[shawnmcclelland]

Design and Slides aren't built for phones. On a touch device with a screen smaller than an iPad (under 744px) they now show a short hand-off page instead of the app: share the link through the OS share sheet, or email it to yourself, and pick it up on a desktop or iPad.

Before and after (375px wide)

	Before	After
Slides
Design

How it works

• New UnsupportedDeviceGate in @agent-native/toolkit/app/shared, wired through a new unsupportedDevice option on AppProviders. Slides and Design each pass it from their root.tsx.
• Applies only to touch devices whose screen's shorter side is under 744px, so a narrowed desktop window, an iPad in Split View or Slide Over, and an iPad in any orientation keep the app, while a phone turned sideways is still gated.
• Sits outside the session gate, so a signed-out phone sees the page before sign-in.
• The title names what was being opened on deck and design routes ("Open this deck on a larger screen").
• "Share link" leads where navigator.share exists. "Email me the link" appears only when the signed-in address is known, addressed to that user, so a signed-out visitor never gets a blank To field. Without share support, email leads when shown and "Copy link" is the fallback or the only action.
• Not gated: host embeds (embed token or embedded=1), Slides share and present routes, Design /present/ and /visual-edit.
• Strings are added to all 11 toolkit locales. The non-English translations are first drafts and want a native review.

Things to know

• Design's editor and shared design view are the same /design/<id> route, so a shared Design link is now gated on a phone too.
• It cannot show the actual deck or design name, because that needs a data fetch before sign-in.
• The toolkit's AppProviders.spec.tsx has one test that fails in my environment on a missing window.localStorage; I did not run it against a clean checkout.
• The screenshots live on the throwaway branch screenshots/mobile-unsupported-page, which can be deleted after merge.

Checked

• pnpm guards (92 checks) passes, and oxfmt is clean.
• Verified in the browser at phone size on Slides and Design: the page shows on /home and the editor routes, Design /present/ is not gated, and 768px stays in the app.
• The share sheet itself is untested on a real phone; the preview browser has no share API, so I only saw the fallback layout.

[github-actions]

Here's a visual recap of what changed:

Open the full interactive recap

[shawnmcclelland]

Addressed the review-body feedback on the latest head: a failed clipboard write now shows "Couldn't copy the link" on the button (copy action and share fallback), with a spec for it and the string in all 11 locales. I did not change anything for the possible Slides embed-token mismatch: the review marked it unconfirmed, and embeds are exempt by design (the prop is omitted whenever sessionBypass is true).

🤖 Addressed by Claude Code

[shawnmcclelland]

Addressed the review-body feedback on the latest head: the gate's media query subscription now falls back to addListener/removeListener when addEventListener is missing, matching the existing pattern in markdown-renderer.tsx, so a pre-Safari-14 browser no longer throws during subscribe. Added a spec that drives the legacy API. I did not change the mailto encoding; the review did not establish a concrete mail-client failure.

🤖 Addressed by Claude Code

[builder-io-integration]

Builder reviewed your changes — looks good ✅

Review Details

Incremental review summary

The latest revision adds a Safari-compatible MediaQueryList subscription fallback and a regression test for the legacy listener API. The earlier signed-out email, narrow iPad, clipboard-feedback, and Slides embed-gating concerns are all addressed in the current diff. The hand-off gate remains constrained to touch devices whose physical screen’s shorter side is below the stated 744px threshold, and the routes, session integration, and localized messages appear internally consistent.

I found no confirmed actionable issues. One agent raised that some small Android tablets would also be gated; however, that is consistent with the PR’s explicit rule of gating touch devices below the iPad-sized threshold, so I did not report it as a defect. Mailto construction was also independently assessed and found valid.

🧪 Browser testing: Skipped — browser-test-planner is not available in this environment; the dev server is running.