Code Mode

Code Mode is a second MCP server for agents that work better by writing code than by chaining many tool calls.

https://mcp.lookio.app/mcp/code

It has two tools. The standard server at /mcp is unchanged and stays the default.

The API description stays in the sandbox, so it never fills the agent’s context, and the two tool descriptions have a fixed size whatever the API grows into.

Calling the API

Inside execute, request({ method, path, query, body }) calls an endpoint and returns the parsed response: { data, request_id } and, for a list, has_more and next_cursor. A failed call throws an Error carrying the API’s message.

const failed = [];
let cursor;

do {
  const page = await request({
    method: "GET",
    path: "/v1/resources",
    query: { limit: 100, ...(cursor ? { cursor } : {}) },
  });
  for (const resource of page.data) {
    if (resource.status === "failed") {
      await request({ method: "POST", path: `/v1/resources/${resource.id}/reindex` });
      failed.push({ id: resource.id, title: resource.title });
    }
  }
  cursor = page.next_cursor;
} while (cursor);

return { reindexed: failed.length, failed };

Only what the script returns, and what it logs with console.log, goes back to the agent. The script should filter and summarise inside the sandbox rather than return raw rows.

Limits

Every request() counts against the credential’s rate limit, exactly like the matching HTTP call.

Same permissions, same costs

Code Mode goes through the same routes, validation and scope checks as an HTTP request. A path the connection has no scope for fails with insufficient_scope. A script cannot do more than the connection already may.

Costs are the same too, and a loop multiplies them. A script that calls POST /v1/assistants/{assistant_id}/query 100 times asks 100 questions and spends the credits of 100 answers. Limit the query scope on connections you give to Code Mode, and tell the agent to ask before it loops over questions.

What a script cannot do

• Open a network connection. There is no fetch and no file system. request() is the only way out.
• Upload a file, which needs a streamed body, or stream an answer.
• Set headers, including Idempotency-Key.
• Reach the engine, the database or another workspace.

Connecting

Connect to the Code Mode URL the same way as the standard server. See Connect an AI client. A token requested for the standard server only is refused here, and the reverse. A token requested with no resource works for both.

The sandbox is a boundary against the code, not against the content. Text from your resources flows back to the agent and can try to influence the next script. What bounds that is the reach of the connection, so give it narrow scopes. See Safety and permissions.