web-screenshot

name	web-screenshot
description	Capture a specified HTTP(S) webpage as a verified PNG with viewport, full-page, or unique-element modes.

Web Screenshot

Use this skill when the user gives a concrete webpage URL and asks for a screenshot. It is independent from the platform-specific capture command.

Workflow

1. Require the user's exact HTTP(S) URL and an explicit output directory. Do not invent a URL or write into the repository.

2. Run one of these commands:

   social-capture webpage "https://example.com" --output-dir "E:\temp\web"
   social-capture webpage "https://example.com" --output-dir "E:\temp\web" --mode full-page
   social-capture webpage "https://example.com" --output-dir "E:\temp\web" --mode element --selector "main article"
   

3. Use --viewport WIDTHxHEIGHT when a deterministic viewport is needed; the default is 1440x900. --wait SECONDS controls the post-navigation wait.

4. Read manifest.json after the command. Treat the capture as successful only when the item has status: "ok" and contains at least one part, then verify the PNG exists and its recorded SHA-256, dimensions, mode, and final URL are usable.

Modes and boundaries

• viewport captures the current viewport and is the default.
• full-page captures one PNG of the complete document. Before the screenshot it performs a finite lazy-load warm-up over the document height recorded immediately after navigation: it scrolls in bounded viewport-sized steps, waits briefly at each step, and waits a bounded time for current images and fonts. If lazy loading grows the document, it rescans only the newly added range until the height is stable or the round limit is reached, then returns to the top. It never auto-scrolls indefinitely. The manifest records image_count, loaded, failed, pending, initial_height, final_warmup_height, rounds, executed_steps, and timed_out; individual external image failures do not fail the page capture. The warm-up is capped at 4 rounds, 64 scroll positions total, 120 ms per step/poll, and 10 seconds total.
• element requires --selector and succeeds only when exactly one matching element is visible. Zero or multiple visible matches are failures.
• The command accepts HTTP(S) URLs only. It does not support batches, cookie-file input, PDF/JPEG output, device emulation, or login bypass.
• The command first tries the configured Chrome CDP endpoint. If it cannot connect, the webpage command may launch and clean up a temporary Chrome for public pages; platform capture retains its existing CDP requirements.

If navigation, element matching, or browser capture fails, report the manifest failure and its error kind. Never expose Cookie values, tokens, signatures, or unsanitized signed URLs in a response; use the redacted manifest URL instead.