Hello Peter, Thank you for flagging this. I worked on some MIDI permissions changes previously, and if I recall correctly the WebView difference is because of legacy applications that we couldn't expect to be updated.
Transferring the MIDIAccess object should only be done for new applications after the feature lands, so I expect that existing applications will not be affected by this change. I have made a note to test WebView specifically before we launch this to stable. Best, Michael On Thu, Aug 27, 2026 at 9:35 AM Peter Birk Pakkenberg <[email protected]> wrote: > Hi, > > I just wanted to flag that WebView has a slightly odd permission model for > MIDI API usage, so you should test that this works as expected in a WebView > application. > > Specifically: > > - Normal midi permission is automatically granted. This is unlikely to > cause problems > - midi-sysex permission is in a perpetual "prompt" state, and every > usage of a midi-sysex API will trigger a callback to the embedding > application to ask for permission. See > WebChromeClient.onPermissionRequest > > <https://developer.android.com/reference/android/webkit/WebChromeClient#onPermissionRequest(android.webkit.PermissionRequest)> > and > the RESOURCE_MIDI_SYSEX > > <https://developer.android.com/reference/android/webkit/PermissionRequest#RESOURCE_MIDI_SYSEX> > request > type. I can't say for certain if this is going to cause any issues in > practice. Applications that actually grant this permission will likely > grant it consistently. > > > Sincerely, > [image: Google Logo] > Peter Birk Pakkenberg > Software Engineer > [email protected] > > > On Tue, 25 Aug 2026 at 23:02, Chromestatus < > [email protected]> wrote: > >> *Contact emails* >> [email protected] >> >> *Specification* >> https://webaudio.github.io/web-midi-api/#dom-midiaccess >> >> *Summary* >> WebMIDI MIDIAccess objects are now transferable and exposed to workers. >> This allows developers to synchronize and schedule MIDI events with better >> accuracy and performance. >> >> *Blink component* >> Blink>WebMIDI >> <https://issues.chromium.org/issues?q=customfield1222907:%22Blink%3EWebMIDI%22> >> >> *Web Feature ID* >> web-midi <https://webstatus.dev/features/web-midi> >> >> *Motivation* >> Scheduling and handling MIDI events on the main thread can result in poor >> performance and scheduling accuracy. Allowing MIDIAccess objects to run on >> Worker threads can solve real-world performance and jitter issues in Web >> MIDI applications. Please see discussion here for more details: >> https://github.com/WebAudio/web-midi-api/issues/99 >> >> *Initial public proposal* >> *No information provided* >> >> *Goals for experimentation* >> None >> >> *Requires code in //chrome?* >> False >> >> *Tracking bug* >> https://crbug.com/379805727 >> >> *Estimated milestones* >> >> No milestones specified >> >> >> *Link to entry on the Chrome Platform Status* >> https://chromestatus.com/feature/5383093186854912?gate=5419197688578048 >> >> This intent message was generated by Chrome Platform Status >> <https://chromestatus.com>. >> >> -- >> You received this message because you are subscribed to the Google Groups >> "blink-dev" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion visit >> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/6a8e10eb.8ed5e303.498bb.04f3.GAE%40google.com >> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/6a8e10eb.8ed5e303.498bb.04f3.GAE%40google.com?utm_medium=email&utm_source=footer> >> . >> > -- You received this message because you are subscribed to the Google Groups "blink-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CA%2BuAeqSUjY%3DA_O5LE7umrEuvfG9y7Z_o8%2B6eNHVLRux9QQS6EQ%40mail.gmail.com.
