Execute Workflows Skill

Use this skill when the user asks to run JavaScript, execute code in the page or on the server, or batch several tool calls into one.

Rule: Use execute only

There are no separate run-JS tools. Always use the MCP tool execute.

Run JavaScript in the browser page

Use execute with page.evaluate():

// execute tool, code:
return await page.evaluate(() => document.title);

You have access to page (Playwright Page) and callTool(name, input, returnOutput?) inside the execute VM. Use await with callTool.

Run JavaScript on the server (Node VM, no DOM)

Use execute without page.evaluate() — e.g. Buffer, crypto, or multiple callTool calls:

return Buffer.from('hello').toString('base64');

Batch multiple tool calls

Use execute and call tools via await callTool(name, input, returnOutput?):

await callTool('interaction_fill', { selector: 'e3', value: 'user@test.com' });
await callTool('interaction_click', { selector: 'e7', waitForNavigation: true });
const snapshot = await callTool('a11y_take-aria-snapshot', {}, true);
return snapshot;

Max 50 callTool calls per execution. Pass true as third argument to include that tool’s output in the response toolOutputs.

Node platform (backend debugging)

On Node platform, execute has no page; use callTool only. See commands/node/execute.md.

References

• Browser: commands/browser/execute.md — page, callTool, VM API
• Node: commands/node/execute.md — callTool only