# Visual Verification > Verify application UI changes with uploaded screenshot or video artifacts Use when this capability is needed. - Skill: `tomevault-io/visual-verification` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/visual-verification` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/visual-verification/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/visual-verification --- # visual-verification Use this skill when the goal is to verify UI changes inside the application and return visual evidence in the Open-Inspect session. `agent-browser` remains the low-level browser tool. This skill defines the workflow contract for using it reliably. ## Key Fact `upload-media` is a **bash command** installed on PATH. Run it with your Bash tool, not as an MCP tool or tool binding. For videos, use `agent-browser record` directly, then probe and upload the resulting MP4 with `upload-media`. ## When To Use It - Verify a UI change after editing code - Capture before/after screenshots for comparison - Confirm responsive layout differences at a chosen viewport - Produce an uploaded screenshot or short video artifact the user can review in-session ## Success Criteria The task is not complete until all of these are true: 1. The changed UI is opened in the browser. 2. The capture mode is chosen explicitly: viewport screenshot, full-page screenshot, or video. 3. The viewport is set explicitly or reported as a deliberate default. 4. A screenshot or video is uploaded in the same prompt. 5. The returned `artifactId` is reported back to the user. 6. The response states what was verified and what dimensions/mode were used. ## Required Workflow 1. Open the target page with `agent-browser open`. 2. If viewport matters, set it explicitly with `agent-browser set viewport `. 3. Wait for the page to settle before capture. 4. Choose one of: - Viewport screenshot for above-the-fold or device-specific review - Full-page screenshot for full document review - Video recording for interaction flows, animations, transitions, or multi-step behavior 5. Upload the capture immediately with matching metadata. 6. Report the result with the artifact ID and actual capture settings. ## Default Decision Rules - Use a viewport screenshot when validating a specific visible state, modal, interaction, or desktop/mobile layout. - Use a full-page screenshot when the user asks for the whole page or when vertical content is part of the verification. - If the user names a device or screen size, set the viewport explicitly. - If the user does not specify dimensions and layout matters, choose a reasonable viewport and report it. - If the screenshot is intended to prove a fix, prefer stating exactly what was checked, not only that a screenshot was taken. - Use a video when the proof depends on seeing interaction over time, such as opening a menu, dragging, typing, navigating between states, or watching an animation complete. ## Using Screenshots From Other Sources If the screenshot already exists as a file — for example, captured via Playwright MCP (`playwright_browser_take_screenshot`), a manual capture, or any other tool — skip the `agent-browser` steps and upload the file directly: ```bash upload-media /path/to/existing-screenshot.png \ --caption "Description of what was captured" \ --source-url "$URL" ``` Add `--full-page` or `--viewport '{"width":1512,"height":982}'` as appropriate. The same reporting template and guardrails below still apply. For a dedicated upload-only workflow, see the `upload-screenshot` skill. ## Recommended Commands Viewport capture: ```bash agent-browser open "$URL" && \ agent-browser set viewport 1512 982 && \ agent-browser wait 2000 && \ agent-browser screenshot --json /tmp/verify.png && \ upload-media /tmp/verify.png \ --caption "UI verification screenshot" \ --source-url "$URL" \ --viewport '{"width":1512,"height":982}' ``` Full-page capture: ```bash agent-browser open "$URL" && \ agent-browser set viewport 1512 982 && \ agent-browser wait 2000 && \ agent-browser screenshot --full --json /tmp/verify-full.png && \ upload-media /tmp/verify-full.png \ --caption "Full-page verification screenshot" \ --source-url "$URL" \ --viewport '{"width":1512,"height":982}' \ --full-page ``` Annotated capture for review/debugging: ```bash agent-browser open "$URL" && \ agent-browser wait 2000 && \ agent-browser screenshot --annotate --json /tmp/verify-annotated.png && \ upload-media /tmp/verify-annotated.png \ --caption "Annotated UI verification screenshot" \ --source-url "$URL" \ --annotated ``` Video recording for interaction flows: ```bash set -e agent-browser open "$URL" agent-browser set viewport 1512 982 agent-browser snapshot -i STARTED_AT_MS=$(date +%s%3N) agent-browser record start /tmp/opencode/menu-recording.mp4 recording_started=1 cleanup_recording() { if [ "${recording_started:-0}" = "1" ]; then agent-browser record stop || true fi } trap cleanup_recording EXIT interaction_exit_code=0 agent-browser click "[data-testid=settings]" || interaction_exit_code=$? agent-browser wait 1000 || interaction_exit_code=$? agent-browser record stop recording_started=0 trap - EXIT ENDED_AT_MS=$(date +%s%3N) PROBE_JSON=$(ffprobe -v error -print_format json -show_streams -show_format /tmp/opencode/menu-recording.mp4) DURATION_MS=$(node -e 'const p=JSON.parse(process.argv[1]); const v=(p.streams||[]).find((s)=>s.codec_type==="video")||{}; const d=Number(v.duration ?? p.format?.duration); console.log(Math.max(1, Math.round(d * 1000)));' "$PROBE_JSON") DIMENSIONS=$(node -e 'const p=JSON.parse(process.argv[1]); const v=(p.streams||[]).find((s)=>s.codec_type==="video")||{}; console.log(JSON.stringify({width:Number(v.width),height:Number(v.height)}));' "$PROBE_JSON") upload-media /tmp/opencode/menu-recording.mp4 \ --artifact-type video \ --caption "Menu interaction recording" \ --source-url "$URL" \ --duration-ms "$DURATION_MS" \ --recording-started-at "$STARTED_AT_MS" \ --recording-ended-at "$ENDED_AT_MS" \ --dimensions "$DIMENSIONS" \ --truncated false \ --has-audio false exit "$interaction_exit_code" ``` ## Reporting Template Include the following in the final response: - What UI change or state was verified - Whether the capture was viewport, full-page, or video - The viewport used - The source URL - The uploaded artifact ID - Any limitation, such as auth gating, loading issues, or unverified states Example: ```text Verified the updated settings page header. Capture mode: viewport Viewport: 1512x982 Source: http://127.0.0.1:3000/settings Uploaded artifact: abc123 ``` ## Guardrails - Do not claim the screenshot or video was uploaded unless the upload command returned an artifact ID. - Do not report viewport metadata you did not explicitly set or verify. - Do not use `upload-media` in a later prompt; it is prompt-scoped. - Do not leave an active recording open. Always run `agent-browser record stop` if a recording was started. - If the user asked for a full-page screenshot, do not use viewport-only capture. - If the UI requires interaction before it matches the expected state, perform that interaction before capturing. - For video metadata, use the encoded MP4 dimensions and duration from `ffprobe`; do not reuse the requested viewport as video dimensions. - Prefer stable selectors such as `[data-testid=...]`, `[data-clear-completed]`, or `#todo-title`. Run `agent-browser snapshot -i` before recording when selectors or accessible names are uncertain. ## Relationship To `agent-browser` - Use `agent-browser` directly for open-ended browsing, debugging, auth flows, snapshots, and custom inspection. - Use `visual-verification` when the deliverable is proof that a UI change works and the user should receive an uploaded screenshot or video artifact. --- > Source: [ColeMurray/background-agents](https://github.com/ColeMurray/background-agents) — distributed by [TomeVault](https://tomevault.io).