A plugin that provides language-server support for YAML, CSS, and JSON files in VMark. Language servers add editor features such as validation, completion, and information when hovering over code.

Use it when editing VMark YAML, CSS, or JSON, including GitHub Actions workflows and issue templates.

It helps catch configuration and syntax problems while files are being edited and provides context-sensitive suggestions. The listed setup also recognizes common GitHub workflow and issue-form files.

vmark-lsp — Plugin by xiaolai

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Claude Code

/plugin marketplace add xiaolai/vmark

agentmods

npx agentmods add plugins/xiaolai/vmark/vmark-lsp

Clone the repo

git clone --depth 1 https://github.com/xiaolai/vmark

Made for: Claude Code.

Per session not measured What this adds to a session before it is invoked.

When invoked not measured Not applicable: nothing here is loaded into a session.

Security scan A 0 findings. Scan, not verified.

Origin original No closer match found in the catalogue.

Security

Grade A, and why

vmark-lsp scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude/plugins/vmark-lsp/.claude-plugin/plugin.json · 160 lines

How it starts

The opening of the file, as written. The whole thing — 160 lines — stays where its author put it; the contents beside it link to each section on GitHub.

{
  "name": "vmark-lsp",
  "description": "Language servers for VMark's YAML, CSS and JSON.",
  "version": "1.0.0",
  "author": {
    "name": "VMark"
  },
  "lspServers": {
    "yaml": {
      "command": "yaml-language-server",
      "args": [
        "--stdio"
      ],
      "extensionToLanguage": {
        ".yml": "yaml",
        ".yaml": "yaml"
      },
      "settings": {
        "yaml": {
          "validate": true,
          "completion": true,
          "hover": true,
          "format": {
            "enable": false
          },
          "schemaStore": {
            "enable": true
          },
          "schemas": {
            "https://www.schemastore.org/github-workflow.json": [
              ".github/workflows/*.yml",
              ".github/workflows/*.yaml",
              "website/.github/workflows/*.yml"
            ],
            "https://www.schemastore.org/github-issue-forms.json": [
              ".github/ISSUE_TEMPLATE/*.yml"
            ]
          },
          "yamlVersion": "1.2"
        }
      }
    },
    "css": {
      "command": "vscode-css-language-server",
      "args": [
        "--stdio"
      ],
      "extensionToLanguage": {
        ".css": "css"
      },
      "settings": {
        "css": {
          "validate": true,
          "lint": {
            "unknownProperties": "error",
            "unknownAtRules": "ignore",
            "duplicateProperties": "warning",
            "emptyRules": "warning"
          }
        }
      }
    },
    "json": {
      "command": "vscode-json-language-server",
      "args": [
        "--stdio"
      ],
      "extensionToLanguage": {
        ".json": "json",
        ".jsonc": "jsonc"
      },
      "settings": {
        "json": {
          "validate": {
            "enable": true
          },
          "schemas": [
            {
              "fileMatch": [
                "command-error-baseline.json"
              ],
              "schema": {
                "type": "object",
                "des

Read the full file on GitHub · 160 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

2d ago First seen · 160 lines scan A 2f7c9fff8c16

Subscribe to this mod's changes

vmark-lsp is a plugin published in the GitHub repository xiaolai/vmark (544 stars, last pushed 2d ago), licensed ISC. Its token cost is not measured: this kind of file is read by the harness, not the model. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Frontend

vmark-lsp

Getting it into your agent

Grade A, and why

Nothing flagged

How it starts

What this file has done since we first saw it

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