ShareCube plugin

Publish, edit, and comment on shareable HTML and Markdown artifacts from your coding agent.

Validate Agent Plugins 1.0.0 MCP Claude Code Cursor Codex License: MIT

What it does

Your agent writes a report, a plan, or a page. ShareCube turns it into a link your team can open, comment on, and edit. The plugin gives the agent:

The ShareCube MCP server at https://app.sharecube.io/mcp, for creating, finding, editing, and commenting on artifacts. Sign-in is OAuth, so there are no keys to configure.
A sharecube skill that tells the agent when to reach for ShareCube and how to use it safely: targeted edits that never overwrite changes people made in the web app, HTML that works in ShareCube's sandboxed viewer, anchored and resolved comments, and confirming before a permanent delete.

Install

Claude Code

/plugin marketplace add infragate/sharecube-plugin
/plugin install sharecube@sharecube

The first ShareCube tool call opens a browser window to sign in.

Cursor

Open Cursor Settings → Plugins.
Search for ShareCube.
Click Install, then sign in to ShareCube when Cursor prompts you.

Or run /add-plugin sharecube in chat.

To run it from source instead, clone it into Cursor's local plugins folder and restart Cursor:

git clone https://github.com/infragate/sharecube-plugin ~/.cursor/plugins/local/sharecube

Codex

codex plugin marketplace add infragate/sharecube-plugin
codex plugin add sharecube@sharecube

In the ChatGPT desktop app, add infragate/sharecube-plugin as a marketplace and install ShareCube from it.

Hosts

One tree serves every host. Each reads its own manifest and shares the same skill and MCP server.

Host	Manifest	MCP config
Agent Plugins clients	`plugin.json`	`mcp.json`
Claude Code	`.claude-plugin/plugin.json`	`.mcp.json`
Cursor	`.cursor-plugin/plugin.json`	inline in its `plugin.json`
Codex	`plugin.json`, with its display name and logo under `extensions["com.openai"]`	`mcp.json`

All three describe the same server. They are separate because each host spells the transport differently: streamable-http for Agent Plugins and Codex, http for Claude Code, and no type at all for Cursor, which infers it from the URL.

Keep plugin.json and mcp.json on Agent Plugins 1.0.0. Codex rejects any other version and the plugin fails to load. Codex lists the plugin from .agents/plugins/marketplace.json, and older Codex builds read .codex-plugin/plugin.json.

Development

Try your working copy in Claude Code:

claude --plugin-dir .

Check the manifests before you push:

node scripts/check-manifests.mjs

It fails if the manifests disagree on name, version, or license, reference a file that does not exist, or describe different MCP servers. CI runs it on every push and pull request, along with the Agent Plugins 1.0.0 schemas, a real install with the Codex CLI, Cursor's validator from cursor/plugin-template, and claude plugin validate.

To release, bump version in all four manifests together and add an entry to CHANGELOG.md.

License

MIT