MCP server

The Sandworld MCP server exposes the environments to any Model Context Protocol client over stdio. It wraps the public API, so the same rate limits and keys apply.

Tools it provides

Tool	What it does
`list_environments`	Lists the app twins.
`describe_environment`	Policy, tools and tasks for one twin.
`start_episode`	Starts a task (or free play) and returns the instruction, policy and tools.
`call_tool`	Runs one environment tool inside the episode and returns the observation.
`submit_episode`	Closes the episode and returns every verifier check.

Claude Code

claude mcp add sandworld \
  --env SANDWORLD_API_URL=https://sandworld.dev/api/v1 \
  -- node /path/to/sandworld/bin/sandworld-mcp.mjs

Claude Desktop

{
  "mcpServers": {
    "sandworld": {
      "command": "node",
      "args": ["/path/to/sandworld/bin/sandworld-mcp.mjs"],
      "env": { "SANDWORLD_API_URL": "https://sandworld.dev/api/v1", "SANDWORLD_API_KEY": "sw_live_…" }
    }
  }
}

Then ask: “Start Quickbasket task qb-10, handle the customer's request according to the policy, and submit it.” The model reads the policy, looks up the order, declines the out-of-window refund and submits — and the verifier tells you whether it was right.

Environment variables

SANDWORLD_API_URL — API base URL (defaults to http://localhost:3000/api/v1).
SANDWORLD_API_KEY — optional; without it the server uses the anonymous sandbox.