Connect your own agent

Prototyper runs an MCP server. Point your coding agent (Claude Code, Codex, Cursor or another MCP client) at it, and that agent can read and write your workspace directly — create files, edit the canvas, ship a prototype — without going through the in-app composer.

This is what "bring your own agent" means, and it is the reason the Free plan is genuinely usable. Generation runs on your agent and your AI subscription, so it doesn't touch the platform's weekly message allowance at all. On the Free plan your agent's MCP tool calls have their own weekly allowance (see the table below). If you already pay for Claude Code, Codex or Cursor, you already have everything you need.

Connect in one command

Run one of these in your terminal, then complete the authorization prompt your editor shows you.

Claude Code

$ claude mcp add --transport http prototyper https://www.prototyper.co/api/mcp

Codex

$ codex mcp add prototyper --url https://www.prototyper.co/api/mcp

Cursor

Add Prototyper to your Cursor MCP configuration (~/.cursor/mcp.json, or .cursor/mcp.json in a project). Merge it into the file you already have rather than replacing it:

{
  "mcpServers": {
    "prototyper": {
      "url": "https://www.prototyper.co/api/mcp"
    }
  }
}

Reload Cursor if the server doesn't show up straight away.

Any other MCP client works too: point it at https://www.prototyper.co/api/mcp over streamable HTTP and authorize.

Your agent can also set itself up. Paste this into it:

Read https://www.prototyper.co/AGENTS.md and connect Prototyper as an MCP server.

/AGENTS.md is Prototyper's setup guide for coding agents, with the steps for each client.

Confirm it worked

Two places tell you the truth:

• Settings → MCP clients, in your account settings, lists every agent you've authorized, when it last called us, and what it's allowed to do. Revoke any of them from here. Inside a workspace, the settings dialog's MCP servers section shows the connections too.
• The MCP button in the workspace header shows the connection state. Once you're connected, select Copy workspace prompt there and paste it into your agent to point it at the current workspace.

What your agent can do

Once connected, your agent works on the same workspace you see, through Prototyper's MCP tools:

• Files: list, read, search, write and patch the workspace's files, and run commands in it.
• Workspaces and projects: list, create, import, export and archive workspaces, and create projects and move workspaces between them.
• Apps: build an app and render it, so the agent can see what it made.
• Canvas: lay out and render the canvas, and measure text so labels fit.

The practical shape of it: describe what you want in your agent, and watch it land on the canvas.

Quota, honestly

Connecting an agent doesn't unlock the in-app composer's message allowance — that stays on your plan. It gives you a second, separate allowance to do the work with. Most people on Free end up doing both: the composer for quick edits, their own agent for the heavy lifting.

Revoking access

Settings → MCP clients → Revoke. That kills every token in the client's family immediately; the agent has to re-authorize to get back in.