Screenshot Capture Comes to Workflows and MCP
2026-08-27 · workflow & MCP release
A workflow or an MCP client can now write a screenshot straight to a file — cropped, redacted, and never seen by the agent's own context.
Screenshots straight from a workflow or MCP call
The new browser.screenshot step captures the page — or a selector / ref / region crop of it — and writes a PNG to a file on the machine running SideButton, returning only the path it wrote. The screenshot MCP tool gained the same path option: pass it and the tool writes the file instead of returning image bytes; leave it out and nothing changes for existing callers. A bundled docs_screenshot workflow wires the whole sequence together as a ready-made recipe. Step types now number 46 (43 implemented).
Redact before the pixel is captured
The new inject_css MCP tool injects a CSS rule into the page — the main use is blurring or hiding sensitive elements right before a screenshot, so no unredacted image ever exists. Both tools are batchable, so a single browser_batch call can navigate, blur the sensitive selectors, wait, and screenshot-to-file in one round trip. A that never got a value now fails the step loudly instead of being treated as a literal string — previously a missing redaction value silently styled nothing, and the run reported success over an unredacted shot.
Nothing escapes the sandbox
Every path either tool writes is contained to the home directory of the user running SideButton — .. traversal and symlinks that escape it are rejected, matching the rule publish_artifact already enforces. publish_artifact now also expands a leading ~/, so a path a screenshot step just wrote can be published verbatim.
Self-hosted releases (npm) are covered in their own posts — latest: SideButton 1.5.5. Complete change list: Changelog.