# iPX for iOS

ipx's page in an app, with the audio played by the phone rather than the page: it plays on with
the screen locked, and the lock screen, Control Center, headphones and a car over Bluetooth or USB
drive it. Everything you see is the page, as on the home screen; the app adds the player behind it.

## Build it

On a Mac with Xcode:

```sh
brew install xcodegen
cd ios && xcodegen generate && open iPX.xcodeproj
```

Set your team under Signing & Capabilities, pick your phone, and run. The project is generated
from `project.yml`, so `.xcodeproj` is not in git: edit the yml. Nothing on Tower can build it.

A free personal team works, but a build on it expires after seven days and is reinstalled from
Xcode. A paid account ($99 a year) makes that a year and adds TestFlight. Playing with the screen
locked is a plist key (`UIBackgroundModes: audio`), not an entitlement, so it works on either.
CarPlay does not: Apple grants `com.apple.developer.carplay-audio` on request (granted for team
8743L8D729 on 2026-11-09), and the App ID needs it ticked under Additional Capabilities.

## Which server

The first launch asks, with `https://ipodderx.sdf1.net` filled in; a bare host gets `https://`.
Shake the phone to change it. Plain `http://` only on your own network
(`http://192.168.1.130:8099`), which is all `NSAllowsLocalNetworking` allows. Sign in on the page
that follows, through Cloudflare Access or ipx's own form; the cookies that leaves are what the
player uses (`CookieBridge`). `-ipx.server <url>` as a launch argument overrides it for a run. `-ipx.noBadgePrompt YES` skips the badge permission dialog, which covers the page in a simulator run nobody is there to tap.

### Opening with no connection

The page's service worker, which keeps iPX readable offline in a browser (#389), runs in the app
only for a server in `WKAppBoundDomains` in `project.yml` (#435): `ipodderx.sdf1.net`, with
Cloudflare Access's and Authentik's hosts for signing in. For those the web view is app-bound, and
iPX opens without a connection from the second launch on (the first installs the worker). What
that costs:

* The web view goes nowhere outside the list. A link to anywhere else opens in Safari; an
  embedded player from another site in an item's text may not load.
* A server not in the list still opens, but WebKit then cuts the bridge, so the page plays its own
  audio: no lock screen, no CarPlay, nothing kept on the phone. That includes the LAN address.
  Another server means adding it to the list (ten at most) and building again.
* Signing in that leaves those hosts, through another identity provider, opens in Safari and does
  not come back. Add its host too.

A debug build adds `localhost`, so a simulator can test the worker against a page served on the Mac.

## Player token

The player normally rides on the web view's cookie, which ends with Cloudflare Access's session.
To make it outlast that, shake the phone, choose Player Token and enter an ipx API token (the
page's Settings, API tokens) and the address to send it to, `https://ipxapi.sdf1.net`. The token is
kept in the keychain (`Credentials.swift`). The player's audio, positions, read flags, artwork and
the unread badge go to that address with `Authorization: Bearer`; the page still signs in as it
did, at the server address. Without a token the player sends only the cookie, as before.

`ipxapi.sdf1.net` is the tunnel's route to the same ipx-web as `ipodderx.sdf1.net`, with no Access
application in front, which would turn a bearer header away. Cloudflare's firewall (a custom rule
on the `sdf1.net` zone) blocks every request to it except a bearer-token one for `/api/feeds`,
`/api/me`, `/api/art`, `/api/entries/*` and `/media/*`; ipx still checks the token.

## How it hangs together

| | |
|---|---|
| `Sources/App.swift` | the app and its one scene |
| `Sources/WebViewController.swift` | the `WKWebView`, the server question, a page that will not load |
| `Sources/Bridge.swift` | the messages to and from `web/src/native.ts` |
| `Sources/Playback.swift` | `AVPlayer`, the audio session, now playing, the remote commands, saving positions |
| `Sources/CookieBridge.swift` | the web view's cookies into `HTTPCookieStorage.shared`, for the player |
| `Sources/Server.swift` | which server |
| `Sources/Intents.swift`, `Shared/PlayPauseIntent.swift` | Siri and Shortcuts (#427) |
| `Sources/LastPlayed.swift` | the last episode and its place, so Resume works with the app closed |
| `Widgets/`, `Shared/Snapshot.swift`, `Sources/WidgetFeed.swift` | the widget (#428), and what the app writes for it |

### Siri and Shortcuts

With nothing to set up, Siri answers "Resume iPX" (or "Play iPX"), "Pause iPX", "Skip forward
in iPX", "Skip back in iPX", "Set a sleep timer in iPX" and "How many unread in iPX"; each is also
an action in the Shortcuts app. The playback ones are `AudioPlaybackIntent`s, which iOS runs in the
app and lets start audio with the phone locked. Resume carries on with what is loaded, or else the
last episode from where it got to (`LastPlayed`), which plays without the page: opening the app
afterwards shows the page with nothing in its player, while the lock screen has it.

