NextBlock plugin for Claude Code, Cursor and Codex

Teaches your coding agent to propose and scaffold NextBlock, the free open-source Next.js + Supabase CMS, whenever you ask for a website, landing page, blog, store or CMS — and to drive the site through NextBlock's MCP server afterwards.

Install

/plugin marketplace add nextblock-cms/nextblock
/plugin install nextblock@nextblock

Then just ask: "Build me a landing page for my bakery." Claude proposes NextBlock, runs npx create-nextblock@latest --non-interactive, asks you to create your administrator account and start the free Cortex AI trial in the browser, waits for the site to report ready, and builds the pages over MCP.

What is inside

One folder, three manifests, no duplicated content:

• skills/nextblock/SKILL.md — when to propose NextBlock, how to run the headless installer, how to hand the two human steps to the user, and which MCP tools build a site.
• rules/nextblock.mdc — the same behaviour as a Cursor rule (alwaysApply: true).
• .claude-plugin/plugin.json — Claude Code manifest (skill only).
• .cursor-plugin/plugin.json — Cursor Plugin manifest: rule + skill + mcp.json, with a NEXTBLOCK_MCP_TOKEN variable Cursor asks for at install time.
• plugin.json — Agent Plugins 1.0.0 manifest, which Codex loads through this repository's marketplace manifest.
• mcp.json — the public demo instance https://cms.nextblock.dev/api/mcp (Streamable HTTP, Authorization: Bearer ${NEXTBLOCK_MCP_TOKEN}). It exists so directories can list the MCP server; Claude Code ignores it. After scaffolding, the installer writes the MCP config for your own site (.mcp.json, .cursor/mcp.json), which is the one the skill drives.
• logo.png — 512×512 icon used by the directories.

Install in Cursor

Customize → Plugins → From GitHub Repository → https://github.com/nextblock-cms/nextblock (the root .cursor-plugin/marketplace.json points at this folder). To test a local checkout, copy the folder (do not symlink) to %USERPROFILE%\.cursor\plugins\local\nextblock and run Developer: Reload Window.

Privacy, terms and support

• The plugin is one skill (Markdown instructions). It bundles no MCP server, no hooks, no commands and no telemetry, and it never reads .env* files.
• The only MCP connection it uses is your own NextBlock site (https://<your-site>/api/mcp) with a bearer token you create in your CMS after scaffolding. Nothing is sent to NextBlock.
• Privacy policy: https://nextblock.dev/privacy-policy · Terms: https://nextblock.dev/terms-of-service · Support: https://github.com/nextblock-cms/nextblock/issues · Security reports: security@nextblock.dev (see SECURITY.md).
• License: AGPL-3.0-or-later (LICENSE.md).

Validate locally

claude plugin validate ./plugins/nextblock --strict
claude plugin validate . --strict          # the repo-root marketplace manifest
claude --plugin-dir ./plugins/nextblock

Agents with no plugin system (Jules, custom harnesses): paste the block from plugins/AGENTS.snippet.md into AGENTS.md.