conda · wolfv · Jul 24, 2026 · Jul 24, 2026 · Jul 27, 2026 · Jul 27, 2026
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+# CEP XXXX - Subdirs and virtual packages for iOS and Android
+
+<table>
+<tr><td> Title </td><td> Subdirs and virtual packages for iOS and Android </td>
+<tr><td> Status </td><td> Draft </td></tr>
+<tr><td> Author(s) </td><td> Wolf Vollprecht &lt;wolf@prefix.dev&gt;</td></tr>
+<tr><td> Created </td><td> Jul 24, 2026</td></tr>
+<tr><td> Updated </td><td> Jul 27, 2026</td></tr>
+<tr><td> Discussion </td><td> NA </td></tr>
+<tr><td> Implementation </td><td> https://github.com/conda/rattler (feat/ios-android-subdirs) </td></tr>
+</table>
+
+> The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT",
+  "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as
+  described in [RFC2119][RFC2119] when, and only when, they appear in all capitals, as shown here.
+>
+> More specifically, violations of a MUST or MUST NOT rule MUST result in an error. Violations of the
+  rules specified by any of the other all-capital terms MAY result in a warning, at discretion of the
+  implementation.
+
+## Abstract
+
+This CEP defines conda subdirs for packages targeting Apple's iOS and Google's Android, together
+with two virtual packages, `__ios` and `__android`, for OS-version compatibility. It maps the PyPI
+wheel-tag model for these platforms ([PEP 730] for iOS and [PEP 738] for Android) onto conda's
+existing subdir and virtual-package machinery.
+
+## Motivation
+
+conda has no standard way to describe packages built for mobile operating systems. Python and the
+wider native toolchain ecosystem now support iOS and Android as target platforms, and conda build
+tools can produce packages for them. Common subdir and virtual-package names are needed so those
+packages can be described and consumed consistently across implementations.
+
+## Specification
+
+### Subdirs
+
+This CEP defines the following subdirs. As per [CEP 26](./cep-0026.md), each subdir is
+single-architecture and follows the `<os>-<arch>` syntax.
+
+#### iOS
+
+| Subdir               | Architecture | Platform variant              |
+| -------------------- | ------------ | ----------------------------- |
+| `ios-arm64`          | `arm64`      | Device (`iphoneos`)           |
+| `iossimulator-arm64` | `arm64`      | Simulator (`iphonesimulator`) |
+| `iossimulator-64`    | `x86_64`     | Simulator (`iphonesimulator`) |
+
+#### Android
+
+| Subdir            | Architecture | Android ABI   |
+| ----------------- | ------------ | ------------- |
+| `android-aarch64` | `aarch64`    | `arm64-v8a`   |
+| `android-armv7a`  | `armv7a`     | `armeabi-v7a` |
+| `android-64`      | `x86_64`     | `x86_64`      |
+| `android-32`      | `x86`        | `x86`         |
+
+### Virtual packages
+
+The following virtual packages extend [CEP 30](./cep-0030.md). Their build strings MUST be `0`.
+
+#### `__ios`
+
+`__ios` MUST be present when the target subdir is `ios-*` or `iossimulator-*`, and MUST NOT be
+present otherwise. Its version MUST represent the iOS version available in the target environment,
+for example `13.0`. A package requiring iOS 13.0 or newer depends on `__ios >=13.0`.
+
+The version MUST be overridable with `CONDA_OVERRIDE_IOS` when set to a non-empty valid version
+string. Without an override, an implementation MAY use a detected native version or a
+build-tool-supplied target version; if neither is available, the version MUST be `0`. The override
+MUST be ignored for other target subdirs.
+
+#### `__android`
+
+`__android` MUST be present when the target subdir is `android-*`, and MUST NOT be present otherwise.
+Its version MUST represent the Android API level available in the target environment, for example
+`21`. A package requiring API level 21 or newer depends on `__android >=21`.
+
+The version MUST be overridable with `CONDA_OVERRIDE_ANDROID` when set to a non-empty valid version
+string. Without an override, an implementation MAY use a detected native API level or a
+build-tool-supplied target API level; if neither is available, the version MUST be `0`. The override
+MUST be ignored for other target subdirs.
+
+The `__unix` virtual package MUST be present for every subdir defined by this CEP.
+
+## Rationale
+
+- **Separate iOS device and simulator subdirs.** iOS provides one API but two incompatible ABIs:
+  `iphoneos` for devices and `iphonesimulator` for simulators. Even when both use `arm64`, a binary
+  built for one cannot run on the other, and a fat binary cannot span the two ABIs. The existing
+  `osx-*` subdirs are also unsuitable because iOS and macOS have significant platform differences
+  despite both using the Darwin kernel.
+- **No separate iPadOS subdirs.** iPadOS is not distinct from iOS for development purposes. Binaries
+  built for the `iphoneos` and `iphonesimulator` ABIs can also be deployed to iPads.
+- **The `ios` and `iossimulator` OS tokens.** Apple's `iphoneos` and `iphonesimulator` names identify
+  vendor ABIs. The conda token identifies the operating system, so `ios` follows CPython's platform
+  name and includes iPads. The `simulator` suffix records the ABI split without implying an
+  iPhone-only target.
+- **Version in a virtual package.** Encoding the minimum OS version in the subdir, as PyPI does in a
+  wheel tag, would multiply the number of subdirs and move compatibility resolution out of the
+  solver. `__ios` and `__android` reuse conda's existing version-compatibility mechanism.
+
+## Rejected ideas
+
+- **`ios-simulator-*` subdirs.** A second dash does not conform to CEP 26. The simulator variant is
+  therefore folded into the OS token.
+- **An `ios-64` subdir.** Apple does not provide an x86_64 iOS device ABI.
+- **Using `armv7l` for Android.** Android's `armeabi-v7a` uses the softfp calling convention and
+  Bionic, unlike the ABI represented by `linux-armv7l`. The `armv7a` token keeps these incompatible
+  targets distinct.
+- **Using `linux-*` for Android.** Modeling Bionic as a C standard-library variant in `linux-*` would
+  put incompatible binaries in the same subdir and rely on every package declaring an exact standard
+  library constraint. Android also has its own userspace ABI, dynamic linker, and platform APIs, so
+  it receives separate subdirs.
+
+## References
+
+- [PEP 730 - Adding iOS as a supported platform][PEP 730]
+- [PEP 738 - Adding Android as a supported platform][PEP 738]
+- Reference implementation: conda/rattler, branch `feat/ios-android-subdirs`
+
+## Copyright
+
+All CEPs are explicitly [CC0 1.0 Universal](https://creativecommons.org/publicdomain/zero/1.0/).
+
+[RFC2119]: https://www.ietf.org/rfc/rfc2119.txt
+[PEP 730]: https://peps.python.org/pep-0730/
+[PEP 738]: https://peps.python.org/pep-0738/