Add plugin validation workflow

Adds a GitHub Actions workflow that validates marketplace.json and each
plugin's plugin.json against their JSON schemas on PRs. Includes a
Node.js validation script and adds missing category/tags fields to the
plugin schema.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: ericzakariasson

.github/workflows/validate-plugins.yml

@@ -0,0 +1,24 @@
+name: Validate plugins
+
+on:
+  pull_request:
+    paths:
+      - ".cursor-plugin/marketplace.json"
+      - "**/plugin.json"
+      - "schemas/**"
+
+jobs:
+  validate:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 20
+
+      - name: Install dependencies
+        run: npm install --no-save ajv ajv-formats
+
+      - name: Validate plugin definitions
+        run: node scripts/validate-plugins.mjs

schemas/plugin.schema.json

@@ -57,6 +57,15 @@
       "items": { "type": "string" },
       "description": "Keywords for discovery and search."
     },
+    "category": {
+      "type": "string",
+      "description": "Plugin category for marketplace classification."
+    },
+    "tags": {
+      "type": "array",
+      "items": { "type": "string" },
+      "description": "Tags for filtering and discovery."
+    },
     "commands": {
       "$ref": "#/$defs/stringOrStringArray",
       "description": "Glob pattern(s) or path(s) to command files."

scripts/validate-plugins.mjs

@@ -0,0 +1,102 @@
+#!/usr/bin/env node
+
+import { readFileSync, existsSync } from "fs";
+import { resolve, dirname } from "path";
+import { fileURLToPath } from "url";
+import Ajv from "ajv";
+import addFormats from "ajv-formats";
+
+const __dirname = dirname(fileURLToPath(import.meta.url));
+const root = resolve(__dirname, "..");
+
+function loadJSON(path) {
+  return JSON.parse(readFileSync(path, "utf-8"));
+}
+
+const marketplaceSchema = loadJSON(
+  resolve(root, "schemas/marketplace.schema.json")
+);
+const pluginSchema = loadJSON(resolve(root, "schemas/plugin.schema.json"));
+
+const ajv = new Ajv({ allErrors: true });
+addFormats(ajv);
+
+const validateMarketplace = ajv.compile(marketplaceSchema);
+const validatePlugin = ajv.compile(pluginSchema);
+
+let errors = 0;
+
+function fail(message) {
+  console.error(`ERROR: ${message}`);
+  errors++;
+}
+
+// 1. Validate marketplace.json
+const marketplacePath = resolve(root, ".cursor-plugin/marketplace.json");
+
+if (!existsSync(marketplacePath)) {
+  fail(".cursor-plugin/marketplace.json not found");
+  process.exit(1);
+}
+
+const marketplace = loadJSON(marketplacePath);
+
+if (!validateMarketplace(marketplace)) {
+  fail("marketplace.json schema validation failed:");
+  for (const err of validateMarketplace.errors) {
+    console.error(`  ${err.instancePath || "/"}: ${err.message}`);
+  }
+}
+
+// 2. Validate each plugin
+for (const entry of marketplace.plugins ?? []) {
+  const pluginDir = resolve(root, entry.source);
+  const pluginJsonPath = resolve(pluginDir, ".cursor-plugin/plugin.json");
+
+  // Check source directory exists
+  if (!existsSync(pluginDir)) {
+    fail(
+      `Plugin "${entry.name}": source directory "${entry.source}" does not exist`
+    );
+    continue;
+  }
+
+  // Check plugin.json exists
+  if (!existsSync(pluginJsonPath)) {
+    fail(
+      `Plugin "${entry.name}": missing .cursor-plugin/plugin.json in "${entry.source}"`
+    );
+    continue;
+  }
+
+  const pluginJson = loadJSON(pluginJsonPath);
+
+  if (!validatePlugin(pluginJson)) {
+    fail(
+      `Plugin "${entry.name}": plugin.json schema validation failed (${entry.source}/.cursor-plugin/plugin.json):`
+    );
+    for (const err of validatePlugin.errors) {
+      const detail =
+        err.keyword === "additionalProperties"
+          ? `${err.message}: "${err.params.additionalProperty}"`
+          : err.message;
+      console.error(`  ${err.instancePath || "/"}: ${detail}`);
+    }
+  }
+
+  // Check that marketplace name matches plugin name
+  if (pluginJson.name && pluginJson.name !== entry.name) {
+    fail(
+      `Plugin "${entry.name}": marketplace name does not match plugin.json name "${pluginJson.name}"`
+    );
+  }
+}
+
+// 3. Report results
+if (errors > 0) {
+  console.error(`\nValidation failed with ${errors} error(s).`);
+  process.exit(1);
+} else {
+  console.log("All plugins validated successfully.");
+  process.exit(0);
+}