Downloads, PDFs and domain policies

Collect files the browser downloads, print pages to PDF, and fence where tabs may go.

Downloads

browser_download {action: "list"} reports downloads observed while the debugger is attached to a shared tab. Extension mode uses tab-specific browser events, so another tab’s downloads stay private even on the same website. It reports the suggested filename and progress; the local file path is unavailable in this mode. Developer mode reports files in the context’s download directory (~/.browspark/downloads/<context> unless overridden at launch), including their paths.

{action: "wait", urlContains, timeoutMs} returns a matching completed download immediately, or waits for one to complete. Use it right after clicking an “Export CSV” button; a file path is included when available.

PDF

browser_pdf prints the current page like Print → Save as PDF: format (A4, Letter, Legal), landscape, printBackground, scale, and path to write somewhere other than the artifacts directory. Returns the file path.

Domain policies

browser_policy restricts where a tab may navigate and load resources from. allow is an allow-list (everything else is blocked); block is a deny-list. Subdomains match, non-HTTP schemes always pass, and blocked navigations fail with ERR_BLOCKED_BY_CLIENT.

{ "action": "set", "tabId": 1234, "allow": ["example.com", "cdn.example.net"] }

With default: true the policy applies to every tab the agent opens from now on, which is the way to keep a scraping run on the sites you intend:

{ "action": "set", "default": true, "block": ["doubleclick.net", "google-analytics.com"] }

status shows the active policy; clear removes it. Policies are enforced through Chrome’s Fetch domain so they cover subresources, not just top-level navigation.