if a variable is directly exported e.g. via

`export VARIABLENAME=VARIABLEVALUE`, it is not loaded. The export would need to be split of and be in its own line, e.g

VARIABLENAME=VARIABLEVALUE
export VARIABLENAME

The PATH variable is treated differently than all other variables, as it is an aggregate of all PATH variables found in

the files and in the environment. Also, the current working directory `.` is automatically added to the path, so a

download of the Snyk CLI into the current working directory by an LSP client would yield a found Snyk CLI for the

Language Server.

In addition to configuring variables via config files, Snyk LS adds the following directories to the path on linux

and macOS:

• /bin
• $HOME/bin
• /usr/local/bin
• $JAVA_HOME/bin

If no JAVA_HOME is set, it automatically searches for a java executable first in path, then in the following directories

and adds the parent directory of its parent as JAVA_HOME. The following directories are recursively searched:

• /usr/lib
• /usr/java
• /opt
• /Library
• $HOME/.sdkman
• C:\Program Files
• C:\Program Files (x86)

The same directories are searched for a maven executable and the parent directory is added to the path.

Snyk CLI

To find the automatically managed Snyk CLI,

the XDG Data Home

and `PATH` path are automatically scanned for the OS-dependent file, e.g. `snyk-macos` on macOS,

`snyk-linux` on Linux and `snyk-win.exe` on Windows, and the first path where it is found is added to the environment.

It is later used for all functionality that depends on the CLI.

Setting environment variables globally

If you want to have the environment variables available system-wide, you would need to add the variables

to `/etc/environment` or on macOS to `/etc/launchd.conf` or set them via `launchctl` in a shell script. The former two

locations are automatically read by snyk lsp. On Windows, a user variable can be defined via the UI for the user or

system-wide. In a file like `~/.profile` it would like this:

SNYK_TOKEN=
DEEPROXY_API_URL=https://deeproxy.snyk.io/

# export variables, but make sure the export is not on the same line as the variable definition
export SNYK_TOKEN
export DEEPROXY_API_URL

Authentication to Snyk

The Snyk LS authentication flow happens automatically, unless disabled in configuration, and is as follows. When Snyk

Language Server starts, it:

• If the endpoint is a snykgov.io endpoint, or the authenticationMethod is set to `oauth`, it authenticates via OAuth2.

This opens a browser window.

• If the authentication method is not `oauth`, it tries to retrieve a token using the Snyk CLI token authentication.
• If the CLI is not authenticated either, it opens a browser window to authenticate
• If there are problems opening the browser window, the auth URL can be copied to the clipboard (via implementation

of `snyk.copyAuthLink`). _Note that there is a requirement to have `xsel` or `xclip` installed for Linux/Unix users

for this feature._

After successfull authentication in the web browser, the Snyk Language Server

automatically retrieves the Snyk authentication credentials and uses them for further requests.

Run Tests

go test ./...

If you have any issues with running pact, please extend your PATH env.

For example:

PATH=$PATH:$PWD/.bin/$(go env GOOS)-$(go env GOARCH)/pact/bin make test

The output should look like this (it is running against the Snyk Code API and using the real CLI):

?       github.com/snyk/snyk-ls        [no test files]
ok      github.com/snyk/snyk-ls/code   24.201s
ok      github.com/snyk/snyk-ls/diagnostics    26.590s
ok      github.com/snyk/snyk-ls/iac    25.780s
?       github.com/snyk/snyk-ls/lsp    [no test files]
ok      github.com/snyk/snyk-ls/oss    22.427s
ok      github.com/snyk/snyk-ls/server 48.558s
ok      github.com/snyk/snyk-ls/util   9.562s

Test Github Action locally

You can test github actions locally using act.

Install act & prerequisites

brew install act

# if you don't have docker desktop you can use minikube (a one-node kubernetes distribution)
brew install --cask virtualbox # you need to enable the virtualbox extension in macOS settings
brew install minikube
minikube start
eval $(minikube docker-env) # gives you a fully functional docker environment

Run act

act --secret SNYK_TOKEN=$SNYK_TOKEN --secret DEEPROXY_API_URL=$DEEPROXY_API_URL