visual_check
Set visual baselines for pages or elements, then check new screenshots against them to identify visual regressions with a diff image and pass/fail verdict.
Instructions
Named visual-regression baselines — no screenshot-path bookkeeping. action='set' captures the session page (or one element via selector) as the baseline for 'name'; action='check' captures again and returns a hard verdict: passed (diff_percentage vs max_diff_percent, default 0.5%), plus a diff image with changed pixels highlighted. Baselines are stored per project+name. If a check fails on an intended change, re-baseline with action='set'. Prefer selector-scoped baselines for components — full pages flake more (animations, dynamic content).
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| name | Yes | Baseline name, e.g. 'dashboard-desktop' (letters, digits, . _ -) | |
| action | No | set = capture/replace the baseline; check = compare current state against it (default: check) | |
| selector | No | Scope the baseline to one element (recommended for components) | |
| full_page | No | Full scrollable page vs viewport when no selector (default: true) | |
| threshold | No | Per-channel color tolerance 0-255 before a pixel counts as different (default: 10) | |
| session_id | Yes | Session ID | |
| max_diff_percent | No | Max % of differing pixels to still pass (default: 0.5) |