Yes, a coding agent can set up paid subscriptions for a browser extension, as long as the payments service gives it tools to act with. Toolaby has an MCP server and a Claude Code plugin. Through them, Claude Code, Cursor, Codex, VS Code with Copilot, Gemini CLI or Windsurf create the plans, wire the extension, put the paid feature behind gate() and prove it unlocks with a test purchase, all on Test, where nothing is charged. You approve the sign-in, connect Stripe for Live and upload to the Chrome Web Store yourself.
This guide gives your agent Toolaby, signs it in, asks for the work, shows how it checks itself, and lists the steps that stay yours.
Before you begin
- A workspace on Toolaby, and Node.js 20 or later.
- A coding agent that connects to MCP servers.
- Your extension's folder. No extension yet? The agent can make one with
npx -y toolaby@latest create <tool-id>.
1. Give your agent Toolaby
npx -y toolaby@latest agentsThis registers Toolaby's MCP server in each coding agent it finds on your machine: Claude Code, Codex, Cursor, VS Code and Gemini CLI. Restart the agent, or reload its MCP servers.
In Claude Code you can install the plugin instead. It brings the same server, skills for selling a feature, pricing, testing and shipping, and five commands such as /toolaby:sell and /toolaby:ship:
/plugin marketplace add toolaby/claude-plugin
/plugin install toolaby@toolabyIn Cursor by hand, add the server to ~/.cursor/mcp.json:
{
"mcpServers": {
"toolaby": { "command": "npx", "args": ["-y", "toolaby@latest", "mcp"] }
}
}Build with an agent has the setup for every client.
2. Sign in once
Ask the agent to sign in. It calls toolaby_sign_in, which answers a link and a code: open the link, check the code and approve. The agent's next call works. The server acts on Test. For Live, a second server named toolaby-live runs npx -y toolaby@latest mcp --live, with a sign-in of its own.
3. Ask for the work
Open your extension's folder in the agent and say what you want in one sentence:
Add a Pro plan at $4 a month with a 7-day free trial, and make the CSV export a Pro feature.
The agent then:
- makes the tool where there is none (
toolaby_create_tool), then wires the extension withnpx -y toolaby@latest wire <tool-id>, which adds the client and writesTOOLABY.md, the file it reads for this project's rules; - adds the plan (
toolaby_add_plan), then the feature and the plan that unlocks it (toolaby_set_features); - puts
toolaby.gate({ feature: 'export' })before the export, and shows the paywall when it refuses; - checks its work, below, and ends with what changed and the steps left for you.
Every MCP tool is also a command of npx -y toolaby@latest, so you can see and repeat what the agent did.
4. How the agent checks its work
The agent says it is done only after these pass:
npx -y toolaby@latest check --jsonin the extension's folder exits0.- Once built,
check --json --browser --built <folder>loads the extension in Chromium, and its background and pages start without an error. test-unlock <tool-id> --plan <plan-id>makes a buyer of your own on Test with the plan, andcheck --browser --as <plan-id>proves the paid feature unlocks for them.
5. What stays yours
| The agent does | You do, once |
|---|---|
| Create and change plans, trials, features and the Free plan on Test | Approve the sign-in, on each side |
Write the code behind gate(), and fix what check reports | Connect Stripe on Live, under Configure → Payments |
| Prove a paid feature unlocks on Test | Upload the zip to the Chrome Web Store, and submit it |
| Copy the tool to Live and pack the store zip | Make the first real purchase on Live |
On Live, a change the agent asks for first answers a confirmation code, which it sends only on your word.
Moving from ExtensionPay
In Claude Code, /toolaby:move-from-extensionpay runs the move. In any agent, ask it to follow Move from ExtensionPay: your ExtensionPay calls keep working, answered by Toolaby.
Common questions
Does the agent see my Stripe keys?
No. Stripe is connected in the dashboard, and no Stripe key goes into your extension or the chat. The tool key in your extension (tk_…) is public by design.
Which coding agents work?
Any agent that starts an MCP server from a command: npx with the arguments -y toolaby@latest mcp. Without MCP, an agent can run the same commands in a terminal.
Can I do the same without an agent?
Yes. The dashboard and the command line do everything the agent does. See Add payments to a Chrome extension.