authorgravatar for me@t3.ggTheo Browne <me@t3.gg> 2026-10-06 23:56:59-07:00
committergravatar for noreply@github.comGitHub <noreply@github.com> 2026-10-06 23:56:59-07:00
log4b063a042ec93418a196c020b852459f57e17b57
tree225a9727457624b472a932d78fc6c30defaf4812
parentf60367b8cb5e4a7e5e12dd01dc3889618151b1be
signature Signed by PGP key B5690EEEBB952194

fix(mcp): agent HTML pages stop painting slab backgrounds (#16752)

Co-authored-by: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

1 files changed, 2 insertions(+), 0 deletions(-)

packages/shared/src/htmlRender.ts+2
...@@ -261,7 +261,9 @@ export const HTML_RENDER_THEME_GUIDE = [...@@ -261,7 +261,9 @@ export const HTML_RENDER_THEME_GUIDE = [
261/** Agent-facing layout rules for a page that sits inside a reply. */261/** Agent-facing layout rules for a page that sits inside a reply. */
262export const HTML_RENDER_LAYOUT_GUIDE = [262export const HTML_RENDER_LAYOUT_GUIDE = [
263 `The frame is borderless on the thread's background, as wide as the reply column (${HTML_RENDER_COLUMN_WIDTH}px on desktop by default, wider if the reader widens chat, about 360px on phones), and its left edge lines up with your reply text.`,263 `The frame is borderless on the thread's background, as wide as the reply column (${HTML_RENDER_COLUMN_WIDTH}px on desktop by default, wider if the reader widens chat, about 360px on phones), and its left edge lines up with your reply text.`,
264 "The page sits on the thread's own background, so by default leave html, body, and the outermost element with no background color. This overrides general style preferences such as a fixed black page background.",
264 "Use a fluid width with no horizontal padding on the outermost element, and no outer card, border, or banner title: the page is part of your reply.",265 "Use a fluid width with no horizontal padding on the outermost element, and no outer card, border, or banner title: the page is part of your reply.",
266 "If a box needs its own background (a mock of a specific screen, a panel that must stand apart), give it at least 16px of padding on every side and var(--radius) corners, so content never touches its edge.",
265 "Give charts fixed pixel heights rather than heights that scale with width.",267 "Give charts fixed pixel heights rather than heights that scale with width.",
266 "Let content set the page's height. Avoid viewport-based heights such as 100vh or height:100% on html or body; the frame grows to fit the page, so they can make it grow again and again.",268 "Let content set the page's height. Avoid viewport-based heights such as 100vh or height:100% on html or body; the frame grows to fit the page, so they can make it grow again and again.",
267].join(" ");269].join(" ");