> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mythex.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# MCP (Claude, Codex, Cursor)

> Connect Claude, Codex, or Cursor to Mythex — paste the MCP URL, click Connect, approve on Mythex.

# MCP — build from Claude, Codex, or Cursor

Mythex exposes a **remote MCP server**. External agents (Claude, Cursor, Codex) code in your cloud sandbox; Mythex provides the VM, preview, and publish.

## The simple flow (recommended)

1. Copy your MCP URL from **[Account settings](https://mythex.ai/settings)** → **MCP / Claude**\
   Production: `https://mcp.mythex.ai/mcp`
2. In the client, add that URL as a custom MCP / connector
3. Click **Connect**
4. Your browser opens Mythex — sign in if needed, click **Allow access**
5. You’re done. Chat in Claude/Cursor and build

Anyone can Connect. **Tool calls** need a Mythex **Pro** account (and credits for sandbox time).

### Claude

**Settings → Connectors → Add custom connector** → paste MCP URL → **Connect** → approve on Mythex.

### Cursor

Add the server with only the URL (Settings → MCP, or `.cursor/mcp.json`):

```json theme={null}
{
  "mcpServers": {
    "mythex": {
      "url": "https://mcp.mythex.ai/mcp"
    }
  }
}
```

Toggle the server on → **Connect** when Cursor prompts → approve on Mythex.

Local dev can use `http://localhost:4000/mcp` the same way.

## Requirements for tools

* **Pro** plan (Connect works without it; tools return an upgrade error)
* Credits on your balance (empty balance → sandbox wake refused / sandboxes pause)

## What the client can do

* Create / open projects and wake sandboxes
* Read, write, edit, search files; run `bash`
* Preview via `set_run_config` / start / logs
* Env keys (set secrets you provide — values are not listed back)
* Database, storage, publish, checkpoints
* Browser run, web/media helpers, export/import, GitHub, domains

## What stays private

* Mythex agent system prompts and internals
* Platform secrets and other users’ projects
* Raw secret **values** via `list_env_keys` (keys only)

## Credits

* The external model is billed by that provider (Claude / Cursor / etc.)
* Mythex credits pay for live sandbox time and published hosting
* Empty balance → sandbox wake refused / sandboxes pause

## Related

* [Account settings](/account/settings)
* [Credits](/billing/credits)
* [Sandbox](/features/sandbox)