### The widget

Small and medium on the home screen, circular and rectangular on the lock screen: All
Subscriptions' unread count and the last episode, with a Resume or Pause button (the same
`PlayPauseIntent`). The widget has no sign-in and no player, so it draws what the app last wrote
to the App Group `group.net.sdf1.ipx` (`Snapshot`), and the app asks WidgetKit to redraw on a play,
a pause, a new episode or a new count, not on every position saved, since iOS rations redraws.
With the app closed, ipx's push (#433) carries `content-available`, which wakes the app for a
moment to give the widget the new count; iOS rations those wakes too, so the widget can trail the
icon. `Shared/` is built into both targets, with `WIDGET` set in the widget's, where the player
does not exist.

## The messages

The page's half is `web/src/native.ts`, and `node tests/native-bridge.ts` holds it to these. A
change to them is a change to both halves in one commit, and the page has to be deployed before
an app that needs it.

Page to app, on `webkit.messageHandlers.ipx`:

| | |
|---|---|
| `{t:"ready", version, rate, volume}` | the bridge is in |
| `{t:"load", url, enc, feedId, guid, title, feedTitle, artwork, position, duration, rate, volume}` | the element's `src` was set to an audio file |
| `{t:"play"}` `{t:"pause"}` `{t:"stop"}` | |
| `{t:"seek", to}` `{t:"rate", v}` `{t:"volume", v}` | |
| `{t:"position", url}` | save where we are; a path, not a time, since a page frozen in the background holds an old one |
| `{t:"keep", url}` `{t:"unkeep", url}` | keep a file on the phone, or let it go: the page's path for it, `/media/42` or `/media/42/deadair` (#425) |
| `{t:"clearKept"}` | signing out: everything kept goes |
| `{t:"sleep", secs}` | pause after `secs`, fading out over the last ten; 0 turns the timer off (#429) |
| `{t:"unread", n}` | All Subscriptions' unread count, whenever the page's list is drawn with a new one: the icon's badge (#421) |
| `{t:"haptic", kind}` | a press felt: `tap`, `done` (marked read) or `warn` (an error) (#430) |
| `{t:"route", x, y, w, h}` | open the AirPlay picker, pointing at the page's button, in the web view's points (#429) |

App to page, as `window.ipxNative.on(...)`:

| | |
|---|---|
| `{t:"time", cur, dur}` | `timeupdate` |
| `{t:"meta", dur}` | `loadedmetadata`: the page seeks to where you left off |
| `{t:"state", playing}` | `play` or `pause` |
| `{t:"ended"}` | |
| `{t:"error", message}` | the page says so |
| `{t:"kept", urls, keeping}` | what the phone holds and is fetching, at `ready` and after each change; sent whether or not anything plays |
| `{t:"keepFailed", url, message}` | one that could not be kept, and why |
| `{t:"host", can}` | at `ready`: what this build does itself (`sleep`, `route`), so a page newer than the app offers only those |
| `{t:"push", token, sandbox}` | at `ready` and when Apple gives a new one: the phone's push token, for the page to register with ipx (`POST /api/push/devices`) (#433) |
| `{t:"sleep", left}` | at `ready`, while the timer runs: seconds left, for a page that reloaded |
| `{t:"slept"}` | the timer ran out and playback paused |
| `{t:"replaced"}` | the car chose another episode; the page's player bar closes without saving |

The app writes the position (every ten seconds and on pause) and marks an item read at 90%, from
its own clock, so both happen while the page is frozen. Video stays in the page.

## Not yet

* Without the player token the cookie is the only credential: when Cloudflare Access's expires
  mid-drive, playback stops with "Sign in again", and opening the app signs in.
* CarPlay (`CarScreen.swift`) reads ipx with the player's credentials and nothing else: launched
  by the car with the phone's app never opened since a restart, it has only cookies saved to disk,
  and without the player token a lapsed Access cookie shows "iPX can't reach your server". Its
  lists need a connection; a kept episode plays without one once it is picked.