command-center/agent/managed-skills/browser-screenshot-disk-and-cookies/SKILL.md

name, description

name	description
browser-screenshot-disk-and-cookies	Save omp managed-browser screenshots to real files (tab.screenshot path is silently ignored) and reset the shared Chromium cookie jar between persona captures.

Screenshots to disk with the omp browser eval helper

Traps (both cost a full re-capture to discover)

1. tab.screenshot({ path }) ignores path silently — the option is not in its schema ({selector, fullPage, silent, annotate, format, quality, ifChanged, threshold}). The image attaches inline to the tool result and nothing is written to disk; ls shows an empty dir. Inline images may also be dropped from transcript archives later, so "attached to chat" is not "saved".
2. The shared managed Chromium keeps cookies across tabs and turns (profile persists after tab.close()). A second capture script that expects the anonymous view lands signed-in and waitForSelector("testid/…") fails fast.

Procedure

Write files via tab.run, which exposes the raw Puppeteer page — its screenshot({path}) does write:

const dir = "/tmp/<session-dir>";
const tab = await browser.open({ name: "caps", url });
const shot = (file) =>
  tab.run(async ({ page }, f) => { await page.screenshot({ path: f }); return f; },
          { args: [`${dir}/${file}.png`] });

await tab.clearCookies();            // ALWAYS before an anonymous capture
await tab.goto(url);
await tab.waitForSelector("testid/first-state");
await shot("1-anonymous");
// ...drive states with direct helpers: click/fill("testid/<id>", ...) ...
await shot("2-next-state");
await tab.close();

Verify with ls -la <dir> && file <dir>/*.png — do not trust silent success.

Notes

• Selectors accept testid/<id> handler; prefer it over CSS on [data-testid].
• tab.run(fn, { args }): functions receive {tab, page, browser, wait, assert} first, then each arg; a bare code string runs in an isolated runtime, not the page — document is undefined there. Use direct helpers or tab.evaluate (page-global expression; top-level return invalid) for page access.
• Byte-identical PNG sizes between two frames = same view; fine as proof of a round-trip (state A → B → A).