feat(codex): Add repo-local plugin marketplace support

Add Codex marketplace metadata and a repo-local plugin scaffold so the repository can be installed as a Codex plugin without duplicating the skills catalog.

Document the new integration path and cover it with a regression test to keep the marketplace entry and plugin manifest in sync.

.agents/plugins/marketplace.json

@@ -0,0 +1,20 @@
+{
+  "name": "antigravity-awesome-skills",
+  "interface": {
+    "displayName": "Antigravity Awesome Skills"
+  },
+  "plugins": [
+    {
+      "name": "antigravity-awesome-skills",
+      "source": {
+        "source": "local",
+        "path": "./plugins/antigravity-awesome-skills"
+      },
+      "policy": {
+        "installation": "AVAILABLE",
+        "authentication": "ON_INSTALL"
+      },
+      "category": "Productivity"
+    }
+  ]
+}

README.md

@@ -211,6 +211,15 @@ If you use Claude Code and prefer the plugin marketplace flow, this repository n
 
 This installs the same repository-backed skill library through Claude Code's plugin marketplace entrypoint.
 
+### Option C: Codex plugin marketplace metadata
+
+If you use Codex and prefer a marketplace-style plugin source instead of copying skills into `.codex/skills/`, this repository now ships:
+
+- `.agents/plugins/marketplace.json`
+- `plugins/antigravity-awesome-skills/.codex-plugin/plugin.json`
+
+The Codex plugin points at the same curated `skills/` tree through a repo-local plugin entry, so the library can be exposed as an installable Codex plugin source without duplicating the catalog.
+
 ## Choose Your Tool
 
 | Tool           | Install                                                                  | First Use                                              |

docs/users/codex-cli-skills.md

@@ -25,6 +25,8 @@ Install the library into your Codex path, then invoke focused skills directly in
 npx antigravity-awesome-skills --codex
 ```
 
+If you prefer a plugin-style Codex integration, this repository also ships repo-local plugin metadata in `.agents/plugins/marketplace.json` and `plugins/antigravity-awesome-skills/.codex-plugin/plugin.json`.
+
 ### Verify the install
 
 ```bash

plugins/antigravity-awesome-skills/.codex-plugin/plugin.json

@@ -0,0 +1,38 @@
+{
+  "name": "antigravity-awesome-skills",
+  "version": "8.10.0",
+  "description": "Repository-backed Codex plugin for the Antigravity Awesome Skills library.",
+  "author": {
+    "name": "sickn33 and contributors",
+    "url": "https://github.com/sickn33/antigravity-awesome-skills"
+  },
+  "homepage": "https://github.com/sickn33/antigravity-awesome-skills",
+  "repository": "https://github.com/sickn33/antigravity-awesome-skills",
+  "license": "MIT",
+  "keywords": [
+    "codex",
+    "skills",
+    "agentic-skills",
+    "developer-tools",
+    "productivity"
+  ],
+  "skills": "./skills/",
+  "interface": {
+    "displayName": "Antigravity Awesome Skills",
+    "shortDescription": "1,328+ reusable skills for coding, security, product, and ops workflows.",
+    "longDescription": "Install the Antigravity Awesome Skills catalog as a Codex plugin and expose the repository's curated skills library through a single marketplace entry.",
+    "developerName": "sickn33 and contributors",
+    "category": "Productivity",
+    "capabilities": [
+      "Interactive",
+      "Write"
+    ],
+    "websiteURL": "https://github.com/sickn33/antigravity-awesome-skills",
+    "defaultPrompt": [
+      "Use @brainstorming to plan a new feature.",
+      "Use @test-driven-development to fix a bug safely.",
+      "Use @lint-and-validate to verify this branch."
+    ],
+    "brandColor": "#111827"
+  }
+}

plugins/antigravity-awesome-skills/skills

@@ -0,0 +1 @@
+../../skills

tools/scripts/tests/codex_plugin_marketplace.test.js

@@ -0,0 +1,61 @@
+const assert = require("assert");
+const fs = require("fs");
+const path = require("path");
+const { findProjectRoot } = require("../../lib/project-root");
+
+const projectRoot = findProjectRoot(__dirname);
+const marketplacePath = path.join(projectRoot, ".agents", "plugins", "marketplace.json");
+const marketplace = JSON.parse(fs.readFileSync(marketplacePath, "utf8"));
+
+assert.strictEqual(
+  marketplace.name,
+  "antigravity-awesome-skills",
+  "Codex marketplace name should match the repository plugin name",
+);
+assert.strictEqual(
+  marketplace.interface?.displayName,
+  "Antigravity Awesome Skills",
+  "Codex marketplace display name should be present",
+);
+assert.ok(Array.isArray(marketplace.plugins), "marketplace.json must define a plugins array");
+assert.ok(marketplace.plugins.length > 0, "marketplace.json must contain at least one plugin");
+
+const pluginEntry = marketplace.plugins.find((plugin) => plugin.name === "antigravity-awesome-skills");
+assert.ok(pluginEntry, "marketplace.json must include the antigravity-awesome-skills plugin entry");
+assert.deepStrictEqual(
+  pluginEntry.source,
+  {
+    source: "local",
+    path: "./plugins/antigravity-awesome-skills",
+  },
+  "Codex plugin entry should resolve to the repo-local plugin directory",
+);
+assert.strictEqual(
+  pluginEntry.policy?.installation,
+  "AVAILABLE",
+  "Codex plugin entry must include policy.installation",
+);
+assert.strictEqual(
+  pluginEntry.policy?.authentication,
+  "ON_INSTALL",
+  "Codex plugin entry must include policy.authentication",
+);
+assert.strictEqual(
+  pluginEntry.category,
+  "Productivity",
+  "Codex plugin entry must include a category",
+);
+
+const pluginRoot = path.join(projectRoot, "plugins", "antigravity-awesome-skills");
+const pluginManifestPath = path.join(pluginRoot, ".codex-plugin", "plugin.json");
+const pluginManifest = JSON.parse(fs.readFileSync(pluginManifestPath, "utf8"));
+
+assert.strictEqual(pluginManifest.name, "antigravity-awesome-skills");
+assert.strictEqual(pluginManifest.version, "8.10.0");
+assert.strictEqual(pluginManifest.skills, "./skills/");
+
+const pluginSkillsPath = path.join(pluginRoot, "skills");
+assert.ok(fs.existsSync(pluginSkillsPath), "Codex plugin skills path must exist");
+assert.ok(fs.statSync(pluginSkillsPath).isDirectory(), "Codex plugin skills path must be a directory");
+
+console.log("ok");

tools/scripts/tests/run-test-suite.js

@@ -14,6 +14,7 @@ const LOCAL_TEST_COMMANDS = [
     [path.join(TOOL_TESTS, "apply_skill_optimization_security.test.js")],
     [path.join(TOOL_TESTS, "build_catalog_bundles.test.js")],
     [path.join(TOOL_TESTS, "claude_plugin_marketplace.test.js")],
+    [path.join(TOOL_TESTS, "codex_plugin_marketplace.test.js")],
     [path.join(TOOL_TESTS, "installer_antigravity_guidance.test.js")],
     [path.join(TOOL_TESTS, "jetski_gemini_loader.test.cjs")],
     [path.join(TOOL_TESTS, "npm_package_contents.test.js")],