Use Volter World with a coding agent

Have your coding agent set up a world for your app, run its tests there, and show you what the app did at each vendor.

A coding agent is optional; manual setup teaches the same workflow without one. Use Node 22.6 or newer and npm.

Claude Code, Cursor, VS Code and Codex drive Volter World through volter mcp, an MCP server whose tools are the volter command's own verbs, and learn it from the volter-world skill. One command installs both into the agents on your machine. Then you ask in plain words.

The appCopy Anchor Link

An app that creates a Stripe customer with the real Stripe SDK, and names its key in .env.example:

{ "name": "acme-web", "private": true, "type": "module", "dependencies": { "stripe": "17.7.0" }, "devDependencies": { "@volter/world": "3.0.63", "@volter/twin-stripe": "3.0.1" } }

STRIPE_SECRET_KEY=

import Stripe from 'stripe';

const stripe = new Stripe(process.env.STRIPE_SECRET_KEY);
const customer = await stripe.customers.create({ email: '[email protected]' });
console.log(`created ${customer.id}`);

1. Install the command and the twinCopy Anchor Link

npm install
npx volter --version

2. Give your agent the toolsCopy Anchor Link

npx volter agents install finds the coding agents on your machine and puts the skill and the MCP server into each: Claude Code (claude mcp add, and ~/.claude/skills/volter-world), Cursor (~/.cursor/mcp.json), VS Code (.vscode/mcp.json in this project) and Codex (~/.codex/config.toml and ~/.codex/AGENTS.md). Name one to set up only that agent. Here it is VS Code, whose server entry lives in the project:

npx volter agents install --vscode --yes

for      VS Code
skill    volter-world
.vscode/mcp.json: added the volter server

It changes only its own volter entry and its own skill folder; running it again changes nothing. Without a flag it sets up every agent it finds, and without --yes it asks first:

$ npx volter agents install
for      Claude Code, Cursor
skill    volter-world
server   volter mcp

Install? [y/N]

Restart the agent so it starts the server.

3. AskCopy Anchor Link

Paste this into your agent. The platform's Get started and a world's Connect menu offer the same text with your platform's address filled in.

Set up Volter World for this app, so its calls to Stripe, Slack, GitHub, OpenAI and the other services it uses go to local twins instead of the real APIs. The app keeps its real SDKs and code.

1. You have the Volter World tools (volter mcp). If the `volter` command is missing, install it: `npm install -g @volter/world`.
2. In the app's folder, world_init (`npx volter world init`). Show me the vendors it detected and why, before keeping them.
3. Start it with world_up, then run the tests inside it: world_run (`npx volter world run -- <the test command>`). Fix anything that fails because a call went to the real service.
4. Tell me what the app did at each vendor (world_log (`npx volter world log`)), and give me the dashboard link (world_view).

The agent's tools run the same commands you would, and answer what they answer. Here are those commands, as the agent runs them.

npx volter world init

  stripe | installed 3.0.1 | injector | STRIPE_TWIN_URL | env: STRIPE_SECRET_KEY; npm: stripe
COVERED: every detected vendor has a twin in world acme-web.

npx volter world up
npx volter world run -- node signup.mjs

created cus_twin_1

npx volter world log

stripe   customer.create        customer:cus_twin_1

For the dashboard the agent calls world_view, which runs the world with its dashboard and hands you the link; npx volter world view is the same from a terminal.

4. Share it with your teamCopy Anchor Link

A world on your machine is yours. To share one, your agent signs the command in to your team's platform, and you approve the sign-in in your browser: the agent cannot. Then it links this world to one on the platform, making it there from this world's vendors, and pushes:

$ volter login https://your-platform.example
approve    https://your-platform.example/-/cli/approve?code=QWER-TYUI
$ volter remote add origin acme/web --create
$ npx volter world changeset -m "The signup flow"
$ npx volter world push

The MCP tools are platform_login, remote_link (with create: true), world_changeset and world_push. Use the hosted product covers the platform itself.

Clean upCopy Anchor Link

npx volter world down

The tools and flags are in the CLI reference.

Keep the selected implementationCopy Anchor Link

Give the agent the exact catalog package/version you chose and ask it to preserve that source in .volter/world.json. Review detected vendors before keeping them; never use a real credential to pass SDK validation. If a call fails, use recovery to distinguish routing, data, scenarios, unsupported operations and runtime failures. To open a dashboard, use inspect a World; to test forms and sessions, use browser testing. Platform sign-in still requires the person’s browser approval.